JPH0833003B2 - Automatic turning weir - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an automatic turning weir (gate) for weiring a river or a waterway for water intake.

(Prior Art) A river or waterway is usually provided with a gate in order to keep the upstream water level almost constant. Conventionally, as this gate, there is one that operates by utilizing a float, and as one of them, there is an automatically operable tenter gate 1 as shown in FIG. In the figure, an arm 4 is fixed in an upstream / downstream direction to a main shaft 3 rotatably provided above the water channel 2, and an arc-shaped door body 5 centered on the main shaft 3 is provided at an upstream end of the arm 4. It is fixed and arranged so that the water channel 2 can be dammed up. On the other hand, a counterweight 6 is adjustably mounted below the downstream end of the arm 4. A static water reservoir 7 and a float chamber 9 communicating with the static water reservoir 7 via an overflow weir 8 are provided on the side of the water channel 2, and the low water reservoir 7 has a water inlet 10 in the upstream water channel of the gate 1. The float chamber 9 is connected to the gate 1 through a small-diameter outlet 11.
Is connected to the downstream waterway. And the float chamber 9
The float 12 accommodated therein is suspended at the upstream end of a float arm 13 fixed to the main shaft 3 by extending in the same direction as the arm 4. The weir length of the overflow weir 8 is made sufficiently larger than the cross-sectional area of the outlet 11.

Next, the operation of the gate 1 will be described. Gate 1
When the water levels of the upstream water channel and the still water reservoir 7 become slightly higher than the weir top of the overflow weir 8, the weir top of the overflow weir 8 is made sufficiently larger than the cross-sectional area of the outflow port 11. So float room 9
The water level in the inside rises, and as a result, the float 12 and the door body 5 rise and the amount of downflow increases, and the water level in the upstream water channel of the gate 1 becomes low. On the other hand, if the water level in the still water pond 7 drops, the float chamber 9
Since the amount of inflow into the inside of the float chamber 9 decreases and the rise of the water level in the float chamber 9 stops, the gate 1 is stationary. Since the action when the water level in the upstream waterway of the gate 1 is lowered is self-explanatory, its explanation is omitted.

By the way, in order to improve the opening / closing accuracy of the gate 1, the plane area of the float 12 may be reduced. In this case, however, the buoyancy is reduced. Therefore, first, the distance from the spindle 3 to the door body 5 (hereinafter, The arm length of the door body 5) is shortened to reduce the resistance torque of the watertight rubber (not shown) attached to the door body 5, and secondly, the distance from the main shaft 3 to the center of the float 12, that is, the float arm 13 It is necessary to increase the length. In other words, it is necessary to increase the ratio of the arm length of the float 12 to the arm length of the door body 5 (hereinafter referred to as the arm length ratio).

However, in the prior art shown in FIG. 6, when the water flow in the water channel 2 is large and the water level difference between the upstream and downstream sides of the gate 1 is small, the height at which the float 12 can move up and down is extremely small, while the door body Since the velocity of the water flow passing below 5 is small, there is a problem that the upstream water level cannot be kept constant unless the door 5 is opened and closed greatly. This means that the arm length ratio between the door body 5 and the float 12 has to be made extremely small due to hydraulic restrictions, which is a negative factor in improving the opening / closing accuracy.

Therefore, the present inventor has proposed a gate 14 as shown in FIG. 7 (see Japanese Patent Application No. 1-173232). Conventional gate 1
The part different from (see Fig. 6) is a closed chamber inside the float 15.
It is divided into 15a and an upper chamber 15b arranged above it.
The reason is that the inside of b is communicated with the water passage on the downstream side of the gate 14 through the flexible communication pipe 16 that penetrates the sealed chamber 15a. As a result, the float 15 moves up and down while the water inside the upper chamber 15b flows in and out, so that the acting force acting on the float 15 is
As long as the water levels in the float chamber 9 and the downstream water channel do not change significantly regardless of whether the float chamber 9 is moved up or down, there is no theoretical restriction on the length of the float arm 13; Then, the arm length of the float 15 can be increased.

