JPH045560Y2 - - Google Patents

Description

[Detailed explanation of the invention] (a) Industrial application field This invention regulates the flow rate of rivers and lakes, and is a water gate installed across the flow channel for water intake and flood control. This relates to a water gate with a siphon that forms a channel.

(b) Prior Art Several proposals have already been made regarding water gates with siphons as extremely efficient technology for adjusting the flow rate of rivers and the like. For example, the applicant's own invention, ``Sluice gate with siphon''
Publication No. 155412, Figures 7 A and B and JP-A-58-
No. 106008, Figure 8 A and B). Conventionally, in order to adjust the amount of water discharged, it was necessary to electrically move the water gate up and down, which caused problems in terms of personnel arrangement and mechanical maintenance, or if only natural overflow without moving parts was used, the water level on the upstream side would rise rapidly. However, the invention has the function of suctioning overflow water and discharging it to the downstream side by the siphon action, so the flow velocity in the pipe increases rapidly and a large amount of water can be discharged. Experimentally, compared to general overflow, with the same overflow width and same overflow water depth, it is possible to obtain eight times the discharge capacity. In this way, the water gate with a siphon has the effect of being able to quickly adjust the discharge amount q in response to fluctuations in the water level h on the upstream side without having to constantly move the water gate up and down (Figure 9).

(c) Problems that the invention aims to solve In Fig. 7A, when the upstream water level rises and rubs against the bottom apex 2 of the siphon pipe provided at the spout 1, the overflow water leaves a gap in the siphon pipe. This will result in natural overflow within the pipeline. (h ₁ in Fig. 9) When the water level rises further and the tip 9 of the straight portion of the spout 1 comes into contact with the water surface on the upstream side, the discharge port 3 also becomes full of water, and the tip 9 becomes a siphon-on breaker and the siphon action begins. At this time, a large amount of water is sucked upstream from the spout 1, but along with this suction, a large amount of air is also sucked in, creating air bubbles that collide with the straight part of the tip of the spout 1 and the wall inside the siphon pipe. This creates a siphon flow that generates noise and vibration. (Figure 9 h ₁
and h ₂ ) When the water level rises further and reaches the top apex 4 of the siphon pipe, air suction ends and the air bubbles in the siphon pipe disappear, the pipe becomes full of water and the siphon flow rate reaches its maximum. It becomes a pipe flow. (Fig. 9 h ₂ ) The noise and vibration of the siphon pipe then subsides. Noise becomes a major source of pollution if there are houses near rivers, and repeated vibrations require excessive strength in manufacturing, and the welded parts of the steel plates accumulate metal fatigue, which easily breaks if there are defects. There is a risk.

As a conventional technique proposed for the purpose of solving this problem, Japanese Patent Application Laid-Open No. 1983-1999 shown in Figs. 11 and 12
There is a publication number 86208. As shown in the figure, a large number of partition walls 20 are arranged in the left and right direction inside the gate main body, and a siphon conduit 30a is formed between each partition wall, and the level of the spout 11a of the siphon is changed for each siphon, and each siphon is The spout level of the breaker 22 connected to the breaker 22 was also changed.

Specifically, in the rooms 21 divided by the partition walls 20, the bottom plates 16a are installed independently using cross beams so as to form a curved surface, and the bottom plates 16a are mounted above the bottom plates 16a at a required interval. Attach the face plate 17a, and then attach the bottom plate 16a, the top plate 17a, and the partition wall 20.
This constitutes the siphon conduit 30a. In addition, this siphon pipe 30a changes the level of each spout 11a as shown in the figure, and is provided with a hole at the top apex 14a of each siphon pipe 30a and a breaker 22 extending above the water surface on the upstream side. There is. Therefore, the timing of the start and end of the siphon action of the siphon pipe 30a separated by the partition wall 20 can be shifted, thereby reducing the simultaneous occurrence of noise and vibration and sudden large-scale discharge.

However, as shown in FIG. 11 and FIG.
It is difficult to align the heights of the spout 11a horizontally and to vary the position of the spout 11a vertically. In other words, since it is an integral water gate, the position of the skin plate 18a facing perpendicularly to the upstream side must remain constant. This condition does not hold unless everything changes. This requires an extremely complicated and cumbersome manufacturing process.

Furthermore, since a large number of steel pipes are bent and protrude forward from the top apex of each siphon flow path, floating objects on the upstream water surface (driftwood, dust, etc.) may collide with the tip of the siphon breaker and cause damage. , failures such as locking and blocking, which impede control of the siphon action, or resonance, which further promotes vibration, cannot be ignored.

On the other hand, although this flood gate with a siphon has the advantage of being able to quickly respond to water level fluctuations upstream, there is also the risk that a large amount of water will suddenly start being released downstream, leading to flooding or accidents in small and medium-sized rivers downstream before any warning is reached.

