JP6789765B2 - Detachable ultrasonic flowmeter - Google Patents

Description

The present invention relates to a removable ultrasonic flowmeter, and more particularly to a flowmeter that can be retrofitted to the outer peripheral surface of a pipe.

Ultrasonic flow meters are used to measure the flow rate of fluid flowing through a pipe. Patent Document 1 discloses an ultrasonic flowmeter that can be retrofitted to the outer peripheral surface of a pipe through which a fluid to be measured flows.

Explaining the flowmeter disclosed in Patent Document 1, this flowmeter is a reflection type, so-called V-arrangement type flowmeter in which the first and second ultrasonic elements are arranged on the same side with respect to the pipe. Ultrasonic waves reflected and propagated on the inner wall of the pipe are detected. The flowmeter is not limited to the reflection type (V arrangement type), and a transmission type (Z arrangement type) flowmeter is also known.

The flowmeter disclosed in Patent Document 1 discloses a case in which the first and second ultrasonic elements are housed. The case consists of a hinged lower half and an upper half. The case is fixed to the pipe by fastening the lower half and the upper half that sandwich the pipe with bolts and nuts, respectively. One of the halves has a through hole extending in the radial direction and a band-shaped fixing member hinged to the half. The strip-shaped fixing member extends across the ultrasonic element and is positioned and fixed to the half by bolts.

After attaching the case to the pipe, insert the ultrasonic element into the through hole, and then fasten the strip-shaped fixing member with bolts. As a result, the ultrasonic element in the through hole is in contact with the pipe. In addition, Patent Document 1 discloses that the acoustic coupling medium between the ultrasonic element and the pipe, that is, the couplant material may be grease or metal foil.

Japanese Unexamined Patent Publication No. 56-133620

In the conventional retrofit type ultrasonic flowmeter, the two case halves are fixed to the pipe by fixing them with bolts and nuts, and the band-shaped fixing member that fixes the ultrasonic element housed in the through hole of the case is fixed with bolts. By fastening, it can be retrofitted to the peripheral surface of the pipe.

An object of the present invention is to provide a removable ultrasonic flowmeter that can simplify the installation work of an ultrasonic flowmeter that is retrofitted to the peripheral surface of a pipe.

The above technical problems are according to the present invention.
An opening composed of a first and second halves or a case body and a lid, formed by an end wall of the first and second halves or an end wall of the case body and an end of a lid, and piping through the opening. A case with a space for piping where
The first sensor member and the second sensor member housed in the case,
It is formed inside the first half or the case body, and the guide surface defining the moving direction of the first sensor member,
A first urging member for urging said piping space along said first sensor member on the guide surface,
A coplant that is arranged facing the piping space and can move together with the first sensor member that moves along the guide surface .
Two inclined portions provided on the second half or the lid facing the piping space and inclined to each other,
Said first, have a fixing member for forming the casing by said cover and a second half or the case body is fixed to one another,
When the piping is arranged in the piping space and the first and second halves or the case body and the lid form the case, the first urging member causes the first sensor member and the lid. By providing an ultrasonic flow meter characterized in that the couplant is compressed between the tubing and the tubing is positioned by the couplant and the two inclined portions projecting toward the piping space. Achieved.

Other objectives and effects of the invention will become apparent from the following detailed description of preferred embodiments of the invention.

It is a figure for demonstrating the whole structure of the ultrasonic flowmeter of an Example. FIG. 1 is a functional block diagram of the illustrated ultrasonic flowmeter. It is a figure for demonstrating the V arrangement of the sensor member of a reflection type flowmeter. It is a figure for demonstrating the Z arrangement of the sensor member of a transmission type flow meter. It is sectional drawing of the sensor head of V arrangement of the ultrasonic flowmeter of 1st Example. FIG. 5 is a front view of the sensor head shown in FIG. 5, in which the case body and the lid are hinged. FIG. 5 is an explanatory view of the operation of the swing hook which is the fixing member of the sensor head shown in FIG. 5, where (I) shows the swing hook in the released state and (II) shows the swing hook in the state immediately before locking. (III) shows a rocking hook in the locked state. FIG. 6 shows a modified example of the illustrated sensor head, and the lid can be completely opened. FIG. 6 shows a modified example of the illustrated sensor head, and the opening at the end of the head is a front view pentagon. It is a perspective view of the sensor head of the ultrasonic flowmeter of the 2nd Example. FIG. 10 is a cross-sectional view of the sensor head shown in FIG. 10, in which sensor members are arranged in Z. FIG. 11 is a diagram for explaining the shape of the opening at the end of the illustrated sensor head, and the opening through which the pipe is inserted is typically a front view pentagon. It is a figure for demonstrating the relative relationship of the 1st and 2nd sensor members when attached to the pipes of different diameters, (I) is the case where the pipe has a relatively small diameter, and (II) Is the case where the pipe has a relatively large diameter. Similar to FIG. 13, it is a figure for demonstrating the relative relationship of the 1st and 2nd sensor members when attached to the pipes having different diameters. 10A and 10B are views for explaining a process of closing the first and second cases of the Z-arranged sensor heads shown in FIG. 10 so as to sandwich the pipe, FIG. 10I is a cross-sectional view, and FIG. 10 is a diagram for explaining a state when the first and second cases of the Z-arranged sensor heads shown in FIG. 10 are closed so as to sandwich the pipe and fixed to the pipe. FIG. ) Is a front view. It is sectional drawing of the ultrasonic flowmeter of the 3rd Example. FIG. 17 is a front view of the illustrated ultrasonic flowmeter.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

