Ultrasonic transducer fixture, injection molding die and ultrasonic type flow meter

Abstract

To provide an ultrasonic transducer fixture capable of stabilizing the posture of an ultrasonic transducer and preventing measurement accuracy from reducing.SOLUTION: An ultrasonic transducer fixture 5 of an ultrasonic type flow meter 100 including an ultrasonic transducer 1 and a passage formation part 3 including a measurement passage 32 passing a fluid F to be measured and a mounting part 41 having a contact part 42 contacting the ultrasonic transducer 1 and arranging the ultrasonic transducer 1 so that a propagation direction D faces the measurement passage 32 includes: a base 51 positioned on the side opposite to the contact part 42 through the ultrasonic transducer 1; three projection parts 52 projecting from the inner surface of the base 51 facing the ultrasonic transducer 1 and contacting a second surface 16 positioned on the side opposite to a first surface 15 positioned on the propagation direction D side of the ultrasonic transducer 1; and a connection part 53 capable of attachably and detachably connecting the base 51 to the mounting part 41.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an ultrasonic transceiver fixture, an injection mold, and an ultrasonic flow measurement device.

Background Art

[0002] Conventionally, an ultrasonic flow measurement unit shown in Patent Document 1 that measures the propagation time of ultrasonic waves and measures the flow rate of a fluid to be measured is known. This ultrasonic flow measurement unit has a fixing plate for attaching an ultrasonic transceiver to an opening of an ultrasonic transceiver fixing member. The fixing plate sandwiches the outer peripheral edge of the ultrasonic transceiver between the ultrasonic transceiver fixing member to fix the ultrasonic transceiver.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the fixing plate described in Patent Document 1 may have a bias in contact with the ultrasonic transceiver, and there may be a partial play or a weak contact part between the fixing plate and the ultrasonic transceiver. Therefore, the ultrasonic transceiver may vibrate due to the vibration of the piezoelectric element, the mounting position of the ultrasonic transceiver may shift, and the measurement accuracy may decrease.

Means for Solving the Problems

[0005] The ultrasonic transceiver fixture according to the first aspect of the present disclosure includes an ultrasonic transceiver that transmits ultrasonic waves in a predetermined transmission direction and receives ultrasonic waves, a measurement flow path through which the fluid to be measured flows and is defined by the inner wall surface of the wall portion, and a mounting portion having a contact portion that contacts the ultrasonic transceiver and arranges the ultrasonic transceiver such that the transmission direction faces the measurement flow path. The ultrasonic transceiver fixture of the ultrasonic flow measurement device includes a base portion located on the opposite side of the contact portion via the ultrasonic transceiver, three protruding portions that protrude from the inner surface of the base portion facing the ultrasonic transceiver and contact a second surface located on the opposite side of a first surface located on the transmission direction side of the ultrasonic transceiver, and a connection portion that detachably connects the base portion to the mounting portion.

Effect of the Invention

[0006] According to the ultrasonic transceiver fixture of the present disclosure, the posture of the ultrasonic transceiver can be stabilized, and the effect of preventing a decrease in measurement accuracy can be achieved.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

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Figure 11

Figure 12

Figure 13

Mode for Carrying Out the Invention

[0008] Hereinafter, embodiments of the ultrasonic flow measurement device will be specifically described with reference to the drawings. Note that the present invention is not limited by the following embodiments. Also, hereinafter, throughout all the figures, the same or corresponding elements will be given the same reference numerals, and duplicate explanations will be omitted.

[0009] FIG. 1 is a partial cross-sectional view showing a configuration example of an ultrasonic flow measurement device 100 according to an embodiment. As shown in FIG. 1, the ultrasonic flow measurement device 100 is a device that transmits and receives ultrasonic waves between two ultrasonic transceivers 1 to measure the propagation time of the ultrasonic waves, and measures the flow rate of the fluid F to be measured flowing through the measurement flow path 32.

[0010] For convenience of explanation hereinafter, as shown in FIG. 1, an X direction, a Y direction orthogonal to the X direction, and a Z direction orthogonal to both the X direction and the Y direction are defined. The X direction is the flow direction of the fluid F to be measured. The Y direction is a direction orthogonal to the paper surface in FIG. 1. The Z direction is the vertical direction. Also, one side of the X direction is also referred to as "upstream", the other side as "downstream", and further, one side of the Z direction is also referred to as "upper" and the other side as "lower". However, the orientation of the ultrasonic flow measurement device 100 is not particularly limited. Also, in the present embodiment, gases such as city gas and LP gas are exemplified as the fluid F to be measured.

