JP4055057B2 - Downstream water level control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a downstream water level control device that controls a gate according to the amount of water used in a downstream area in a gate provided in a waterway or a river.
[0002]
[Prior art]
In general, when water is taken from a river or irrigation canal, a gate is installed in the middle of the entrance, irrigation canal, and diversion work in order to secure the upstream water level and flow rate. As an example of conventional water intake, as shown in FIG. 5, a water channel 1 is provided from an upstream river A to a downstream river B, and a plurality of water distribution works 2 a, 2 b, 2 c are installed in the water channel 1 and directly downstream thereof. Are provided with gates 3b, 3c, 3d, respectively, so that water can be stably supplied to the water separators 2a, 2b, 2c. The gate 3a becomes a water intake gate.
[0003]
When water is used in any of the water diversion works 2, for example, the water diversion works 2b, the gate opening degree of the upstream gate 3b is automatically reset according to the amount of water used. An example of such a flow rate response gate will be described with reference to the gate shown in FIG.
[0004]
As shown in FIG. 6, the water channel 1 is provided with a gate (tenter gate) 3 b, and a pit 4 having a concave cross section is formed along the side wall of the water channel 1.
In the gate 3b, a main arm 6 is fixed to a rotating shaft 5 crossing the water channel 1 in the upstream and downstream directions, a door body 7 is mounted on the upstream side of the main arm 6, and a counterweight 8 is provided on the downstream side.
[0005]
In the pit 4, two partition plates 9 are attached at intervals in the upstream and downstream directions, and are divided into a still water basin 10, a float chamber 11, and a basin 12 from the upstream side. Further, the upstream side of the door body 7 of the gate 3 b communicates with the hydrostatic pond 10 through the inflow port 13, and the downstream side of the door body 7 communicates with the recreational pond 12 through the outflow port 14.
[0006]
The still water pond 10 is provided with a water injection tank 15 and a water replenishment pipe 16 that are open at the top, and the bottom of each is in communication with the float chamber 11. A float 17 is accommodated in the float chamber 11, and the interior of the float 17 communicates with the basin 12. The float 17 is connected to a float arm 18 fixed to the rotating shaft 5.
A water level detection float 19 is installed in the basin 12, a rod 20 is vertically attached to the lower part of the water level detection float 19, a valve body 21 is connected to the lower part thereof, and the valve body 21 is arranged below. The drain port 22 is positioned so as to open and close.
[0007]
This gate 3b normally operates at a water level between the upper opening of the water injection tank 15 (above the normal water level) and the opening 16a of the peripheral wall of the refill pipe 16, but the water surface of the water channel 1 is at the upper water level (note When it rises from the opening of the water tank 15, it flows over the upper end of the water injection tank 15, and water suddenly flows into the float chamber 11 to raise the float 17 and evacuate the door body 7 from the water channel 1. Further, when the water level becomes equal to or lower than the lower limit water level (opening 16 a of the refill water pipe 16), water does not enter the float chamber 11, and the door body 7 also descends as the float 17 descends. Furthermore, when the water level detection float 19 is lowered, the drainage port 22 on the side of the basin 12 is closed by the valve body 21, but since water slightly flows out from the leakage port 23, the float 17 is lowered and the door body 7 is lowered. Fully closed.
[0008]
On the other hand, a gear mechanism 24 is attached to the rotating shaft 5 of the gate 3b. The adjustment part of the water intake height of the water injection tank 15 and the refilling pipe 16 arranged in the hydrostatic pond 10 is connected to the gear outer peripheral part of the gear mechanism 24 through a wire, and the water level detection float 19 is similarly inserted through a spring. The gear mechanism 24 is connected to the outer periphery of the gear. With this configuration, the gear outer peripheral portion rotates in accordance with the opening degree of the door body 7 to pull the wire, the height positions of the water level detection float 19, the water filling tank 15 and the water refilling pipe 16 are changed, and the gate 3b is operated. The water level is corrected.