With reference to FIG. 1, the ultrasonic flow meter 200 of the embodiment is composed of a sensor head 2 and a controller 4. The sensor head 2 and the controller 4 have a separate structure, and the sensor head 2 and the controller 4 have a separate structure. It is connected by a cable 6. The sensor head 2 is detachably attached to the peripheral surface of the rigid pipe 10. Further, a cable connected to an external device (not shown) such as a PLC is connected to the surface of the controller 4 opposite to the surface to which the cable 6 is connected. Through this cable, the controller 4 outputs an on / off signal regarding the flow rate of the fluid flowing through the pipe to an external device such as a PLC. In the following embodiment, the head-amplifier separated type ultrasonic flowmeter 200 shown in FIG. 1 will be mainly described, but the head-amplifier integrated ultrasonic flowmeter in which the head and the amplifier are integrated will be used. Needless to say, the present invention can be applied.

FIG. 2 is a functional block diagram of the ultrasonic flow meter 200 of the embodiment. The controller 4 has a control unit 12, a storage unit 14, a transmission amplification unit 16, and a reception amplification unit 18. The transmission amplification unit 16 and the reception amplification unit 18 are connected to the transmission / reception switching circuit 20.

The analog signal generated by the transmission signal generation unit 22 included in the control unit 12 is supplied to the first and second ultrasonic elements 24 and 26 via the transmission / reception switching circuit 20 via the transmission amplification unit 16 and is supplied to the first and second ultrasonic elements 24 and 26. Ultrasonic waves are generated from the first and second ultrasonic elements 24 and 26.

The ultrasonic waves generated from the first ultrasonic element 24 are incident on the fluid passing through the pipe 10 (FIG. 1). The ultrasonic waves propagating in the fluid are received by the second ultrasonic element 26, and the second ultrasonic element 26 outputs an analog signal based on the received ultrasonic waves. The analog signal output from the second ultrasonic element 26 is supplied to the reception amplification unit 18 through the transmission / reception switching circuit 20.

The reception amplification unit 18 amplifies the analog signal received from the transmission / reception switching circuit 20 and converts it into a digital signal by the A / D conversion circuit. This digital signal is supplied to the control unit 12.

On the other hand, the ultrasonic waves generated by the second ultrasonic element 26 are incident on the fluid passing through the pipe 10 (FIG. 1). The ultrasonic waves propagating in the fluid are received by the first ultrasonic element 24, and the first ultrasonic element 24 outputs an analog signal based on the received ultrasonic waves. The analog signal output from the first ultrasonic element 24 is supplied to the reception amplification unit 18 through the transmission / reception switching circuit 20.

The reception amplification unit 18 amplifies the analog signal received from the transmission / reception switching circuit 20 and converts it into a digital signal by the A / D conversion circuit. This digital signal is supplied to the control unit 12.

By executing the program stored in the storage unit 14, the control unit 12 realizes the functions of the signal calculation unit 30, the flow rate calculation unit 32, and the comparison / determination unit 34. The signal calculation unit 30 measures the time difference Δt based on the digital signal given from the reception amplification unit 18. This time difference Δt is the time t1 until the ultrasonic wave output by the first ultrasonic element 24 is received by the second ultrasonic element 26, and the ultrasonic wave output by the second ultrasonic element 26 is the first ultrasonic element. It is the difference from the time t2 until it is received by 24. The flow rate calculation unit 32 calculates the velocity of the fluid flowing in the pipe 10 based on a predetermined formula based on the time difference Δt measured by the signal calculation unit 30, and calculates the flow rate of the fluid by another predetermined formula. Calculated based on.

The controller 4 has an operation unit 36 (FIG. 1) such as a button operated by the user, a display unit 38 (FIG. 1) composed of a 7-segment LED and a thin display, and an interface with an external device. It has an output unit 40 (FIG. 2) such as a connector to be configured. In FIG. 2, in the ultrasonic flowmeter integrated with the head amplifier, the sensor head 2 (function) is incorporated in the controller 4. On the other hand, in the ultrasonic flowmeter 200 of the head / amplifier separation type, it is free where the head and the amplifier are separated. For example, the reception amplification unit 18, the transmission amplification unit 16, and the transmission / reception switching circuit 20 may be incorporated in the sensor head 2.

