JPH04309614A - Flow response gate for irrigation channel - Google Patents

Abstract

PURPOSE:To flow water to downstream side in proper quantities by adjusting the opening of a gate, which is provided at a branch of an irrigation channel, according to the level and quantity of water on the downstream side. CONSTITUTION:A gate body 40 is provided transversely to an irrigation channel, and the inside of a float chamber 47 in which a float 84 connected to the gate body 40 is connected to an irrigation channel on the upstream side of the gate body 40 through an water supply port 52. Further it is connected to a retarding basin 48 provided in the irrigation channel on the downstream side of the gate body 40 through an exit port 55a. An water level detecting float 57 under which a bottleneck valve 59 is provided in series is floated on the retarding basin 48 so that the bottleneck valve 59 can be moved back and forth freely toward the exit port 55a, and the water level detecting float 57 is suspended from an arm for water level detecting float 67 which is rotated in connection with the gate body 40. Thus, as flow delivered from the exit port 55a is varied, the float 84 is moved up and down, and the arm for water level detecting float 67 is moved to move the position of the water level detecting float 57. When a series of these operations are balanced at a pre-set level, the gate body is stopped.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow response gate for an irrigation canal that utilizes natural forces to take water from a river to an irrigation canal or divert water from an irrigation canal.

0002

[Prior art] The traditional method of irrigating rice fields is so-called natural water diversion, in which a fixed amount of water is continuously applied using natural water level differences, and the minimum flow rate of the canal was about half of the maximum flow rate. . In recent years, as pump irrigation has become more widespread in conjunction with farmland irrigation, water is forcibly taken from canals, causing water shortages and excesses in various locations, and this tendency is especially severe in the winter when only farmland irrigation is used. It has become. In addition, in winter, when water resources are depleted, the flow rate decreases dramatically to a few tenths of the maximum flow rate for irrigation of fields, and it is known that the water flow in canals becomes similar to still water, which occurs in lakes and marshes. Seishes that were previously hidden can now be found in waterways. For this reason, the water surface rises and falls at intervals of about ten minutes, causing problems with water diversion, and also causing significant water shortages and excesses downstream.

[0003] Therefore, as shown in FIG. 6, the applicant has proposed a water intake gate 1 for keeping the downstream water level constant. This device is equipped with a control device room 6 on the side of a gate body 3 provided in a waterway 2, which is divided into a float chamber 4 (float 5) for operating the gate body 3, and a water level detection tank on the downstream side of the float chamber 4. 7 is installed, and communicates with the downstream water channel of the gate 1 via a water inlet 8. There is a gate 1 on the upstream side of float chamber 4.
A water inlet 9 communicating with the upstream waterway is opened. A floating body 10 is floated in the water level detection tank 7, and a flow rate control valve 11 is connected to the bottom thereof so that a control water level can be set (see Japanese Patent Application No. 63-326668).

In addition, as a water diversion gate, as shown in FIG. 7, the float chamber 4 has a small-diameter water inlet 8, and an overflow weir 12 is provided on the upstream side of the float chamber 4 to keep the upstream water level constant. A gate 13 for this purpose is disclosed in Japanese Unexamined Patent Publication No. 3-39513. Note that when the flow rate is low, the change in flow rate becomes particularly large, so basically the upstream water level is maintained constant as described above, but as shown in Figure 8, a large diameter overflow weir 14 and a small diameter overflow weir 14 are used. By connecting the overflow weir 15 at different heights and using a gate installed in the control equipment room 6, changes in the upstream water level can be allowed within a certain limit, and the minimum required for the downstream diversion works can be used. Flow rate can flow.

However, there is usually a sufficient distance between the intake gate 1 and the downstream diversion works shown in FIG. 6, and the water level difference between the two points varies depending on the flow rate. If the water level is kept constant, if the flow rate is large, water will overflow at the downstream diversion site. In addition, the water level needs to be kept low to prevent seiche and moisture damage, and the amount of water used fluctuates greatly, and the waterway 2
In order to increase the storage capacity of the water, it is necessary to lower the water level appropriately in advance. Therefore, there was a problem in that the water level had to be manually reset every time the flow rate changed.

[0006] Furthermore, the system that maintains the upstream water level constant as shown in Figure 7 is a system that allows water to flow down depending on the circumstances of the diversion works, regardless of the amount of water used downstream. There was a significant surplus and shortage of water, and while we were worried about water shortages, we also had the problem of water being wasted. As shown in Figure 8, when the flow rate is low, gates have been used that allow changes in the water level upstream of the gate within a certain limit and maintain a constant opening. Of course, the problem of water shortages was solved because a nearly constant flow rate was flowed, but the problem was that water was sent without taking into account downstream conditions, which accelerated the tendency to overwater.

[0007] The problem with the prior art described above is due to the fact that too much emphasis is placed on either the upstream or downstream circumstances. Therefore, a gate that maintains the water level difference between each diversion works at a constant level has been proposed as a new indicator that can comprehensively grasp the situation both upstream and downstream (see Japanese Patent Application No. 2-20840). ), it is effective in drainage channels that store floodwater for a long time in so-called creek areas. As shown in FIG. 9, this gate 16 has a water level detection float 18 with a guide plate 17 fixed to its upper part floating on the upstream side of the float chamber 4 in the control device chamber 6 on the side thereof, and a water level difference detection float 18. 19, a link arm 21 is attached to an arm shaft 20 that supports the door body 3, and a link arm 21 is attached to the guide plate 1 via a bar 22.
It is connected to an L-shaped arm 23 that is connected to the L-shaped arm 7.

