JP5645127B2 - Ultrasonic transceiver unit - Google Patents

Description

  The present invention relates to an ultrasonic transmission / reception unit used when measuring the flow rate of a fluid in a cross section to be measured such as an open channel.

  Management of the intake flow rate of a hydropower plant is important for the proper operation of the facilities of the power plant. In hydroelectric power generation, the output of the generator changes depending on the flow rate of water, and there is also an influence on the downstream side. Therefore, it is necessary to appropriately control the flow rate. For example, in small hydroelectric power generation, water is taken from a water channel branched from a river and the flow rate of water flowing through the water channel is managed. The water channel branched from the river is called “open channel” or “open channel”.

  When the flow rate is measured by opening, the flow velocity distribution of a predetermined section of opening is obtained, and the flow velocity distribution data is multiplied by the opening cross-sectional area. In general, a propeller velocimeter or the like is used for the above flow velocity measurement.

In some cases, a flow rate measurement method using ultrasonic waves may be employed. In this case, the flow rate measurement uses the function of an ultrasonic flow velocity distribution meter (ADCP).
As an example of a method for measuring the flow rate of a water channel using ultrasonic waves, the ultrasonic flow rate measurement method of Patent Document 1 is disclosed. In Patent Document 1, the water channel is divided into a central portion, a peripheral portion closer to the wall surface or the bottom surface than the central portion, and an outer edge portion close to the wall surface or the bottom surface. Then, the flow velocity distribution around the water channel is measured with ultrasonic waves. That is, the flow rate of water is measured using ultrasonic waves using the Doppler method or the cross-correlation method. The flow velocity distribution in the central portion of the water channel is a technique in which the flow rate of the entire water channel is obtained by interpolation using the measured flow velocity distribution in the peripheral region.

JP 2010-190775 A

  Now, when performing the flow measurement of the opening using the ultrasonic Doppler flow velocity distribution method, it is important to accurately install an ultrasonic sensor that transmits and receives ultrasonic waves. In the technique disclosed in Patent Document 1, a plurality of ultrasonic sensors are attached to a bowl-shaped sensor jig in a flow measuring device. The hook-shaped sensor jig is lowered from above into water in the vertical direction, ultrasonic waves are transmitted and received by the ultrasonic sensor submerged in water, the flow velocity is measured, and the flow rate is measured.

When the opening flow rate measurement is performed with the same configuration as the bowl-shaped sensor jig in the above-mentioned Patent Document 1, the bowl-shaped sensor jig 80 such as a column or a single pipe is opened as shown in FIG. It is attached using a goniometer 81 or the like to a reference rod fixed mount 72 such as a temporary scaffold that is bridged to the fence 70. However, the ultrasonic wave 51 oscillated from the ultrasonic sensor 50 in water due to the bending of the bowl-shaped sensor jig 80 due to the influence of the fluid flow or the error in the installation angle of the bowl-shaped sensor jig 80. The incident angle is different from the design. As a result, an error in the flow velocity measurement occurs.
As a solution, a three-dimensional angle meter can be attached to the ultrasonic sensor 50 attached to the bowl-shaped sensor jig 80. However, a simple method is desired to use the three-dimensional goniometer because of the high installation cost and difficulty in wiring such as a cable connected to the ultrasonic sensor 50.

  The problem to be solved by the present invention is that the installation angle in the ultrasonic transmission / reception device used when measuring the flow rate of the fluid to be measured is always kept constant, and the flow rate of the fluid to be measured can be measured stably. An ultrasonic transmission / reception unit is provided.

(First invention)
A first invention according to the present application relates to an ultrasonic transmission / reception unit (10) for keeping an installation angle of an ultrasonic transmission / reception device constant at all times.
That is, a reference rod (20) that stands in a direction perpendicular to the fluid to be measured, and a support that is positioned at the lower end side of the reference rod (20) and is perpendicular to the axial direction of the reference rod (20). A shaft (30), a measuring device fixed body (40) rotatably supported with respect to the support shaft (30), and an ultrasonic transmission / reception device (50) fixed to the measuring device fixed body (40) ), And the ultrasonic transceiver (50) and the measuring instrument fixture (40) so as to reduce the fluctuation caused by the fluid to be measured with respect to the ultrasonic transceiver (50) and the measuring instrument fixture (40). A cover member (60) for covering.