The first and second ultrasonic elements 24 and 26 are arranged in a V arrangement (FIG. 3) or in a Z arrangement (FIG. 4). In FIGS. 3 and 4, reference numeral 42 indicates an acoustic coupling medium, that is, a coplant.

The coplant material is an elastic coplant material such as polymer rubber (silicone rubber, epiclohydrin rubber, nitrile rubber, hydrogenated nitrile rubber, fluororubber, etc.) and gel-like substances (silicone gel, urethane gel, etc.). Is good. This capplant material effectively exerts an acoustic coupling effect under an appropriate compressive force. This compressive force is provided by an urging member (typically a spring force).

A control output based on a preset threshold value (set value) is output to the display of the display unit 38 and the external device through the output unit 40. In addition, a pulse is output for each integrated flow rate. Further, for example, the flow rate measurement value is digitally output using communication.

Hereinafter, examples of an ultrasonic flowmeter to which the present invention is applied will be described, and the same elements as those described above are designated by the same reference numerals.

First Example (FIGS. 5 to 9) :
5 and 7 show the sensor head 50 included in the ultrasonic flow meter of the first embodiment. In the sensor head 50, the first and second ultrasonic elements 24 and 26 are arranged in V. The case 52 is composed of a case main body 54 and a flat lid 56, and the lid 56 can be opened to one side with respect to the case main body 54 by a hinge 58 (FIG. 6). Further, a hook 60 is provided on the side opposite to the hinge 58, and the intermediate portion of the hook 60 in the longitudinal direction is pivotally supported by the case body 54. The support shaft of the swing hook 60 is indicated by reference numeral 60a.

The case body 54 has openings 62 (FIG. 6) on both end walls thereof. In this embodiment, the flat lid 56 shapes the opening 62 into a rectangular front view.

The pipe 10 is inserted into the case 52 through the opening 62. The opening 62 is sized to accommodate, for example, a pipe having a diameter of 1 inch. Of course, the size of the opening 62 can be arbitrarily set, but it is preferable to set the opening 62 to a size corresponding to the value of the maximum diameter of the pipe 10 to which the sensor head 50 can be attached.

The first sensor member 64 and the second sensor member 66 are arranged on the case main body 54 at intervals in the longitudinal direction of the pipe 10. The first sensor member 64 includes a first ultrasonic element 24 and a first wedge member 68. The second sensor member 66 includes a second ultrasonic element 26 and a second wedge member 70.

The first sensor member 64 is urged in the direction of the lid 56 by the first urging member 72. The second sensor member 66 is urged in the direction of the lid 56 by the second urging member 74. Specifically, the first and second urging members 72 and 74 are composed of compression springs. Explaining the urging directions of the first and second urging members 72 and 74 in more detail, the first sensor member 64 is urged by the first urging member 72 in the diameter direction of the pipe 10 and in the direction of the lid 56. Similarly, the second sensor member 66 is urged by the second urging member 74 in the radial direction of the pipe 10 and in the direction of the lid 56.

With reference to FIG. 5, the movement direction of the first sensor member 64 is guided by two vertical surfaces of the case main body 54, one of the vertical walls 54a and the intermediate wall 77, which oppose each other. Here, "perpendicular" is a concept with respect to the axis of the pipe 10, and in other words, is the diameter direction of the pipe 10. The intermediate wall 77 is located between the first and second sensor members 64 and 66. The direction of movement of the second sensor member 66 is guided by two vertical surfaces that oppose each other, the intermediate wall 77 and the other vertical wall 54b of the case body 54. That is, the first sensor member 64 and the second sensor member 66 are guided in the radial direction of the pipe 10 and in the direction of the lid 56.

In FIG. 5, each of the first sensor member 64 and the second sensor member 66 is urged toward the pipe by being guided by the intermediate wall 77, the vertical wall 54a, and the vertical wall 54b. For example, a configuration in which the first sensor member 64 and the second sensor member 66 move together is also possible. In this case, the first sensor member 64, the second sensor member 66, and the intermediate wall 77 move together while being guided by the vertical wall 54a and the vertical wall 54b.

FIG. 6 shows a state in which the sensor head 50 is attached to the pipe 10 of 1 inch or less. The arrow A in the figure indicates the direction of urging by the first and second urging members 72 and 74. From the arrow A in FIG. 6, it can be seen that the first and second sensor members 64, 66 are urged in the direction of the lid 56. By fixing the lid 56 connected to the case body 54 by the hinge 58 with the hook 60, the sensor head 50 can be attached to the desired position of the pipe 10.