The guide plate 17 has grooves 24 of the same shape formed in the upper and lower parts thereof, and is positioned by a fixed shaft 25 in the groove.
A vertical groove 26 is formed in the center of the guide plate 17, and a rectangular plate 28 with an inclined lower end and an adjustment groove 27 is formed in the center of the guide plate 17.
A floating shaft 29 is provided in the vertical groove 26 so as to be movable up and down.
It is said that it can be moved by. Further, the water level difference detection float 19 is connected to a rope 31 via a spring 30, and the rope 31 is guided by the adjustment groove 27 and wound around an engagement shaft 32 that is movable in the horizontal direction. Fluctuations in the water level downstream of the gate 16 act on the guide plate 17 via the L-shaped arm 23 and the rope 31 as the float 5 and the water level difference detection float 19 move up and down. Since the guide plate 17 is connected to a water level detection float 18 that detects the upstream water level, this balance is adjusted by the shapes of the grooves 24 and the adjustment grooves 27.

[0009]

[Problems to be Solved by the Invention] By the way, in drainage canals in so-called creek areas, drainage during floods is limited to pumps, so plans have been made to store flood water in the waterways. Therefore, in such waterways, it is impossible to set a target water level because the water level is determined by natural conditions. Therefore, in order to ensure fairness in reservoir-type waterways, there is no other way than to maintain a constant water level difference between each diversion facility, as in the prior art. However, in irrigation canals and dual-purpose canals that do not require flood storage, it is actually necessary to allow some degree of water level fluctuation in response to changes in water usage downstream, but this is not the goal. This does not mean that the water level itself disappears. Therefore, it is possible to operate based on the downstream water level without depending on the water level difference. In addition, in order to open and close a gate installed in the middle of a waterway, it is necessary to consider both upstream and downstream circumstances, but if we do not focus on the downstream circumstances, the problem of water surplus and shortage will not be resolved. , the degree of lightness and weight is naturally determined.

However, when the above-mentioned gates are installed in series, they raise and lower the water level uniformly and take on the storage function, and when they are installed over the entire section of a waterway that is usually over 10 km long, the use of water downstream of the gates is limited. In order to follow changes in quantity,
Since there are differences in water level fluctuations depending on the installation location of natural water diversion, pump water diversion, or water diversion work, there is no problem as long as water level fluctuations are allowed to some extent and the overall required storage function is provided, but with conventional technology, There were problems in that there were parts that did not suit the actual situation of each diversion works, and some diversion works became difficult to divert water. Also, since it operates based on the water level difference, if there is an error, the error in each section will accumulate. Therefore, in order to strictly maintain the water level difference between the water diversion works, guide plates 17 with different groove shapes are provided, resulting in a significantly complicated structure and an increase in costs. An object of the present invention is to provide a flow rate response gate for an irrigation canal that operates a gate body to determine a downstream water level in accordance with the flow rate.

[0011]

[Means for Solving the Problems] In order to achieve the above object, the present invention has a gate body provided across a waterway, a float interlocking with the gate body, and a float housing the float. The interior of the room is communicated with the water channel on the upstream side of the door body through a small water replenishment port, and is also communicated with a water reservoir provided in the water channel on the downstream side of the gate body via a leakage port and a relatively large outlet. A water level detection float is floated on the water level detection float, a constriction valve connected to the water level detection float is made to face the outlet so as to be movable forward and backward, and the water level detection float is mounted on a water level detection float arm that rotates in conjunction with the door body. It is characterized by being suspended via a spring. The water level detection float arm is designed to measure the water level (hereinafter referred to as the planned water level) when the lower end of the door body is assumed to flow the maximum amount of water (hereinafter referred to as the planned water amount) and not to raise the dam at all. ) (hereinafter referred to as the planned opening degree), it is best to fix it so that it is closest to the water level detection float pulley. Furthermore, the length and rotation angle of the water level detection float arm are selected so that the water level at the downstream water diversion location is appropriate. In the following, the water level at the downstream diversion work position determined for each gate opening based on the arm length and rotation angle described above will be referred to as the planned diversion water level.

[0012] At the check gate, protection measures are required for the upstream diversion works. Therefore, secondly, to set the allowable lower limit water level (hereinafter referred to as the permissible lower limit water level) and upper limit water level (hereinafter referred to as the permissible upper limit water level) within the limits that do not interfere with water diversion. , the above-mentioned water replenishment port is set at the height of the allowable lower limit water level, and the upstream waterway and the float chamber are communicated through a water injection tank that constitutes a hydraulic weir and has a crest slightly lower than the allowable upper limit water level. , is used. It goes without saying that the length of the crest of the weir should be sufficiently larger than the size of the outlet.

[0013] When the flow rate is large, the permissible range of water level fluctuation is small, but when used for a variety of purposes, even if the flow rate is high, the variation in the flow rate may be large. In such cases, it becomes necessary to protect the diversion works from changes in flow rate. In addition, when the flow rate is extremely low, in order to suppress the occurrence of seiche, the allowable upper limit water level must be lowered according to the flow rate, and since the change in flow rate becomes large, it is necessary to increase the storage function. is desirable. Therefore, in preparation for such severe usage conditions, the third method is to suspend the water replenisher cylinder and the water tank by means of a water refill port arm and a water tank arm that rotate in conjunction with the gate. Use.

