JP7797763B2 - Ultrasonic vortex flowmeter and method for manufacturing the ultrasonic vortex flowmeter - Google Patents

Description

This disclosure relates to ultrasonic vortex flowmeters and the like.

Conventionally, an ultrasonic vortex flowmeter has been known in which a pair of ultrasonic sensors are placed opposite each other across a measuring tube having a component in the flow path that generates Karman vortices, and the flow rate of a fluid passing through the measuring tube is measured by detecting Karman vortices in the flow path (see Patent Document 1).

In Patent Document 1, the case (housing) of the ultrasonic vortex flowmeter is composed of an amplifier case that houses a circuit board, a bottom plate that closes the bottom of the amplifier case, and a main body case that holds a measuring tube to house an ultrasonic sensor and is assembled to the amplifier case. This allows the bottom plate of the amplifier case to separate the space inside the case into one that houses the circuit board and one that holds and houses the measuring tube.

JP 2010-164371 A

However, in Patent Document 1, the manufacturing process requires two steps: a step of assembling the bottom plate to the amplifier case while the circuit board is housed in the amplifier case, and a step of assembling the main body case while holding the measuring tube to the amplifier case integrated with the bottom plate. This can result in a relatively large number of man-hours in the manufacturing process.

In view of the above issues, the objective is to provide technology that can reduce the number of steps required in the manufacturing process of ultrasonic vortex flowmeters.

In order to achieve the above object, in one embodiment of the present disclosure,
a measuring tube having a flow path including a member for generating Karman vortices in a fluid flowing therethrough;
a pair of ultrasonic sensors fixed to the measuring pipe so as to face each other across the flow path of the measuring pipe and detecting the Karman vortex;
a substrate electrically connected to the pair of ultrasonic sensors;
a housing that houses a measuring unit including a portion of the measuring pipe to which the pair of ultrasonic sensors are fixed and the substrate in different compartments by a partition wall,
the housing includes a first housing portion and a second housing portion that are separated from each other;
a first partition wall portion corresponding to a part of the partition wall portion is provided in the first housing portion, and a second partition wall portion corresponding to the remaining part of the partition wall portion is provided in the second housing portion;
An ultrasonic vortex flow meter is provided.

In another embodiment of the present disclosure,
a first step of attaching the substrate to the inside of the first housing part or the second housing part;
a second step of attaching the measuring pipe including the pair of ultrasonic sensors to the inside of the first housing portion or the second housing portion;
a third step of assembling the first housing part and the second housing part together,
A method for manufacturing the above ultrasonic vortex flowmeter is provided.

The above-described embodiment reduces the number of steps required in the manufacturing process of an ultrasonic vortex flowmeter.

FIG. 1 is an exploded perspective view showing an example of an ultrasonic vortex flowmeter. FIG. 1 is an external view illustrating an example of an ultrasonic vortex flowmeter. FIG. 1 is a cross-sectional view showing an example of an ultrasonic vortex flowmeter. FIG. 1 is a cross-sectional view showing an example of an ultrasonic vortex flowmeter. FIG. 1 is a cross-sectional view showing an example of an ultrasonic vortex flowmeter.

The following describes the embodiment with reference to the drawings.

[Structure of ultrasonic vortex flowmeter]
The structure of an ultrasonic vortex flowmeter 1 according to this embodiment will be described with reference to FIGS.

Figure 1 is an exploded perspective view showing an example of an ultrasonic vortex flowmeter 1. Figure 2 is an external view showing an example of an ultrasonic vortex flowmeter 1. Specifically, Figure 2 is a side view of the ultrasonic vortex flowmeter 1 viewed from the negative Y-axis direction along the Y-axis. Figures 3 to 5 are cross-sectional views showing an example of an ultrasonic vortex flowmeter 1. Specifically, Figure 3 is a cross-sectional view of the ultrasonic vortex flowmeter 1 at the center in the Y-axis direction, taken along a plane parallel to the X-axis and Z-axis, and Figures 4 and 5 are cross-sectional views taken along lines A-A and B-B in Figure 2, respectively.

The following description may use a Cartesian coordinate system defined by the X-axis, Y-axis, and Z-axis shown in Figures 1 to 5. The positive X-axis direction (+X) and negative X-axis direction (-X) may be collectively referred to as the X-axis direction. Similarly, the positive Y-axis direction (+Y) and negative Y-axis direction (-Y) may be collectively referred to as the Y-axis direction. Similarly, the positive Z-axis direction (+Z) and negative Z-axis direction (-Z) may be collectively referred to as the Z-axis direction.