Then, when the sensor head 50 is attached to the pipe 10, the sensor head 50 is pressed by the first and second urging members 72 and 74 in the direction of the lid 56 via the first sensor member 64 and the second sensor member 66. The pipe 10 is pressed against the lid 56 in the opening 62. That is, the pipe 10 is locked by the lid 56. With reference to FIG. 5, of course, the first sensor member 64 and the second sensor member 66 pushed up by the first and second urging members 72 and 74 have a guide function of the vertical walls 54a and 54b and the intermediate wall 77. The first and second sensor members 64 and 66 are always maintained in a state of being in pressure contact with the pipe 10 via the coplant 42 by being displaced in the radial direction of the pipe 10 and in the direction of the lid 56.

Here, the coplant 42 protrudes from the bottom surfaces of the first wedge member 68 and the second wedge member 70 by a predetermined amount when not pressed against the pipe. In other words, the first wedge member 68 and the second wedge member 70 each have a contact surface that comes into contact with the pipe, and the coplant 42 is configured to protrude from these contact surfaces by a predetermined amount. When the case body 54 is pressed against the pipe, the coplant 42 is compressed until it no longer protrudes from the contact surface. The amount of crushed plant 42 at this time is preferably between 15% and 45%. As a result, high transmission efficiency of ultrasonic waves can be maintained.

As described above, in this embodiment, in order to specify the crushing amount (compression amount in the radial direction of the pipe) of the coplant 42, the bottom surface of the first wedge member 68 and the second wedge member 70, that is, the contact surface with the pipe 10. A recess is formed, and the coplant 42 is accommodated in the recess. The depth of the recess and the thickness of the coplant 42 are designed to the optimum dimensions so that the transmission efficiency of ultrasonic waves becomes high when the case body 54 is pressed against the pipe.

FIG. 7 is a diagram for explaining the operation of the hook 60 included in the embodiment. The hook 60 has an elongated shape extending in the vertical direction, and a support shaft 60a is provided at an intermediate portion thereof. The support shaft 60a is fixed to the case body 54. A compression spring 80 is interposed between the lower end of the swing hook 60 and the case body 54. On the other hand, a claw 82 is formed at the upper end of the swing hook 60. When the lid 56 is closed, the claw 82 can engage with the stepped portion 84 formed by the groove 56a of the lid 56. That is, when the lid 56 is closed, the hook 60 of the case body 54 is automatically locked to the step portion 84 of the lid 56, whereby the lid 56 is fixed to the case body 54. The urging force of the first and second urging members 72 and 74 ensures the engagement between the claw 82 and the stepped portion 84. Therefore, the first and second urging members 72 and 74 maintain a state in which the lower end surface of the lid 56 is substantially seated on the upper end surface of the case body 54. Further, the compression spring 80 described above urges the claw 82 in the direction of entering the groove 56a. That is, the urging force of the compression spring 80 ensures the locked state of the swing hook 60, and this locked state is automatically formed by the operation of closing the lid 56. That is, the spring-loaded hook 60 fixes the lid 56 and the case body 54 by snap locking. Then, the urging force of the compression spring 80 keeps the case body 54 closed by the lid 56.

6, in the example shown in FIG. 7, a lid 56 which hinged and fixed to the case body 54 with the pivot hook 60, a modification of the fixing method will be described with reference to FIG. As can be seen immediately from FIG. 8, the modified lid 90 is completely separable from the case body 54. The lid 90 has a plurality of legs 90a, and has a claw 92 at the tip of the legs 90a. On the other hand, the case body 54 has a step portion 94 for receiving the claw 92, and when the case body 54 is closed by the lid 90, the claw 92 is locked to the step portion 94 and the lid 90 is locked.

FIG. 9 is a diagram for explaining a modified example of the shape of the opening 62. With reference to FIG. 9, the lid 56 is provided, for example, with a chevron-shaped refraction, so that the opening 62 is shaped like a pentagon with an upwardly convex upper edge defined by the lid 56. By forming the opening 62 into a pentagonal shape in this way, the positioning function of the pipe 10 by the opening 62 can be further improved. That is, the pentagonal opening 62 enables positioning in which the axial positions of the pipes 10 having different diameters can be aligned in the vertical direction.

Second Example (FIGS. 10 to 16) :
10 to 16 show a sensor head 100 included in the ultrasonic flow meter of the second embodiment. With reference to FIG. 11, in the sensor head 100, the first and second ultrasonic elements 24 and 26 are arranged in Z. In the description of the sensor head 100, the same reference reference numerals are given to the same elements as those described in the sensor head 50 related to the first embodiment described above.

With reference to FIG. 11, the Z-arranged sensor head 100 has a case 102 composed of a first half 104 and a second half 106. The first and second halves 104 and 106 are connected by a hinge 58 and are fixed to each other by a swing hook 60 (FIG. 12). Of course, even in the Z-arranged sensor head 100, as a method of fixing the first half 104 and the second half 106, the first half 104 and the second half 106 are used as described with reference to FIG. It may be completely separable, and a fixing method having a structure including the legs 90a, the claws 92, and the step portion 94 shown in FIG. 8 may be adopted.