[0014]

[Operation] If there is no major change in the amount of water used, the outflow port is partially narrowed by the constriction valve, the amount of outflow from the outflow port and the amount of inflow from the water replenishment port are balanced, and the door body remains stationary. However, if the amount of water used downstream changes and the water level at the downstream water diversion location fluctuates, the effect will spread to the water level immediately downstream of the upstream gate. Therefore, if the amount of water used downstream increases, the water level detection float will lower and the outlet will be narrowed, the water level in the float chamber will rise and the door will open, and the water level at the downstream water diversion location will return to its original level. . At this time, even if the constriction valve is fitted to the outflow port, a small amount of water in the float chamber flows out from the leakage port into the retarding basin, so the door body does not open more than necessary. Moreover, it goes without saying that when the amount of water used downstream decreases, the door body closes and the water level at the downstream water diversion location returns to its original level. Therefore, since it immediately responds to the water level downstream, it is impossible for the downstream area to have a significant surplus or shortage of water for a long period of time. In addition, the water level at the downstream diversion work location in an equilibrium state varies depending on the opening degree of the gate body and ultimately the flow rate, but in a state close to the planned opening degree, the water level at the downstream diversion work location is close to the planned water level. Since the length and rotation angle of the arm can be set according to the actual situation of the diversion works, if the flow rate decreases, the water level at the downstream diversion work position will automatically be appropriately lowered. In addition, the planned water level for each diversion work location can be determined according to the actual circumstances of the diversion work, such as changes in flow rate due to each diversion and regional differences, without causing any problems with water diversion.

Furthermore, if the amount of water used downstream increases and the water level at the downstream diversion works falls, the upstream gate will open and the downstream water level will return to normal, as described above. Instead, the water level upstream will drop. The effect spreads to each upstream gate one after another, so normally the water stored in all upstream sections is used little by little. Therefore, the unevenness of the water level received by the one-way diversion works is small, and the period of time is extremely short. Additionally, the amount of water intake from the water intake gate will eventually increase, so the water level in all sections will return to normal over time. However, if there is an abnormal increase in the amount of water used, replenishment from upstream cannot keep up, and the water level upstream may drop considerably. In case the flow into the float chamber is drastically reduced and the downstream water level is low, the outflow is completely closed by a constriction valve, so there is an outflow from a leakage port, etc., where a part of the outflow is cut out. Therefore, the gate opening degree becomes smaller and the upstream water level is maintained at or above the allowable lower limit water level set according to the actual situation. Therefore, there is no problem with water diversion upstream. In addition, if the water level upstream reaches the lower limit of permissible water level and there is a shortage of water sent downstream, the storage capacity in the area where the shortage occurs will naturally be consumed, and the impact will spread downstream as necessary. Therefore, the storage capacity of the entire upstream and downstream sections can be used. Therefore, the difference between the planned water level and the allowable lower limit water level can be small.

[0016] Furthermore, if the amount of water used downstream decreases, the upstream gate closes, and the upstream water level rises. The influence spreads upstream one after another,
Normally, a small amount is stored in each section upstream. Therefore, the deviation in water level in one section upstream is small and the time period is short. Additionally, the amount of water intake from the water intake gate will eventually decrease, so the water level in all sections will return to normal over time. However, if the decrease in water usage is abnormal, there will be no time for the upstream gate to close, and the upstream water level will reach the permissible upper limit water level.
Water flows into the float chamber from the water injection tank, the gate opens, and the upstream water level is maintained at the allowable upper limit water level. The effect can spread downstream one after another as needed, so water can be stored in the entire upstream and downstream section. In addition, in the event that the reservoir cannot be partitioned off, the most downstream drainage gate will open as described below.
Excess water is dumped into the drain. Therefore, since there is no safety problem, there is no need to target extremely abnormal situations, and the difference between the allowable upper limit water level and the planned water level can be small.

Next, the problem of the allowable upper limit water level and the allowable lower limit water level will be explained. When the flow rate is high, if the water level difference between the allowable lower limit water level, allowable upper limit water level, and planned water level is reduced, fluctuations in the water level upstream of the gate concerned will be reduced.
Of course, there will be no problem with the water diversion immediately upstream, but since the influence will be dispersed little by little to each downstream section, there will be no problem with the water diversion downstream. Furthermore, as the flow rate decreases, the position of the water injection tank gradually becomes lower, thereby suppressing the occurrence of seiche. Furthermore, the lower the flow rate, the more severe the fluctuation in the flow rate becomes, so if the amount of descent of the water filler port is made greater than the amount of descent of the water tank, the storage function can also be increased.

[0018] Furthermore, if different gate opening characteristics are required depending on the water diversion means and water diversion locations, it is sufficient to simply determine the length and rotation angle of the water level detection float arm.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described with reference to the accompanying drawings. First, since the main purpose of the present invention is to streamline the management of the entire waterway, the configuration of the entire waterway will be explained. As shown in FIG. 1, a water intake gate 33 is provided on the side bank of a river 32, and a concrete waterway 34 having a rectangular cross section is connected downstream thereof. Check gates 35 are installed immediately downstream of the main diversion works of the water channel 34, and the downstream end of the water channel 34 is connected to a drainage channel 37 via a drain gate 36 that maintains the upstream water level constant. In the embodiment, a radial gate is used, but since the present invention relates to a gate operating device, a roller gate may be used depending on the installation conditions.