[0011] The ultrasonic flow measurement device 100 includes two ultrasonic transceivers 1, a flow path forming section 3, two ultrasonic transceiver fixtures 5, a measurement circuit board 7, and a measurement circuit cover 8.

[0012] FIG. 3 is a perspective view showing the ultrasonic transceiver 1. As shown in FIG. 3, the ultrasonic transceiver 1 transmits ultrasonic waves based on a control signal. Further, when the ultrasonic transceiver 1 receives ultrasonic waves, it outputs a detection voltage corresponding to the received ultrasonic waves.

[0013] The ultrasonic transceiver 1 includes a metal plate 11, an insulating vibration damping member 12, an ultrasonic oscillation element 13, an acoustic matching body 14, and two lead wires 17.

[0014] The metal plate 11 is a metal plate material such as iron, stainless steel, brass, copper, aluminum, nickel-plated steel plate, etc., and has rigidity. The surface of the ultrasonic transceiver 1 including one surface of the metal plate 11 located on the downward side in FIG. 1 is the first surface 15, and the surface of the ultrasonic transceiver 1 including the other surface of the metal plate 11 located on the upward side in FIG. 1 is the second surface 16. The metal plate 11 has a circular periphery, for example. The metal plate 11 has a central portion 11a that is recessed in the direction from the second surface 16 toward the first surface 15 (transmission wave direction D), and an annular peripheral portion 11b that extends in the extending direction of a plane orthogonal to the transmission wave direction D from the upper end of the central portion 11a. Thus, the metal plate 11 has a shape in which the first surface 15 bulges toward the transmission wave direction D, and the second surface 16 is recessed toward the transmission wave direction D.

[0015] The ultrasonic oscillator 13 transmits ultrasonic waves corresponding to a drive signal to the outside in a predetermined carrier wave direction D when the drive signal is input. Further, when the ultrasonic oscillator 13 receives ultrasonic waves from the outside, it outputs a detection voltage corresponding to the received ultrasonic waves. As such an ultrasonic oscillator 13, a known ultrasonic oscillator can be used, for example, a known piezoelectric ceramic vibrator can be used. Of the ground electrode and the non-ground electrode of the ultrasonic oscillator 13, one is located on the upper surface and the other is located on the bottom surface. The ultrasonic oscillator 13 is attached to the center of the second surface 16 and is located on the second surface 16. The bottom surface of the ultrasonic oscillator 13 is soldered to the metal plate 11 with solder, conductive paste, etc., and is electrically connected to the metal plate 11. The ultrasonic oscillator 13 is formed such that the dimension in the X direction is larger than the dimension in the Y direction and has directivity in the X direction.

[0016] The acoustic matching body 14 has a function of efficiently propagating the ultrasonic waves oscillated by the ultrasonic oscillator 13 to the fluid F to be measured. The acoustic matching body 14 is, for example, a glass hollow sphere joined with a thermosetting resin. Further, the acoustic matching body 14 may be one in which an acoustic film is formed on the sound wave radiation surface of a ceramic porous body. The acoustic matching body 14 can efficiently propagate ultrasonic waves to the fluid F to be measured by setting the thickness to a thickness of λ / 4.

[0017] The insulating vibration damping member 12 is a member that functions to suppress the external propagation of the vibration of the ultrasonic oscillator 13 and to shorten the reverberation time. The insulating vibration damping member 12 is formed in an annular shape and has elasticity. When the vibration of the ultrasonic oscillator 13 on the transmission side of the ultrasonic transceiver 1 propagates to the ultrasonic oscillator 13 on the reception side of the ultrasonic transceiver 1, a component derived from the vibration is mixed into the output detection voltage, resulting in measurement noise in the ultrasonic transceiver 1 on the reception side. The insulating vibration damping member 12 suppresses the external propagation of the vibration of the ultrasonic oscillator 13 and shortens the reverberation time, thereby reducing measurement noise. The insulating vibration damping member 12 covers the entire outer peripheral edge of the metal plate 11, but is not limited thereto and may cover a part thereof. The insulating vibration damping member 12 is located across from the first surface 15 to the second surface 16 of the ultrasonic transceiver 1. The insulating vibration damping member 12 has a protrusion 25 that protrudes inward from the inner edge on the second surface 16 side.

[0018] The insulating vibration damping member 12 is formed of a thermoplastic resin having a low glass transition point, such as a thermoplastic elastomer material or a crystalline polyester. Examples of the thermoplastic elastomer material include a styrene-based elastomer, an olefin-based elastomer, and a polyester-based elastomer.