Furthermore, as shown in Figure 7B and Figure 8B, for example, the formation of the siphon pipes is the same across the entire width of all the water gates, so the changes in flow condition proceed in perfect agreement over the entire width. However, due to the large flood from the upstream side, a siphon flow is generated all at once, and when the water level further reaches the top apex 4 of the siphon pipe, the pipe flow starts all at once, causing a sudden change in which a large amount of discharged water rushes downstream. There are also great concerns about what will happen. In order to solve the above-mentioned problems, this design minimizes the noise and vibration that occur at the highest level when transitioning from siphon flow to pipe flow, and even if a large flood occurs that exceeds the water gate, the water level on the downstream side remains unchanged. The purpose of the present invention is to provide a new water gate with a siphon that smooths out large fluctuations in water as smoothly as possible.

(d) Means for solving the problem The water gate with a siphon according to the present invention divides the siphon pipe 30 in the width direction by the partition wall 15,
The upper surface plate 17 bent from the spout 11 of each siphon conduit 30 to form the upper surface of the conduit is fixed at a different height from that of other adjacent siphon conduits, and the upper surface plate 17 is bent for each siphon conduit 30. top vertex 1
4 and the siphon-on breaker formed at the tip 19 are formed at different heights, and each spout 1
The above-mentioned problem was solved by forming the cross-sectional area of the pipe 1 to be larger than the cross-sectional area of the discharge port 13 of the conduit.

An example of the configuration of this invention will be explained based on the drawings. FIG. 1 is a side view of the water gate with a siphon of this invention cut at the top apex 14 of the siphon pipe 30 along a vertical plane perpendicular to the river width. .

Saifon pipes 30, 3 mounted above the water gate 10
0′, 30″… Pipe top plate 17, 17′, 17″…
Since all adjacent conduits are combined with different heights, the heights at which the top apex 14 of the conduit and the tip 19 of the top plate protrude are changed. The cross-sectional area of the spout 11 may be the same or different, but the cross-sectional area of the spout 11 may be the same or different;
It is always set larger than the cross-sectional area of . From Figure 2A to Figure 2D, each siphon pipe divided by forming a step is connected to a vertical plane aa' parallel to the river width.
They are front sectional views taken along bb', cc', and dd'.

(e) Effect Since this siphon pipe has the above-described configuration, when the water level on the upstream side rises and reaches the top of the bottom of the divided pipe, overflow begins along the bottom plate 16 of the pipe. At this time, the spatial distance H ₁ between the water level in the pipe and the upper surface vertices 14, 14', 14'', etc. of the channel,
Since the vertices of the upper surfaces of H ₂ , H ₃ . . . form a step, a corresponding difference occurs between them. When the water level is in the state shown in Fig. 2, the discharge port 13 in the pipes A and C in Fig. 2 with the smallest H is already filled with overflow water, so the siphon action begins and the flow velocity increases rapidly. On the other hand, the sucked air bubbles collide with the tube wall, causing noise and vibration.

However, in the pipe shown in FIG. 2B, H ₂ is large and the discharge port 13' is not full of water, so natural overflow continues. This is called natural overflow within the pipeline.

In addition, in the pipe D where the top apex of Fig. 2 D is the lowest, the siphon breaker at the tip of the spout is completely submerged in the water, and there is no suction of air from the spout, resulting in a siphon flow that discharges the maximum amount of water and is noisy. And the vibration has subsided. This is called pipe flow.

When the water level rises further and shifts to the state shown in FIG. 3, air is no longer sucked in the pipes A and C of FIG. 3, and the siphon action is at its peak, resulting in a pipe flow in which a large amount of water continues to be discharged.

In the conduit shown in FIG. 3B, H ₂ contracts and siphon action begins, resulting in a siphon flow.

In the pipe shown in FIG. 3D, the water level exceeds the top apex 14 and overflows, resulting in natural overflow on the pipe.

When the water level fluctuates in multiple pipes divided in this way, the four types of flow regimes: natural overflow in the pipe, siphon flow, pipe flow, and natural overflow on the pipe shift sequentially with a time lag. The action of going occurs.

(F) Embodiment FIGS. 1 to 3 show a first embodiment of this invention. In this example, the distance (12 to 14,
12' to 14', 12'' to 14'', ...) are constant, but in the second embodiment shown in FIGS. 4 and 10 A, B, and C, the bottom apexes 12 of each pipe are aligned Align,
Since the top surface apex 14 is stepped, the height of the siphon conduit 30 is different.

In this example, the cross section of the water gate 10 with a siphon is obtained by providing the top plate 17 of the pipe at a predetermined distance on the outer periphery of the gate body 100 surrounded by the bottom plate 16 of the pipe and the skin plate 18. Door body 1
00 and the siphon conduit 30 are integrated. Since the door main body 100 is provided with a partition plate 31 and a reinforcing member 32 having the same length as the door body inside, it is easy to work and has reliable strength. The partition wall fixed to the strong door main body 100 firmly supports the upper surface plate 17 of the conduit and forms a plurality of divided conduits. The water gate 10 with a siphon having such a configuration is characterized by being easy to work and having high reliability in terms of strength. Furthermore, since the pipes 30, 30', and 30'' have different water conduction cross-sectional areas, the amount of discharge flowing through the pipes and pipes at the bottom, middle, and high of the water level is large and large in the four states.
By selecting and combining medium and small sizes, it is possible to design the optimum water gate with siphon according to the characteristics of the river.

