JPH05824Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field to Which the Invention Pertains] The present invention relates to a detection device for an ultrasonic flowmeter that allows easy measurement of the flow rate of fluid in underground water pipes.

[Prior art and its problems]

Conventionally, when tap water is distributed from a water treatment plant to a general household, the flow rate measurement locations are the water distribution destination (water treatment plant, water supply station, etc.), the water receiving point (general household), and a branch from the main large-diameter water main. Flowmeters are not installed in small water distribution pipes that are buried in a mesh pattern on general roads and are intended to distribute water to general households.

Therefore, it is not possible to grasp the flow rate of the water distribution pipes, which make up the majority of the water distribution pipes, which poses an obstacle in formulating an efficient water distribution plan.

On the other hand, generally each home or factory is provided with a water meter. Charges for the amount of water used are paid based on the measured value of this meter. This aggregated quantity is the effective amount of water, that is, the amount of water charged. It would be ideal if the amount of water supplied by a waterworks office and the effective amount of water were the same, but in reality they are almost never the same. This is because tap water sent from a distribution reservoir reaches each home or factory through long water pipes. At that time, tap water leaks every time it passes through damaged pipes or pipes with disconnected joints, which reduces the amount of water supplied to households and factories. Water that disappears without being used by users is water leakage.

Normally, water pipes are 1.2m or more for water pipes, and water pipes for water supply pipes are
It is buried at a depth of 0.45m. Therefore, water leakage has conventionally been detected by moving a water leakage detector along the water pipe on the ground while looking at a water pipe installation diagram.

However, it is very complicated to detect water leaks by moving the water leak detector along water pipes over a wide area. Therefore, if there was a device that could easily detect whether there is a leak in underground water pipes existing in a certain area,
Water leaks can be detected easily by using such a device to find the area where water leaks exist, and then using a leak detector to search for leaks only in underground water pipes located in the leak area. becomes.

[Purpose of invention]

The present invention has been devised in view of these points, and is an ultrasonic flowmeter detection device that can easily measure the flow rate of fluid in underground water pipes and can also be suitably used to detect the presence or absence of water leakage. The purpose is to provide equipment.

[Key points of the idea]

Fire hydrants are installed in various places along underground water pipes. On the other hand, households and factories hardly use water at night. Therefore, at night, the flow rate in the water pipes is based on the minimum flow rate including water leakage, and is only increased by the amount of water used temporarily, such as in flush toilets. Therefore, measure the minimum flow rate in the water pipe at night at the fire hydrant, save the measurement data, and then measure the minimum flow rate in the water pipe at night again, for example, six months later. If there is a change when comparing the measured data, it is determined that there is a water leak in the underground water pipe existing in the area of the measured point (fire hydrant) where the change occurred. In that case, if you use a leak detector to search for leaks only from underground water pipes in that area,
Water leakage can be easily detected.

Therefore, in order to be able to measure such a minimum flow rate in a water pipe, the present invention uses a pair of ultrasonic transducers and a branch pipe for connecting a fire hydrant that is branched from a water pipe buried underground. a mounting base having dual arms having a distance such that the ultrasonic transducer is attached to each of the dual arms, and a rod-shaped member fixed to the mounting base;
holding means provided on the mount and/or rod-shaped member to hold the mount and/or rod-shaped member to the fire hydrant and/or branch pipe; ) The rod-shaped member is connected to the fire hydrant and (or)
The ultrasonic transducer is held in a branch pipe, and the flow rate of the fluid in the water pipe is measured by receiving the reflected wave of the ultrasonic wave emitted toward the water pipe from one of the pair of ultrasonic transducers. It is characterized by being made to obtain.

According to an embodiment of the present invention, the branch pipe for connecting a fire hydrant is arranged in a fire hydrant pit, and the holding means holds the mounting base and/or the rod-shaped member to the fire hydrant and/or the branch pipe. In this state, the fire hydrant pit is filled with water to the extent that the ultrasonic transducer is immersed therein, and the measurement is performed.

