JP3752245B2 - Garbage relief device for water intake - Google Patents

Description

  The present invention relates to a debris relief device for an intake of a waterway that is provided in a water intake that is open on a side surface of the waterway, and that allows waste flowing from the upstream of the waterway to flow into the water intake to escape downstream of the waterway.

2. Description of the Related Art Conventionally, as a dust escape device for intakes of this type of water channel, for example, one described in Patent Document 1 (Japanese Patent Laid-Open No. 10-8439) is known.
As shown in FIG. 8, this trash relief device for the intake of the water channel is provided in the intake 4 of the intake channel that is open on the side surface of the water channel C, and flows from the upstream of the water channel C to flow into the intake port 4. Dust is released downstream of the water channel C.

The dust escape device Da includes a screen Sa provided so as to block the opening surface of the water intake 4 of the water channel C. The screen Sa is formed by communicating a number of discs 1 with the shaft 2. A plurality of cylindrical members 3 formed so as to be rotatable about the shaft 2 are formed in a plurality of rows so that the discs 1 of the adjacent cylindrical members 3 are alternately meshed with each other.
The cylindrical member 3 is rotated in the same direction in conjunction with each other by a drive mechanism (not shown) including a motor and a pulley that transmits rotation of the motor to the shaft.
When the dust escape device Da is used to allow dust flowing from the upstream of the water channel C to flow into the water intake 4 to escape downstream of the water channel, the shaft 2 of each cylindrical member 3 of the screen Sa is driven by the drive mechanism at the time of water intake. Rotate with.

  At this time, the water flowing in from the water channel C passes between the discs 1 and 1 and flows into the intake channel side from the intake port 4, while flowing from the upstream side of the water channel C and entering the intake port 4. Is blocked by the disc 1 of the cylindrical member 3 of the screen Sa and pressed against the outer peripheral surface on the water channel C side by the water flowing into the water intake 4. The dust pressed against the outer peripheral surface of the cylindrical member 3 on the water channel C side is adjacent to the downstream side of the cylindrical member 3 where the dust adheres to the outer peripheral surface of the water channel side by the rotation of the cylindrical member 3. Then, they are sequentially transferred and escape from the most downstream cylindrical member 3 to the downstream of the water channel.

Japanese Patent Laid-Open No. 10-8439

By the way, in such a conventional trash relief device Da for a water intake of a water channel, the discs 1 of the respective cylindrical members 3 must be engaged with each other and all the cylindrical members 3 must be rotated. However, there is a problem that the manufacturing and installation of the apparatus are complicated.
In addition, when the dust adhered to the cylindrical member 3 of the screen Sa has a smooth surface such as a resin bag, the dust slides with respect to the cylindrical member 3 and the downstream cylindrical member. There is also a problem that it may not be possible to transfer to No. 3, and the garbage may not be allowed to escape downstream.

  The present invention has been made in view of the above problems, and provides a dust relief device for a water intake that simplifies the structure and reliably discharges dust that flows into the water intake downstream. The purpose is to do.

  In order to achieve such an object, a waste relief device for a water intake of the water channel of the present invention is provided at a water intake opening on the side surface of the water channel having a bottom surface and a pair of side surfaces erected on the bottom surface, In a waste relief device for a water intake of a water channel that allows waste flowing from the upstream of the water channel to flow into the water intake to the downstream of the water channel, it is rotatably provided on one side edge upstream of the water intake. A reticulated screen that is positioned at two positions, a closed position that closes the water intake by rotation and a protruding position that protrudes toward the water channel by rotation, and a drive mechanism that rotates the screen to the closed position and the protruding position. And has.

Therefore, when using the dust evacuation device for the water intake of this water channel, the screen provided at the water intake is made to stand by in the closed position.
At this time, a part of the water flowing from the upstream of the water channel flows into the water intake. And only water flows in between the wire meshes, while dust adheres to the screen.

Then, in the closed position, the drive mechanism is operated before dust accumulates to some extent on the screen and affects water intake.
When the drive mechanism is actuated, the screen is rotated about the upstream side edge of the water intake, and the screen is projected to the protruding position on the water channel side.
At this time, at the projecting position, the dust on the screen is separated from the water flow flowing into the water intake and exposed to the water flow flowing from the upstream to the downstream of the water channel. A part of the dust on the screen is released to the downstream of the water channel by the water flow flowing from the upstream to the downstream, and a part of the dust is pressed against the screen.