The weight and height of the counterweight 6 attached to the downstream end of the arm 4 can be adjusted so that the position of the center of gravity of the entire device is diagonally above and upstream of the main shaft 3 when the gate 14 is fully closed. In the fully opened state, the main shaft 3 is arranged diagonally above and on the downstream side. From the above,
At the time of flood, due to the action of the center of gravity, the float 15 rises while discharging the water inside the upper chamber 15b, the lower end of the door body 5 rises in the air, and the gate 14 is fully opened. When the water level of the waterway 2 becomes low after the flood, the float 15 descends and the door 5 descends due to the weight of the closed chamber 15a below the float 15 exposed in the air. Therefore, weiring will be started again.

(Problems to be Solved by the Invention) However, even in the above configuration, the arm length of the door body 5 is still large, and the bottom surface of the float chamber 9 is deep, so that the arm length ratio of the door body 5 and the float 15 is very different. In fact, the plane area of the float 15 is still large, and the problem that it requires an installation space remains.

In addition to the fact that the arm length ratio between the door body 5 and the float 15 is small, the float 15 is directly suspended from the float arm 13 so that the float 15 is displaced in the up / down direction as it goes up and down. Therefore, the clearance between the float 15 and the float 15 in the float chamber 9 must be wide, and therefore the acting force acting on the float 15 does not decrease easily. On the other hand, when the resistance of the door body 5 starts to move, It means that the door body 5 moves excessively because it decreases from frictional resistance to dynamic frictional resistance, and as a result, when the flow rate is small, the door body 5 constantly repeats opening and closing and the water surface is not constant. There was a problem.

It is an object of the present invention to provide an automatic turning weir capable of ensuring stable operation of a float that operates a door body and performing stable weiring.

(Means for Solving the Problem) In order to achieve the above object, the present invention provides a main shaft rotatably at a position lower than a designed water level on both walls of a water channel, and the main shaft traverses a water channel arranged on the upstream side. The door body is fixed via an arm, and a float chamber accommodating a float is provided laterally of the door body along the water channel, and a still water pond communicating with the door body upstream side of the water channel and the door body downstream side of the water channel. A water reservoir is provided to communicate with the float chamber and the still water reservoir, and the inside of the float is communicated with the water reservoir, and a column is erected above the main shaft of the side wall of the water channel. A lower arm projecting in the upstream and downstream directions is rotatably provided by a lower shaft provided in the upper arm, and an upper arm having substantially the same length as the upstream side of the lower arm is rotatably moved toward the column toward the upstream side. The upper arm tip and the lower arm. A vertical member supported by the upstream side front end of the boom and a horizontal rail fixed to the vertical member and protruding to the upstream side are provided, and a roller movably provided on the horizontal rail is erected on the float. The link is axially supported by the provided connecting member, and a link having substantially the same length as the downstream side portion of the lower arm is fixed to the main shaft toward the downstream side, and the downstream side tip portion and the link tip portion of the lower arm are provided. Is rotatably connected by a connecting member.

(Operation) Since the present invention is configured as described above, since the main shaft is pivotally supported at a position below the designed water level, the pivot angle of the door body that opens and closes the water channel increases, but the arm length is significantly longer. It becomes smaller, and the resistance torque when the door operates becomes smaller.

On the other hand, since the lower shaft of the lower arm that transmits the lifting and lowering of the float is located above the main shaft by the connecting material, the space above the conventional float chamber becomes wider, and the bottom of the float chamber can be manufactured by slightly dug. Good, the arm length of the float can be increased, and the arm length ratio of the door body and the float can be significantly increased.

In addition, since the upstream side of the lower arm is a link mechanism, the horizontal rail rotates while keeping horizontal, and the roller moves on the horizontal rail, so the float can be vertically moved up and down at a fixed position. The gap between the float chamber and the float chamber can be minimized.

Therefore, not only the plane area of the float can be reduced, but also the water area thereof can be reduced. For this reason, even if the float moves up and down slightly, the water surface in the float chamber moves largely in the direction opposite to the float, the acting force acting on the float disappears, and the door body does not uselessly move and operates efficiently.

(Example) Hereinafter, an example of the present invention is described based on an accompanying drawing. As shown in FIG. 3, the water channel 17 is provided with a gate 18 for damming its flow, and the door body 19 crossing the water channel 17 is
Thick plate longitudinal girders 20 arranged at both ends thereof and the door body 19 are integrally fixed to the longitudinal girders 20 integrally with the door body 19 at a position approximately midway on the downstream side surface of the door body 19. A torsion girder 21 that forms a box-shaped cross section and a longitudinal girder that is fixed near the lower end of the door body 19
A horizontal girder 22 (see FIG. 1) fixed to 20 is assembled. Then, the arms 23, 23 are respectively fixed to positions on the downstream side of the longitudinal girders 20 on both sides and at a position approximately at the middle height.