(Glossary)
The “measuring fluid” refers to the fluid that measures the flow rate of the fluid that flows in a water channel such as open channel.

(Function)
The reference rod (20) is set up in the vertical direction by being fixed to, for example, a reference rod fixing base provided above the water channel through which the fluid to be measured flows. The lower end side of the reference rod (20) is immersed in the fluid to be measured. The measuring instrument fixed body (40), which is located on the lower end side of the reference rod (20) and is rotatably provided on the support shaft, maintains a horizontal state by receiving buoyancy when immersed in the fluid to be measured. Become. That is, even if the deflection due to the fluid to be measured with respect to the reference rod (20) causes a change in the installation angle, the installation angle with respect to the vertical direction in the ultrasonic transmission / reception device (50) fixed to the measuring instrument fixing body (40) is Will always be held constant. As a result, transmission / reception of ultrasonic waves by the ultrasonic transmission / reception apparatus (50) is stabilized.
In addition, since the oscillation by the fluid to be measured with respect to the ultrasonic transmission / reception device (50) and the measuring instrument fixing body (40) is reduced by the cover member (60), the transmission / reception of the ultrasonic waves is stabilized.
Accordingly, it becomes possible to stably measure the flow rate of the fluid to be measured.

(Variation 1 of the first invention)
In the first invention, the support shaft (30) may employ a three-dimensional joint (for example, a universal joint).

(Function)
Since the measuring instrument fixed body (40) is pivotally supported by the three-dimensional joint so as to be rotatable in the three-dimensional direction, the horizontal state is always maintained in water against the swinging force in the three-dimensional direction.

(Variation 2 of the first invention)
The first invention may be provided with a level installation surface (21) on which the level (11) is installed on the side of the reference rod (20) opposite to the measuring instrument fixing body (40).

(Function)
By installing the spirit level (11) on the spirit level installation surface (21), the reference rod (20) can stand upright almost certainly at an installation angle with respect to the vertical direction. Thereby, it becomes easier in that the measuring instrument fixing body (40) always maintains a horizontal state as compared with the case where the reference rod (20) is inclined with respect to the vertical direction.

(Variation 3 of the first invention)
In the first invention, the cover member (60) may be configured to be held by a connecting member (61) capable of absorbing a swinging force caused by a fluid to be measured.

(Function)
Even if the cover member (60) is swung by the fluid to be measured, the connecting member (61) absorbs the rocking force, so that the movement of the fluid to be measured inside the cover member (60) is reduced. Thereby, the swinging power with respect to the reference rod (20) is reduced.

  According to the first invention described above, the installation angle in the ultrasonic transmission / reception apparatus used when measuring the flow rate of the fluid to be measured can be kept constant, and the flow rate of the fluid to be measured can be stably measured. It was possible to provide an ultrasonic transmission / reception unit.

It is a schematic perspective view when measuring the fluid to be measured flowing through the eyelid using the ultrasonic transmission / reception unit of the embodiment of the present invention. FIG. 2 is a cross-sectional view of opening when measuring a fluid to be measured in FIG. 1. It is a schematic perspective view when measuring the to-be-measured fluid which flows through an opening using the ultrasonic transmission / reception unit of other embodiment of this invention. FIG. 4 is a sectional view of opening when measuring a fluid to be measured in FIG. 3. It is a schematic perspective view when measuring the to-be-measured fluid which flows through an opening using the ultrasonic transmission / reception unit of another embodiment of this invention. FIG. 6 is a sectional view of opening when measuring the fluid to be measured in FIG. 5. It is sectional drawing of an opening when measuring the fluid to be measured which flows through an opening using the conventional ultrasonic transmission / reception apparatus.

Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIGS. 1 and 2, the ultrasonic transmission / reception unit 10 according to the present embodiment includes a reference rod 20, a support shaft 30, a measuring instrument fixing body 40, an ultrasonic transmission / reception device 50, and a cover member 60. . In this embodiment, it is used as an example when measuring the flow rate of water, which is the fluid to be measured flowing through the opening.

