JPH08128026A - Overflow weir - Google Patents

Abstract

PURPOSE: To improve an overflow weir which is used to control water draining quantity from irrigation water. CONSTITUTION: A weir mainbody 1 mounted on a diversion stand 2 is formed in a hollow box shape, with the front as a closed face 11 facing a flow passage in the upstream U, a water draining distribution port 12 open to the back in communication with the downstream D and a movable weir plate loosely fitted to both side faces in parallel to the flow direction to open the effective area of an overflow port 15 in an adjustable manner. A float 3 may be more preferably provided to elevate the movable weir plate with the change of a water level. Since right-and-left symmetrical water pressure is applied to the movable weir plate to offset frictional force between the weir mainbody and the weir plate, the weir plate is smoothly moved in the weir mainbody. If the float is used, small buoyancy is required and the capacity of the diversion stand can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overflow weir that is attached to a water distribution stand for adjusting the amount of water provided in a flow path for irrigation water or the like and that controls the amount of water discharged downstream to a constant level.

[0002]

2. Description of the Related Art A water diversion stand is a kind of water tank made of concrete or the like, which is installed in important places such as irrigation channels. It receives irrigation water from the upstream side and adjusts the flow rate to the downstream side. A facility that functions to control the amount of water discharged. The water diversion stand causes an unbalanced flow fluctuation such that the flow of diversion increases due to the inflow of rainwater or the stop of other diversion, or conversely, the amount of diversion on the upstream side increases and the flow on the downstream side becomes insufficient. The purpose is to mitigate and adjust so that a fixed amount of diversion can always be sent to the downstream side.

In order to satisfy this function, conventionally, an overflow weir is provided in front of the water discharge opening of the water diversion stand so that the amount of water discharged from the water diversion stand to the downstream side can be kept constant. The weir plate is fitted to the weir body so that the position can be adjusted manually or by interlocking with a connected float. 5 to 7 are three-sided views (partial cross-sections) showing typical examples of conventional technology, and show a concrete configuration in which an overflow weir is installed in a diversion stand to control the amount of water discharged to the downstream side. is there. In the figure, a water diversion stand 2a is a water tank which is provided in a flow path for irrigation and communicates with an upstream side U and a downstream side D, and a weir body 1a is attached to a front surface facing the flow direction of the water diversion stand 2a. . The water distribution stand 2a is surrounded by a vertical side plate formed of concrete, and a water discharge opening 22a is cut out on the front surface facing the flow so as to communicate with the downstream side. The weir main body 1a has a movable weir plate 14a, which is provided on the front surface of the water diversion stand 2a and has a circulation port 12a whose opening width is substantially the same as that of the water discharge opening 22a. Movable dam plate 1
Attach the hanging support metal fitting 18a to the center of the top surface of 4a.
8a is fastened to a horizontal connecting rod 17a. Connection rod 1
A float 3a is suspended from the left and right ends of 7a and floats in the upstream water in the water diversion stand 2a.

As a result of this construction, the position of the movable dam plate moves up and down in conjunction with the position of the float, and if the position of the float moves up and down due to fluctuations in the water level, the position of the movable dam plate also moves up and down by the same vertical distance. There is no change in the relative position of the flow outlet 12a with respect to W, and a constant amount of water discharge is maintained regardless of the change in water level. The positional relationship between the float and the flow port is 1
It is possible to adjust by arranging a large number of through holes 19a in 8a and appropriately moving the fastening position with the connecting rod 17a up and down as desired.

[0005]

The movable weir plate absorbs the fluctuation of the water level by interlocking with it and maintains a constant amount of water discharge. Therefore, the response of the position of the movable weir plate depends on the overflow weir. It is a factor that greatly affects the quality of the function. In the case of the conventional technique, it goes without saying that the position of the movable dam plate is manually moved, but even when the float is floated in the water diversion stand and the position of the movable dam plate is automatically responded to the fluctuation of the water level position. Since it is inevitable that the movable dam plate itself receives the water pressure in the water diversion stand from the front,
It cannot move unless the friction force between the weir body and the movable weir plate induced by the pressing force is overcome. That is, the relationship between the movement of the movable weir plate and the response of the float starts or stops based on the balance between the weight of the movable weir plate and the buoyancy of the float, but other than that, frictional action between the movable weir plate and the weir body Another element that cannot be ignored.

Since the frictional force can be calculated by the product of the water pressure and the coefficient of friction, the buoyancy of the float increases as the water level rises in an attempt to pull up the movable dam plate, while the water pressure in the water diversion stand also increases. At the same time, the frictional force acting on the movable weir plate is increased and is increased, so the deterrent force that conversely restrains the operation of the movable weir plate that tries to interlock with the movement of the float also increases, and the overflow weir that moves to maintain a fixed amount of water discharge. The function of is greatly reduced.

In order to solve this problem, it is necessary to increase the capacity of the float to strengthen the buoyancy so as to sufficiently overcome the frictional force, but this makes the float larger and accommodates it. Since the capacity of the water stand must be increased and the burden of equipment costs and installation area must be increased, it is natural that a more effective solution is desired. In order to solve the above-mentioned problems, the present invention does not require an increase in the size of a water diversion stand or an increase in the capacity of the float, and a new overflow weir having a function of always maintaining a stable quantitative water discharge. For the purpose of provision.