[0019] In addition, the thermoplastic resin used for the insulating vibration damping member 12 has a functional group that is easily adsorbed to the metal plate 11 and adheres closely to the metal plate 11. Thereby, the insulating vibration damping member 12 effectively suppresses the vibration of the metal plate 11. Further, the thermoplastic resin used for the insulating vibration damping member 12 has electrical insulation properties.

[0020] As shown in FIG. 1, the flow path forming portion 3 includes a wall portion 31, two mounting portions 41, and four support portions 46. The material constituting the flow path forming portion 3 is not particularly limited, but for example, it is composed of a synthetic resin or a metal material, or a combination of a synthetic resin and a metal material.

[0021] The wall portion 31 is formed in a cylindrical shape, and the fluid F to be measured flows through the internal space in one direction. The wall portion 31 includes a measurement flow path 32 defined by the inner wall surface of the intermediate portion in the X direction. The measurement flow path 32 extends, for example, in the horizontal direction.

[0022] The two mounting portions 41 are arranged with the first surfaces 15 of the two ultrasonic transceivers 1 facing the wave transmission direction D. Thereby, the ultrasonic transceivers 1 are arranged such that the wave transmission direction D of the ultrasonic waves faces the measurement flow path 32. The internal space of the mounting portion 41 is formed in a cylindrical shape with the central axis extending in the wave transmission direction D, and is provided integrally with the upper wall portion 31 of the flow path forming portion 3. The internal space of the mounting portion 41 communicates with the measurement flow path 32 but may be separated by a partition wall. The two mounting portions 41 are arranged side by side in the X direction.

[0023] The mounting portion 41 includes a contact portion 42. The upper opening end of the mounting portion 41 forms the contact portion 42. The contact portion 42 extends, for example, on a plane orthogonal to the wave transmission direction D. The contact portion 42 contacts the insulating vibration damping member 12 on the first surface 15 of the ultrasonic transmitter / receiver 1. The contact portion 42 is formed in an annular shape and contacts the insulating vibration damping member 12 in a liquid-tight manner.

[0024] Among the ultrasonic transmitter / receivers 1 mounted on the mounting portion 41, the ultrasonic transmitter / receiver 1 located on the upstream side in the X direction is inclined in both the X direction and the Z direction within the XZ plane, such that the wave transmission direction D is downward and toward the downstream side. Also, among the ultrasonic transmitter / receivers 1 mounted on the mounting portion 41, the ultrasonic transmitter / receiver 1 located on the downstream side in the X direction is inclined in both the X direction and the Z direction within the XZ plane, such that the wave transmission direction D is downward and toward the upstream side. Thereby, the ultrasonic waves transmitted by the upstream ultrasonic transmitter / receiver 1 enter the measurement flow path 32 through the internal space of the upstream mounting portion 41 and are reflected at least once by the wall portion 31. Then, the ultrasonic waves reflected by the wall portion 31 enter the downstream mounting portion 41 from the measurement flow path 32 and are detected by the downstream ultrasonic transmitter / receiver 1. Also, the ultrasonic waves transmitted by the downstream ultrasonic transmitter / receiver 1 enter the measurement flow path 32 through the internal space of the downstream mounting portion 41 and are reflected at least once by the wall portion 31. Then, the ultrasonic waves reflected by the wall portion 31 enter the upstream mounting portion 41 from the measurement flow path 32 and are detected by the upstream ultrasonic transmitter / receiver 1. In the present embodiment, the receiving-side ultrasonic transmitter / receiver 1 receives the ultrasonic waves reflected at least once by the wall portion 31, but is not limited thereto. The upstream ultrasonic transmitter / receiver 1 and the downstream ultrasonic transmitter / receiver 1 may be provided at positions facing each other in a direction intersecting the X direction, and the receiving-side ultrasonic transmitter / receiver 1 may receive the ultrasonic waves that have not been reflected by the wall portion 31.

[0025] The mounting portion 41 has two engaging convex portions 43 formed on its outer peripheral surface. The two engaging convex portions 43 are symmetrically positioned with respect to a plane passing through the central axis of the mounting portion 41. The engaging convex portion 43 is a protrusion protruding from the outer peripheral surface in the radial direction centered on the central axis of the mounting portion 41. The engaging convex portion 43 is a protrusion that engages with the connecting portion 53. More specifically, the two engaging convex portions 43 are located on one side and the other side in the Y direction with the central axis of the mounting portion 41 interposed therebetween, and the other engaging convex portion 43 is located behind one engaging convex portion 43 shown in FIG. 1. By the engagement between the engaging convex portion 43 and the connecting portion 53, the ultrasonic transceiver fixture 5 is attached to the mounting portion 41.