Next, the screen is rotated in the direction opposite to the original rotation so that the screen is located at the closed position.
At this time, the dust remaining on the screen is exposed to the water flow flowing from the upstream to the downstream of the water channel and is released to the downstream of the water channel.
Also, at this time, water flows relatively from the back surface of the screen to the front surface, and the force of water acts on the dust on the screen so as to move away from the screen. It becomes easy to be exposed to the flow of water flowing from the upstream to the downstream of the water channel, and is surely released to the downstream of the water channel.

  As a result, this device is a simple mechanism for opening and closing the screen, so that the structure can be simplified, and the drive mechanism allows the screen to be projected from the closed position to the projected position and then returned to the closed position. Since the adhering dust can be exposed to the flow of water flowing from the upstream to the downstream of the water channel, the dust that flows into the intake port can be surely released downstream. Further, the operation mechanism of the apparatus can be improved as much as the drive mechanism is stopped and driven when necessary until dust is collected on the screen to some extent.

In addition, if necessary, the screen is connected to the upstream main screen and the downstream edge of the main screen at the downstream edge of the main screen. It has the structure provided with the subscreen which covers between the side edges.
Even if the screen rotates and the space between the downstream edge of the main screen and the other edge of the downstream side of the intake port opens, the secondary screen covers this, so even if the screen is in the protruding position, Can be prevented from flowing into the water intake from this time.

Further, if necessary, the secondary screen upstream end edge is rotatably supported by the downstream downstream edge of the main screen, and the secondary screen is provided on the side surface of the water channel downstream from the other side edge of the intake port. A guide mechanism is provided for guiding the downstream end edge of the water channel so as to be movable along the side surface of the water channel.
Since the downstream edge of the slave screen is guided by the guide mechanism, the slave screen moves smoothly, the screen is easily positioned at the protruding position and the closed position, and dust can be surely released downstream.

  Furthermore, if necessary, the guide mechanism includes a roller provided at the downstream edge of the secondary screen and a rail provided on a side surface of the water channel on which the roller rolls. With a simple structure, the downstream edge of the slave screen can be reliably held movably on the side surface of the water channel, and dust can be prevented from flowing from the water intake.

Further, if necessary, the drive mechanism includes a rotation shaft to which an upstream end edge of the screen is fixed, a bearing provided at the water intake and rotatably supporting the rotation shaft, and a rotation shaft. It is set as the structure provided with the rotation part which rotates. The screen can be rotated with a simple structure. Further, the rotation shaft can be smoothly rotated, and accordingly, the screen can be easily moved to the protruding position or the closed position.
Moreover, the said rotation part is provided with the motor and the gear mechanism which transmits rotation of this motor to the said rotating shaft as needed. The structure can be simplified.

Furthermore, if necessary, when the lower edge of the water intake is higher than the bottom surface of the water channel and a step surface is formed between the lower edge and the bottom surface, the bottom edge of the screen is below the lower edge. A large number of rods substantially corresponding to the height of the stepped surface extending in a comb-like shape are arranged in a row. Since the rod is interposed between the screen and the bottom of the water channel even when the screen is moved between the closed position and the projecting position, even if the gap between the lower edge of the screen and the lower edge of the intake port is opened, this screen Garbage that tries to enter the water intake from the lower edge of the lens hits the rod and is prevented from entering.
And, if necessary, when the lower edge of the water intake is higher than the bottom surface of the water channel and a step surface is formed between the lower edge and the bottom surface, the lower end portion of the screen is on the water intake side. In the closed position, a packing that contacts the stepped surface is provided.
For this reason, in a closed position, packing can contact | abut to a level | step difference surface, while preventing inflow of the dust from the lower end edge side of a screen, a screen can be supported with respect to the water pressure of the water which flows into a water intake from a water channel. Further, when the screen is positioned from the protruding position to the closed position, the packing abuts against the lower step surface of the water intake and absorbs the impact generated on the screen.

  As described above, according to the waste relief device for a water intake of the water channel of the present invention, it is provided on the one side edge on the upstream side of the water intake so as to be rotatable, and the closed position and the rotation close the water intake by the rotation. Since the apparatus has a mesh-like screen positioned at two positions of the protruding position protruding toward the water channel side, and a drive mechanism for rotating the screen to the closed position and the protruding position, this apparatus can easily open and close the screen. Because of this mechanism, the structure can be simplified, and the drive mechanism allows the screen to move the screen from the closed position to the protruding position and then return it to the closed position. Because it can be exposed to the flow of water flowing through the trash, it is possible to reliably release the trash that will flow into the water intake to the downstream. In addition, it is only necessary to stop the drive mechanism and drive it when necessary until dust accumulates on the screen to some extent, so that the operation efficiency of the apparatus can be improved accordingly.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A detailed description will be given below of a debris escape device for a water intake according to the best mode for carrying out the present invention, with reference to the accompanying drawings.