The direction of the arm 23 is substantially horizontal when the gate 18 is fully closed, and the tip of the main shaft 24 having a handle on both sides is loosely fitted from the outside into a hole formed in the downstream end of the gate 18. Are connected by a spring pin 25 and one main shaft 23
Is rotatably supported by a main bearing 26 embedded in the wall of the water channel 17, and the other main shaft 24 is axially supported by and penetrates the main bearing 26 embedded in the wall of the water channel 17, A secondary bearing 28 (see FIG. 2) embedded in the outer wall is rotatably supported by the auxiliary bearing 28, which crosses a water reservoir 27 arranged in parallel. Further, a static water reservoir 29 is provided on the side of the door body 19 across the wall of the water channel 17, and a float chamber 30 and a water transfer reservoir 27 are provided in order toward the downstream side. The still water reservoir 29 communicates with the upstream water passage of the gate 18 through a water passage 31 formed in the wall,
The still water reservoir 29 is connected to the float chamber 30 via the overflow weir 32. The float chamber 30 communicates with the water reservoir 27 via the small-diameter outflow pipe 33 arranged at the bottom, and the water reservoir 27 is downstream of the gate 18 via the water inlet 34 formed in the wall of the waterway 17. It is connected to the side canal (see Figures 1 and 2).

Next, the structure of the overflow weir 32 will be described. As shown in FIG. 2, a tank-shaped water injection tank with an upper opening inside the still water reservoir 29.
35 is arranged such that the height of its upper end is appropriately lower than the planned water level at which a predetermined weir should rise, and a water injection pipe 36 is connected to the lower part of the water injection tank 35 via a square screw, and the other end of the water injection pipe 36. Is opened in the float chamber 30 at a position lower than the lower end of the float 37 in the lowest state. Inlet 35a of water injection tank 35
The vicinity is surrounded by a cylindrical dustproof and waveproof tube 38. Further, the circumference of the water injection tank 35 is made sufficiently larger than the cross section of the outflow pipe 33, and the water area of the water injection tank 35 is made as small as possible by overflowing the water from the bend of the water injection tank 35.

The float 37 provided in the float chamber 30 has a closed portion 37a formed in the lower portion thereof, a water guiding portion 37b above the closed portion 37a, and a vent hole 37c formed in the top plate. Further, a pair of vertically projecting guide rods 39, 39 are fixed to the bottom surface near the center of the upstream side wall surface and the center of the downstream side wall surface of the float chamber 30, and the guide rod 39 is a guide pipe fixed to the float 37. Since the float 37 moves up and down along the guide rod 39 and the position of the float 37 in the float chamber 30 is fixed, the gap between the float 37 and the float 37 is made as small as possible. Further, a water guiding hole 41 opening at the lower end of the water guiding portion 37b penetrates the sealing portion 37a and is connected to a flexible water guiding pipe 42 of a sufficient length at the lower end of the float 37 so as not to hinder the lifting and lowering of the float 37. The tip of the water conduit 42 penetrates the wall of the float chamber 30 and opens in the water reservoir 27. The sizes of the outflow pipe 33 and the water conduit 42 are determined so that the opening / closing speed of the gate 18 is appropriate.

The main shaft 24 traversing the water reservoir 27 described above has a link 44 of a connecting device 43 fixed to a central position thereof, and a connecting member 46 is rotatably connected to a tip end thereof via a lower connecting pin 45. There is. In addition, above the main shaft 24 that has traversed the headwater reservoir 27,
A lower shaft 48 pivotally supported by a pair of columns 47, 47 standing on the upper surface of the water reservoir 27 is rotatably provided parallel to the main shaft 24. On this lower shaft 48, a pair of lower arms 49, 49 located inside the pair of columns 47, 47 and extending in the upstream / downstream direction.
The upper end of the connecting member 46 is rotatably connected to the downstream side end of the lower arm 49 via an upper connecting pin 50 connecting the pair of lower arms 49, 49. In this configuration, the line connecting the main shaft 24, the lower connecting pin 45 of the connecting device 43, the upper connecting pin 50, and the lower shaft 48 forms a parallelogram to form a link mechanism.