  The reference rod 20 is vertically attached to a reference rod fixing mount 72 such as a temporary scaffold that bridges the upper portion of the reference rod 20 to the unfolding cage 70. The lower end side of the reference bar 20 is submerged in water.

  The support shaft 30 is provided on the lower end side of the reference rod 20 that is submerged in water, and is provided in a direction perpendicular to the axial direction of the reference rod 20.

  The measuring instrument fixing body 40 is a member that attaches and fixes an ultrasonic transmission / reception device 50 that is an ultrasonic measuring instrument, and is pivotally supported with respect to the support shaft 30. As a result, the measuring instrument fixed body 40 submerged in water inevitably always maintains a horizontal state due to its own buoyancy. Therefore, even if the installation angle change such as deflection occurs with respect to the reference rod 20, the installation angle with respect to the vertical direction in the ultrasonic transmitting / receiving apparatus 50 fixed to the measuring instrument fixing body 40 is always kept constant. Become. As a result, transmission / reception of the ultrasonic waves 51 by the ultrasonic transmission / reception apparatus 50 is stabilized, so that the flow rate of water in the cross section to be measured of the eyelid 70 can be measured stably.

  The ultrasonic transmission / reception device 50 includes an ultrasonic oscillation unit and an ultrasonic reception unit. The ultrasonic oscillating unit is composed of a piezoelectric element, and oscillates an ultrasonic pulse wave 51 from the piezoelectric element toward the bottom surface of the opening 70, for example. In addition, the ultrasonic wave receiving unit receives a reflected wave reflected by the ultrasonic pulse wave 51 oscillated from the ultrasonic wave oscillating unit hitting the wall surface 71 of the measurement target cross section of the eyelid 70.

  The cover member 60 covers the periphery of the ultrasonic transmission / reception device 50 and the measuring instrument fixing body 40 in order to reduce the fluctuation caused by the flow of water. For example, as shown in FIG. 1, the cover member 60 may be a ship-shaped box 60a that reduces the resistance caused by the flow of water. Further, the inside of the cover member 60 is filled with water flowing through the opening 70. Moreover, the cover member 60 is preferably made of plastic. The reason is that the plastic material has good permeability of the ultrasonic wave 51 and the acoustic impedance is relatively close to water.

The cover member 60 is preferably held on the reference rod 20 or the reference rod fixing base 72 by a connecting member 61 capable of absorbing the swinging force caused by the flow of water. For example, as shown in FIG. 1, the upper part of a cover member 60 that is a ship-shaped box 60 a is lifted by connecting members 61 composed of wires 62 at four places, and the wire 62 is fixed to a substantially intermediate position of the reference rod 20. It can be fixed with the tool 63.
Alternatively, as shown in FIG. 3, the upper part of the cover member 60 that is a ship-shaped box 60 a is lifted by the connecting member 61 composed of the wire 62 at the four places, and the wire 62 is fixed to the reference rod fixing mount 72. be able to.

  Since the cover member 60 has a boat shape, swinging due to the flow of water can be reduced. Further, even if the cover member 60 is swung by the flow of water, the swing is absorbed by the wire 62, so that the movement of water inside the cover member 60 is reduced. Accordingly, the swinging force with respect to the reference rod 20 is further reduced, so that the influence of the water flow on the reference rod 20 itself is reduced.

The cover member 60 is not limited to the ship-shaped box 60a described above, and may have other shapes. For example, as shown in FIG. 5, it can be a spherical box 60b or a bowl-shaped box. Even if the cover member 60 is a spherical box 60b, a flowing water inlet through which water flowing through the opening 70 enters the inside of the spherical box 60b is provided at the middle or upper part of the spherical box 60b. Is provided. Since the upper part of the bowl-shaped box is open, water flows from the opening into the box-shaped box.
The difference between the spherical box 60b and the ship-shaped box 60a is the degree of resistance to the flow of water, and the effect is almost the same as that of the ship-shaped box 60a.

  The method of allowing the coupling member 61 to absorb the swinging force caused by the flow of water is not limited to the wire 62 described above, and may be another method. For example, as shown in FIG. 6, when the cover member 60 is a spherical box 60 b, the spherical upper portion can be fixed to the reference rod 20 via an elastic member 64, for example. In that case, the swing of the cover member 60 is absorbed by the elastic member 64.