As shown in FIGS. 2 to 4, the check gate (hereinafter referred to as gate) 35 has a pair of gate arms 39 attached to a horizontal gate shaft 38 rotatably supported on both sides of the water channel 34. An arcuate door body 40 centered on the gate shaft 38 is fixed to the upstream end of the waterway 3.
It crosses 4. Near the downstream end of the gate arm 39,
A pair of guide rails 41 are fixed, and the shaft of a counterweight 42 is loosely fitted thereto, and suspended by suspension bolts 43, so that the height and weight are adjustable. Further, a stopper 44 is provided below near the downstream end of the gate arm 39.

A control device room 45 is provided on the side of the water channel 34, and a still water pond 4 is connected to the water channel 34 upstream of the door body 40.
A float chamber 47 is provided downstream of the float chamber 6 , and a retarding pond 48 downstream of the float chamber 47 is communicated with the water channel 34 downstream of the door body 40 .

Further, a water replenishment pipe 50 of the water replenishment device 49 opens on the upstream side of the float chamber 47, and the other end stands upright in the water in the still water pond 46, and is loosely fitted into a water replenishment pipe 51 outside of the water replenishment pipe 50. The upper end of the refill cylinder 51 is open to the atmosphere. Further, a small water replenishment port 52 is bored on the side of the water refill cylinder 51. Further, a dust seal 53 is attached to the lower end of the water filler tube 51, and the side of the water filler port 52 is surrounded by a dustproof and waveproof tube 54.

Furthermore, a drain pipe 5 is provided downstream of the float chamber 47.
5 is open, and its tip is connected to the middle part of a vertically arranged pipe to form a T-shape, and both the upper and lower ends of this pipe are open into the water in the retarding basin 48. Further, the size of the outlet 55a above the drain pipe 55 is the same as that of the water replenishment port 52.
It is sufficiently large compared to . In addition, the outlet 55a
The water level detection float 5 of the water level control device 56 is placed directly above the water surface.
7 is floated, a constriction valve 59 is fixed below the connecting rod 58 passing through the center, and a packing 60 is located below the constrictive valve 59 in the vertical portion below the drain pipe 55 and is fixed to the connecting rod 58. As a result, the lower vertical portion of the drain pipe 55 is closed. A leak port 61 is formed by cutting out a portion of the outflow port 55a. The leak port 61 is the float chamber 47
It does not matter where the drain pipe 55 is bored, but in this embodiment, the lifting and lowering of the constriction valve 59 also has the effect of removing the garbage. The size of the leakage port 61 is not very large, since the door body 40 only needs to be closed at a speed that does not cause the upstream water level to fall below the allowable lower limit water level.
In order to prevent the constriction of the outlet port 55a of No. 9 from becoming meaningless and to reduce the vertical movement of the constriction valve 59, the outlet port 55a is
is large enough.

Further, a water level detection float rope 64 is fixed to the upper end of the spring 63 of the water level correction device 62 fixed to the upper end of the connecting rod 58 of the water level control device 56, and this rope 64 is suspended on a water level detection float pulley 65. The other end is a pin 6 for a water level detection float at the tip of an arm 67 for a water level detection float fixed to a rotation shaft 66 that is rotatably supported horizontally.
It is fixed to 8. Also, a small gear 69 fixed to the rotation shaft 66 and a large gear 70 fixed to the gate shaft 38
are engaged, and the position of the water level detection float pin 68 is at the planned opening degree k defined above, that is, the gate 35
The lower end of the door body 40 is closest to the water level detection float pulley 65 at an opening degree equal to the above-mentioned planned water level w.

FIG. 5 shows the relationship between the opening degree of the gate 35 or the percentage of flow rate and the water level, where the flow rate is 100 when the planned opening degree k and the planned water level w are used.
E indicates the opening degree of the gate, and lowercase letters b, c, f, and g indicate the relationship with the flow rate. Curve A is a curve showing the water level immediately downstream of the gate 35 when the water level at the downstream diversion level is set to the planned water level w for any flow rate. In this state, the water level detection float 57 is in the state of ■ in FIG. The water level detection float 57 is attached when the water level is at the planned water level w both upstream and downstream. However, as mentioned above, when the flow rate is low, it is better to keep the water level appropriately low, so for the diversion works upstream of the gate 35, the planned water level should be appropriately lower than the planned water level w for each flow rate, so that the planned diversion water level is curved. It is determined as shown in b. Curve c shows the minimum water level for diversion in the downstream diversion works for each flow rate. The actual water level at the diversion work position when the gate 35 is fully closed, point 2, is set at a position appropriately lower than the midpoint height between the curve c and the planned water level w. In addition, in a state of intermediate flow rate, the water level at the actual diversion work position, point f, is set at a position appropriately lower than the height midway between the planned water level w and the curve c, and in this state, the water level at the actual diversion work position, point f, is downstream water level,
Point g is calculated, and finally, the opening degree of the gate 35 is calculated from the calculated downstream water level and the curve b, and point (2) is calculated. The length and rotation angle of the water level detection float arm 67 are determined so as to draw a curve D passing through the above points ■, ■, and ■. The curve showing the water level at the downstream diversion work position calculated from the above curve D for each degree of opening of the gate 35 will be hereinafter referred to as the planned diversion water level.