Next, the interlocking device 51 will be described. Post 47 above the lower shaft 48
An upper shaft 52 is rotatably supported and is horizontally rotatably provided, and a pair of upper arms 53, 53 extending upstream are fixed to the upper shaft 52. Then, the lower arm 49 is connected to the upstream end of the lower arm 49 and the upper arm 53, and the lower support pin 54
One vertical member 56 is provided via the upper support pin 55. Vertically from the vertical material 56 to the upstream, the lower rail 57
The float 37 is supported by a connecting member 60 having a roller 59 loosely fitted between the upper rail 58 and the upper rail 58. In this configuration, the lower shaft 48,
The line connecting the lower support pin 54, the upper support pin 55, and the upper shaft 52 forms a parallelogram to form a link mechanism.

Further, a branch arm 61 projects below the lower arm 49 fixed to a lower shaft 48 pivotally supported by the support column 47, and a counterweight 62 is attached by the branch arm 61. The position of the counterweight 62 viewed from the lower shaft 48 is slightly higher than the direction opposite to the position where the center of gravity of the gate 18 is viewed from the main shaft 24 of the gate 18. In addition, support 47
The tip of the guide rod 39 described above is fixed to the frame 63 that is supported by and is attached to the upstream side. Further, when the arm 23 of the gate 18 is upright, a stopper 64 is fixed to the side wall of the water channel 17 so as to support the arm 23 at a position in contact with the downstream side thereof.

Next, the details of the configuration will be described. First, at a predetermined design water level to be dammed up, and above that, the upper limit water level is set within the practically allowable limit, and the downstream water level is the planned water level and the upstream water level is the upper limit water level. , If the water levels in the water conduit 37b of the float chamber 30 and the float 37 become equal, the weight of the counterweight 62 is adjusted so that the gate 18 closes, and the flat area of the float 37 is the water level in the float chamber 30. If the water level reaches the upper limit, the gate
18 is large enough to open.

Since the weight of the counterweight 62 and the horizontal position of the counterweight 62 in the state where the downstream water level is the designed water level and the upstream water level is the upper water level are determined upstream,
Next, the height of the counterweight 62 in this state will be described. Prior to determining this height, first, at each opening below the above opening, the height of the entire center of gravity is made as high as possible within the limit where the gate 18 can be reliably opened. The height of the counterweight 62 is determined so that the position is like that.

Note that the problem of the position of the center of gravity of the whole will be supplemented. In the present invention, as described above, the gate 18 and the exercise device 51 are provided.
Etc. are distributed and supported by three axes, so the term "center of gravity of the whole" does not seem to be appropriate, but since the whole body rotates as a unit, mechanically all parts are It can be considered that it is supported by the lower shaft 48 of the interlocking device 51. Therefore, assuming that all of the gates 18 etc. are directly supported by the lower end, if the weight and center of gravity of the portion excluding the counterweight 62 are preselected, the weight and position of the counterweight 62 are Can be easily obtained based on the above-mentioned constitutional requirements.

The height of the upper end of the closed portion 37a of the float 37 is, with respect to the gate 18 arranged in the uppermost stream of the water channel 17, the torque in the closing direction generated by exposing a part of the closed portion 37a in the air,
The sum of the friction resistance torque of the gate 18 should be appropriately smaller than the torque in the opening direction due to the eccentric force of its own weight, and when multiple gates 18 are installed in the same water channel, they should become smaller in order as they go downstream. To

In addition, regarding the inflow means to the float chamber 30 and the structure for communicating with the downstream side water channel, a structure in which a water pipe that allows communication between the still water reservoir 29 and the headwater reservoir 27 is arranged (Japanese Patent Application No. 63-326668).
No.)) may be combined. Also, the structure is such that the center of gravity of the entire rotating part is set higher than the axis so that the gate 18 is fully opened during a flood, but if there is a spillway upstream, the gate 18 will not be fully opened during a flood. It is good to

 Next, the operation will be described.