As shown in Figures 1 to 5, the ultrasonic vortex flowmeter 1 includes a main body 10, a substrate 20, a communication line 30, a case 40, a gasket 50, a grommet 60, O-rings 70 and 80, and a screw 90.

The ultrasonic vortex flowmeter 1 generates Karman vortices in the fluid flowing through the flow path of the measuring tube 11 using a vortex generator 110 placed within the flow path (pipe) of the measuring tube 11, and measures the flow rate of the fluid by detecting the Karman vortices in the flow path with a pair of ultrasonic sensors 14, 15.

The main body 10 includes a measuring pipe 11, mounting portions 12 and 13, and ultrasonic sensors 14 and 15.

The measuring pipe 11 is a pipe through which the fluid whose flow rate is to be measured flows. The measuring pipe 11 has a substantially circular flow path cross section and is arranged to extend along the X-axis. Specifically, the measuring pipe 11 includes a measuring pipe 11A in the center in the X-axis direction, an inlet pipe 11B connected to the measuring pipe 11A in the negative X-axis direction and allowing the fluid to flow into the measuring pipe 11A, and an outlet pipe 11C connected to the measuring pipe 11A in the positive X-axis direction and allowing the fluid to flow out of the measuring pipe 11A. The measuring pipe 11A is housed in a case 40. Hereinafter, the measuring pipe 11A, the mounting parts 12 and 13 provided on the measuring pipe, and the ultrasonic sensors 14 and 15 may be referred to as the "measuring part" for convenience.

As shown in Figure 3, a cylindrical vortex generator 110 is provided in the flow path of the measuring tube 11A.

The vortex generator 110 is positioned upstream of the X-axis position where the ultrasonic sensors 14 and 15 are installed, i.e., on the negative X-axis side.

In addition, the measuring pipe 11A is provided with bosses 111-114 for fixing the measuring pipe 11 to the case 40.

Boss 111 is located toward the positive X-axis direction from the center of the X-axis direction where ultrasonic sensors 14, 15 of measuring pipe 11A are located, and protrudes in the positive Z-axis direction from the circular top portion in the positive Z-axis direction. The width of boss 111 in the Y-axis direction is approximately the same as that of bosses 113, 114. "Approximately" is intended to allow for manufacturing errors, for example, and will be used in the same sense hereinafter. Boss 111 fits into groove 414 of case 40 (case member 41).

Boss 112 is located closer to the positive X-axis direction from the center of the X-axis direction where ultrasonic sensors 14 and 15 of measuring pipe 11A are located, and protrudes in the negative Z-axis direction from the circular top portion in the negative Z-axis direction. The width of boss 112 in the Y-axis direction is set larger than that of bosses 111, 113, and 114. Boss 112 fits into groove 415 of case 40 (case member 41).

Boss 113 is located toward the negative X-axis direction from the center of the measuring pipe 11A in the X-axis direction where the ultrasonic sensors 14 and 15 are located, and protrudes in the positive Z-axis direction from the circular top portion in the positive Z-axis direction. The width of boss 113 in the Y-axis direction is approximately the same as that of bosses 111 and 114. Boss 113 fits into groove 424 of case 40 (case member 42).

The boss 114 is located closer to the negative X-axis direction from the center of the X-axis where the ultrasonic sensors 14, 15 of the measuring pipe 11A are located, and protrudes in the negative Z-axis direction from the circular top portion in the negative Z-axis direction. The width of the boss 114 in the Y-axis direction is approximately the same as that of the bosses 111, 113. The boss 114 fits into the groove 425 of the case 40 (case member 42).

Mounting portions 12 and 13 are provided on measuring pipe 11A and are used to mount ultrasonic sensors 14 and 15, respectively.

The mounting portion 12 is located at the center of the measuring tube 11A in the X-axis direction, at the circular top in the positive Z-axis direction, and has a roughly rectangular parallelepiped shape with each side aligned with the X-axis, Y-axis, and Z-axis. The mounting portion 12 has an opening in the positive Z-axis direction and an internal space in which the ultrasonic sensor 14 can be attached.