[0009]
The gate 3b (including 3c and 3d) having the above-described configuration is downstream when the amount of water used in the downstream region increases and the downstream water level decreases, or when the amount of water used in the downstream region decreases. When the water level rises, first, the water level detection float 19 detects the downstream water level. As the water level detection float 19 operates, the water level in the float chamber 11 changes, and the door body 7 is raised or lowered by the operation of the float 17 to adjust the gate opening.
[0010]
Therefore, the door body 7 is opened and closed by opening and closing the drain port 22 of the float chamber 11 so that the water level immediately downstream of the gate 3b becomes a water level immediately downstream according to the opening degree (hereinafter referred to as a set water level). The water level in the downstream diversion work 2b is maintained at a substantially constant level regardless of the flow rate.
[0011]
[Problems to be solved by the invention]
However, in the flow rate response gate described above, when the amount of water used in the downstream diversion plant 2b increases and the water level in the water channel 1 decreases, the set water level immediately rises as the gate 3b opens. However, the opening operation of the gate 3b does not stop immediately. Therefore, the water level of the downstream gate 3c rises due to the flood wave caused by the gate 3b being opened too much, and the water level immediately downstream of the gate 3b rises to the set water level corresponding to the opening degree by the backwater (backwater). Only when the water level detection float 19 detects this, the opening operation of the gate 3b is stopped. Therefore, when the waterway distance between the gates is long, it takes time until the water level detection float 19 detects the water level by the backwater, and during that time, the gate 3b moves more excessively, and the water level detection float 19 detects the water level by the backwater. In such a case, it is necessary to close the gate 3b. If the gate 3b is too closed, there is a problem that a fluttering phenomenon occurs.
[0012]
Moreover, in the responsiveness of the gate 3b, if the opening speed of the gate 3b is large, the gate 3b opens too much, and as a result, the supply amount of water becomes excessive and the downstream water level becomes too high. Eventually, the gate 3b shifts to a closing operation, but this time it closes more than necessary. Thus, the conventional flow control device has a problem that the gate 3b repeats opening and closing operations, and the water level is not stable. On the other hand, if the opening speed of the gate 3b is too small, the response of the gate 3b is delayed and the water level error becomes large. Therefore, an appropriate opening / closing speed of the gate 3b is required, but the appropriate opening / closing speed varies depending on the flow rate, and it is difficult to control the opening / closing speed according to the flow rate. That is, when the amount of water distribution in the downstream changes suddenly, the gate 3b repeats opening and closing operations, the water level or the water level difference of the water channel is not stable, or the response of the gate 3b is delayed and the water level error becomes large. It was.
[0013]
Then, this invention is made | formed in view of the said situation, and it aims at providing the downstream water level control apparatus which can supply water stably to a downstream area.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is a float chamber in which a float that is interlocked with a door body capable of opening and closing a water channel and moving up and down through a float arm is provided on the side of the water channel. And a hydrostatic pond connected to the upstream water channel of the door body is provided on the upstream side of the float chamber, and communicated to the downstream water channel of the door body on the downstream side of the float chamber. Establish a reservoir,
One end is opened at the upstream lower limit water level position, the other end is connected to the float chamber with a water injection pipe connected to the float chamber, and the float chamber and the recreational pond are communicated with a hole smaller than the diameter of the water injection pipe,
Provided to cover the cylinder gate at the opening of the water injection pipe, and to accommodate the water level detection float in the basin,
A first sheave is fixed above the cylinder gate, and a second sheave is disposed above the water level detection float.
The second sheave is supported by one end of an oscillating arm that bears the middle part and moves up and down alternately, and the other end of the oscillating arm is connected to the float arm by a link mechanism, Actuating the second sheave in the opposite direction to the lifting and lowering movement;
A wire rope is wound around the sheaves, and the cylinder gate and the water level detection float are connected to both ends of the wire rope.