FIGS. 1 to 4 show a dust relief device D1 for the intake of the water channel C. FIG.
For example, the waste relief device D1 for the intake of the water channel C is installed in the intake 12 that is open to the side surface 11 of the water channel C having the bottom surface 10 and a pair of side surfaces 11 standing on the bottom surface 10. The waste that flows from the upstream of the water channel C and tries to flow into the intake port 12 is released to the downstream of the water channel C. The lower edge 15 of the water intake 12 is formed at a position higher than the bottom surface 10 of the water channel C, and a step surface 16 is formed between the lower edge 15 of the water intake 12 and the bottom surface 10 of the water channel C.

More specifically, the waste relief device D1 for the intake port of the water channel C is provided at the one side edge 13 on the upstream side of the intake port 12 so as to be rotatable, and the closed position A for closing the intake port 12 by the rotation and the rotation. A net-like screen S that is positioned at two positions of the protruding position B that protrudes toward the water channel C, and a drive mechanism 40 that rotates the screen S to be positioned at the closed position A and the protruding position B are provided.
The screen S is connected to the upstream main screen 20 and the downstream end edge 25 of the main screen 20, and the downstream end 25 of the main screen 20 and the downstream side of the intake port 12 at the projecting position B of the screen S. And a sub-screen 21 covering between the other side edges 14.

The main screen 20 and the sub-screen 21 include an outer peripheral frame 22, a plurality of bar-shaped receiving members 22a installed on the frame 22 at equal intervals, and a wire mesh 23 supported by the frame 22 and the receiving member 22a. And is formed.
The main screen 20 covers between the one side edge 13 on the upstream side of the water intake 12 and the other side edge 14 on the downstream side at the closed position A of the screen S.
The sub-screen 21 is disposed so as to have the same plane as the main screen 20 at the closed position A of the screen S, and is provided so as to face the side surface 11 of the water channel C on the downstream side of the water intake 12. Yes. Furthermore, a shaft 26 that communicates the upstream edge 24 of the slave screen 21 and the downstream edge 25 of the main screen 20 is provided, and the slave screen 21 has the downstream edge of the main screen 20 around the shaft 26. 25 is rotatably supported.

Further, a guide mechanism 30 that guides the downstream edge 27 of the secondary screen 21 movably along the side surface 11 of the water channel C is provided on the side surface 11 of the water channel C downstream of the other side edge 14 of the intake port 12. It has been.
The guide mechanism 30 is provided with a pair of rollers 31 provided at the upper and lower ends of the downstream edge 27 of the slave screen 21 and a pair of rollers 31 provided on the side surface 11 of the water channel C corresponding to the rollers 31 and the rollers 31 roll. The rail 32 is provided.

Further, a large number of dust avoidance rods 28 extending downward from the lower edge 34 are arranged in a comb-like shape on the lower edge 34 of the screen S.
Further, at the closed position A, the screen S abuts on the step surface 16 below the intake port 12 at the closed position A on the lower end portion 34a of the main screen 20 and the secondary screen 21. A packing 29 that prevents the inflow of dust from the lower end edge 34 side and supports the screen S against the water pressure of water flowing from the water channel C to the water intake 12 is provided. The packing 29 is formed of a rubber plate, for example, and has a certain degree of elasticity.

The drive mechanism 40 includes a rotation shaft 41 to which the upstream edge 33 of the main screen 20 is fixed, a bearing 42 provided at the water intake 12 and rotatably supporting the rotation shaft 41, and the rotation shaft 41. The rotating part 43 to rotate is provided.
A pair of bearings 42 are provided on one side edge 13 on the upstream side of the water intake 12 in the vertical direction.
The rotating part 43 is provided on the upper side of the one side edge 13 on the upstream side of the water intake port 12, and a motor 44 capable of rotating forward and reverse, and the rotation of the motor 44 on the rotating shaft 41. The gear mechanism 45 which transmits is comprised.