First, the graph in FIG. 5 shows the relationship between the gate opening and the water level. In the above configuration, the flat surface area of the float 37 and the weight and position of the counterweight 62 determine the downstream water level to the planned water level. Therefore, the state in which the upstream water level reaches the upper limit water level is referred to as pattern III, the fully closed state of the gate 18 is referred to as pattern I, and the intermediate state between the above pattern I and pattern III is referred to as pattern II. Also, the curve is
The downstream water level for each opening angle of the gate is shown, and the curve shows the water level in the float chamber 30 in which the gate 18 stands still.The opening direction torque due to the eccentric force causes the opening direction torque due to the buoyancy acting on the float 37. Float needed to balance
This can be understood by comparing the water level difference between 37 and 37 with the curve.

As already explained in the above configuration, pattern II
In I, when the water level in the float chamber 30 is at an intermediate height between the upstream and downstream water surfaces, the closing torque due to the eccentricity of its own weight and the opening torque due to the buoyancy acting on the float 37 The plane area of the float 37 is determined so that the gate 18 opens when the water level in the float chamber 30 becomes equal to the upstream water level in equilibrium, but the resistance torque in the opening and closing directions of the gate 18 is of course equal. Therefore, in other words, in the above configuration, the water level in the float chamber 30 is equal to the upstream water level,
When the water level difference between the inside and outside of the gate 37 becomes equal to the water level difference between the upstream and downstream sides of the gate 18, it is expected that the float 37 will generate a torque that is twice the resistance torque of the gate 18. This is the same in Pattern II, but
In II, as shown in Fig. 5, as the flow rate decreases, the upstream / downstream water level difference, which is the root of the buoyancy of the float 37, increases, while the upstream / downstream water pressure difference acting on the gate 18 increases. Although there is a slight increase in the resistance torque due to the increase, the resistance torque due to its own weight is large, so in Plan II there is a margin in the plane area of the float 37 compared to Pattern III, and the water level in the float chamber 30 becomes the upstream water level. Float 37 if equal
The buoyancy acts on the gate 18 to open it, and when it becomes equal to the downstream water level, the buoyancy acting on the float 37 disappears and the gate 18 is closed by the action of the eccentric force of its own weight.

On the other hand, the water level difference between the upstream and downstream of the outflow pipe 33 and the float chamber 30
Since the flow rate of the passage varies depending on the gate opening,
The upstream water level when the station is in a stationary state varies slightly depending on the flow rate. However, the perimeter of the water injection tank 35 is
Since it is made sufficiently large compared to the cross section, the overflow level itself in the water injection tank 35 is extremely small, and the difference in the upstream water level based on the difference in the overflow level does not matter at all in practice. Very small. Further, from the above configuration, the gate 18 naturally opens and closes when the flow rate increases or decreases, but the inflow amount to the float chamber 30 needs to increase when opening and decrease when closing, so this also causes slight fluctuations in the upstream water level. Will be a factor. However, since the perimeter of the water injection tank 35 is large and the overflow water source is extremely small as described above, the amount of inflow into the float chamber 30 immediately increases or decreases as the upstream water level begins to rise and fall. Also, the horizontal rails 57 and 58 of the interlocking device 51 and the roller 5
By using 9 to prevent the displacement of the float 37 in the upstream / downstream direction and minimizing the gap in the float chamber 30, the water level in the float chamber 30 immediately rises / falls as the running water increases or decreases, By the operation, the gate 18 follows without delay. Therefore, except in the case of a sudden flood, the change in the amount of inflow into the float chamber 30 is insignificant, and therefore the change in the upstream water level can be regarded as extremely small and almost constant.

Next, the operation of the water guiding portion 37b of the float 37 will be described. First, if the water level difference between the upstream and downstream of the waterway 17 is small,
Since the flow velocity of the water flow passing under the door body 19 is small, it is hydraulically required that the door body 19 be greatly moved up and down even if the increase / decrease in the flow rate is very small. Therefore, in addition to increasing the arm length ratio of the door body 19 and the float 37, the float 37
The water conduit 37b therein communicates with the downstream water channel. Therefore, if the movement of the door body 19 is insufficient and the water levels in the float chamber 30 and the downstream water channel do not change, the water level difference between the inside and outside of the float 37 does not change, so the operating force acting on the float 37 disappears. The float 37 can be raised and lowered. Therefore, the door body 19
Movement becomes agile, and the arm 23 of the door 19 is shortened,
In addition, the rotation angle of the arm 23 can be increased.