Note that the amount of fluctuation of the second sheave can be adjusted by changing the length of the swing arm or the bearing position.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
A downstream water level control apparatus according to an embodiment of the present invention will be described with reference to FIGS. In addition, the member equivalent to the member demonstrated by the prior art attaches | subjects the same code | symbol, and abbreviate | omits description.
As shown in FIGS. 1 and 2, the downstream water level control device includes a pair of main arms fixed to the rotary shaft 5, which is rotatably supported by bearings 5 a installed on both walls of the water channel 1. A door body 7 is provided at the upstream end of 6. A pit 4 provided along the water channel 1 for controlling the door body 7 is provided with a still water pond 10, a float chamber 11, and a basin 12. The upstream side of the door body 7 is communicated with the still water basin 10 through the inlet 13, and the downstream side of the door body 7 is communicated with the basin 12 through the outlet 14.
[0016]
In addition, the hydrostatic pond 10 is provided with a water injection pipe 25 formed in a substantially L shape, one of which opens upward and the other communicates with the float chamber 11. The opening 25 a of the water injection pipe 25 has a flange shape. A cylindrical cylinder gate 26 having a closed upper end is in contact with the opening 25a. The cylinder gate 26 has an elevating function, and this elevating operation is controlled by a draft moving means described later.
In the raising / lowering operation of the cylinder gate 26, when the cylinder gate 26 is raised, a gap is formed between the cylinder gate 26 and the water injection pipe 25, the opening 25a is opened, and water flows in. Further, when the cylinder gate 26 is in the lowest position (abutted state), there is no inflow from the opening 25a into the float chamber 11. A hole is formed in the upper end of the cylinder gate 26 to prevent the periphery of the opening 25a from becoming a negative pressure state when the water injection pipe 25 is opened. The height of the opening 25 a of the water injection pipe 25 (H 1 in FIG. 1) is set to the lower limit water level in the water channel 1 on the upstream side of the door body 7.
[0017]
As shown in FIG. 1, the float chamber 11 and the basin 12 are connected by a drain port 22 having a sufficiently smaller diameter than the water injection pipe 25, and the float 17 accommodated in the float chamber 11 passes through a flexible pipe 27. The inside of the float communicates with the reservoir 12. Further, the float 17 is suspended by a float arm 28 extending upstream from the rotary shaft 5. Accordingly, the rotary shaft 5 rotates to the left or right in conjunction with the lifting / lowering operation of the float 17, and the door body 7 is interlocked in the same direction as the lifting / lowering operation of the float 17 to open and close the water channel 1. ing.
[0018]
Further, as shown in FIGS. 1 and 2, a water level detection float 19 is accommodated in a cylindrical breakwater wall 29 provided in the basin 12, and the water level detection float 19 is suspended from one end of a wire rope 30. Yes. The other end of the wire rope 30 is connected to the cylinder gate 26, and the cylinder gate 26 can be lifted by the load of the water level detection float 19.
[0019]
Next, the structure of the draft moving means will be described. As shown in FIGS. 1 and 3, the wire rope 30 is wound around a fixed sheave (first sheave) 31 to suspend a lower cylinder gate 26, and an axially movable sheave (second sheave). The lower water level detection float 19 is wound around the suspension 32.
The shaft-moving type sheave 32 is supported by one end of a swing arm 34 having an intermediate portion supported by a shaft column 33 and having both ends alternately swingable in the vertical direction. Further, the other end of the swing arm 34 is connected to an intermediate portion of the float arm 28 via a linkage 35 to form a link mechanism. Therefore, the sheave 32 changes the height position by the operation in the reverse direction with respect to the operation in the rotation direction of the float arm 28. The sheave 32 also operates in the reverse direction with the door body 7.
The water level detection float 19 and the cylinder gate 26 have their weights adjusted so as to be in a suspended state when the downstream water level is at the suspension draft position of the water level detection float 19. Accordingly, the draft of the water level detection float 19 moves due to the movement of the sheave 32 due to the change in the downstream water level or the change in the opening degree of the door body 7.
