Clamp-on ultrasonic transmitter / receiver

Abstract

A clamp-on ultrasonic transmitter / receiver that prevents the base from slipping or sliding in the horizontal direction. [Solution] The pedestal 4 is composed of a base 4a on which a measurement pipe P is placed and an ultrasonic transmitter / receiver 4b connected to the base 4a. The base 4a, which is an acoustic matching layer, is in close contact with a piezoelectric vibrator 4c and is composed of a main body 4d extending diagonally upward and a rib 4e extending below the main body 4d in a direction perpendicular to the axis. A first fixed portion 4f, which is a screw hole in a housing 2c, extends perpendicular to the axis from the center of the bottom surface of the rib 4e. After aligning the first fixed portion 4f with a third fixed portion 2d, which is a through-hole arranged inside the housing 2c, a screw body is screwed from below to the second fixed portion 4o so as to sandwich the third fixed portion 2d between them, thereby preventing the base 4a from slipping or escaping in the horizontal direction.

Description

[Technical Field]

[0001] The present invention relates to a clamp-on type ultrasonic transmitting and receiving device in which an ultrasonic transmitting and receiving unit is fixed to a measuring pipe made of synthetic resin afterwards. [Background technology]

[0002] Patent Document 1 discloses a clamp-on ultrasonic transmitting / receiving device that transmits and receives guided waves, which are ultrasonic waves that propagate through a measuring pipe in which a fluid flows, using a pair of piezoelectric vibrators. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6106338 Summary of the Invention [Problem to be solved by the invention]

[0004] In a clamp-on ultrasonic flowmeter that propagates such guided waves through a measuring tube, ultrasonic waves from a pair of piezoelectric vibrators and ultrasonic waves that enter and exit the piezoelectric vibrators must be propagated obliquely to the measuring tube, which is held horizontally, via an acoustic matching layer that is assembled and arranged obliquely. However, when holding the measuring tube, a pressing force from above on the measuring tube may cause the acoustic matching layer that is arranged obliquely to shift and move, and the positional relationship between the acoustic matching layers and the measuring tube may easily change, which may affect measurement accuracy.

[0005] An object of the present invention is to solve the above-mentioned problems and to provide a clamp-on type ultrasonic transmitter-receiver device that can ensure measurement accuracy by arranging a piezoelectric vibrator so as to transmit and receive in an obliquely upward direction and preventing the base from slipping or slipping in the horizontal direction, which is caused by arranging an acoustic matching layer obliquely with respect to the measuring pipe. [Means for solving the problem]

[0006] In order to achieve the above object, a clamp-on type ultrasonic transmitting and receiving device according to the present invention comprises a holding part that sandwiches and holds a straight-shaped measuring tube, and a pair of piezoelectric vibrators that transmit and receive ultrasonic waves, the holding part being provided on a main body and comprising a base part on which the measuring tube is placed, and a pressing piece that is provided on a lid part connected to the main body and presses the measuring tube on the base part from above, in the clamp-on type ultrasonic transmitting and receiving device, the base part comprises a base part made of an acoustic matching layer and an ultrasonic transmitting and receiving part connected to the base part, the base part is in close contact with the piezoelectric vibrators that transmit and receive ultrasonic waves, and comprises a cylindrical main body part that extends obliquely upward in the direction of the central axis of the piezoelectric vibrators, and a rib part that extends below the main body part in a direction perpendicular to the axis and a hole-shaped fixed portion extending from the center of the bottom surface of the rib portion in the direction perpendicular to the axis, The upper end surface of the main body is curved so as to come into close contact with the measuring pipe. The base part is fixed to the main body part by inserting a rod-shaped part of the fixing part, which has a rod-shaped part, into the fixed part through a through hole formed in the main body part and fixing the rod-shaped part to the fixed part. It is characterized by the following. [Effects of the Invention]

[0007] According to the clamp-on type ultrasonic transmitting / receiving device of the present invention, the piezoelectric vibrator is arranged so as to transmit and receive in an obliquely upward direction, and the base part, on which the acoustic matching layer is arranged obliquely upward with respect to the measuring tube, is fixed to the housing part via the rib part in the direction perpendicular to the axis, i.e., in the direction perpendicular to the central axis of the measuring tube, so that the base part remains immobile even if the measuring tube is strongly pressed by the holding part when clamped on.