The gear mechanism 45 includes a worm 46 provided on the rotation shaft 41 of the motor 44 and a worm wheel 47 provided on the rotation shaft 41 coaxially with the rotation shaft 41.
In addition, the rotating part 43 is provided with a handle 48 for releasing the transmission of the motor 44 and rotating the rotating shaft 41. It is also possible to turn the turning shaft 41 by manually turning the handle 48.

When the screen S is projected from the closed position A to the projecting position B, the rotation shaft 41 is rotated by a predetermined angle via the gear mechanism 45 by the normal rotation of the motor 44 or the handle 48 of the rotation unit 43. To do.
Further, when the screen S is retracted from the protruding position B to the closed position A, the rotation direction of the rotating shaft 41 is reversed via the gear mechanism 45 by the reverse rotation of the motor 44 or the handle 48, and the protruding position B It is performed by rotating it by a predetermined angle in the direction opposite to the direction of rotation rotated.
Thus, in order to position the screen S at the two positions of the closed position A and the protruding position B, the rotating shaft 41 can be rotated by rotating the motor 44 of the rotating portion 43 forward and backward, and the structure is simple. Become.

Further, the intake port dust escape device D1 for the water channel C is provided with a control mechanism 50 for controlling the drive mechanism 40. The control mechanism 50 includes, for example, a water channel detection sensor (not shown) that detects the water level of the water channel C, and an intake water level detection sensor (not shown) that detects the water level of the intake channel extending from the intake port 12. Is provided. Then, the control mechanism compares the water level detected by the water channel water level detection sensor with the water level of the water intake channel detected by the water channel water level detection sensor, and the water level of the water intake channel is different from the water level of the water channel C by a predetermined difference. When it is lowered, the drive mechanism 40 is operated.
Furthermore, the control mechanism 50 is provided with a flow velocity detection sensor (not shown) that detects the flow velocity Va of the water flowing through the water intake 12. Then, based on the detection result of the flow rate detection sensor, the control mechanism rotates the motor 44 so that the moving speed Vb of the upstream edge of the screen S is faster than the water flow rate Va of the water intake 12. Switching means for varying the speed is provided.

Accordingly, when using the water intake dust removal device D1 for the water channel C, first, the water intake dust discharge device D1 for the water channel C is first installed in the water intake port 12 of the water channel C, as shown in FIG. As described above, the screen S is kept waiting at the closed position A.
At this time, a part of the water flowing from the upstream of the water channel C flows into the water intake 12. And while only water flows in through the wire mesh 23 from the water intake 12, the flow of dust is stopped on the screen S and is pushed onto the screen S and attached by the flow of water flowing into the water intake 12. .

Specifically, at the closed position A, the water intake 12 is covered with the main screen 20, so that dust adheres to the main screen 20. When a large amount of dust adheres to the main screen 20, the amount of water flowing into the intake channel from the intake port 12 decreases, and the water level of the intake channel gradually becomes lower than the water level of the water channel C.
When the water level in the intake channel becomes lower than the water level in the water channel C by a predetermined difference, this is detected by the water channel level detection sensor and the intake channel level detection sensor of the control mechanism 50, and the control mechanism 50 operates the drive mechanism 40.

When the drive mechanism 40 is actuated, as shown in FIG. 4B, the motor 44 of the pivot part 43 is actuated to rotate the pivot shaft 41 by a predetermined angle (about 15 ° in this embodiment). The downstream edge 25 of the main screen 20 protrudes toward the water channel C, and the screen S is positioned at the protruding position B. At this time, the upstream side edge 24 of the secondary screen 21 moves to the center side of the water channel C, and the roller 31 provided on the downstream side edge 27 of the secondary screen 21 moves on the rail 32, and the downstream side of the secondary screen 21. The side edge 27 moves on the side surface 11 of the water channel C.
At this time, the rotation shaft 41 is provided with a bearing 42, and the downstream edge 27 of the slave screen 21 is smoothly moved by the roller 31 and the rail 32, so that the screen S is easily moved to the protruding position B. .

  At this time, the dust on the main screen 20 is exposed to the water flow flowing from the upstream to the downstream of the water channel C, and a part of the dust on the main screen 20 is released downstream of the water channel C. Further, since the secondary screen 21 covers the space between the downstream edge 25 of the main screen 20 and the downstream other edge 14 of the water intake port 12, the screen S is located at the protruding position B, and Even if there is a gap between the downstream end edge 25 and the other side edge 14 on the downstream side of the intake port 12, dust flowing into the intake port 12 from this interval can be blocked by the secondary screen 21.