The mounting portion 13 is located at the center of the measuring tube 11A in the X-axis direction, at the circular top in the negative Z-axis direction, and has a roughly rectangular parallelepiped shape with each side aligned with the X-axis, Y-axis, and Z-axis. The mounting portion 13 has an opening in the negative Z-axis direction and an internal space capable of accommodating the ultrasonic sensor 15.

The ultrasonic sensor 14 is attached to the mounting portion 12. The ultrasonic sensor 14 includes a piezoelectric element 141, fixing members 142 and 143, and a cover member 144.

The piezoelectric element 141 is positioned at the innermost part of the internal space of the mounting portion 12 (the end in the negative Z-axis direction).

The fixing members 142 and 143 are positioned adjacent to the piezoelectric element 141 in the positive Z-axis direction so as to fill the space between the piezoelectric element 141 and the cover member 144.

The lid member 144 is heat-welded to the end of the mounting portion 12 facing the positive Z-axis direction, thereby closing the opening at that end. Furthermore, the surface of the lid member 144 facing the positive Z-axis direction is configured to have a predetermined gap with a predetermined portion provided inside the case member 41.

The ultrasonic sensor 15 is attached to the mounting portion 13. The ultrasonic sensor 15 includes a piezoelectric element 151, fixing members 152 and 153, and a cover member 154.

The piezoelectric element 151 is positioned at the innermost part of the internal space of the mounting portion 13 (the end in the positive Z-axis direction).

The fixing members 152 and 153 are positioned adjacent to the piezoelectric element 151 in the negative Z-axis direction so as to fill the space between the piezoelectric element 151 and the cover member 154.

The lid member 154 is heat-welded to the end of the mounting portion 13 facing the negative Z-axis direction, thereby closing the opening at that end. The surface of the lid member 154 facing the negative Z-axis direction is configured to have a predetermined gap with a predetermined portion provided on the inside of the case member 41.

The measuring section of the main body 10 (the measuring pipe 11A, the mounting sections 12 and 13 provided on the measuring pipe 11A, and the ultrasonic sensors 14 and 15) is housed in the space SP1 inside the case 40.

The board 20 is electrically connected to the ultrasonic sensors 14, 15 via predetermined conductors and performs various processes based on signals output from one of the ultrasonic sensors 14, 15 and received by the other ultrasonic sensor. These processes include measuring (calculating) the flow rate of the fluid flowing through the measuring tube 11 based on the signals from the ultrasonic sensors 14, 15. Specifically, the ultrasonic waves output from one of the ultrasonic sensors 14, 15 are modulated by Kármán vortices generated downstream of the vortex shedder 110 due to the flow of the fluid to be measured, and then received by the other ultrasonic sensor. The board 20 then uses this signal to calculate the measured flow rate of the fluid to be measured. The board 20 transmits the results of the processes to the outside via the communication line 30.

The substrate 20 has a roughly rectangular parallelepiped shape and is a flat plate with its sides aligned with the X-axis, Y-axis, and Z-axis, and is placed in a space SP2 separated from the space SP1 inside the case 40.

The communication line 30 is used for communication between the board 20 and an external device. This allows the results of processing on the board 20 to be output to the external device.

The communication line 30 is arranged to extend from the space SP2 of the case 40 in the negative direction of the X axis.

The case 40 (an example of a housing) is used to secure the components of the ultrasonic vortex flowmeter 1, such as the main body 10, the circuit board 20, and the communication line 30. The case 40 houses the measurement section of the main body 10, the circuit board 20, and the base end of the communication line 30, and holds the main body 10 in a manner that exposes the rest of the body 10 except for the inlet pipe 11B, the outlet pipe 11C, and the base end of the communication line 30.

The case 40 includes case members 41 and 42 that are assembled so as to face each other in the X-axis direction. The case members 41 and 42 are, for example, resin molded parts.

Case member 41 (an example of a first housing unit) is positioned opposite case member 42 in the positive X-axis direction. Case member 41 has a generally rectangular parallelepiped shape with sides aligned along the X-axis, Y-axis, and Z-axis, and has an opening in the negative X-axis direction where case member 42 is positioned.

The case member 41 includes a partition wall portion 411, a through hole 412, a groove portion 413, groove portions 414 and 415, and seat portions 416, 417, and 418.