The first sensor member 64 located on the upstream side and the first urging member 72 for urging the first sensor member 64, the second sensor member 66 located on the downstream side and the second urging member 74 for urging the second sensor member 74 are the axes of the pipe 10. They are arranged apart from each other in the direction and sandwiching the pipe 10. The first sensor member 64 located on the upstream side is arranged obliquely with respect to the diameter direction of the pipe 10, and the inclination direction is defined by the inner surface of the first cylinder portion 110 that receives the first sensor member 64. That is, the inner surface of the first cylinder portion 110 constitutes a first guide surface that defines the inclination direction of the first sensor member 64 and the displacement direction of the first sensor member 64.

In the second embodiment shown in FIG. 11, the first sensor member 64 slides in an oblique direction with respect to the axial direction of the pipe, but the present invention is not limited to this, and for example, the pipe The first sensor member 64 may be slid in the radial direction (the direction perpendicular to the axial direction of the pipe). However, by sliding the first sensor member 64 in the oblique direction, there is an advantage that the range of pipe diameters that can be handled is widened as compared with the case where the first sensor member 64 is slid in the radial direction. The same applies to the second sensor member 66. Further, the cross section of the first tubular portion 110 may be a circle or an ellipse, or may be a rectangle or other polygon.

Similarly, the second sensor member 66 located on the downstream side is arranged obliquely with respect to the diameter direction of the pipe 10, and the inclination direction is defined by the inner surface of the second cylinder portion 112 that receives the second sensor member 66. ing. That is, the inner surface of the second cylinder portion 112 constitutes a second guide surface that defines the inclination direction of the second sensor member 66 and the displacement direction of the second sensor member 66.

In the Z-arranged sensor head 100, the pipe 10 to which the sensor head 100 is attached is restricted to, for example, a pipe having a diameter of 1 inch or less. Therefore, the inclination angles of the first and second tubular portions 110 and 112 described above are set so as to have a positional relationship in which ultrasonic waves can be mutually received when the pipes having a diameter in this range are arranged in Z. The trajectory of the ultrasonic wave is shown by reference numeral 114 in FIG. The relative positions of the first and second tubular portions 110 and 112 in the axial direction and the inclination angle with respect to the diameter direction of the pipe 10 are set so as to match the locus 114.

For convenience of explanation, the shape of the opening 62 on the end face of the case 102 will be described first with reference to FIG. The opening 62 has a front-view pentagonal shape with two inclined edges 104a and 104b intersecting the acute angles of the first half 104. The pentagon has a horizontally extending base 106a and vertical edges 106b, 106c extending vertically from both ends thereof and parallel to each other, and these elements are formed by a second half 106. In FIG. 12, the two inclined edges 104a and 104b are configured to intersect at an acute angle, but may be configured to intersect at an obtuse angle, for example.

In the pentagonal opening 62, the pipe 10 is guided by the two inclined edges 104a and 104b of the first half 104 by urging the pipe 10 relatively strongly from the second half 106 side to the first half 104 side. Therefore, the piping 10 is positioned. In order to achieve this, the second half 106 is provided with an additional first urging member 120, with reference to FIG. The additional first urging member 120 exerts an urging force in the direction of the first half 104. It is preferable that the additional first urging member 120 is arranged on the side opposite to the second tubular portion 112 in the axial direction of the pipe 10, that is, at a position corresponding to the first tubular portion 110.

As a modification, an additional second urging member (not shown) may be arranged in the first half 104 at a position corresponding to, for example, the second tubular portion 112. The additional second urging member exerts an urging force in the direction of the second half 106. Of course, this additional second urging member has a smaller urging force than the additional first urging member 120 (the urging force of the additional first urging member 120> the urging force of the additional second urging member). ).

As described above, it has been described that the pipe 10 is guided by the two inclined edges 104a and 104b of the first half 104 to position the pipe 10, but instead of the first half 104, such an inclined edge 104a, 104b may be provided in the second half 106. In this case, contrary to the example shown in FIG. 12, it is needless to say that the pipe 10 may be pressure-welded to the two inclined edges of the second half 106.

Assuming that the applicable pipe 10 has a diameter of 1 inch or less, the first and first pipes 10 (L) having a large diameter and a small diameter pipe 10 (S) having a small diameter are compared with each other. It will be described with reference to FIGS. 13 and 14 that the positions of the two sensor members 64 and 66 are automatically adjusted.