Next, the operation of providing the arm 23 of the gate 18 in water will be described. For the above reasons, it is possible to reduce the distance from the main shaft of the gate 18 to the door body 19 and increase the distance to the float 37, and by doing so, the watertight rubber attached to the door body 19 The resistance torque of the float 37 is reduced, and as a result, the operating torque of the float 37 is increased and the plane area of the float 37 can be reduced. From this point of view, since the main shaft 24 is provided in the water, the length of the arm 23 can be made extremely small, and the length can be almost the height of the door body 19.
Not only the flat area of the float 37 becomes smaller, but also the gate 18
Moves very little, so the flow rate does not change significantly and the upstream water level stabilizes.

A supplementary explanation will be given regarding the necessity for the gate 18 to move in small steps. In recent years, upland irrigation has become widespread, and joint projects for water supply and agricultural water have been carried out.In these cases, however, the discharge in winter is extremely small compared to the cross section of the canal, and the opening of the gate 18 is within 2 cm. There is only one thing. In the prior art, in such a case, the gate 18 fluctuates greatly as described above, so that the amount of downflow changes drastically and the upstream water level also changes unsafely and constantly. The cause is that the dynamic friction coefficient is smaller than the static friction coefficient, so that once it starts moving, the resistance torque of the gate 18 is drastically reduced, while the operating force acting on the float 37 slightly moves up and down the float 37. Does not disappear at the position,
Moreover, since the arm length ratio of the door body 19 and the float 37 is small, the door body 19 widens and opens and closes.

From the above viewpoint, in the present invention, the arm length of the door body 19 is made as small as possible by providing the main shaft 24 below the water surface as described above, while the water is introduced into the float 37 and the bottom surface of the float chamber 30. By digging deep in, the arm length of the float 37 is maximized. Therefore, although it is a matter of comparison, if the door 19 moves up and down slightly,
Float 37 moves greatly. Further, since the clearance between the float chamber 30 and the float 37 is made as small as possible, when the door 19 moves up and down slightly, the water surface in the float chamber 30 moves in the direction opposite to the float 37 and is large in the float 37. A braking force is generated, and since the arm length of the float 37 is increased, a large braking torque is exerted, so that the movement of the door body 19 becomes extremely small. Even if the degree of opening and closing of the gate 18 is insufficient, the gap in the float chamber 30 is made as small as possible, so the gate 18 moves quickly. Therefore, no matter how small the movement of the gate 18, the upstream water level cannot change greatly due to the insufficient movement of the gate 18.

The above-mentioned planned water level is, to be exact, the planned water level and is adjusted by artificially adjusting the amount of water taken in, so in the plan, only in the case of drought once every ten or more years. It is said that this will not happen, but in reality, in the peak period of water demand due to literally watering of the rice paddy, it is normal to raise the water level to the planned water level every year. Therefore, if the flow rate decreases after the downstream water level reaches the planned water level, it is necessary to immediately close the gate 18 automatically to secure the upstream water level. Even in such a case, in the present invention, as described in the above configuration, in the state of the pattern III, the gate 18 is configured to be closed by the action of its own weight when the water levels inside and outside the float 37 become equal, and the pattern II In, there is no problem because the position of the center of gravity is on the upstream side of pattern III and it is easier to close.

Further, since the height of the upper end of the water injection tank 35 is slightly lower than the designed water level, the upstream water level is almost equal to the designed water level in most of the area of Pattern II. However, when the downstream water level approaches the planned water level, the upstream water level gradually rises above the planned water level, and when the downstream water level reaches the planned water level, the upstream water level reaches the upper limit water level.