The water intake gate 33 will now be described. In addition to the above configuration, using existing technology, the water level detection float is housed in a water level detection float chamber that communicates with outside water through a small diameter hole, and when the river water is rising, water is injected into the water level detection float chamber using a siphon. However, once the flood has subsided, a siphon breaker turns off the siphon and stops water injection, so it will not open during flooding of the river 32.

Returning to the main topic, the allowable lower limit water level w1 is determined at an appropriate interval from the planned water level of the water diversion work upstream of the gate 35.
A tolerable upper limit water level w2 is set, and the height of the water refilling port 52 of the water refilling device 49 is adjusted to the height of the allowable lower limit water level w1. In addition, a water injection device 71 is provided on the upstream side of the float chamber 47.
The water injection pipe 72 is open, and the other end stands upright in the water in the still water pond 46, and is loosely fitted to the guide pipe 73 on the outside, and above it a water injection tank 74 consisting of a hydraulic weir is fixed, The height of its upper end is made slightly lower than the allowable upper limit water level w2, and its circumference is made sufficiently larger than the outlet 55a. Further, a dust seal 75 is attached to the lower end of the guide pipe 73, and the outside of the water tank 74 is surrounded by a dustproof and waveproof tube 76.

Furthermore, in this embodiment, in order to cope with particularly severe conditions, the water replenishment cylinder arm 78 and the water injection tank arm 79 of the upper and lower limit water level correction device 77, which are fixed to the rotation shaft 66, are fixed. , a water replenishment cylinder rope 80 and a water tank rope 81 are fixed to the tip of each via a pin, and a water refill cylinder pulley 82 and a water tank pulley 83 are provided in the middle, respectively, to connect the water refill cylinder 51 and the water tank rope 81. A water tank 74 is suspended. The position of each pin is fixed so that it is farthest from each pulley when the gate 35 is at the planned opening degree k. In addition, in a state close to the planned opening degree k, the difference in height between the allowable lower limit water level w1, allowable upper limit water level w2, and the planned diversion water level is small; Compared to this, the drop in the allowable lower limit water level w1 is appropriately large, and the drop in the allowable upper limit water level w1 is appropriately large.
2 is appropriately reduced, and as the gate 35 closes, the height difference between the allowable upper limit water level w2 and the allowable lower limit water level w1 increases.

A float 84 is housed in the float chamber 47, the lower part of which is sealed to form a sealed part 85, a flexible tube 87 is opened at the bottom of the water guide part 86 above the sealed part 85, and the other end is closed. It opens into the reservoir 48 downstream of the gate 35. The length of the flexible tube 87 is made sufficiently large so as not to restrict the movement of the float 84. Also float 84
Although the top surface of is covered, a vent hole 88 is bored. The height of the sealing part 85 of the most upstream gate 35 is set so that the torque due to exposure of the sealing part 85 to the air is slightly smaller than the torque of eccentric force due to its own weight, which will be described later. The upper end of the sealing portion 85 of the gate 35 is set appropriately lower than this. Note that the height of the sealed portion 85 in the water intake gate 33 is set to the height of the planned water level w in the state of the planned opening degree k.

Furthermore, a suspension rod 90 of an interlocking device 89 is fixed to the upper end of the float 84, and a roller 91 attached to the upper end is fixed to the gate shaft 38 of the gate 35 and protrudes upstream. It is fitted into an involute groove 92a at the tip of the float arm 92. Also, a pair of guide rods 93 fixed to the bottom surface of the float chamber 47 stand upright, and this guide tube 93 fixed to the float 84
The gap between the float chamber 47 and the float 84 is made as small as possible.

Next, the details of the configuration will be explained. In the present invention, the gate 35 is operated using the difference in water level between upstream and downstream, so if the difference in water level between upstream and downstream becomes small, flow rate adjustment becomes impossible. Furthermore, if flow rate adjustment continues indefinitely, the water level upstream will rise unnecessarily in the event of a flood. Therefore, the flow rate adjustment stop opening degree is set by comprehensively taking these things into consideration. The guide rail 41 of the gate 35 is fixed so as to be vertical when the flow rate is adjusted and stopped. Further, the weight of the counterweight 42 is set to be appropriately light so that the gate 35 can be reliably closed if the water levels in the float chamber 47 and the float 84 are equal. In addition, since the water level difference between the upstream and downstream of the gate 35 is the height difference between the curve c of the upstream gate 35 and the curve b of the gate, the upstream and downstream water level difference in the state of flow adjustment stop opening can be easily calculated. It is determined by Therefore, the planar area of the float 84 is made large enough to ensure that the gate 35 opens when the water level difference between the inside and outside reaches the water level difference. Further, the height of the counterweight 42 is set as high as possible within a limit that allows the gate 35 to open reliably at all opening degrees below the above-mentioned flow rate adjustment stop opening degree.

Further, as the most downstream drainage gate 36, a roller gate is used when installation of a radial gate is not permitted due to the situation at the installation location. However, in any case, the set water level is set slightly higher than the planned water level scheduled at the gate 35 immediately upstream.