FIG. 13 (I) shows an example in which the sensor head 100 is attached to the small-diameter pipe 10 (S). FIG. 13 (II) shows an example in which the sensor head 100 is attached to the large-diameter pipe 10 (L). The first and second sensor members 64 and 66, whichever have a small diameter or a large diameter, are urged toward the pipe 10 by the first and second urging members 72 and 74, respectively, and then The first and second sensor members 64 and 66 are guided by the inner surface of the first and second tubular portions and are in a state of being in pressure contact with the pipe 10 as in FIG.

As described above, the first and second tubular portions 110 and 112 are inclined with respect to the diameter direction of the pipe 10 in accordance with the ultrasonic trajectory 114 (FIG. 11). From this, as shown in FIG. 14, the separation distance between the first and second sensor members 64 and 66 in the small diameter pipe 10 (S), that is, the axial distance D1 of the pipe 10 is a large diameter. It is smaller than the separation distance D2 between the first and second sensor members 64 and 66 in the pipe 10 (L) (D1 <D2). In FIG. 14, P (S) indicates the position of the second sensor member 66 when the small-diameter pipe 10 (S) is used, and P (L) is the second sensor member 66 when the large-diameter pipe 10 (L) is used. Indicates the position of the sensor member 66 of.

FIG. 15 shows a state in which the sensor head 100 is being attached to the small-diameter pipe 10 (S). Then, the state in which the small-diameter pipe 10 (S) is housed in the case 102 and the sensor head 100 is completely attached to the pipe 10 (S) is shown. It can be seen that the first and second sensor members 64 and 66 are urged and displaced in the direction of pressure contact by the first and second urging members 72 and 74, respectively.

As described above, since the second half 106 is provided with the additional first urging member 120, the pipe 10 (S) has two mutually inclined edges of the opening 62 defined by the first half 104. As described above, the pipe 10 (S) is positioned by being pressed against the 104a and 104b. The same applies to the large-diameter pipe 10 (L).

FIG. 16 shows a state when the sensor head 100 is attached to the small diameter pipe 10 (S). This state is formed by locking the first half 104 with the swing hook 60. Then, in this state, the first and second halves 104 and 106 are in a state in which the surfaces facing each other are substantially in contact with each other. Then, it can be understood that the first and second sensor members 64 and 66 are in a state of being in pressure contact with the pipe 10 by the first and second urging members 72 and 74, respectively, and are displaced.

Third Example (FIGS. 17 and 18) :
Since the flow meter 150 of the third embodiment is a modification of the sensor head 100 included in the flow meter of the second embodiment described above, the reference reference numeral used in the description of the sensor head 100 can be added to the flow meter 150. The characteristic portion of the flow meter 150 of the third embodiment will be described by omitting the description.

In the flow meter 150 of the third embodiment, the transmission amplification unit 16 and the electronic component 152 constituting the transmission / reception switching circuit 20 (FIG. 2) are housed in the second half 106. Then, signals are supplied from the electronic component 152 to the first and second ultrasonic elements 24 and 26 through the internal wirings 154 and 156. This third embodiment describes a specific example of an ultrasonic flowmeter integrated with a head amplifier to be assembled to the pipe 10, and is not limited to the transmission type ultrasonic flowmeter but is attached to the reflection type ultrasonic flowmeter. Is the same. The cable connecting the ultrasonic element and the electronic component 152 across the first and second halves 104 and 106 is inserted through a flexible member (bellows member) arranged in the vicinity of the hinge 58. To. Further, in other drawings as well, an appropriate wiring layout can be designed with reference to FIGS. 17 and 18.

As described above, according to the first to third embodiments, the present invention can be effectively applied to either a V-arranged type, that is, a reflection type flow meter or a Z-arranged type, that is, a transmission type flow meter. Explained. Further, as is clear from FIGS. 12 and 13 showing the Z-arranged type, that is, the transmission type flowmeter, when the lid 56 is fixed to the case body 54, the two inclined edges 104a and 104b and the second sensor member 66 By contacting the three points of and with the pipe, the pipe can be positioned at a desired position in the opening 62. More specifically, since the two inclined edges 104a and 104b have a shape extending along the axial direction of the pipe, when the lid 56 is fixed to the case body 54, it is in the longitudinal direction of the sensor head 100. It is positioned so that it is substantially parallel to the axial direction of the pipe.

In addition, the two inclined edges 104a and 104b extend from the first sensor member 64 so as to be separated from each other on both sides, and are in a plane passing through the first and second ultrasonic elements 24 and 26 and the central axis of the pipe. On the other hand, they have the same inclination angle (in FIG. 12, they are symmetrical). Therefore, the pipe can be positioned so that the first and second ultrasonic elements 24 and 26 and the central axis of the pipe are located on the same plane while the lid 56 is fixed to the case body 54. As a result, it is possible to prevent a decrease in the reception sensitivity of ultrasonic waves. This applies not only to the Z-arranged flowmeter shown in FIG. 12 but also to the V-arranged type, that is, the reflective type flowmeter shown in FIG.