[Example of idea]

FIG. 1 shows the measurement principle of the detection device for an ultrasonic flowmeter according to the present invention. In FIG. 1, 1 is a T-shaped pipe connected to a main water pipe (not shown), and this T-shaped pipe 1 is connected to a straight pipe 2 and a fire hydrant 4, which form part of the water pipe. It consists of a branch pipe 3. In addition, 6 is a connection flange of the branch pipe 3, and 8 is a connection flange of the fire hydrant 4. 10 and 12 are a pair of ultrasonic transducers arranged to sandwich the fire hydrant 4. Arrows indicate the direction of fluid flow. Thus, the ultrasonic waves 11 emitted from one of the transducers 10 and 12 are reflected by the inner wall of the conduit and received by the other. In this way, the flow rate within the T-tube 1, that is, the water pipe, can be measured.

As mentioned above, at night, the flow rate Q in the water pipe is
As shown in FIG. 2, the minimum flow rate Qm including water leakage is only increased by the temporary amount of water used, for example, in flush toilets. In addition, in FIG. 2, T indicates time, and time points T ₁ to _{T 4} indicate, for example, times when a flush toilet is used.
Therefore, the measurement data (minimum flow rate) obtained in this way is set as Q _n1 . Then, for example, perform a similar measurement six months later or one year later, and let the measurement data at that time be Q _n2 . If the measured data Q _n1 and Q _n2 are different, it can be determined that a new water leak has occurred in the water pipe or that the amount of water leaking has increased in a certain area of the fire hydrant used for the measurement.

FIG. 3 is a schematic diagram of an embodiment of the present invention. In FIG. 3, reference numeral 16 denotes a mounting base having double arms with a distance that allows a fire hydrant to be held therebetween, and ultrasonic transducers 10 and 12 are respectively attached to the double arms. The ultrasonic transducers 10 and 12 consist of a transducer (not shown) and a molding material surrounding the transducer. As shown in FIG. 4, the ultrasonic transducers 10 and 12 are mounted within U-shaped covers 18 and 20, respectively. In this embodiment, the covers 18, 20 are fixed to the mounting base 16 by means such as welding or screws, but the covers 18, 20 are
8 and 20 may be integrally molded with the mounting base 16. Elongated holes 22, 23, 24 and 25 are provided in both side walls of the covers 18 and 20, respectively. After appropriately setting the positions of the transducers 10 and 12, the elongated holes 22 and 2 of the transducers 10 and 12 are
3, 24, 25 through screws 26, 27, 28,
29, the transducers 10, 12 can be fixed to the covers 18, 20, respectively. Further, the mount 16 is provided with a leaf spring 30, and as will be described later, the mount 16 can be held on the fire hydrant by sandwiching the fire hydrant with the leaf spring 30.

Further, in this embodiment, a pipe 34 is fixed to the mounting base 16 with a flange 36 so as to extend on the side opposite to the transducers 10 and 12. Inside this pipe 34 are cables 3 connected to transducers 10 and 12, respectively.
1 and 32 are shown. Further, a holder 38 is provided on the pipe 34 so as to be movable up and down, and the holder 38 has a rubber band 40 at its tip. This band 40 has a hook 4 at one end.
2, and after wrapping it around the fire hydrant, the holder 38, that is, the pipe 34, can be held on the fire hydrant by hooking the hook 42 to the hanging hole 44 of the holder 38. Note that the holder 38 is fixed to the pipe 34 by a screw 46.

Next, the manner of use of the detection device for an ultrasonic flowmeter according to the present invention shown in FIG. 3 will be explained with reference to FIGS. 5 to 7. As shown in FIG. 5, the T-shaped pipe 1 is the main pipe 54, 56 of underground water pipe
It is connected to the. A fire hydrant pit 60 is placed around the fire hydrant 4 connected to this T-shaped pipe 1.
is formed and is normally closed by a pit lid (not shown). Therefore, first remove the pit cover, hold the pipe 34 and insert the mounting base 16 (including the transducers 10 and 12) into the pit 60 from the ground surface, and as shown in FIG. A leaf spring 30 is attached to the branch pipe. Similarly, as shown in FIG.
The holder 38, that is, the pipe 34, is held in the fire hydrant by wrapping the hook 42 into the hanging hole 44. After that, attach the holder 38 to the pipe 34.
It is fixed with screws 46. In this way,
The detection device 14 has two locations, upper and lower, that is, the location of the leaf spring 30, the location of the holder 38, and the location of the band 40.
and held by the fire hydrant 4. Therefore, the positional relationship between the transducers 10, 12 and the T-tube 1 is clearly fixed. In that case, as is clear from FIG. 5, the transducers 10, 12 are not in close contact with the T-tube 1. Therefore, in order to improve the propagation of the ultrasonic waves, water 58 is injected into the pit 60 so that the transducers 10 and 12 are immersed therein. By opening the cap 50 of the fire hydrant 4 and using tap water flowing into the water pipe as the water 58, the temperature characteristics of the water 58 and the fluid in the water pipe can be matched. Thereafter, either connect the cables 31 and 32 directly to the ultrasonic flow meter converter, or as shown in FIG. Nipitu 60
A lid 62 is placed on the cap 62, and the cables 31 and 32 are led out through the hole 64 of the lid 62 and connected to a converter 66, thereby measuring the flow rate.