[0008] Therefore, even if a pressing force is applied from an oblique direction relative to the central axis of the base, the position of the piezoelectric vibrator is not affected, and the base can be prevented from escaping or sliding horizontally, eliminating the risk of the positional relationship between the piezoelectric vibrators fluctuating and enabling stable measurements. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of a state in which a clamp-on type ultrasonic transmitting / receiving device is attached to a measuring pipe. [Figure 2] FIG. 2 is a perspective view showing the state of FIG. 1 with the cover portion opened. [Figure 3] FIG. 2 is a cross-sectional view taken along the line AA′ in FIG. [Figure 4] FIG. 2 is an exploded perspective view of a base and a housing. [Figure 5] FIG. 2 is a perspective view of the assembled ultrasonic transmitting and receiving unit. [Figure 6] FIG. 2 is a perspective view of the assembled ultrasonic transmitting and receiving unit as seen from below. [Figure 7] FIG. 2 is a perspective view of a housing unit to which a pair of base units are attached. [Figure 8] 10 is a perspective view of the housing unit to which the pair of base units are attached, as viewed from below. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described in detail based on the illustrated embodiment. FIG. 1 is a perspective view of a clamp-on ultrasonic transmitter / receiver attached to a synthetic resin measuring pipe, FIG. 2 is a perspective view of the state in which the lid is opened from the state in FIG. 1, and FIG. 3 is a cross-sectional view taken along line A-A' in FIG. 1.

[0011] The clamp-on type ultrasonic transmitting and receiving device 1, which is a roughly rectangular parallelepiped, is composed of a main body 2 on which the measurement pipe P is placed and to which a connection cable can be connected at the bottom, and a lid 3 which is openably connected to the main body 2 via an opening / closing part 2a. A pair of piezoelectric vibrators which transmits and receives ultrasonic waves to and from the measurement pipe P is arranged in two positions in the longitudinal direction of the main body 2.

[0012] The holding section that clamps and holds the straight-tube-shaped measurement pipe P is composed of a base section 4 provided on the main body section 2, a side wall section 2b, and a pressing piece 3b provided on the lid section 3. The base section 4 is attached inside a housing section 2c provided inside the main body section 2. The housing section 2c is provided inside the main body section 2 as shown in Figures 2 and 3, and is fixed to the main body section 2 by a screw body.

[0013] Fig. 4 is an exploded perspective view of the base 4 and the housing 2c, Fig. 5 is a perspective view of the base 4, and Fig. 6 is a perspective view of the base 4 as viewed from below. Fig. 7 is a perspective view of the housing 2c to which a pair of bases 4 are attached, and Fig. 8 is a perspective view of the housing 2c to which a pair of bases 4 are attached as viewed from below.

[0014] The pedestal 4 is composed of a base 4a on whose upper surface the measurement pipe P is placed, and an ultrasonic transmitter / receiver 4b consisting of multiple parts connected to the base 4a. The upper surface of the base 4a is shaped like a saucer with an arc-shaped cross section so that the measurement pipe P can be placed on it.

[0015] The base 4a, which is an acoustic matching layer that propagates ultrasonic waves, is made of synthetic resin and is attached to the piezoelectric vibrator 4c. The base 4a is composed of a cylindrical main body 4d that extends diagonally upward in the direction of the central axis of the piezoelectric vibrator 4c, and a rib 4e that extends below the main body 4d in a direction perpendicular to the axis and has a horizontal bottom surface.

[0016] A threaded hole-shaped first fixed portion 4f is formed on the horizontal bottom surface of this rib portion 4e in the direction perpendicular to the axis from the center of the bottom surface, that is, in the direction perpendicular to the central axis of the measurement pipe P to be placed.