Next, as shown in FIG. 4C, the rotation shaft 41 is rotated in the direction opposite to the initial rotation so that the screen S is positioned at the closed position A.
At this time, in the protruding position B, some of the dust remaining on the main screen 20 is pressed against the main screen 20 by the flow of water flowing from the upstream to the downstream in the water channel C. In the process of moving and returning the main screen 20 to the closed position A, the main screen 20 is exposed to the water flow in the water channel C and is released downstream of the water channel C.

Further, at this time, water flows relatively from the back surface to the front surface of the screen S, and the water force acts on the dust on the main screen 20 so as to be separated from the screen S. Is easily exposed to the flow of water that is separated from the screen S and flows from the upstream to the downstream of the water channel C, and dust can be easily released downstream of the water channel C.
Furthermore, since the rotational speed of the rotational shaft 41 is controlled so that the moving speed Vb of the upstream side edge 33 of the main screen 20 is faster than the flow speed Va of the water in the water channel C, the screen S applied to dust. The force of water in the direction away from the water channel becomes relatively large and can be easily put on the flow of water flowing from the upstream to the downstream of the water channel C. Therefore, dust can be easily released downstream of the water channel C.

Further, while the screen S moves to the two positions of the closed position A and the protruding position B, even if the packing 29 at the lower end of the screen S is separated from the lower step surface 16 of the water intake 12, the screen S and the water channel C. By the dust avoidance rod 28 provided in the gap between the bottom surface 10 and the bottom surface 10, it is possible to prevent the dust from entering the water intake 12 from the lower edge of the screen S.
When the screen S is located at the closed position A, the packing 29 provided at the lower end of the screen S comes into contact with the stepped surface 16 on the lower side of the water intake 12. For this reason, the impact which arises in the screen S when closing is absorbed.
Thereafter, the screen S is kept in the closed position A until the water level in the intake channel becomes lower than the water level in the water channel C by a predetermined difference. When the screen S becomes lower by the predetermined difference again, the drive mechanism 40 is operated to turn the rotating shaft 41. Rotate.

Next, FIGS. 5 to 7 show a dust relief device D2 for water intakes of a water channel C according to another best mode for carrying out the present invention.
The water inlet dust relief device D2 of the water channel C has substantially the same configuration as the water inlet dust relief device D1 of the water channel C, but unlike the above, the downstream edge 25 of the main screen 20 In the closed position A, the width is formed so as to be located in the middle of the water intake 12. Also, the sub-screen 21 is different from the above in the closed position A of the screen S, from the downstream edge 25 (middle of the water intake 12) of the main screen 20 to the downstream side of the downstream side edge 14 of the water intake 12. It is extended to. In the closed position A of the screen S, the water intake 12 is covered with the main screen 20 and the half on the upstream side of the sub-screen 21. Other than this, the configuration is the same as described above.

  As shown in FIG. 7 (a), when using this water channel C intake trash relief device D2, in advance, the water channel C intake trash relief device for the water channel C water intake trash relief device D2 is used. Install D2. Normally, the screen S is kept waiting at the closed position A, and only dust of water flowing into the intake channel is attached to the screen S. Then, when a predetermined difference occurs between the water level in the intake channel and the water level in the water channel C, the water level detection sensor and the intake channel level detection sensor of the control mechanism detect this, and the control mechanism activates the drive mechanism 40.

When the drive mechanism 40 is actuated, as shown in FIG. 7B, the motor 44 of the drive unit is rotated to rotate the rotation shaft 41 by a predetermined angle (about 60 ° in this embodiment). When the screen S reaches the protruding position B, the rotation of the rotation shaft 41 is stopped.
At this time, the flow of water from the upstream side to the downstream side of the water channel C passes through the secondary screen 21 from the back surface side of the secondary screen 21, so that the dust on the secondary screen 21 is separated from the secondary screen 21 to the water channel C. To the downstream. Part of the dust on the main screen 20 is caused to flow downstream by the flow of water flowing from the upstream to the downstream in the water channel C, and part of the dust is pressed against the main screen 20.

Next, as shown in FIG. 7C, the rotation shaft 41 is rotated in the direction opposite to the initial rotation so that the screen S is positioned at the closed position A.
When the screen S returns to the closed position A, the dust pressed against the main screen 20 is exposed to the water flow in the water channel C and is released to the downstream of the water channel C.
Other actions and effects are the same as those described above.