[0020]
Next, the water level adjustment effect | action of a downstream water level control apparatus is demonstrated.
First, when the amount of water intake in the downstream water distribution plant 2 increases, the water level immediately downstream of the door body 7 decreases, the water level of the reservoir 12 decreases, and the water level detection float 19 descends. Further, as the water level detection float 19 descends, as shown in FIG. 3, the cylinder gate 26 connected to the water level detection float 19 and the wire rope 30 is lifted upward, and the opening 25a of the water injection pipe 25 is moved from the fixed position. The amount of water supplied to the float chamber 11 through the water injection pipe 25 increases, water flows into the float chamber 11 more than the amount of water flowing out from the drain port 22, and the water level in the float chamber 11 gradually rises. Due to the rise of the water level in the float chamber 11, the float 17 housed in the float chamber 11 rises while discharging the water inside the float from the flexible tube 27 to the basin 12, and the rotating shaft 5 is connected via the float arm 28. It rotates in the clockwise direction in FIGS. Thereby, the door body 7 is also raised, the opening degree is increased, and the water level in the water divider 2 can be recovered.
[0021]
Next, the anti-hunting action of the draft moving means will be described. The draft is the position of the side surface where the current water level detection float 19 is in contact with the water surface.
As described above, when the downstream water level falls and the water level detection float 19 falls, the float 17 rises. As shown in FIG. 4, when the float 17 rises, the main arm 6 rotates clockwise by an angle θ, and the door body 7 rises. Further, the linkage 35 connected to the float arm 28 is pushed up, and the swing arm 34 rotates around the shaft column 33 in the clockwise direction in FIG. As a result, as shown in FIG. 4, when the center position of the sheave 32 is lowered by ΔH, the water level detection float 19 is heavier than the cylinder gate 26. Therefore, the water level detection float 19 is lowered accordingly and the draft rises. As a result, a buoyancy greater than the balance is generated in the water level detection float 19, and the cylinder gate 26 is lowered through the wire rope 30 to reduce the amount of water from the water injection pipe 25 to the float chamber 11. As a result, the rising speed of the float 17 decreases, and the opening speed of the gate 3 decreases. As a result, the draft of the water level detection float 19 slowly returns to the original suspended state. This draft feedback adjusts the opening degree (control amount) of the cylinder gate 26 to prevent the door body 7 from rising too much and restore the downstream water level. Therefore, downstream overflow due to excessive opening of the gate 3 does not occur.
[0022]
Further, when the water intake amount in the water diversion work 2 is rapidly increased and the water level in the vicinity of the water level detection float 19 is rapidly lowered, the cylinder gate 26 is rapidly raised in conjunction with the lowering of the water level detection float 19. When the downstream water level is below the suspension draft position of the water level detection float 19, the position of the cylinder gate 26 is lowered by opening the door body 7 and lowering the sheave 32. When the downstream water level further recovers and the water level detection float 19 reaches or exceeds the suspended draft position, the water level detection float 19 is lowered according to the opening degree of the door body 7 by the draft moving means. Opening at the opening does not cause overflow in the downstream area. Further, since the operation of the sheave 32 in the water level detection float 19 and the link mechanism is quicker than the detection of the downstream water level by the backwater, the door body 7 does not cause hunting that repeats the opening and closing operation.
[0023]
In addition, when the downstream water level and the water level detection float 19 are in a suspended state in which the positions of the draft lines coincide with each other, the inflow amount from the opening 25a of the water injection pipe 25 and the outflow amount from the drain port 22 become the same. The water level becomes constant, the movement of the float 17 is stabilized, and the gate 3 is in a balanced state.