[0008]

The overflow weir according to the present invention comprises:
It is attached to a diversion stand for adjusting the amount of water provided in the flow path of irrigation water, etc., and is installed for the purpose of controlling the amount of water discharged to the downstream side constantly, and faces the flow path of the weir body 1 consisting of a hollow box body. The front surface is a closed surface 11, and the back surface facing the closed surface 11 is fixed to the front inner wall 21 of the water discharge opening 22 of the water diversion stand 2 to open a circulation port 12 communicating with the water discharge opening 22. The movable barrier plate 14 is loosely fitted on both side surfaces of the weir body 1 parallel to the flow direction of the weir body 1 so that the effective area of the overflow port 15 can be adjusted so that the above-mentioned problems can be solved. Settled.

In this basic structure, the positional relationship between the movable dam plate 14 and the connecting rods 17 connected to the lid plates 16 fixed in common to the respective top surfaces of the two movable dam plates 14 facing each other. It is a preferred embodiment that the floats 3 are movably suspended.

[0010]

In the overflow weir of the present invention, the weir body mounted in the water diversion stand has a three-dimensional box shape instead of the flat plate shape as in the prior art. The front face facing the upstream side is closed, and the overflow port opens on the side face orthogonal to the flow direction. Since the movable weir plate receives the water pressure in the water diversion stand evenly from the left and right, symmetrical pressure forces act on the weir body, cancel each other out and disappear, and the movable weir plate and the weir induced by the pressure force. There is no friction between the bodies. Therefore, the movable barrier plate is guided only by the balance with the buoyancy of the float that responds to the water level.

[0011]

1 is a sectional side view of an embodiment of the present invention, FIG. 2 is a plan view, and FIG. 3 is a partial sectional front view. The weir body 1 of the overflow weir is made of a hollow rectangular parallelepiped, and the front surface facing the flow direction in the water diversion stand 2 is in contact with the closed surface 11, and the back surface facing the closed surface is in contact with the front inner wall 21 of the water diversion stand 2. The mounting surface 13 is mounted on the mounting surface 13. The mounting surface 13 is provided with a flow port 12 that is open at a position substantially overlapping the water discharge opening 22 of the water diversion stand 2.

The overflow port 15 through which the water flowing into the water diversion stand 2 flows into the weir body is formed by penetrating the upper part of the movable weir plate 14 which is loosely fitted to the left and right side surfaces of the weir body. . The top surfaces of the movable barrier plates 14 on both sides are fixed by being joined by a cover plate 16, and a vertical suspension metal fitting 18 fixed to the center of the cover plate 16 has a horizontal connecting rod 17 and a penetrating member appropriately selected. Hole 1
9 are connected by bolts and nuts which are fastened together, and the floats 3 are suspended from both ends of the connecting rod 17 via suspension rods 31. With this configuration, the water distribution stand 2
The water that has flowed in from the upstream side U flows into the weir body of the overflow weir from the side overflow port 15, converts the direction to a right angle in the box-shaped weir body, and then discharges the water from the circulation port 12. Water is discharged to the downstream side D via the section 22.

FIGS. 4A, 4B, and 4C are plan views showing different embodiments of the present invention, and the cross section of the weir body 1 is shown in FIG.
An example that is a polygon instead of a quadrangle like the example in (A)
It shows a case of a curved tubular body instead of a rectangular box body as shown in FIG. It goes without saying that in any of the examples, the overflow ports opening on the side surface of the weir body are symmetrically provided on the left and right sides, and the applied water pressures cancel each other out so that no frictional force is generated.

[0014]

As described above, according to the present invention, the overflow weir is three-dimensionally constructed, and the water flowing in from the side surfaces cancels out the water pressure action of each other and does not induce the frictional force. The operation of the movable weir plate that moves up and down together with the float that moves up and down is extremely light, and the function is maintained extremely smoothly. Since the operation of the movable weir is light, the necessary buoyancy of the float is also small, and the advantages of reducing the burden on the equipment such as downsizing of the float and the volume of the water diversion stand are great.

[Brief description of drawings]

FIG. 1 is a side sectional view of an embodiment of the present invention.

FIG. 2 is a plan view of the embodiment.

FIG. 3 is a partially sectional front view of the same embodiment.

FIGS. 4A to 4C are plan views of different embodiments according to FIGS.

FIG. 5 is a side sectional view of an example of a conventional technique.

FIG. 6 is a plan view of the same prior art.

FIG. 7 is a partially sectional front view of the same conventional technique.

[Explanation of symbols]

 1 Weir main body 2 Water diversion stand 3 Float 11 Closed surface 12 Flow port 13 Mounting surface 14 Movable weir plate 15 Overflow port 16 Lid plate 17 Connecting rod 18 Suspension metal fitting 19 Through hole 21 Front inner wall 22 Water discharge opening 31 Suspension support Rod W water surface

Claims (2)

[Claims] 1. An overflow weir, which is attached to a water distribution stand for adjusting the amount of water provided in a flow path for irrigation water and controls the amount of water discharged to the downstream side at a constant level, comprises a weir body 1 made of a hollow box. A front surface facing the flow path is a closed surface 11, and a rear surface facing the closed surface 11 is fixed to a front inner wall 21 of a water discharge opening 22 of the water diversion stand 2 and a flow port communicating with the water discharge opening 22. A movable dam plate 14 is loosely fitted to both side surfaces parallel to the flow direction of the weir main body 1 so as to adjust the effective area of the overflow port 15 so as to be adjustable. Overflow weir characterized by. 2. The positional relationship with the movable dam plate 14 according to claim 1, wherein the positional relationship with the movable dam plate 14 is changed to both ends of a connecting rod 17 that is connected to a cover plate 16 that fixes respective top surfaces of two facing movable dam plates 14. An overflow weir characterized by suspending floats 3 freely.