With the above configuration, the reference rod 20 is tilted with respect to the vertical direction, or an error in the installation angle occurs, or the reference rod 20 itself is bent by the influence of the water flow of the opening 70. Even if bending occurs, the measuring instrument fixing body 40 always maintains a horizontal state. As a result, the installation angle of the ultrasonic transmission / reception device 50 is always kept constant, so that correction such as angle correction becomes unnecessary. Since the transmission / reception of the ultrasonic waves 51 by the ultrasonic transmission / reception device 50 is stabilized, the flow rate of the fluid to be measured can be stably measured.
In addition, since the inside of the cover member 60 is filled with water flowing through the opening 70, the influence of the refraction angle when the ultrasonic wave 51 passes through the cover member 60 is eliminated.
From the above, the ultrasonic transmission / reception unit 10 of the present embodiment does not need to use an angle meter or the like as in the prior art. Furthermore, it is not necessary to consider the installation error of the ultrasonic transmission / reception device 50.

  The support shaft 30 may employ a three-dimensional joint. An example of a three-dimensional joint is a universal joint. As a result, the measuring instrument fixed body 40 is pivotally supported by the three-dimensional joint so as to be rotatable in the three-dimensional direction, so that the horizontal state is always maintained in water even with respect to the swinging force in the three-dimensional direction.

The reference bar 20 is preferably provided with a level installation surface 21 on which the level 11 is installed on the side opposite to the measuring instrument fixing body 40. For example, as shown in FIG. 1, a level attachment plate 22 having the level installation surface 21 is fixed near the upper end of the reference rod 20. The level installation surface 21 is a surface perpendicular to the axial direction of the reference rod 20.
By installing the level 11 on the level level installation surface 21 described above, the reference bar 20 can be fixed to the reference bar fixing base 72 such as the temporary scaffold, with the installation angle with respect to the vertical direction being almost surely vertical. Can do. As a result, it becomes easier in that the measuring instrument fixing body 40 always maintains a horizontal state as compared with the case where the reference rod 20 is inclined with respect to the vertical direction.

The present invention relates to the manufacturing of ultrasonic flowmeters, the surveying service industry for measuring the amount of water in rivers, etc., the information for performing data measurement and data collection for judging the necessity of river dredging work and repair of river opening It has applicability in the service industry.

DESCRIPTION OF SYMBOLS 10 Ultrasonic transmission / reception unit 11 Level 20 Reference rod 21 Level installation surface 22 Level attachment plate 30 Spindle 40 Measuring instrument fixed body 50 Ultrasonic transmission / reception apparatus (ultrasonic sensor) 51 Ultrasonic 60 Cover member 60a Hull shape Box 60b Spherical box 61 Connecting member 62 Wire 63 Fixing tool 64 Elastic member 70 Opening 71 Wall surface 72 Reference rod fixing mount 80 Sensor jig 81 Angle meter

Claims (4)

An ultrasonic transmission / reception unit for constantly maintaining the installation angle of the ultrasonic transmission / reception device,
A reference rod that stands vertically to the fluid to be measured;
A support shaft located at the lower end side of the reference rod and provided perpendicular to the axial direction of the reference rod;
A measuring instrument fixed body that is pivotally supported with respect to the support shaft;
An ultrasonic transmission / reception device fixed to the measuring instrument fixed body;
A cover member for covering the ultrasonic transmission / reception device and the measuring instrument fixing body so as to reduce the swing of the ultrasonic transmission / reception apparatus and the measuring instrument fixing body due to the fluid to be measured;
Ultrasonic transmission / reception unit.   The ultrasonic transmission / reception unit according to claim 1, wherein the support shaft is a three-dimensional joint.   The ultrasonic transmission / reception unit according to claim 1, further comprising a level installation surface on which the level is installed on a side opposite to the measuring instrument fixed body of the reference rod. Said cover member, the ultrasonic transmit-receive unit according to any one of claims 1 to 3 is configured to be held by absorption linkage member swinging force by the fluid to be measured.

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