[0026] The four support portions 46 support the measurement circuit board 7. The four support portions 46 are each a columnar body and extend upward from the upper surface of the wall portion 31. Another two support portions 46 are located behind the two support portions 46 shown in FIG. 1.

[0027] FIG. 2 is a perspective view showing a configuration example of the ultrasonic transceiver fixture 5. The ultrasonic transceiver fixture 5 functions to fix the ultrasonic transceiver 1 to the flow path forming portion 3. The ultrasonic transceiver fixture 5 is an injection molded product of a resin material.

[0028] As shown in FIG. 2, the ultrasonic transceiver fixture 5 includes a base portion 51, three protrusion portions 52, two connecting portions 53, two restricting portions 54, and a vibration suppressing portion 55.

[0029] The base portion 51 is formed, for example, in a plate shape. The base portion 51 is located on the opposite side of the contact portion 42 via the ultrasonic transceiver 1 and covers the second surface 16. The base portion 51 has a shape in which the inner surface 57 is concave.

[0030] The three protrusions 52 are protrusions that protrude from the inner surface 57 of the base 51 facing the ultrasonic transmitter / receiver 1. The three protrusions 52 have tips that contact the second surface 16 of the peripheral edge 11b of the metal plate 11 and bias the metal plate 11 toward the contact portion 42. The three protrusions 52 are arranged at equal intervals in the circumferential direction centered on the center C of the base 51 at intervals of 120 degrees when viewed from the wave transmission direction D. The protrusion 52 extends in an arc shape in the circumferential direction centered on the center C of the base 51 when viewed from the wave transmission direction D and extends along the inner edge on the second surface 16 side of the insulating vibration damping member 12. The protrusion 52 contacts the peripheral edge 11b of the metal plate 11 around the ultrasonic oscillation element 13.

[0031] The two connecting portions 53 detachably connect the base 51 to the mounting portion 41. The connecting portion 53 is formed in a claw shape and extends from the base 51 toward the mounting portion 41. More specifically, the connecting portion 53 has a first connecting portion 63 that extends from the base 51 radially outward centered on the center C of the base 51, and a second connecting portion 64 that is continuous with the tip of the first connecting portion 63 and extends in the wave transmission direction D. The two connecting portions 53 are symmetrically positioned with respect to a plane passing through the center C of the base 51 when viewed from the wave transmission direction D. More specifically, the two connecting portions 53 are symmetrically positioned with respect to the XZ plane.

[0032] The connecting portion 53 has an engaging hole 61 that engages with the engaging convex portion 43. The engaging hole 61 is a through-hole that penetrates the connecting portion 53 in the diameter-expanding direction centered on the center C of the base portion 51. Further, the engaging hole 61 is an elongated hole, the proximal end is located at the proximal end of the first connecting portion 63, and the distal end is located in front of the distal end of the second connecting portion 64. Therefore, the end portion of the engaging hole 61 in the direction from the mounting portion 41 toward the base portion 51 is open. Then, as shown in FIG. 1, by covering and pushing in the ultrasonic transceiver 1 mounted on the mounting portion 41, the distal end of the connecting portion 53 gets over the engaging convex portion 43. As a result, the engaging convex portion 43 abuts against the inner edge of the distal end of the engaging hole 61, restricting the movement of the ultrasonic transceiver fixture 5, and the ultrasonic transceiver fixture 5 is locked to the mounting portion 41. As a result, the ultrasonic transceiver 1 is positioned between the three protruding portions 52 and the contact portion 42. And the ultrasonic transceiver fixture 5 and the ultrasonic transceiver 1 are in contact at three points. Also, the three protruding portions 52 bias the metal plate 11 toward the contact portion 42. Thereby, the insulating vibration damping member 12 is crimped to the contact portion 42. Thereby, the posture of the ultrasonic transceiver 1 can be stabilized. Also, the insulating vibration damping member 12 of the ultrasonic transceiver 1 and the contact portion 42 of the flow path forming portion 3 are in liquid-tight contact, sealing the periphery of the space sandwiched between the base portion 51 and the metal plate 11.

[0033] The two restricting portions 54 are each a roof-shaped plate-like body extending from the base portion 51 in the extending direction of the second surface 16. The restricting portion 54 extends in the radial direction centered on the center C of the base portion 51 from the base portion 51 as viewed from the wave transmission direction D.