Next, the operation will be explained. In order for the gate 35 to operate like the upper air, there needs to be a difference in water level between the upstream and downstream sides, so when the water level detection float 57 is artificially attached, the opening of the gate 35 is the planned opening. k, there is no real state in which both the upstream and downstream water levels are equal to the planned water level w. However, if there is no change in the amount of water used upstream and downstream, the downstream diversion work position and the water level immediately downstream will be lower than the flow control stop opening as shown in Figure 5, respectively.
The water level becomes as shown by curve b and curve c, and the outflow port 55a is partially narrowed by the constriction valve 59, and the outflow amount and the water replenishment port 52
The amount of inflow from the gate 35 is balanced and the gate 35 is stationary.

[0034] The dimensions of the waterway 34 are, for example, 3 m wide.
, the gradient is 1/2000, and the distance between the gate and the downstream diversion work is 1000 m. If the amount of water used downstream decreases and the water level at the downstream diversion work rises by 3 cm, the upstream water will increase. The water level immediately downstream of gate 35 rises by about 2 cm. In addition, since the size of the outflow port 55a is sufficiently large, the stenosis valve 5 that moves to open and close the gate 35
The stroke of No. 9 is small, and 2 cm is sufficient. Note that since the water pressure acting on the stenosis valve 59 and the water pressure acting on the packing 60 cancel each other out, there is little resistance as the stenosis valve 59 moves up and down. Therefore, the water level at the downstream diversion site of gate 35 is 3c.
m rises, the water level detection float 57 and the constriction valve 59 rise, and the constriction on the outflow port 55a is alleviated, so the water level in the float chamber 47 decreases, the gate 35 closes and the opening becomes smaller, and the downstream The water level at the diversion works location will return to normal.

As a result, in the case of the gate 35, the water level upstream of the gate rises, but the effect spreads to the upstream gates 35 one after another, and the downstream water level is returned to normal one after another. The difference between the actual water level and the planned water level is small, and the water level in one section is not normal for only a short time. Furthermore, the water intake amount will eventually be reduced by reaching the water intake gate 33 at the most upstream position, so that the water level in the entire section of the waterway will return to normal again after a while.

On the other hand, if the amount of water used increases and the water level at the downstream diversion site drops by 3 cm, the upstream gate 3
The water level immediately downstream of No. 5 will drop by approximately 2 cm. Therefore, the water level detection float 57 and the constriction valve 59 descend, the constriction of the outlet 55a is strengthened, and the water level in the float chamber 47 rises.
The gate 35 opens and the water level at the downstream diversion work position returns to normal.

As a result, in the case of the gate 35, the water upstream of the gate decreases, but the effect spreads to the upstream gates 35 one after another, and the downstream water level returns to normal, so that the actual The difference between the water level and the planned diversion water level is small, and the time that affects one diversion work is short. Furthermore, since the amount of water taken by the water intake gate 33 will eventually increase, the water level in all sections of the waterway will return to normal over time.

As shown in curve A of FIG. 5, when the water level at the downstream diversion work position is maintained at the planned water level w,
The water level immediately downstream of the gate 35 is very close to a sine curve, and the water level correction device 62 according to the present invention is also configured to obtain a curve that is close to a sine curve. Since the waterway 34 is installed with the opening degree equal to the planned opening degree k and the water level of the waterway 34 both upstream and downstream equal to the planned water level w, when the flow rate is close to the planned water volume, the downstream diversion work position As shown by curve B in FIG. 5, the water level at is extremely close to the planned water level w, so there is no problem with water diversion. However, as the flow rate decreases, the water level at the downstream diversion site becomes lower, so moisture damage to seiche and field crops does not occur. Also,
The water level at each diversion work location is determined individually according to the actual situation of each diversion work, so even if the water level is low, it is unlikely that water diversion will be affected. Due to the above-mentioned effects, the gate 35 can be used as the water intake gate 33.

If the increase in the amount of water used is abnormal, the water level upstream of the gate 35 approaches the allowable lower limit water level w1, but since one end of the water replenishment cylinder 51 is open to the atmosphere, the water refill port 52
At the outlet, the upstream and downstream water flows are hydraulically blocked, so the upstream water level is below the allowable lower limit water level w1.
As the water approaches the float chamber 47, the amount of water flowing into the float chamber 47 decreases dramatically.
On the other hand, even if the downstream water level is too low and the constriction valve 59
Even if the outflow port 55a is blocked, there is outflow from the leakage port 14, so the gate 35 closes and the opening becomes small, and the upstream water level is maintained at the allowable lower limit water level w1. At this stage, there is a shortage of water downstream and the water level drops below the planned water level, so the storage capacity of the downstream waterway is utilized. Also, even if the impact of changes in water usage is downstream, the impact will be felt at the upstream gate 3.
5, and finally reaches the water intake gate 33, where the amount of water intake increases, so that over time, the water level in all sections of the waterway returns to normal.

[0040] Also, if the decrease in water usage is abnormal,
The upstream water level rises to the allowable upper limit water level w2, and the water injection tank 74
Overflow water from the upper end flows into the float chamber 47,
Since the circumference of the water filling tank 74 is sufficiently large compared to the outflow port 55a, the water level in the float chamber 47 rises.
The gate 35 opens and the flow rate increases, and the upstream water level is maintained at the allowable upper limit water level w2. The influence of the increase in flow rate spreads to the downstream gate 35, causing the water level in several sections downstream to rise and water to be stored. Further, if the storage cannot be partitioned off in the entire downstream section, the most downstream drainage gate 36 is opened and the excess water is disposed of into the drainage channel 37. Also, when the impact of changes in water usage is felt downstream,
On the other hand, the influence spreads upstream one after another, eventually reaching the most upstream water intake gate 33, and the amount of water intake decreases.
Over time, the water level in all sections of the waterway will return to normal.