Next, the action of opening the gate 18 in the event of a flood will be described. When the flow reaches the flood level up to the opening of Pattern III and the flow rate increases, the downstream water level also rises, but the upstream water level increases more than that and the difference between the upstream and downstream water levels becomes larger than that of Pattern III. Therefore, even if the flow becomes flood and the flow exceeds the planned flow, the opening of the gate 18 cannot be the same as the pattern III, and if the flood occurs, the gate 18 will gradually open (see Fig. 4). However, since the downstream water level rises, it is inevitable that the upstream water level becomes higher than the upper limit water level. However, as the gate 18 opens, the position of the center of gravity of its own weight approaches directly above the axis, so the water level difference between the upstream and the downstream gradually becomes smaller, and if the position of the center of gravity of its own weight reaches the downstream side of the rotating shaft, the gate 18 Begins to open spontaneously due to the action of the center of gravity. Hereinafter, this state is referred to as pattern IV, and pattern II
Explaining the rotation angle of the gate 18 from I to the pattern IV, as described above, the position of the center of gravity is set as high as possible within the limit where the gate 18 can be opened in all the opening angle states of the pattern II. Therefore, the rotation angle between the pattern III and the pattern IV is small, and therefore the water level in the pattern IV does not become significantly higher than the planned water level.

Further, according to a certain design standard, the margin of the waterway 17, that is, the height from the water surface to the upper end of the waterway side wall is required to be about 20 to 30 cm in the case of the planned water level. In case of up to 10 cm is allowed. Therefore,
The plane area of the float 37 may normally be determined based on the pattern III as described in the above configuration. However, due to social special circumstances, when the gate 18 is installed very close to the downstream side and is dammed up, the rotation angle between the patterns III and IV is too large because the position of the center of gravity is low. It cannot be said that the upstream water level becomes too high. In such a case, it can be easily dealt with by increasing the plane area of the float 37 based on the water level of the pattern IV.

It should be noted that after the gate opening is larger than in Pattern III, it cannot be closed automatically immediately even if the flow rate decreases and the downstream water level decreases, but once a flood occurs, it will be It is normal not to take water for a while. However, if it is absolutely necessary to immediately restart the weiring, the weiring can be immediately restarted by once reducing the flow rate at the intake port from the river or the like to expose the closed portion 37a of the float 37 in the air.

Next, the operation after pattern IV will be described. In Pattern IV, when the spontaneous opening movement of the gate 18 begins,
The water in the water guiding portion 37b of the float 37 is discharged through the water guiding pipe 42, the water in the float chamber 30 is replenished from the water injection tank 35 and the outflow pipe port 33, and the float 37 is lifted by the connecting device 43.
Rotate 19 further. Since the above water movement does not occur instantaneously, the gate 18 continues to open at an appropriate speed, and when the arm 23 becomes vertical, the upper and lower ends of the door body 19 become equal, and the arm 23 Is pressed against the stopper 64 and becomes stationary. In particular, at the final stage, as described in the above-mentioned configuration, since the sealing portion 37a of the float 37 is partially exposed to the air and the torque in the closing direction is appropriately made smaller than that in the opening direction, the rotation speed is Is especially small in the arm
23 gently contacts stopper 64. This state will be referred to as pattern V.

The time from the pattern IV to the pattern V is not instantaneous but extremely short. Therefore, the water level of the pattern V is almost equal to that of the pattern IV, but even if the flow rate further increases and the water level rises, the stopper 64 holds the stationary state.

The posture of the door body 19 in the pattern V is the most stable posture in which the projected area viewed from the upstream side is the smallest, the arm 23 is vertical, and the water pressure from the upstream side can be received by the stopper 64.

Next, the action of restarting the weir after the flood has passed will be described. When the flow rate decreases and the water level becomes slightly lower than the water level shown in Pattern V, the gate 18 begins to close, and when the opening in Pattern III is reached, the action of the center of gravity continues the voluntary closing motion and the weiring starts again. It At this time, since the water enters the float 37 and the water in the float chamber 30 is discharged, the speed of the closing motion is determined by their action.

Next, as described above, the opening of the gate 18 is changed to the pattern III.
Considering the water level in the waterway when the spontaneous closing action is started in this state. As described above, after the gate 18 starts to open in the pattern IV, it is necessary that the sealing portion 37a is not exposed to the air for a while. Because, in Pattern IV, the action of the center of gravity is
Since the frictional resistance of 18 is almost the same, the sealed part 37
If a is exposed in the air, the open movement cannot be continued. In the present invention, as described above, in the pattern IV, the sealing portion 37
The upper end of a is submerged. Also, pattern III and pattern
Even between IV, if the upper end of the sealed portion 37a is higher than the downstream water level, the water level difference between the upstream and downstream becomes large by that much, which is not preferable. In addition, the upper end of the closed portion 18a must be below the downstream water level. On the other hand, since the sealing portion 37a needs to be exposed to the air when the gate 18 is closed, the water level of the water channel needs to be appropriately lower than the planned water level in order for the gate 18 to spontaneously start closing. However,
As already explained, at the time of flood, diversion, that is,
Normally, weir does not need to be hurried, and if there is a special situation and you hurry, close the intake gate or
Alternatively, if the uppermost gate 18 is artificially closed, the flow-down amount is temporarily decreased and the water level on the downstream side of the water channel is lowered, so that the gates 18 arranged downstream can be automatically weired one after another.