The partition wall 411 (an example of a first partition wall) is provided in the center of the Z-axis direction inside the case member 41, extending approximately parallel to the X-axis and Y-axis, and divides the internal space of the case member 41 into a space in the positive Z-axis direction and a space in the negative Z-axis direction. This divides the opening of the case member 41 into an opening in the positive Z-axis direction and an opening in the negative Z-axis direction. The end of the partition wall 411 in the negative X-axis direction is located at approximately the same position as the end of the case member 41 in the X-axis direction.

The through-hole 412 is provided on the end face of the case member 41 in the positive X-axis direction, at a position further in the negative Z-axis direction than the partition wall portion 411, and passes through in the X-axis direction between the inside and outside of the case member 41. The measuring tube 11 is inserted through the through-hole 412 so that the outflow tube 11C protrudes outside the case member 41.

The groove 413 (an example of a first groove) is provided on the inner surface of the case member 41 closer to the positive X-axis direction in the positive Z-axis direction than the partition wall 411. The groove 413 includes a pair of grooves 413a, 413b that extend in the X-axis direction on the inner surface facing the positive Y-axis direction and the negative Y-axis direction, respectively. The width of the groove 413 in the Z-axis direction is the same as or slightly larger than the thickness of the board 20, and the distance in the Y-axis direction between the bottoms of the grooves 413a, 413b in the positive Y-axis direction and the negative Y-axis direction is set to be approximately the same as or slightly larger than the dimension of the board 20 in the Y-axis direction. This allows the groove 413 to hold the board 20 when it is inserted.

3, the grooves 413 are provided at two different positions in the Z-axis direction. Specifically, as shown in FIG. 5, one groove 413 is located at a first position in the Z-axis direction inside the case member 41, and includes a pair of grooves 413a, 413b that are located at the same position in the Z-axis direction and are formed in both the positive and negative Y-axis directions inside the case member 41. Similarly, the other groove 413 includes another pair of grooves 413a, 413b that are located at a second position different from the first position in the Z-axis direction. This allows, for example, one board 20 to be mounted in each of the two pairs of grooves 413a, 413b. Furthermore, appropriate grooves 413 can be selected from the two different positions in the Z-axis direction to accommodate different constraints on the manufacturing lines that manufacture the same product (ultrasonic vortex flowmeter 1) and boards 20 with different specifications.

Note that if only one substrate 20 is mounted, only one groove 413 (groove 413a, 413b) may be provided. Alternatively, if three or more substrates 20 are mounted, more grooves than the number of substrates 20 may be provided at different positions in the Z-axis direction. The same may be true for groove 423, described below.

The groove 414 is recessed in the positive Z-axis direction and extends in the X-axis direction at the circular top portion of the inner circumferential surface of the through-hole 412 in the positive Z-axis direction. The boss 111 of the measuring tube 11A is accommodated in the groove 414. The width of the groove 414 (dimension in the Y-axis direction) is approximately the same as that of the grooves 424 and 425 described below.

The groove 415 is recessed in the negative Z-axis direction and extends in the X-axis direction at the circular top portion of the inner circumferential surface of the through-hole 412 in the negative Z-axis direction. The boss 112 of the measuring pipe 11A is accommodated in the groove 415. The width of the groove 415 (dimension in the Y-axis direction) is larger than that of the groove 414 and grooves 424 and 425 described below, to match the width of the boss 112, which is larger than the width of the bosses 111, 113, and 114. This allows the worker to confirm the difference in width between the boss 112 of the measuring pipe 11A and the bosses 111, 113, and 114, and the difference in width between the groove 415 of the case 40 and the grooves 414, 424, and 425, thereby performing assembly work accurately and preventing incorrect assembly.

Seat portions 416-418 are provided for the seating surface of the screw 90.

The seat portion 416 protrudes in the positive Z-axis direction from the end of the case member 41 facing the positive X-axis direction on the end surface facing the positive Z-axis, and has a flat plate shape that is approximately parallel to the Y-axis and Z-axis. At both ends of the seat portion 416 facing the positive Y-axis and negative Y-axis, there are through-holes through which the screws 90 can be inserted approximately along the X-axis direction.