[0034] When the base 51 is divided into two regions, i.e., the first region A1 and the second region A2, by a line connecting the two connecting portions 53, the two restricting portions 54 are located in one of the regions, i.e., the first region A1. The first region A1 is a region located outside in the X direction compared to the second region A2 when the ultrasonic transceiver fixture 5 is attached to the mounting portion 41. Among the three protruding portions 52, one protruding portion 52 is located in the first region A1, and the other two protruding portions 52 are located in the second region A2. Further, among the three protruding portions 52, at least one protruding portion 52 is formed with a recess 59 that engages with the protrusion 25 of the insulating vibration damping member 12. The recess 59 is formed, for example, in the protruding portion 52 located in the first region A1. Thereby, the rotation of the ultrasonic transceiver 1 in the circumferential direction centered on the center C of the base 51 is restricted with respect to the ultrasonic transceiver fixture 5 fixed to the mounting portion 41. Therefore, it is possible to prevent a decrease in measurement accuracy due to the displacement of the ultrasonic transceiver 1.

[0035] The vibration suppression portion 55 is a protrusion that protrudes from the inner surface 57 of the base 51 toward the ultrasonic oscillation element 13, and the tip thereof faces the ultrasonic oscillation element 13. The tip portion of the vibration suppression portion 55 is, for example, a flat surface and faces the ultrasonic oscillation element 13 in the vicinity of the ultrasonic oscillation element 13 of the ultrasonic transceiver 1. Thereby, when the ultrasonic oscillation element 13 causes abnormal vibration, the vibration of the ultrasonic oscillation element 13 can be suppressed by the protruding portion 52 hitting the ultrasonic oscillation element 13.

[0036] As shown in FIG. 1, the measurement circuit board 7 is located above the flow path forming section 3. The measurement circuit board 7 drives two ultrasonic transceivers 1. Further, the measurement circuit board 7 receives the input of the detection voltage output from the ultrasonic transceiver 1, calculates the flow rate of the fluid F to be measured flowing through the measurement flow path 32 based on the propagation time of the ultrasonic waves transmitted and received by the ultrasonic transceiver 1, and outputs it. More specifically, the difference between the first propagation time of the ultrasonic wave from the upstream ultrasonic transceiver 1 to the downstream ultrasonic transceiver 1 and the second propagation time of the ultrasonic wave from the downstream ultrasonic transceiver 1 to the upstream ultrasonic transceiver 1 is proportional to the flow velocity of the fluid F to be measured. Therefore, the measurement circuit board 7 calculates the flow velocity based on the difference between the first propagation time and the second propagation time, multiplies the calculated flow velocity by the cross-sectional area of the known measurement flow path 32 to calculate the flow rate, and uses it as measurement information. The measurement circuit board 7 is arranged parallel to the X direction and is positioned so as to straddle the two ultrasonic transceivers 1. The measurement circuit board 7 is fixed to the tip of the support portion 46. The measurement circuit board 7 includes a connector 71 that outputs measurement information.

[0037] The measurement circuit cover 8 is provided so as to cover the measurement circuit board 7. The measurement circuit cover 8 is locked to the measurement circuit board 7 or the support portion 46. The measurement circuit cover 8 has a flat box shape with an opening at the bottom, and houses the board inside through the opening.

[0038] Then, the lead wire 17 of the ultrasonic transceiver 1 electrically connects the measurement circuit board 7 and the ultrasonic transceiver 1. As described above, the ultrasonic transceiver 1 includes two lead wires 17. One lead wire 17 of the ultrasonic transceiver 1 has one end electrically connected to the upper surface of the ultrasonic oscillation element 13 and the other end electrically connected to the measurement circuit board 7. One lead wire 17 of the ultrasonic transceiver 1 extends in the radial direction centered on the center C of the base 51 from the upper surface of the ultrasonic oscillation element 13 as viewed from the wave transmission direction D. And one lead wire 17 penetrates the insulating vibration damping member 12 in the radial direction centered on the center C of the base 51. Thereby, the middle part of one lead wire 17 is fixed to the insulating vibration damping member 12. The other lead wire 17 of the ultrasonic transceiver 1 has one end electrically connected to the metal plate 11 and the other end electrically connected to the measurement circuit board 7. And the middle part near one end of the other lead wire 17 is fixed to the insulating vibration damping member 12. Thus, a measurement circuit including the measurement circuit board 7 and the ultrasonic transceiver 1 is configured. Since the ultrasonic flow meter 100 includes two ultrasonic transceivers 1, it includes four lead wires 17.