[0041] As mentioned above, over the entire upstream and downstream sections of the waterway, excess water is stored, and if water is insufficient, it is compensated for by the stored amount, so that excess or deficiency of water can be resolved. Therefore, water diversion can be started immediately and water diversion can be stopped at any time. In addition, since the storage amount over the entire section of the waterway can be utilized in this way, there are fewer changes in the water level overall. Therefore, when the flow rate is large, the heights of the water replenishment port 52 and the water tank 74 may remain constant in a normal waterway where the flow rate does not change much.

Next, the operation of the upper and lower limit water level correction device 77 will be explained. Normally, when the flow rate is high, the change in flow rate is small, but in cases where most of the flow rate is used for field irrigation, even if the flow rate is high, the change is large. In addition, if water is mixed in with water diversion works that naturally divert water, such as water for rice fields, it is vulnerable to changes in water level. In addition, the amount of water used is drastically reduced and the water level rises, causing a seiche. Therefore, in preparation for such a case, an upper and lower limit water level correction device 77 is provided, so that when the flow rate is large and the opening degree of the gate 35 is large, the height difference between the upper end of the water injection tank 74 and the water filler port 52 is corrected. It can be reduced. Therefore, fluctuations in the water level in the water diversion works are extremely small, so there is no problem with water diversion. Also, since the water level fluctuates little, the adjustment function in one section is reduced, but since the adjustment is distributed over a wide range of sections, a considerable flow rate adjustment function remains. In addition, if the flow rate decreases, the amount of water diverted to each diversion works will also decrease, and the water level in the irrigation canal downstream of the diversion works will also decrease, so even if the water level in the canal 34 becomes somewhat low, there will be no problem with water diversion. On the other hand, as the flow rate decreases, the change in the amount of water used increases, and therefore a larger flow rate adjustment function is required. Regulatory function increases. Furthermore, as the gate 35 closes, the height of the water tank 74 also decreases, so even if the water level rises abnormally due to flow rate adjustment, the degree of rise is small, and therefore no seiche occurs in any case. .

Next, the operation in the case of a flood will be explained. When floodwaters flow into a certain section of the waterway 34, the upstream gates 35 are closed one after another, and finally the water intake gate 33 is closed, reducing the water intake amount, but the maximum opening of the water intake gate 33 is the same as the planned opening. degree k, and the height of the upper end of the sealed portion 85 of the float 84 of the water intake gate 33 is at the planned opening degree k.
Since it is set equal to the planned water level w, even if the water level of the river 32 rises above the planned water level w, the closing action will not be affected. Therefore, if the inflow of flood water increases further, the system will eventually become fully closed and water intake will be stopped. Further, if a full-scale flood occurs thereafter, water is injected into the water level detection float chamber by a siphon, so that the water intake gate 33 remains fully closed during the flood. In addition, in the event of a flood, water diversion at each diversion works is stopped, so all gates 35 are close to fully closed, so the height of the water injection tank 74 is considerably lowered by the upper and lower limit water level correction device 77. has been done. Therefore, the water level upstream of the gate 35 immediately downstream of the section into which the floodwaters are flowing immediately reaches the allowable upper limit water level w2 and the gate 35 opens, and the influence spreads downstream, and each gate 35 opens one after another. , and finally the drain gate 36 opens and all of the flood water is dumped into the drain 37.

[0044] As the amount of inflow of flood water increases, the opening degree of the gate 35 gradually increases and the water level also rises. gate 35
When the opening degree reaches the flow rate adjustment stop opening degree, the minimum eccentric force necessary for closing remains.
Although the water level difference between upstream and downstream is several cm, the entire center of gravity of the gate 35 is set as high as possible, so the angle of intersection between the line connecting the gate axis 38 and the center of gravity and the vertical line is extremely small. Therefore,
When the flow rate increases further and the gate 35 is opened, the difference in water level between upstream and downstream gradually decreases, and finally disappears, and the float 84 rises due to its own weight, discharging the water inside the float 84 , and the sealed part 85 A part of the gate arm 39 is exposed in the air, and the gate arm 39 becomes horizontal and rests supported by the stopper 44.

[0045] Once the flood has subsided and the flow rate has decreased, the water depth will be the smallest at the water level immediately downstream of the water intake gate 33, but at this stage the water level of the river 32 upstream of the water intake gate 33 is large. , the water level is still quite high. Therefore, since water continues to be injected into the water level detection float chamber by the siphon, the water intake gate 33 remains closed, but the water level at the most upstream gate 35 immediately downstream is the lowest among the gates 35. In addition, since the height of the sealed part 85 of the float 84 of the gate 35 at the most upstream side is set at the highest level, when the flood stops and the water level drops to an appropriate level, the weight of the sealed part 85 exposed in the air will cause the The most upstream gate 35 is pulled down and weir raising is automatically restarted. As a result, the downstream flow rate is drastically reduced, so the downstream gates 35 are closed one after another. In this state, some flood water is still flowing into each section, so the water level upstream of each gate 35 is at the allowable upper limit water level w2, and therefore the water level of the river 32 is low. Even if water injection by siphon is stopped, water intake gate 33
won't open. However, if water diversion is resumed downstream and the water level is insufficient due to flooding alone, and the water level at any of the diversion works positions becomes slightly lower than the planned water level, the gate 35 upstream will open and The upstream water level is the allowable upper limit water level w2
The water level rapidly decreases from the state of , and becomes slightly lower than the planned water level, and the gates upstream of the water level open, the influence of which spreads upstream one after another, and finally, the water intake gate 33 opens and water intake resumes. .