The seating surface portions 417 are provided at the corners of the case member 41 facing the positive Y-axis and negative Y-axis directions at the end facing the negative X-axis and the end facing the negative Z-axis, and have a flat plate shape approximately parallel to the Y-axis and Z-axis. The seating surface portions 417 are provided with through-holes that allow the screws 90 to be inserted approximately along the X-axis direction. The corners of the case member 41 facing the negative Z-axis and positive Y-axis directions and the corners facing the negative Z-axis and negative Y-axis directions are recessed inward, as if cut out, beyond the seating surface portions 417 in the positive X-axis direction. This allows the seating surface portions 417 to be exposed when the case member 41 is viewed from the positive X-axis direction, allowing the screws 90 to be inserted through the through-holes in the seating surface portions 417.

The seating surface portion 418 is located at both ends in the positive and negative Y-axis directions, at approximately the same position in the Z-axis direction as the partition wall portion 411 of the case member 41 and at the end in the X-axis direction, and has a flat plate shape approximately parallel to the Y-axis and Z-axis. The seating surface portion 418 is provided with a through-hole that can pass the screw 90 along approximately the X-axis direction. The end faces in the positive and negative Y-axis directions, located at approximately the same position in the Z-axis direction as the partition wall portion 411 of the case member 41, further in the X-axis positive direction than the seating surface portion 418, are recessed inward. This exposes the seating surface portion 418 when the case member 41 is viewed from the positive X-axis direction, allowing the screw 90 to be passed through the through-hole in the seating surface portion 418.

Case member 42 (an example of a second housing unit) is positioned opposite case member 41 in the negative X-axis direction. Case member 42 has a generally rectangular parallelepiped shape with sides aligned along the X-axis, Y-axis, and Z-axis, and has an opening in the positive X-axis direction where case member 41 is positioned.

The case member 42 includes a partition wall 421, a through hole 422, a groove 423, grooves 424 and 425, a protrusion 426, and a screw hole 427.

The partition wall 421 (an example of a second partition wall) is provided in the center of the Z-axis direction inside the case member 42, extending approximately parallel to the X-axis and Y-axis, and divides the internal space of the case member 42 into a space in the positive Z-axis direction and a space in the negative Z-axis direction. The position of the partition wall 421 in the Z-axis direction is approximately the same as that of the partition wall 411 of the case member 41. This allows the partition wall parts 411 and 421 to divide the internal space of the case 40 into a space SP2 in the positive Z-axis direction and a space SP1 in the negative Z-axis direction.

The end of the partition wall 421 in the positive X-axis direction is recessed in the negative X-axis direction at a portion in the Y-axis direction, for example, the center portion in the Y-axis direction, and at this location, a gap is provided between the partition wall 421 and the partition wall 411 (specifically, the packing 50 abutting the partition wall 411). This gap (recess) can be used to pass a conducting wire for electrically connecting the ultrasonic sensors 14, 15 and the board 20.

The through-hole 422 is provided on the end face of the case member 42 in the negative X-axis direction, at a position further in the negative Z-axis direction than the partition wall portion 421, and passes through in the X-axis direction between the interior and exterior of the case member 42. The measuring tube 11 is inserted through the through-hole 422 so that the inlet pipe 11B protrudes outside the case member 42.

Groove 423 (an example of a second groove) is provided on the inner surface of case member 42 closer to the positive X-axis direction than partition wall 421 in the positive Z-axis direction. Groove 423 is provided at approximately the same position in the Z-axis direction as groove 413, facing groove 413 in the X-axis direction. Groove 423 includes a pair of grooves 423a, 423b provided on the inner surface facing the positive Y-axis direction and the negative Y-axis direction, respectively, to extend in the X-axis direction. The width of groove 423 in the Z-axis direction is the same as or slightly larger than the thickness of board 20, and the distance in the Y-axis direction between the bottoms of grooves 423a, 423b in the positive Y-axis direction and the negative Y-axis direction is set to be approximately the same as or slightly larger than the dimension of board 20 in the Y-axis direction. This allows groove 423 to hold board 20 when inserted.

The groove 424 is recessed in the positive Z-axis direction and extends in the X-axis direction at the circular top portion of the inner circumferential surface of the through-hole 422 in the positive Z-axis direction. The boss 113 of the measuring tube 11A is accommodated in the groove 424. The width of the groove 424 (dimension in the Y-axis direction) is approximately the same as that of the grooves 414 and 425.

The groove 425 is recessed in the negative Z-axis direction and extends in the X-axis direction at the circular top portion of the inner circumferential surface of the through-hole 422 in the negative Z-axis direction. The boss 114 of the measuring tube 11A is accommodated in the groove 425. The width of the groove 425 (dimension in the Y-axis direction) is approximately the same as that of the grooves 414 and 424.