[0039] When the ultrasonic transceiver fixture 5 is attached to the attachment portion 41, the three protrusions 52 urge the metal plate 11 toward the contact portion 42. Thereby, the insulating vibration damping member 12 of the ultrasonic transceiver 1 and the contact portion 42 of the flow path forming portion 3 are in liquid-tight contact, and the periphery of the space sandwiched between the base 51 and the metal plate 11 is sealed. Therefore, the contact point between the ultrasonic oscillation element 13 and the lead wire 17 can be protected from moisture.

[0040] Then, as shown in FIG. 1, among the lead wires 17, the portion located outside the ultrasonic transceiver 1 forms an extension portion 21. The extension portion 21 includes a first extension portion 22 that contacts the insulating vibration damping member 12 and a second extension portion 23 that is located closer to the measurement circuit board 7 than the first extension portion 22 in the direction in which the lead wire 17 extends.

[0041] The first extending portion 22 extends in a direction intersecting the wave transmission direction D. More specifically, the two lead wires 17 of the ultrasonic transmitter / receiver 1 located on the upstream side extend toward the upstream side in the X direction. The two lead wires 17 of the ultrasonic transmitter / receiver 1 located on the downstream side extend toward the downstream side in the X direction. That is, the first extending portion 22 extends outward of the ultrasonic flow measurement device 100 in the X direction. The second extending portion 23 curves from the first surface 15 toward the second surface 16 and extends to the measurement circuit board 7.

[0042] Then, as shown in FIG. 2, the restricting portion 54 of the ultrasonic transmitter / receiver fixture 5 covers the first extending portion 22 of the lead wire 17. Accordingly, the restricting portion 54 restricts the lead wire 17 from bending at the base end portion of the extending portion 21 located at the exit from the insulating vibration damping member 12. Thereby, disconnection of the lead wire 17 can be prevented.

[0043] Further, the inner surface 57 of the restricting portion 54 of the ultrasonic transmitter / receiver fixture 5 has a lead wire guiding portion 56. The lead wire guiding portion 56 is located above the first extending portion 22. The lead wire guiding portion 56 is a groove recessed upward and extends in the radial direction centered on the center C of the base portion 51. In the Y direction, the outer edge of the lead wire guiding portion 56 of the restricting portion 54 of the restricting portion 54 is located below the inner edge of the lead wire guiding portion 56, and restricts the lead wire 17 from protruding outward.

[0044] FIG. 4 is a diagram showing a gas meter 120 including the ultrasonic flow measurement device 100.

[0045] The gas meter 120 includes an ultrasonic flow measurement device 100, a housing 121, an inlet base 122, an outlet base 123, an outlet pipe 124, a seal member 125, a display unit 126, and a shut-off valve 127. The housing 121 is a container filled with gas in its internal space. The inlet base 122 is a base connected to the pipe on the gas supply side. The outlet base 123 is a base connected to the pipe on the building side. The outlet pipe 124 is located inside the housing 121 and is connected to the outlet base 123. The ultrasonic flow measurement device 100 is connected to the outlet pipe 124. The shut-off valve 127 is attached to the inlet base 122 and shuts off the inflow of gas into the housing 121 when the control unit of the gas meter 120 determines that there is an abnormality such as gas leakage.

[0046] Thus, in the gas meter 120, the ultrasonic flow measurement device 100 is used not only in the measurement flow path 32 but also in an environment where the whole is located in a gas atmosphere. When the moisture content in the gas is high, the moisture adhering to the measurement circuit board 7 flows along the lead wire 17 toward the ultrasonic transmitter / receiver 1. However, since the base 51 of the ultrasonic transmitter / receiver fixture 5 covers the second surface 16 of the ultrasonic transmitter / receiver 1, it is possible to prevent moisture from accumulating in the recessed second surface 16 of the ultrasonic transmitter / receiver 1. Thereby, the noise of the measurement signal can be suppressed.

[0047] FIG. 5 is a cross-sectional view showing an injection mold 110 for forming the ultrasonic transmitter / receiver fixture 5. As shown in FIG. 5, the injection mold 110 has a cavity 112 and a core 113. The injection gate 111 is an outer surface 58 located on the side opposite to the inner surface 57 in the wave transmission direction D, and an injection gate 111 for injecting a resin material into the region where the protrusion 52 is located as viewed from the wave transmission direction D is arranged. Thereby, the molten resin flowing into the inside of the injection mold 110 from the injection gate 111 first flows into the central portion of the base 51 where the thick protrusion 52 is located and diffuses and flows. Therefore, the filling of the molten resin into the injection mold 110 can be improved, and molding defects can be prevented.