Next, the function of the water guiding portion 86 of the float 84 will be supplemented. When the flow rate increases and reaches a state close to the flow rate adjustment stop opening, the difference in water level between upstream and downstream becomes small, and the height at which the water level in the float chamber 47 can be raised and lowered becomes extremely small. However, on the other hand, the door body 40 cannot be moved sufficiently.
Since the velocity of the flow passing below is also small, unless the door body 40 is moved up and down considerably, the water levels upstream and downstream will not change sufficiently. As described above, when the flow rate is large, the water level tends to change insufficiently, but in this embodiment, water from the water channel 34 on the downstream side is introduced into the water guide section 86 of the float 84. Furthermore, as described above, it is assumed that the water level in the water channel 34 does not change sufficiently, so even if the float 84 goes up and down, the water level inside the float 84 changes only slightly. Therefore, even if the float 84 moves up and down, the operating force acting on it does not change unless the water level in the water channel 34 on the downstream side changes sufficiently, and as a result, the water level in the float chamber 47 changes. Therefore, the flow rate can be adjusted until the water level difference between upstream and downstream becomes extremely small.

Next, the effect of the gap between the float chamber 47 and the float 84 will be explained. When opening and closing the gate 35, the resistance until it starts moving is static frictional resistance, which is relatively large, but once it starts moving, the resistance changes to dynamic frictional resistance, so the resistance is halved.On the other hand, the resistance acting on the float 84 The operating force is quite large and does not decline unless the float 84 moves up and down. Therefore, when the flow rate is low and the opening degree of the gate is small, there is a problem that the gate moves too much and the flow rate fluctuates drastically. Since the gap between the float chamber 8 and the float 84 is made as small as possible by eliminating the movement of The water moves, and therefore the water surface moves in the opposite direction to the float 84, and the actuating force acting on the float 84 disappears, so that each movement of the float 84 becomes extremely small. Therefore, the movement of the gate 35 becomes smooth.

[0048]

[Effects of the Invention] The device according to the present invention installs a water level detection float in a reservoir communicating with a downstream waterway, and operates a constriction valve in accordance with the length and rotation angle of the arm for the water level detection float. Since the door body is operated, water can be conveyed according to the downstream water usage status, and the water level can be set to the most suitable level for the flow rate.The water level can also be selected according to the actual situation of each diversion work. Furthermore, floodwaters can flow down safely. Moreover, compared to conventional gates, the structure is extremely simple because it does not require a guide plate or a rectangular plate provided with a groove having a hydraulic curve as shown in FIG. In addition, waterway management can be done unmanned and without power, so we believe this is a truly timely invention in the current situation where water resources are tight and energy conservation and labor shortages are becoming social issues.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of the entire waterway including its front and rear parts according to an embodiment of the present invention.

FIG. 2 is a plan view of the check gate of the embodiment.

FIG. 3 is a side cross-sectional view showing a limit state in which the flow rate adjustment of the check gate of the embodiment is stopped or started;

FIG. 4 is a side sectional view showing the check gate of the embodiment in a fully closed state.

FIG. 5 is a graph showing the operating characteristics of a check gate according to an embodiment of the present invention.

FIG. 6 is a side sectional view showing a conventional waterway gate.

FIG. 7 is a side cross-sectional view of a conventional gate that maintains a constant upstream water level of water diversion.

FIG. 8 is a partial view showing a conventional outflow mechanism from a float chamber of a gate control device.

FIG. 9 is a side sectional view showing a conventional gate that maintains a constant water level difference between each water diversion facility.

[Explanation of symbols]

34 Waterway 40 Door body 46 Still water pond 47 Float chamber 48 Retarding pond 51 Water replenishment cylinder 52 Water replenishment port 55a Outlet 57 Water level detection float 59 Stenosis valve 61 Leak port 63 Spring 67 Water level detection float arm 74 Water tank 78 Arm for water tank 79 Water tank arm 84 Float w1 Allowable lower limit water level w2 Allowable upper limit water level

Claims (3)

[Claims] Claim 1: It has a gate provided across a waterway and a float interlocked with the door, and the float chamber housing the float is connected to the waterway on the upstream side of the door through a small water supply port. A water level detection float is floated on the water level, and a constriction is connected to the water level detection float. A flow rate response for an irrigation canal, characterized in that a valve is allowed to freely move forward and backward toward the outlet, and the water level detection float is suspended via a spring on a water level detection float arm that rotates in conjunction with the door body. Gate. 2. The water replenishment port is opened in the float chamber and is bored in the side wall of a water replenishment cylinder installed in a still water pond upstream of the door body at a height of the lower limit water level, and is connected to the still water reservoir. 2. The apparatus according to claim 1, further comprising a water injection tank that communicates with the float chamber, has an upper end at a height slightly lower than the allowable upper limit water level, and is comprised of a relatively large weir. 3. The apparatus according to claim 1, wherein the water refill cylinder and the water tank are suspended by a water tank arm and a water tank arm, respectively, which rotate in conjunction with the door body.