The protrusions 426 are provided on the inner surfaces of the case member 42 in the positive and negative Y-axis directions, starting from the end of the case member 42 in the positive X-axis direction and extending in the negative X-axis direction. This prevents the packing 50 from sinking into the internal space of the case member 42, even if a force that slightly shifts the position of the packing 50 in the Y-axis direction is applied to the packing 50 during the manufacturing process of the ultrasonic vortex flowmeter 1. This allows the packing 50 to perform its function more appropriately. For example, as shown in FIG. 4 , the protrusions 426 are provided at four different positions in the Z-axis direction on the inner surface of the case member 42 in the positive Y-axis direction. Specifically, the protrusions 426 may be located at two different positions in the Z-axis direction closer to the positive Z-axis direction than the partition wall 421 on the inner surface of the case member 42 in the positive Y-axis direction, and two different positions in the Z-axis direction closer to the negative Z-axis direction than the partition wall 421 on the inner surface of the case member 42 in the positive Y-axis direction. Similarly, for example, the protrusions 426 are provided at four different positions in the Z-axis direction on the inner surface of the case member 42 facing the negative Y-axis. Specifically, the protrusions 426 may be arranged on the inner surface of the case member 42 facing the negative Y-axis at two different positions in the Z-axis direction closer to the positive Z-axis direction than the partition wall 421, and at two different positions in the Z-axis direction closer to the negative Z-axis direction than the partition wall 421. Furthermore, the protrusions 426 on the inner surface facing the positive Y-axis direction and the protrusions 426 on the inner surface facing the negative Y-axis direction may be aligned in the Z-axis direction so that they are at the same position in the Z-axis direction.

The screw holes 427 extend in the X-axis direction from the end face of the case member 42 facing the positive X-axis direction, and have internal threads formed on their inner surfaces. The screw holes 427 are provided at positions corresponding to each of the six through holes in the seating surfaces 416 to 418 of the case member 41.

The gasket 50 is sandwiched between the end of the case member 41 facing the negative X-axis direction and the end of the case member 42 facing the positive X-axis direction. The gasket 50 is an elastic member made of a rubber or resin material with a relatively high Young's modulus. This improves the waterproof performance of the case 40. The gasket 50 abuts the negative X-axis end faces of the outer wall corresponding to the positive Z-axis, negative Z-axis, positive Y-axis, and negative Y-axis end faces of the case member 41, the negative X-axis end faces of the seating portions 416-418, and the entire negative X-axis end face of the partition portion 411. The gasket 50 also abuts the positive X-axis end faces of the outer wall corresponding to the positive Z-axis, negative Z-axis, positive Y-axis, and negative Y-axis end faces of the case member 42, and the end face of the positive X-axis of the partition portion 421 excluding the recess for passing the conductors.

The grommet 60 (an example of an elastic member) is disposed in the gap in the X-axis direction between the packing 50 abutting against the case member 41 (partition wall portion 411) and a recessed portion of the partition wall portion 421 of the case member 42 in the negative X-axis direction. The grommet 60 is an elastic member made of a rubber material, resin material, or the like with a relatively high Young's modulus. The grommet 60 is relatively larger than the gap between the packing 50 abutting against the partition wall portion 411 and the partition wall portion 421, and elastically deforms so as to be crushed between the packing 50 abutting against the case member 41 (partition wall portion 411) and the partition wall portion 421 of the case member 42. The grommet 60 also has a groove or through-hole that penetrates in the X-axis direction. As a result, grommet 60 can seal the gap in the X-axis direction between partition 421 and packing 50 abutting partition 411, while holding the conducting wires between ultrasonic sensors 14, 15 (piezoelectric elements 141, 151) and substrate 20 in the grooves and through-holes. This allows for a relatively airtight separation between space SP1, where the measurement unit including measurement tube 11A is located, and space SP2, where substrate 20 is located. Therefore, even if a high-temperature fluid flows through the flow path of measurement tube 11A, for example, heat from the fluid is less likely to be transferred to substrate 20, preventing failure of substrate 20 due to overheating. Furthermore, this also prevents failure of substrate 20 due to condensation that may form on the outer surface of measurement tube 11A due to temperature changes.