In the first embodiment and the second embodiment, by using the two inclined edges 104a and 104b, the first and second ultrasonic elements 24 and 26 and the central axis of the pipe are located on the same plane. However, as a specific structure, it is possible to use other than the two inclined edges 104a and 104b. For example, two round bars extending in the longitudinal direction of the sensor head 100 are used at positions symmetrical with respect to the plane passing through the first and second ultrasonic elements 24 and 26 and the central axis of the pipe.

Further, as a supplement to the prior art, it is not easy to grasp how much the tightening method using bolts should be tightened. If the bolts are not tightened sufficiently, the ultrasonic element may not be sufficiently pressed against the pipe, which may lead to a decrease in the ultrasonic reception sensitivity. Further, regarding the mounting device that slides the separation distance of the ultrasonic element in the pipe axis direction, it is not easy to grasp how much the relative distance should be adjusted to optimize the ultrasonic reception sensitivity. On the other hand, according to the ultrasonic flowmeters according to the first embodiment and the second embodiment, even if the diameters of the pipes are different, they can be easily and easily retrofitted to the peripheral surface of the pipes, which is convenient. Is good and has excellent usability.

Further, the technical idea of the present invention will be described from another aspect. The first ultrasonic element that transmits at least one of the transmission of ultrasonic waves to the fluid flowing in the pipe and the reception of ultrasonic waves from the fluid flowing in the pipe. The second ultrasonic element, the first ultrasonic element, and the second ultrasonic element that transmit at least one of the transmission of ultrasonic waves to the fluid flowing in the pipe and the reception of ultrasonic waves from the fluid flowing in the pipe. On / off regarding the flow rate of the fluid flowing through the pipe based on the calculation unit that calculates the flow rate of the fluid in the pipe based on the output signal of at least one of them, the flow rate calculated by the calculation unit, and the predetermined flow rate threshold. An ultrasonic fluid flow sensor that outputs a signal, a sensor unit containing at least one of a first ultrasonic element and a second ultrasonic element, a first housing having a passage in which piping is arranged, and a first housing. It has an engaging portion for engaging with the housing and a contact portion that comes into contact with the first housing when engaged with the first housing by the engaging portion, and is provided in the first housing. With the second housing holding the pipes arranged in the passage and the contact portion of the second housing engaged with the first housing by the engaging portion of the second housing, the second housing Along the contact direction in which the abutting portion abuts on the first housing, the sensor portion is elastically supported by the first housing or the second housing toward the passage. As a result, the user can easily and easily retrofit the peripheral surface of the pipe even if the diameters of the pipes are different by simply performing the simple operation of engaging the second housing with the first housing. can do.

Although the present invention has been described above, the present invention has at least one of the following features, and each feature can be combined in any combination.
(1) It has an urging member that urges a sensor member including an ultrasonic element and a wedge member toward the outer peripheral surface of the pipe. A typical example of the urging member is a compression spring.

(2) An acoustic coupling medium, that is, a couplant material is interposed between the sensor member and the pipe as in the conventional case. The coplant material is an elastic coplant material such as polymer rubber (silicone rubber, epiclohydrin rubber, nitrile rubber, hydride nitrile rubber, fluororubber, etc.) and gel-like substances (silicone gel, urethane gel, etc.). It may also be a capplant material such as a metal foil.

(3) When the case is composed of the first and second halves or the case body and the lid, and when the first and second halves or the case body and the lid are locked with the fixture, the first and first halves are used. The relative position between the half of 2 or the case body and the lid is fixed. For example, when the first and second halves or the case body and the lid are provided with a seating surface in contact with each other, if the pipe has a diameter within the design range, the first, when the case is attached to the pipe, The first and second halves or the case body and the lid are locked by a one-touch type fixture with the seating surfaces of the second half or the case body and the lid in contact with each other. Although not particularly limited, the preferred diameter of the pipe to be applied is several millimeters to 1 inch (about 25 mm). Further, the present invention is suitably applied to hard piping.

(4) When the case is composed of the first and second halves or the case body and the lid, the case has one or more (for example, two) positioning surfaces that come into contact with a part of the pipe. This positioning surface typically constitutes part of an opening in the end wall of the first and second halves or an opening formed by the end wall of the case body and the edge of the lid. This opening has dimensions corresponding to the diameter of the largest pipe of interest. Specifically, when 1 inch (about 25 mm) is set as the maximum diameter, pipes of 1 inch or less are applicable to the ultrasonic flowmeter proposed by the present invention. When the ultrasonic flowmeter of the present invention is attached to a pipe having a diameter equal to or less than a specified value, the case in which the pipe is inserted has a predetermined shape when the first and second halves are closed. Similarly, when the case body is closed with a lid, the case in which the pipe is inserted becomes a case having a predetermined shape. Then, the pipe is in a positioned state by engaging with the above-mentioned opening of the case body.