It is a top view which shows the refuse escape device for water intakes of the waterway which concerns on embodiment of this invention. It is a front view which shows the refuse escape device for water intakes of the waterway which concerns on embodiment of this invention. It is side surface sectional drawing which shows the dust escape device for water intakes of the waterway which concerns on embodiment of this invention. It is a figure which shows the effect | action of the dust escape device for water intakes of the water channel which concerns on embodiment of this invention, (a) is a closed position of a screen, (b) is a protrusion position of a screen, (c) is a screen protrusion. It is a figure which shows each state which returned to the closed position from the position, respectively. It is a top view which shows the garbage escape device for water intakes of the waterway which concerns on another embodiment of this invention. It is a front view which shows the refuse escape device for water intakes of the waterway which concerns on another embodiment of this invention. It is a figure which shows the effect | action of the dust escape device for intakes of the waterway which concerns on another embodiment of this invention, Comprising: (a) is a closed position of a screen, (b) is a protrusion position of a screen, (c) is a screen. It is a figure which shows each state which returned from the protrusion position to the closed position, respectively. It is a figure which shows an example of the conventional dust escape device for water intakes of a water channel.

Explanation of symbols

C Drainage D1 and D2 Dust relief device for water intake S Screen Va Water flow velocity Vb Screen moving speed A Closed position B Projected position 10 Bottom surface 11 Side surface 12 Water intake 13 One side edge of water intake 14 Other side edge 15 Lower edge 16 of intake port Step surface 20 Main screen 21 Subscreen 22 Frame 22a Receiving member 23 Metal mesh 24 Upper end edge of subscreen 25 Downstream end edge 26 of main screen Shaft 27 Downstream side of subscreen End edge 28 Dust avoiding rod 29 Packing 30 Guide mechanism 31 Roller 32 Rail 33 Upstream end edge 40 Drive mechanism 41 Rotating shaft 42 Bearing 43 Rotating portion 44 Motor 45 Gear mechanism 46 Worm 47 Worm wheel 48 Handle 50 Control mechanism

Claims (8)

A bottom surface and a water intake having a pair of side surfaces erected on the bottom surface are provided in a water intake opening on the side surface, and waste flowing from the upstream of the water channel and flowing into the water intake is disposed downstream of the water channel. In the trash relief device for the intake of the waterway to escape,
A net-like screen that is rotatably provided at one side edge on the upstream side of the water intake port and is positioned at two positions, a closed position that closes the water intake port by rotation and a projecting position that protrudes to the water channel side by rotation; A dust relief device for a water intake, comprising a drive mechanism for rotating the screen to the closed position and the protruding position.   The screen is connected to the upstream main screen and the downstream edge of the main screen, and covers the downstream edge of the main screen and the downstream edge of the intake port at the protruding position. 2. A dust escape device for a water intake according to claim 1, further comprising a secondary screen.   An upstream edge of the secondary screen is rotatably supported by a downstream edge of the primary screen, and a downstream edge of the secondary screen is disposed on the side surface of the water channel downstream from the other edge of the intake port. 3. A dust escape device for a water intake according to claim 2, further comprising a guide mechanism that guides the water channel so as to be movable along a side surface of the water channel.   4. The water channel according to claim 3, wherein the guide mechanism comprises a roller provided at a downstream edge of the secondary screen, and a rail provided on a side surface of the water channel on which the roller rolls. Waste relief device for water intake   The drive mechanism includes a rotation shaft to which an upstream edge of the screen is fixed, a bearing provided at the water intake port to rotatably support the rotation shaft, and a rotation unit that rotates the rotation shaft. The waste relief device for a water intake of a water channel according to claim 1, 2, 3, or 4, characterized by comprising:   6. The dust escape device for a water intake according to claim 5, wherein the rotating part comprises a motor and a gear mechanism for transmitting the rotation of the motor to the rotating shaft.   In the case where the lower edge of the water intake is higher than the bottom surface of the water channel and a step surface is formed between the lower edge and the bottom surface, the lower surface edge of the screen has the step surface extending downward from the lower edge. 7. A dust relief device for a water intake according to claim 1, wherein a plurality of rods substantially corresponding to the height are arranged in a comb shape.   When the lower edge of the water intake is higher than the bottom surface of the water channel and a step surface is formed between the lower edge and the bottom surface, the step at the closed position on the water intake side of the lower end of the screen. 8. A dust relief device for a water intake of a water channel according to claim 1, further comprising a packing abutting against the surface.

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