In the embodiment shown in FIG. 3, the leaf spring 30 may be attached to the pipe 34 instead of being attached to the mounting base 16, and may be attached to the standpipe 68 of the fire hydrant 4.

By the way, as shown in FIG. 1, if the pipe diameter R of the straight pipe 2 of the water pipe, that is, the T-shaped pipe 1 is large, measurement is performed by injecting ultrasonic waves into the straight pipe 2 from the outer periphery of the straight pipe 2. However, if the tube diameter is as small as R ₀ , for example, the reflected wave 11' may not be received by the transducer on the receiving side.

The present invention also provides an embodiment that can be applied to a straight T-shaped pipe having a small diameter. 8th
The figures and FIG. 9 illustrate the measurement principle of such an embodiment. That is, in this case, the ultrasonic wave is incident from the transducer 90 or 92 at right angles to the connecting curved part 86 between the straight pipe 82 and the branch pipe 84 of the T-tube 80.
2 or 90 to enable reception of reflected waves. By injecting the ultrasonic wave at right angles to the connecting curved portion 86, the ultrasonic wave is transmitted to the curved portion 86.
You can go straight without being refracted.

FIG. 10 shows another embodiment of the present invention based on such a measurement principle, in which A is a schematic front view thereof, B is a schematic side view thereof, and C is a schematic bottom view thereof. The transducers 90 and 92 are mounted on a mounting base 94 so that their transducers can inject ultrasonic waves at right angles to the connecting curved portion between the straight pipe and the branch pipe of the T-tube. In this case, elongated holes (not shown) for adjusting the positions of the transducers 90 and 92 are provided on the top surface of the mounting base 94, so that the position adjustment bolts 9
6 and 98 are attached to the transducers 90 and 92, respectively, from the upper surface of the mounting base 94. Furthermore, in this embodiment, guide plates 100 and 102 are attached to both sides of the mounting base 94, respectively, and these guide plates 100 and 102 allow the mounting base 94 to be positioned on the surface of the straight pipe of the T-shaped pipe. It can be placed stably. 104 is a column fixed to the mounting base 94. This support is provided with fixing means for holding the detection device 108 according to this embodiment to the fire hydrant, but this is not shown. Also,
Similarly, cables for transducers 90, 92 are also not shown.

Figure 11 shows the detection device shown in Figure 10 attached to a fire hydrant, A is a schematic plan view thereof, B
is a schematic front view thereof, and C is a schematic side view thereof.
As shown in FIG. 11, the detection device 108 is stably placed on the surface of the straight pipe 82 of the T-shaped pipe 80 by the guide plates 100, 102, and is held on the fire hydrant by the post fixing means 106. . In this way, the flow rate can be measured even for straight T-shaped pipes, that is, water pipes with small pipe diameters.

[Effect of idea]

As explained above, in this invention, the flow rate in underground water pipes can be easily measured using the fire hydrant installation location, so if the measurement is performed at night, the minimum night flow rate Q _n Therefore, from the accumulation of this measurement data, it becomes possible to discover whether or not there is water leakage in the area of the fire hydrant subjected to the measurement. Alternatively, by installing a plurality of detection devices according to the present invention at multiple fire hydrants at the same time, it is possible to easily detect the presence or absence of water leakage in water pipes within the fire hydrant area surrounded by the detection devices.
Moreover, the measurement can be performed without stopping the flow of fluid in the water pipe. In this case, in the present invention, the mounting base is configured in a double-arm shape so that the branch pipe for connecting the fire hydrant can be sandwiched between the two arms, and the ultrasonic transducer is attached to each of the dual arms. The detection device can be installed extremely easily. Moreover, fire hydrants that can perform such measurements are usually installed inside fire hydrant pits, but these hydrant pits are often so narrow that workers cannot fit into them. A rod-like member is provided on the mounting base on which the sonic transducer is installed, and the rod-like member is operated from above the fire hydrant pit to attach the detection device to the fire hydrant, thereby greatly simplifying the installation work. I have to. Moreover, since the detection device is fixed to the fire hydrant and/or the branch pipe by the holding means, the positional relationship between the detection device and the fire hydrant does not change during the measurement operation.