[0048] Also, as described above, the connecting portion 53 has an open end in the direction from the mounting portion 41 toward the base portion 51. As a result, the undercut can be eliminated. Therefore, the slide mold becomes unnecessary, and the mold configuration can be simplified.

[0049] According to the ultrasonic transceiver fixture 5 described above, the ultrasonic transceiver 1 is positioned between the three protrusions 52 and the contact portion 42. And since the ultrasonic transceiver fixture 5 and the ultrasonic transceiver 1 are in contact at three points, the rattling of the ultrasonic transceiver 1 can be effectively suppressed, and the posture of the ultrasonic transceiver 1 can be stabilized. As a result, it is possible to prevent a decrease in measurement accuracy due to displacement of the position of the ultrasonic transceiver 1 during measurement.

[0050] Further, the ultrasonic transceiver 1 includes a metal plate 11 having a second surface 16 and an insulating vibration damping member 12 that covers the outer peripheral edge of the metal plate 11, and the three protrusions 52 bias the metal plate 11 toward the contact portion 42. As a result, the pressing force can be effectively transmitted to the insulating vibration damping member 12 through the rigid metal plate 11. Thereby, the ultrasonic transceiver 1 can be brought into close contact with the contact portion 42, and the posture of the ultrasonic transceiver 1 can be further stabilized.

[0051] The front view, rear view, plan view, bottom view, left side view, right side view, perspective view 1, and perspective view 2 of the ultrasonic transceiver fixture 5 according to the present embodiment are shown in FIGS. 6 to 13, respectively. The thin lines shown in each of FIGS. 6 to 13 are all lines representing the shape of the three-dimensional surface. Any one form of the base portion 51, protrusion 52, connecting portion 53, restricting portion 54, and vibration suppressing portion 55 of the ultrasonic transceiver fixture 5, or a partial form of any combination of two or more of these may be a form related to the portion to be registered for design.

[0052] (Other embodiments) (Technology 1) The ultrasonic transceiver fixture of Technique 1 includes an ultrasonic transceiver that transmits and receives ultrasonic waves in a predetermined transmission direction, a measurement flow path through which the fluid to be measured flows and is defined by the inner wall surface of the wall portion, and a mounting portion that has a contact portion in contact with the ultrasonic transceiver and arranges the ultrasonic transceiver such that the transmission direction faces the measurement flow path. The ultrasonic transceiver fixture of the ultrasonic flow measurement device includes a base portion located on the opposite side of the contact portion via the ultrasonic transceiver, three protrusions protruding from the inner surface of the base portion facing the ultrasonic transceiver and contacting a second surface located on the opposite side of a first surface located on the transmission direction side of the ultrasonic transceiver, and a connection portion that detachably connects the base portion to the mounting portion.

[0053] (Technique 2) In Technique 2, the ultrasonic transceiver fixture, in Technique 1, the ultrasonic transceiver has a metal plate having the second surface and an insulating vibration damping member covering the outer peripheral edge of the metal plate, and the three protrusions may bias the metal plate toward the contact portion.

[0054] (Technique 3) In Technique 3, the ultrasonic transceiver fixture, in Technique 1 or 2, the ultrasonic transceiver has an ultrasonic oscillation element attached to the second surface, and the base portion may cover the second surface.

[0055] (Technique 4) In Technique 4, the ultrasonic transceiver fixture, in Technique 2, the ultrasonic flow measurement device has a measurement circuit that calculates the flow rate based on the propagation time of the ultrasonic waves transmitted and received by the ultrasonic transceiver, and a lead wire that electrically connects the measurement circuit and the ultrasonic transceiver and has an intermediate portion fixed to the insulating vibration damping member. The extension portion of the lead wire located outside the ultrasonic transceiver has a first extension portion extending in a direction intersecting the transmission direction and a second extension portion curved in a direction from the first surface toward the second surface and extending to the measurement circuit. The ultrasonic transceiver fixture may have a regulating portion extending from the base portion in the extending direction of the second surface and covering the first extension portion.

[0056] (Technology 5) In Technology 5, the ultrasonic transceiver fixture, in any one of Technologies 1 to 4, the ultrasonic transceiver fixture is an injection molded product of a resin material, the mounting portion has an engaging convex portion that engages with the connecting portion, the connecting portion extends from the base portion toward the mounting portion, the engaging convex portion has an engaging hole that abuts against and is locked to the inner edge, and the engaging hole may have an open end in the direction from the mounting portion toward the base portion.

[0057] (Technology 6) In Technology 6, the ultrasonic transceiver fixture, in any one of Technologies 1 to 5, the ultrasonic transceiver has an ultrasonic oscillation element attached to the second surface, the base portion covers the second surface, and the base portion may have a vibration suppression portion that protrudes from the inner surface of the base portion toward the ultrasonic oscillation element and has a protrusion whose tip faces the ultrasonic oscillation element.