[0017] The length of the screw hole of the first fixed portion 4f is set so as not to reach the main body portion 4d, because if the screw hole reached the main body portion 4d, the ultrasonic waves transmitted and received from the piezoelectric vibrator 4c would be interfered with by the first fixed portion 4p, which is, for example, a metal body, threaded into the screw hole, significantly reducing the propagation efficiency.

[0018] The measurement pipe P can be placed on the base 4a via a thin protective film 4h that covers the upper side of the main body 4d. This protective film 4h is made of a thin, waterproof rubber sheet material or the like, and allows the measurement pipe P to be more tightly attached to the base 4a.

[0019] Furthermore, a flange 4g having a substantially circular ring shape and protruding outward is provided at the end of the main body 4d on the piezoelectric vibrator 4c side. The ultrasonic transmitting / receiving unit 4b includes the piezoelectric vibrator 4c that is in close contact with the end face of the base 4a on which the flange 4g is provided, a piezoelectric vibrator holding part 4i that holds the piezoelectric vibrator 4c from behind, and a connecting part 4j that tightly fixes the base 4a, the piezoelectric vibrator 4c, and the piezoelectric vibrator holding part 4i together.

[0020] The connecting portion 4j is composed of a storage portion 4k that is open at the top and a fixing plate portion 4l that extends horizontally from the bottom of the storage portion 4k. The storage portion 4k can store, in order from the tip, a flange portion 4g, a piezoelectric vibrator 4c, and a piezoelectric vibrator holding portion 4i.

[0021] The storage section 4k is disposed obliquely and is a generally cylindrical body having a bottom, with the top surface and part of the oblique side surface being open. A bottom screw hole 4m is provided in the center of the bottom of the storage section 4k.

[0022] The fixing plate portion 4l is a plate-shaped body for fixing the storage portion 4k to the housing portion 2c, and is provided with a through hole 4n whose central axis is oblique, and a second fixed portion 4o which is a U-shaped cutout piece at the rear end.

[0023] Furthermore, in order to firmly attach the piezoelectric vibrator 4c to the flat side surface at the center of the flange portion 4g of the main body portion 4d, an adjustment screw (not shown) is inserted into the through hole 4n from the back surface of the fixing plate portion 4l, and this adjustment screw is threaded into the bottom screw hole 4m. By adjusting the screwing of this adjustment screw, the piezoelectric vibrator 4c is pressed by the adjustment screw that passes through the bottom hole (not shown) of the piezoelectric vibrator holding portion 4i, and the piezoelectric vibrator 4c can be firmly attached to the contact surface of the main body portion 4d.

[0024] When the base 4 is fixed to the housing 2c, the flange 4g, the piezoelectric vibrator 4c, and the piezoelectric vibrator holder 4i are housed in the housing 4k as described above, and the base 4a and the ultrasonic transmitter / receiver 4b are connected and integrated together. Furthermore, the pressing force of the piezoelectric vibrator 4c against the main body 4d of the integrated base 4 is adjusted using an adjustment screw (not shown).

[0025] Next, the first fixed portion 4f of the rib portion 4e is aligned so that it overlaps with the third fixed portion 2d, which is a through hole located inside the housing portion 2c, and then the first fixed portion 4p, which is a screw body, is screwed from below to clamp the third fixed portion 2d and fix it to the first fixed portion 4f.

[0026] Similarly, after aligning the second fastening portion 4o of the fixing plate portion 4l so that it overlaps with the fourth fastening portion 2e, which is a screw hole located outside the third fastening portion 2d, the second fastening portion 4q, which is a screw body, is screwed from above to the fourth fastening portion 2e so as to sandwich the second fastening portion 4o and fasten it therebetween.

[0027] Figure 7 is a perspective view of the housing 2c with the pair of pedestals 4 attached in this way, and Figure 8 is a perspective view of the housing 2c in this state, viewed from below. The housing 2c with the pedestals 4 attached is placed on the base 2f of the main body 2, and then, as shown in Figure 2, the measurement tube mounting part 2g with the side wall 2b is placed on top of the housing 2c, and then fixed with multiple fixing screws 2h, thereby completing the assembly of the main body 2.