Further, when the upstream water level becomes equal to or lower than the lower limit water level, the water in the float chamber 11 is discharged, the float 17 descends, the cylinder gate 26 descends and comes into contact with the opening 25a of the water injection pipe 25, and the gate 3 close. (If it is necessary to evacuate the door body 7 from the water channel 1 when the upstream water level becomes the flood level, this can be done by adding the water injection tank 15 in FIG. 6.)
[0024]
【The invention's effect】
The present invention has been described as described above. In the invention according to claim 1, the downstream water level control device bypasses the upstream side and the downstream side of the door body with a hydrostatic pond, a float chamber, and a basin, and detects the water level. The cylinder gate is directly operated by detecting the downstream water level by the float, and the amount of water supplied to the float chamber is adjusted. Therefore, for example, when the downstream water level falls, the water level detection float descends and the cylinder gate rises, so that water flows into the float chamber, the float rises, the door body rises, the water flow increases, and the downstream water level returns. By this operation, the downstream water level can be stabilized within an allowable range.
[0025]
In addition, since the second sheave provided above the water level detection float moves up and down following the rise and fall of the float, when the door opens and the running water increases, the water level detection float moves down and the draft moves, By moving the cylinder gate in the closing direction and reducing the amount of water, the float rises, that is, the opening of the door body is controlled. Depending on the sudden lowering of the water level detection float, the cylinder gate first descends regardless of the draft moving means of the water level detection float, and then the drastic rise of the door body is suppressed by the draft moving means. It is possible to prevent a hunting phenomenon caused by opening at an unnecessarily large opening, and to prevent the door body from being opened for an unnecessarily long time and overflowing downstream.
In addition, this configuration is simple using a sheave and a link mechanism, can greatly reduce the cost of waterway facilities and can be easily maintained, and can be adjusted by adjusting the link mechanism. The timing of the door opening / closing operation can be arbitrarily set according to the actual situation.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a downstream water level control apparatus according to an embodiment of the present invention.
FIG. 2 is a plan view of the downstream water level control apparatus shown in FIG.
FIG. 3 is a view showing a state where the water level detection float of the downstream water level control device shown in FIG. 1 is lowered and the cylinder gate is opened.
4 is an explanatory view of a link mechanism of the draft moving means in the downstream water level control device shown in FIG. 1, and shows a state where the position of the sheave is moved in conjunction with the door body.
FIG. 5 is an overall view of a conventional water channel.
FIG. 6 is a cross-sectional view of a conventional flow rate response gate.
[Explanation of symbols]
1 Waterway 5 Rotating shaft 7 Door 10 Still water pond 11 Float chamber 12 Reservoir 17 Float 19 Water level detection float 22 Hole (drain)
25 Water injection pipe 25a Opening 26 Cylinder gate 28 Float arm 30 Wire rope 31 First sheave 32 Second sheave 33 Link mechanism (shaft column)
34 Link mechanism (swinging arm)
H1 Upper and lower water levels

Claims (1)

A float body that can be opened and closed and interlocked with a float arm through a float arm is accommodated in a float chamber provided on the side of the water channel, and the door body is located upstream of the float chamber. Providing a still water pond communicated with the upstream water channel, and providing a recreational pond communicated with the downstream water channel of the door body on the downstream side of the float chamber,
One end is opened at the upstream lower limit water level position, the other end is connected to the float chamber with a water injection pipe connected to the float chamber, and the float chamber and the recreational pond are communicated with a hole smaller than the diameter of the water injection pipe,
Provided to cover the cylinder gate at the opening of the water injection pipe, and to accommodate the water level detection float in the basin,
A first sheave is fixed above the cylinder gate, and a second sheave is disposed above the water level detection float.
The second sheave is supported by one end of an oscillating arm that bears the middle part and moves up and down alternately, and the other end of the oscillating arm is connected to the float arm by a link mechanism, Actuating the second sheave in the opposite direction to the lifting and lowering movement;
A downstream water level control device, wherein a wire rope is wound around both sheaves, and the cylinder gate and the water level detection float are connected to both ends of the wire rope.

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