(G) Effect of the invention In the water gate with a siphon according to this invention, as the water level on the upstream side rises, the siphon action begins in some of the divided pipes, but the flow is still overflowing in other pipes. , the generation of noise and vibration is much smaller than in the conventional technology, in which the siphon effect occurs all at once over the entire width of the river. The highest level of vibration occurs during the final stage of the siphon action (just before the transition to pipe flow), but since this final stage occurs with a time lag in the divided pipes, noise and vibration are dispersed as a whole. This greatly eliminates the causes of pollution, and allows calculations that are advantageous in terms of manufacturing strength.

As an example of the effect, data obtained by measuring the vibration of the second embodiment in terms of acceleration (gal) is shown in FIGS. 5A and 5B. For measurement, a strain gauge type accelerometer capable of measuring both the vertical direction and the direction of the pipe was installed at point S in Figure 4, and the waveform was recorded on an electromagnetic oscillograph through an amplifier to measure vibration acceleration.

In FIG. 5, A is the vertical direction, and B is the pipe direction, and in both cases, it can be seen that even if the flow rate Q rapidly increases, the vibration acceleration (gal) hardly changes and shifts to the pipe flow.

For comparison, Figures 6A and 6B show measurements of the vibration acceleration of a conventional water gate with a siphon, which has the same width and height of the flow path but does not have a step at the tip. It is recognized that the acceleration (gal) is rapidly amplified as the flow rate Q increases.

Another effect of this design is that on the upstream side, rapid discharge occurs in one of the divided pipes due to the siphon action, while overflow or pipe flow occurs in other pipes depending on the water level. As a result of these various changes in flow conditions, it is possible to follow a wide range of fluctuations in water level by adding steps, without significantly impairing the discharge capacity as a whole.

On the downstream side, if there is a sudden rise in the upstream water level, the sudden release of water can be delayed over time to level out the change and give time for response.
It can help prevent floods and accidents.

In addition, unlike the conventional technology shown in Figures 11 and 12, which were developed for almost the same purpose, each siphon pipe has a bottom plate and a top plate of steel plate processed with the same curvature at a height from the foundation. It is sufficient to change only the parts and weld the combination, which is advantageous in that it is easy to work with. In particular, the advantages of the second embodiment shown in FIGS. 4 and 10 are further enhanced.

In the conventional technology, a siphon-on breaker was separately added that bent and extended forward from the apex of the pipe, but in this invention, the cross-sectional area of the spout 11 is always set larger than the cross-sectional area of the discharge port 13. Because there are
It is easy to maintain negative pressure in the pipe, and the tip 19 of the spout acts as a siphon breaker, making it possible to control the siphon flow without adding any special member.

In the case of the prior art, there is also a concern that floating objects on the upstream side collide with the extended siphon breaker 22 and damage it, or that it becomes blocked and prevents control of the siphon flow.

The biggest difference is that with conventional technology, when a major flood occurs where the water level on the upstream side rapidly increases, when the water level reaches the top of all the siphon pipes, overflow begins on the pipes all at once and the water is discharged downstream. As the flow rate increases all at once, the impact on downstream areas changes suddenly. This is a difficult point that cannot be overlooked in view of the original purpose of setting up a siphon pipeline, which is to respond to the sudden impact downstream of a major flood. There are significant differences no matter which aspect of mitigating the impact on the side.

[Brief explanation of the drawing]

Fig. 1 is a part of a side cross section showing the first embodiment of this invention, A, B, C, D in Fig. 2 and A, A in Fig. 3.
B, C, and D are front cross-sectional views showing the effects of the same embodiment, respectively. A and B are diagrams showing the effects of this invention, FIGS. 6A and B are diagrams showing the results of the prior art, and FIGS. 7 A and B and 8 A and B are front cross sections showing different prior art, respectively. Figures and part of the side sectional view, Figure 9 is a diagram showing the effect of siphon, Figure 11 and Figure 1
FIG. 2 is a side view and a front view showing yet another conventional technique. 10... Sluice gate door, 11... Spout, 12... Bottom apex, 13... Discharge port, 14... Top apex, 15
...Partition wall, 16...Bottom plate, 17...Top plate, 1
9... tip, 30... siphon conduit.

Claims (1)

[Scope of utility model registration request] In a water gate with a siphon that forms a siphon pipe that sucks overflow water from the upper surface of the water gate installed across a waterway by a siphon action and discharges it to the downstream side, the siphon pipe 30 is connected to the partition wall 15. The top plate 17, which is divided in the width direction and forms the pipe top surface bent from the spout 11 of each siphon pipe, is fixed at a different height from that of other adjacent siphon pipes, so that each siphon pipe has a corresponding one. The pipe apex 14 of the top plate 17 and the siphon-on breaker formed at the tip 19 are formed at different heights, and the cross-sectional area of each spout 11 is set to be the same as the discharge port 1 of the pipe.
A sluice gate with a siphon characterized by having a larger cross-sectional area than No. 3.