[0028] The lid 3 is also provided with pressing pieces 3b, which are arranged on the closing surface 3a of the lid, and which press the measuring tube P from above by distributing a uniform force so that the pressing surface is a polyhedron consisting of multiple small faces, and which press the measuring tube P on the base 4 from above, a hook-shaped locking part 3d, which is arranged on the outer surface 3c and locks the lockable part 2i, which is arranged on the outer surface 3c, by closing the lid 3, and an unlocking button 3f, which is arranged on the top surface 3e and unlocks the locking part 3d by pressing it.

[0029] An elastic body 3i made of a compression coil spring is built into the gap 3h in the lid 3 between the pressing piece 3b provided on the closing surface 3a and the elastic body fixing part 3g provided on the top surface 3e. As a result, a downward pressing force is always generated in the pressing piece 3b due to the repulsive force of the elastic body 3i, and when the measurement pipe P is placed on the base 4 and the lid 3 is closed and locked, the pressing piece 3b presses the measurement pipe P between itself and the base 4 with an appropriate pressing force from above.

[0030] In particular, in the conventional structure in which pressing force is applied from above mechanically and clamped without using pressing force from a spring or the like, variations in pressing strength occur due to variations in the dimensions of the parts, whereas in this embodiment, the pressing force from the elastic body 3i reduces fluctuations in pressing strength due to variations in the parts of the pressing piece 3b.

[0031] When attaching the clamp-on ultrasonic transmitting and receiving device 1 to the measurement pipe P, the lid 3 is opened, the measurement pipe P is placed on the front and rear bases 4, and the lid 3 is closed, as shown in Figure 2. When the lid 3 is closed, the locking portion 3d of the lid 3 is locked into the lockable portion 2i on the side of the main body 2, and the lid 3 is in the locked state as shown in Figures 1 and 3. This locked state cannot be released unless the unlock button 3f linked to the locking portion 3d is pressed.

[0032] In this way, the straight-tube-shaped measurement pipe P is sandwiched and held by the holding part composed of the base part 4 of the main body part 2, the side wall part 2b, and the pressing piece 3b of the lid part 3. The measurement pipe P held by the holding part of the clamp-on type ultrasonic transmitting and receiving device 1 originally has a circular cross section. As shown in Figure 2, when the measurement pipe P is placed on the base part 4, the side wall parts 2b on both sides of the base part 4 restrict movement of the measurement pipe P in the width direction.

[0033] The piezoelectric vibrators 4c, which are ultrasonic transmitters and receivers and are arranged on the pair of bases 4, alternately transmit and receive ultrasonic waves to measure the propagation state of the guided wave for each fluid flow direction in the measurement pipe P. Various data obtained by the pair of piezoelectric vibrators 4c are transmitted to a processing device, which is an external device, via a connection cable 2j connected to the main body 2.

[0034] In this processing device, the flow rate of the fluid flowing in the measuring pipe P is measured by a known calculation based on the flow velocity calculated based on the time difference in the propagation time of the guided wave in the measuring pipe P and the cross-sectional area of ​​the measuring pipe P.

[0035] The processing device that calculates the flow rate of the fluid may be installed inside the main body 2. In this case, the flow rate, flow rate information, etc. of the fluid calculated by the processing device, which is made up of an IC chip or the like, is transmitted to an external device via the connection cable 2j.

[0036] In this way, in the embodiment, the flow velocity and flow rate of the fluid flowing inside the measuring pipe P are measured based on the time difference in the propagation time of the ultrasonic waves that propagate as guide waves through the measuring pipe P as a medium, but it is also possible to adopt an appropriate flow rate measurement method that uses an ultrasonic beam that propagates through the fluid from a pair of piezoelectric vibrators 4c.