The O-ring 70 is positioned so that it abuts against the outer periphery of the measuring tube 11A near the end in the positive X-axis direction, and along the inner periphery of the through-hole 412. The O-ring 70 is made of a rubber or resin material with a relatively high Young's modulus. This improves the waterproof performance of the case 40 at the through-hole 412 through which the measuring tube 11 passes.

The O-ring 80 is positioned so that it abuts against the outer periphery of the measuring tube 11A near the end facing in the negative X-axis direction, and along the inner periphery of the through-hole 422. The O-ring 80 is made of a rubber or resin material with a relatively high Young's modulus. This improves the waterproof performance of the case 40 at the through-hole 422 through which the measuring tube 11 passes.

There are six screws 90, which are inserted into the six through-holes in the seating surfaces 416-418 of the case member 41 and screwed into the corresponding screw holes 427 in the case member 42. This allows the screws 90 to secure the case members 41 and 42 together.

[How to assemble an ultrasonic vortex flowmeter]
Next, an example of a method for assembling the ultrasonic vortex flowmeter 1 will be described with reference to FIGS.

For example, the ultrasonic vortex flowmeter 1 can be assembled by following the steps (1) to (6) below.

(1) The substrate 20 is inserted into and held in the groove of either the case member 41 or the case member 42 (either the groove 413 or the groove 423).

(2) The measuring tube 11 is inserted into the through-hole 412, 422 of either the case member 41 or the case member 42, and the boss of the measuring tube 11A is aligned with the groove of the case member to position and hold it in place. In the case of the case member 41, the measuring tube 11 is inserted into the through-hole 412 of the case member 41, and the bosses 111, 112 of the measuring tube 11A are aligned with the grooves 414, 415 of the case member 41 to position and hold it in place. Similarly, in the case of the case member 42, the measuring tube 11 is inserted into the through-hole 422 of the case member 42, and the bosses 113, 114 of the measuring tube 11A are aligned with the grooves 424, 425 of the case member 42 to position and hold it in place. In addition, the O-ring 70 provided on the measuring tube 11A is positioned so as to abut against the outer periphery of the measuring tube 11A near the end in the positive direction of the X-axis and along the inner periphery of the through-hole 412. Similarly, the O-ring 80 is positioned so as to abut against the outer periphery of the measuring tube 11A near the end in the negative X-axis direction and along the inner periphery of the through-hole 422.

(3) Connect both ends of the conductor inserted through the through-hole or groove of the grommet 60 to the substrate 20 and the ultrasonic sensors 14, 15 (piezoelectric elements 141, 151).

(4) Install a gasket 50 on the end face of either the case member 41 or the case member 42.

(5) Insert the substrate 20 into the groove of either the case member 41 or the case member 42, and insert the measuring tube 11 into the through-holes 412 and 422. Align the boss of the measuring tube 11A with the groove of the case member, and then abut the case members 41 and 42 via the packing 50. At this time, ensure that the grommet 60 is housed in the recess on the end face of the case member 42 facing the positive X-axis direction.

(6) Screw the screws 60 through the through holes in the seating portions 416-418 and into the screw holes 427 to secure the case members 41 and 42.

Note that the above assembly order and details are merely examples, and the order and details may be changed as appropriate.

[Effect]
Next, the operation of the ultrasonic vortex flowmeter 1 according to this embodiment will be described.

In this embodiment, the ultrasonic vortex flowmeter 1 includes a measuring tube 11, a pair of ultrasonic sensors 14, 15, a substrate 20, and a case 40. Specifically, the measuring tube 11 has a vortex shedder 110 in its flow path that generates Karman vortices in the fluid flowing therethrough. The pair of ultrasonic sensors 14, 15 are fixed to the measuring tube 11 so as to face each other across the flow path of the measuring tube 11 and detect Karman vortices. The substrate 20 is electrically connected to the pair of ultrasonic sensors 14, 15. The case 40 houses the measuring section, including the portions of the measuring tube 11 where the pair of ultrasonic sensors 14, 15 are fixed (mounting portions 12, 13), and the substrate 20 in separate compartments separated by a partition. The case 40 includes a case member 41 and a case member 42 that are separated from each other. A partition member 411, which corresponds to a portion of the partition member, is provided in the case member 41, and a partition member 421, which corresponds to the remaining portion of the partition member, is provided in the case member 42.