Furthermore, ultrasonic transducers are usually attached to water pipes using grease or epoxy adhesive to improve the propagation of ultrasonic waves.
As mentioned above, the fire hydrant pit is too narrow to fit inside, so such conventional technology cannot be adopted. Therefore, in the present invention, we focused on the fact that the fire hydrant pit is a hole with a bottom, and it is difficult to fit inside the fire hydrant pit. The tube is filled with water to the extent that the ultrasonic transducer is immersed in it, thereby intervening water as an acoustic coupling medium between the ultrasonic transducer and the pipe, thereby transmitting ultrasonic waves to the water pipe in the fire hydrant pit. The new problem that arises when installing a transducer is solved by utilizing the properties of the fire hydrant pit.

Furthermore, according to the present invention, the propagation time when the ultrasonic wave is emitted from one ultrasonic transducer and the propagation time when the ultrasonic wave is emitted from the other ultrasonic transducer are used. Therefore, it is possible to easily detect the flow direction of water in the water pipe in the fire hydrant pit.

[Brief explanation of drawings]

Figure 1 is a diagram of the measurement principle of the detection device for an ultrasonic flow meter according to the present invention, Figure 2 is an explanatory diagram for explaining the nighttime minimum flow rate of water pipes, and Figure 3 is an overview diagram of an embodiment of the present invention. , Fig. 4 is a bottom view of the same without the leaf spring, Figs. 5 to 7 are explanatory diagrams for explaining its usage, and Figs. 8 and 9 are the detection for an ultrasonic flowmeter according to the present invention. A principle diagram for explaining another measurement principle of the device, FIG. 10 shows another embodiment of the present invention based on the measurement principle, FIG. 10A is a schematic front view thereof, and FIG. B is a schematic side view thereof. , Figure C is a schematic bottom view of the same, Figure 11 shows the state in which the detection device shown in Figure 10 is attached to a fire hydrant, Figure A is a schematic plan view thereof, Figure B is a schematic front view thereof, Figure C is a schematic side view thereof. 1,80...T-shaped pipe, 2,82...straight pipe, 3,
84...branch pipe, 4...fire hydrant, 10,...12,
90,92... Ultrasonic transducer, 14,
108...Detection device, 16,94...Mounting base, 3
0...Plate spring, 34...Vipe, 38...Holder, 40...Band, 54, 56...Water pipe main, 58...Water, 60...Fire hydrant pit, 86...
...Curved portion, 100... Guide, 104... Support column,
106... Support fixing means.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A pair of ultrasonic transducers and a dual arm part having a spacing that can sandwich a branch pipe for connecting a fire hydrant branched from a water pipe buried underground. A mounting base on which each of the ultrasonic transducers is mounted, a rod-shaped member fixed to the mounting base, and a rod-shaped member provided on the mounting base and/or the rod-shaped member to support the mounting base and/or the rod-shaped member. a holding means for holding the fire hydrant and/or the branch pipe; the holding means holds the mounting base and/or the branch pipe;
A rod-shaped member is held in the fire hydrant and/or the branch pipe, and the reflected wave of the ultrasonic wave emitted toward the water pipe from one of the pair of ultrasonic transducers is received by the other. A detection device for an ultrasonic flow meter, characterized in that it is capable of measuring the flow rate of fluid in a water pipe. 2 Utility Model Registration Scope of Claim 1 In the detection device according to claim 1, the fire hydrant connecting branch pipe is arranged in a fire hydrant pit, and the holding means holds the mounting base and/or rod-like member between the fire hydrant and the fire hydrant. (or) A detection device for an ultrasonic flow meter, characterized in that the fire hydrant pit is filled with water to such an extent that the ultrasonic transducer is immersed in the fire hydrant pit while being held in a branch pipe, and measurement is performed. .