[0037] In this way, according to the clamp-on type ultrasonic transmitting / receiving device of the present invention, the piezoelectric vibrator 4c is arranged so as to transmit and receive in an obliquely upward direction, and the base part 4a, on which the acoustic matching layer is arranged in an obliquely upward direction relative to the measuring tube P, is fixed to the housing part 2c via the rib part 4e in the axial direction, i.e., in the direction perpendicular to the central axis of the measuring tube P, so that the base part 4a remains immobile even if the measuring tube P is pressed hard by the holding part during clamping.

[0038] Therefore, even if a pressing force is applied obliquely to the central axis of the base portion 4a, the position of the piezoelectric vibrator 4c is not affected, and the base portion 4a is prevented from escaping or sliding in the horizontal direction, so there is no risk of the positional relationship between the piezoelectric vibrators 4c changing, and stable measurements can be achieved. [Explanation of symbols]

[0039] 1. Clamp-on ultrasonic transmitter / receiver 2 Main body 2c Housing 2d Third fixed part 2e Fourth fixed part 3 Lid 4 Base 4a Base 4b Ultrasonic transmitter / receiver 4c Piezoelectric vibrator 4d main body 4e Rib section 4f First fixed part 4g Flange 4i Piezoelectric vibrator holder 4j connection part 4k storage section 4l Fixed plate part 4o Second fixed part 4p First fixing part 4q Second fixing part P measurement tube

Claims

1. The measuring pipe has a holding section that holds a straight measuring pipe by sandwiching it, and a pair of piezoelectric vibrators that transmit and receive ultrasonic waves. In a clamp-on type ultrasonic transmitting and receiving device, the holding part is provided in a main body part and is composed of a base part on which the measuring tube is placed, and a pressing piece is provided in a lid part connected to the main body part and presses the measuring tube on the base part from above, the pedestal comprises a base portion made of an acoustic matching layer and an ultrasonic transmitting / receiving portion connected to the base portion, The base portion is in close contact with the piezoelectric vibrator that transmits and receives ultrasonic waves, and is composed of a cylindrical main body portion extending obliquely upward in the direction of the central axis of the piezoelectric vibrator, a rib portion extending below the main body portion in a direction perpendicular to the axis, and a hole-shaped fixed portion extending from the center of the bottom surface of the rib portion in the direction perpendicular to the axis, an upper end surface of the main body forms a curved surface so as to come into close contact with the measuring pipe; A clamp-on type ultrasonic transmitter / receiver device characterized in that the base part is fixed to the main body part by inserting the rod-shaped part of the fixing part, which has a rod-shaped part, into the fixed part by clamping it through a through hole formed in the main body part.

2. The clamp-on type ultrasonic transmitting / receiving device of claim 1, characterized in that the ultrasonic transmitting / receiving unit comprises the piezoelectric vibrator that is in close contact with one end of the base unit, a piezoelectric vibrator holding unit that holds the piezoelectric vibrator from behind, and a connecting unit that tightly fixes the base unit, the piezoelectric vibrator, and the piezoelectric vibrator holding unit together.

3. an end of the main body on the piezoelectric vibrator side is provided with a flange portion that protrudes outward; the connecting portion is composed of a storage portion that is open at the top and a fixing plate portion that is continuous with the bottom of the storage portion, 3. The clamp-on type ultrasonic transmitting / receiving device according to claim 2, wherein the flange portion, the piezoelectric vibrator, and the piezoelectric vibrator holding portion are stored in the storage portion in this order from the tip.

4. 4. The clamp-on type ultrasonic transmitting / receiving device according to claim 3, wherein a notch is provided at the rear end of the fixing plate portion to be fixed to the main body portion by a screw.

5. A clamp-on type ultrasonic transmitter / receiver device as described in claim 1, characterized in that the fixing portion is a screw body.

6. A clamp-on type ultrasonic transmitter / receiver device as described in claim 1, characterized in that the fixed portion is a screw hole.

7. 7. The clamp-on type ultrasonic transmitting / receiving device according to claim 6, wherein the length of the screw hole does not reach the main body portion.

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