As a result, by simply assembling the two case members 41 and 42, it is possible to separate the space SP1 that houses the measuring tube 11 (measuring unit) from the space SP2 that houses the substrate 20. Therefore, compared to a case where three components are required - one case member that houses the measuring tube 11 (measuring unit), one case member that houses the substrate 20, and one case member that corresponds to the partition - the number of manufacturing steps can be reduced. Furthermore, because the number of components can be reduced, costs can be reduced.

In addition, in this embodiment, grooves 413 and 423 may be provided on the inner surfaces of case member 41 and case member 42, respectively. Then, substrate 20 may be fixed by grooves 413 and 423.

This allows the substrate 20 to be fixed in the groove of either the case members 41 or 42 when the case members 41 and 42 are combined, improving workability during the manufacturing process.

In addition, in this embodiment, a gap may be provided between the partition wall portion 411 and the partition wall portion 421, through which a conducting wire may be disposed to electrically connect the substrate 20 and the pair of ultrasonic sensors 14, 15. A grommet 60 may be disposed in this gap.

This allows the gap to be filled by the elastic deformation of the grommet 60. As a result, the gap allows the conductor to be positioned to connect spaces SP1 and SP2, while the grommet 60 can separate spaces SP1 and SP2 with greater airtightness.

In addition, in this embodiment, the manufacturing method of the ultrasonic vortex flowmeter 1 may include first to third steps. Specifically, in the first step, the substrate 20 may be attached to the inside of the case member 41 or the case member 42. In the second step, the measuring tube 11 including the pair of ultrasonic sensors 14, 15 may be attached to the inside of the case member 41 or the case member 42. Then, in the third step, the case member 41 and the case member 42 may be assembled.

This allows the ultrasonic vortex flowmeter 1 to be assembled.

Although the embodiments have been described in detail above, the present disclosure is not limited to such specific embodiments, and various modifications and variations are possible within the scope of the gist described in the claims.

1 ultrasonic vortex flowmeter 10 main body 11 measuring pipe 11A measuring pipe 11B inlet pipe 11C outlet pipe 12 mounting portion 13 mounting portion 14 ultrasonic sensor 15 ultrasonic sensor 20 substrate 30 communication line 40 case 41 case member 42 case member 50 packing 60 grommet 70 O-ring 80 O-ring 110 vortex generator 111 boss 112 boss 113 boss 114 boss 141 piezoelectric element 142 fixing member 143 fixing member 144 cover member 151 piezoelectric element 152 fixing member 153 fixing member 154 cover member 411 partition wall portion 412 through hole 413 groove portion 414 groove portion 415 groove portion 416 seat portion 417 seat portion 418 seat portion 421 partition wall portion 422 through hole 423 Groove 424 Groove 425 Groove 426 Protrusion 427 Screw hole SP1 Space SP2 Space

Claims (4)

a measuring tube having a flow path including a member for generating Karman vortices in a fluid flowing therethrough;
a pair of ultrasonic sensors fixed to the measuring pipe so as to face each other across the flow path of the measuring pipe and detecting the Karman vortex;
a substrate electrically connected to the pair of ultrasonic sensors;
a housing that houses a measuring unit including a portion of the measuring pipe to which the pair of ultrasonic sensors are fixed and the substrate in different compartments by a partition wall,
the housing includes a first housing portion and a second housing portion that are separated from each other;
a first partition wall portion corresponding to a part of the partition wall portion is provided in the first housing portion, and a second partition wall portion corresponding to the remaining part of the partition wall portion is provided in the second housing portion;
Ultrasonic vortex flow meter. a first groove and a second groove are provided on inner surfaces of the first housing portion and the second housing portion, respectively;
the substrate is fixed by the first groove and the second groove;
2. The ultrasonic vortex flowmeter of claim 1. a gap is provided between the first partition wall and the second partition wall, through which a conducting wire is disposed to electrically connect the substrate and the pair of ultrasonic sensors;
An elastic member is disposed in the gap.
3. The ultrasonic vortex flowmeter according to claim 1 or 2. a first step of attaching the substrate to the inside of the first housing part or the second housing part;
a second step of attaching the measuring pipe including the pair of ultrasonic sensors to the inside of the first housing portion or the second housing portion;
a third step of assembling the first housing part and the second housing part together,
A method for manufacturing the ultrasonic vortex flowmeter according to any one of claims 1 to 3.