[0058] (Technology 7) The injection mold of Technology 7 is the injection mold of the ultrasonic transceiver fixture of Technology 6, and an injection gate for injecting a resin material is arranged in a region where the protrusion is located on an outer surface that is located on the opposite side of the inner surface in the wave transmission direction and is viewed from the wave transmission direction.

[0059] (Technology 8) The ultrasonic flow measurement device of Technology 8 includes the ultrasonic transceiver fixture of any one of Technologies 1 to 7.

[0060] From the above description, many improvements and other embodiments of the present invention will be apparent to those skilled in the art. Therefore, the above description should be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode of practicing the present invention. Without departing from the spirit of the present invention, the details of its structure and / or function can be substantially changed.

Description of Reference Numerals

[0061] F Fluid to be measured 1 Ultrasonic transceiver 3 Flow path forming section 5 Ultrasonic transceiver fixture 15 First surface 16 Second surface 31 Wall portion 32 Measurement flow path 41 Mounting portion 42 Contact portion 51 Base portion 52 Protrusion 53 Connection portion 100 Ultrasonic flow measurement device 110 Injection mold

Claims

1. An ultrasonic transmitter / receiver that transmits ultrasonic waves in a predetermined transmission direction and receives ultrasonic waves, A flow path through which the fluid to be measured flows, the measurement flow path defined by the inner wall surface of the wall portion, and a mounting portion having a contact portion that contacts the ultrasonic transmitter / receiver and arranges the ultrasonic transmitter / receiver so that the transmission direction faces the measurement flow path, a flow path forming portion having, An ultrasonic transmitter / receiver fixture for an ultrasonic flow measurement device comprising, A base portion located on the opposite side of the contact portion via the ultrasonic transmitter / receiver, Three protrusions protruding from the inner surface of the base portion facing the ultrasonic transmitter / receiver and contacting a second surface located on the opposite side of a first surface located on the transmission direction side of the ultrasonic transmitter / receiver, A connection portion that detachably connects the base portion to the mounting portion, an ultrasonic transmitter / receiver fixture.

2. The ultrasonic transmitter / receiver has a metal plate having the second surface and an insulating vibration damping member covering the outer peripheral edge of the metal plate, The three protrusions bias the metal plate toward the contact portion, the ultrasonic transmitter / receiver fixture according to claim 1.

3. The ultrasonic transmitter / receiver has an ultrasonic oscillation element attached to the second surface, The base portion covers the second surface, the ultrasonic transmitter / receiver fixture according to claim 1.

4. The ultrasonic flow measurement device, A measurement circuit that calculates the flow rate based on the propagation time of ultrasonic waves transmitted and received by the ultrasonic transmitter / receiver, A lead wire that electrically connects the measurement circuit and the ultrasonic transmitter / receiver and has an intermediate portion fixed to the insulating vibration damping member, An extension portion of the lead wire located outside the ultrasonic transmitter / receiver has a first extension portion extending in a direction intersecting the transmission direction and a second extension portion curving from the first surface toward the second surface and extending to the measurement circuit, The ultrasonic transmitter / receiver fixture has a regulating portion extending from the base portion in the extending direction of the second surface and covering the first extension portion, the ultrasonic transmitter / receiver fixture according to claim 2.

5. The ultrasonic transmitter / receiver fixture is an injection molded product of a resin material, The mounting portion has an engaging convex portion that engages with the connection portion, The connection portion extends from the base portion toward the mounting portion and has an engaging hole in which the engaging convex portion abuts against the inner edge and is locked, The engaging hole has an end portion in the direction from the mounting portion toward the base portion opened, the ultrasonic transmitter / receiver fixture according to claim 1.

6. The ultrasonic transmitter / receiver has an ultrasonic oscillator attached to the second surface, The base covers the second surface, The ultrasonic transmitter / receiver fixture according to claim 1, having a vibration suppression portion that protrudes from the inner surface of the base toward the ultrasonic oscillator and has a tip facing the ultrasonic oscillator.

7. An injection mold for the ultrasonic transmitter / receiver fixture according to claim 6, An injection mold in which an injection gate for injecting a resin material is disposed in a region where the protrusion is located on an outer surface located on the opposite side of the inner surface in the wave transmission direction, as viewed from the wave transmission direction.

8. An ultrasonic flow measurement device including the ultrasonic transmitter / receiver fixture according to claim 1.

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