In addition, when a plurality of gates 18 are installed in the same water channel and the downstream gate 18 is closed earlier than the upstream gate 18, the water level of the water channel 17 is dammed up by the downstream gate 18 and upstream. There is a risk that the water level at the position of the gate 18 will not drop and the upstream gate 18 will operate in the same way as at the time of flood, but this can be solved by gradually lowering the height of the upper end of the sealing part 37a toward the downstream side. It

Next, the mechanical action of the gate 18 will be supplemented. Since the twist girder 21 is provided on the back surface of the door body 19, even if the float chamber 30 and the interlocking device 51 are installed on one side of the door body 19, the left and right twists of the door body 19 due to this load are eliminated, and further,
The mounting angles of the pair of left and right arms 23 are equal and the arms
Since 23 is not twisted, the plate thickness of arm 23 can be made thin and can be installed in running water. Further, although a strong water pressure is applied to the lower edge of the door body 19, since the horizontal girder 22 is fixed and strong, stress can be reduced.

(Effects of the Invention) Since the present invention is configured as described above, the main shaft, which is the center of rotation of the door body, is installed at a position lower than the planned water level, and the rotating shaft (lower shaft) of the float is connected by the connecting member. By installing it above the main shaft, the arm length ratio between the door and the float can be remarkably increased, and since the gap between the float and the float chamber is reduced by the connection with the horizontal rail, the rapid vertical movement of the float The movement is suppressed, the movement of the gate becomes extremely smooth, and stable weiring can be performed. Moreover, not only can the entire system be made smaller and the installation location not wide, it is economical, and most of the gate itself is hidden in the waterway at all times, so it does not spoil the landscape.

[Brief description of drawings]

FIG. 1 is a side view showing a vertical cross section in a waterway of a gate according to an embodiment of the present invention, FIG. 2 is a side view showing a vertical cross section of a static water reservoir on the side of the gate of the embodiment, and FIG. FIG. 4 is a plan view of an example gate, FIG. 4 is a side view showing the operation of the example gate, FIG. 5 is a graph showing the relationship between the opening of the example gate and water level, and FIG. FIG. 7 is a side sectional view of another conventional gate. 17 …… Waterway 19 …… Door 23 …… Arm 24 …… Spindle 29 …… Still water reservoir 30 …… Float chamber 37 …… Float 43 …… Coupling device 51 …… Interlocking device

Claims (1)

[Claims] 1. A main shaft is rotatably provided at a position lower than a planned water level on both walls of a water channel, and a door body which crosses the water channel disposed on the upstream side is fixed to the main shaft via an arm, and the main body is provided along the water channel. A float chamber accommodating a float is provided on the side of the door body, and a static water reservoir communicating with the upstream side of the waterway door body and a water guiding reservoir communicating with the downstream side of the waterway door body are provided, and the float chamber and the still water reservoir. And a communication between the inside of the float and the headwater reservoir, a pillar is erected above the main shaft of the side wall of the water channel, and a lower arm protruding upward and downstream by a lower shaft provided on the pillar. Is provided rotatably, and an upper arm having substantially the same length as the upstream side portion of the lower arm is rotatably provided on the strut toward the upstream side, and the upper arm tip portion and the upstream side of the lower arm are provided. Vertical material supported by the tip and the lead A horizontal rail that is fixed to the material and that protrudes to the upstream side is provided, and a roller that is movably provided on the horizontal rail is pivotally supported by a connecting member that is erected on the float, and is substantially at the downstream side of the lower arm. A link having the same length is fixed to the main shaft toward the downstream side, and a downstream side front portion of the lower arm and the link front portion are rotatably connected by a connecting member. Weir.