(5) The moving direction of the sensor member is defined by the guide surface formed on the first half, the second half, or the case body. As a result, the arrangement of the sensor members can be properly maintained for pipes having different diameters.

(6) The present invention can be suitably applied not only to a flow meter in which two sensor members are arranged in V, that is, a reflective flow meter, but also to a flow meter in which Z is arranged, that is, a transmission type flow meter. Since the sensor member is typically spring-loaded in the Z-arranged flow meter, and by providing the above-mentioned guide surface, the first and second ultrasonic elements due to the difference in the diameter of the pipe are provided. The separation distance between them, that is, the radial and longitudinal separation distances of the pipes are automatically adjusted.

(7) In fixing the case to the pipe, a one-touch type fixing tool is preferably adopted as a member operated by the user. The one-touch type means that it can be fixed by one operation of the user. Specific examples of the one-touch type fixture include a swing hook having a locking claw, a clip made of a spring material, and a hook made of a spring material. Further, a snap locking type fixture by combining a swing hook provided with a locking piece and an urging member that urges the hook in the locking direction can be mentioned as a typical example of the one-touch type fixture. ..

10 Rigid piping 24 1st ultrasonic element 26 2nd ultrasonic element 42 Kaplant (acoustic coupling medium)
50 Sensor head of the ultrasonic flow meter of the first embodiment 52 Case 54 Case body 56 Lid 58 Hinge 60 Hook 62 Opening through which piping is inserted 64 First sensor member 66 Second sensor member 72 First urging member (compression spring) )
74 Second urging member (compression spring)
82 Hook claw 100 Z-arranged sensor head 102 Case 104 1st half 106 2nd half 110 1st cylinder (forms a guide surface)
112 Second cylinder (forming a guide surface)
114 Ultrasonic trajectory 120 Additional first urging member

Claims (9)

An opening formed by the end wall of the first and second halves or the end wall of the case body and the end of the lid, which is composed of the first and second halves or the case body and the lid, and piping through the opening. A case with a space for piping where
The first sensor member and the second sensor member housed in the case,
It is formed inside the first half or the case body, and the guide surface defining the moving direction of the first sensor member,
A first urging member for urging said piping space along said first sensor member on the guide surface,
A coplant that is arranged facing the piping space and can move together with the first sensor member that moves along the guide surface .
Two inclined portions provided on the second half or the lid facing the piping space and inclined to each other,
Said first, have a fixing member for forming the casing by said cover and a second half or the case body is fixed to one another,
When the piping is arranged in the piping space and the first and second halves or the case body and the lid form the case, the first urging member causes the first sensor member and the lid. An ultrasonic flow meter characterized in that the capplant is compressed between the pipe and the pipe is positioned by the capplant and the two inclined portions protruding toward the space for the pipe . The opening is composed of a horizontally extending base, two vertical edges extending vertically from both ends and parallel to each other, and two sloping edges extending from the ends of the two vertical edges, respectively.
The bottom and the two vertical edges are formed on the case body, and the two inclined edges are formed on the lid.
The ultrasonic flow meter according to claim 1, wherein the pipe is locked to the two inclined edges. The first and second sensor members are arranged in a reflective manner.
The ultrasonic flow meter according to claim 1 or 2, wherein the moving direction of the first sensor member is the diameter direction of the pipe by the guide surface. The first and second sensor members are arranged in a transmissive manner, the first sensor member is housed in the first half, and the second sensor member is housed in the second half.
The second half includes a second guide surface that defines the moving direction of the second sensor member.
Said first, second sensor member, the movement direction of its first and in alignment with the ultrasonic trajectory between the second sensor member, the ultrasonic flow meter according to claim 1. With additional urging members
The ultrasonic flow meter according to claim 4, wherein a part of the pipe is locked to the opening by the additional urging member. The opening is composed of a horizontally extending base, two vertical edges extending vertically from both ends and parallel to each other, and two sloping edges extending from the ends of the two vertical edges, respectively.
The bottom and the two vertical edges are formed on one of the first or second halves, and the two sloping edges are formed on the other half.
The ultrasonic flow meter according to claim 5, wherein the pipe is locked to the two inclined edges. The ultrasonic flowmeter according to claim 1, wherein the two inclined portions extend in the longitudinal direction of the piping space. The ultrasonic flowmeter according to any one of claims 1 to 7 , wherein the fixing member is a one-touch type that can be fixed by one operation of the user. The fixing member is composed of a hook having a claw and a step portion to which the claw of the hook is locked.
Said hook, said first, provided on one of the lid and the second half of one or the case body,
Said step portion, said first, second half of the other or the is provided et al is in the other of the case body and the lid, the ultrasonic flow meter according to claim 8.

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