JP4644171B2 - Flap gate structure - Google Patents

Description

  The present invention relates to a structure of a flap gate installed in a sewer or the like.

  In the combined sewer system, during heavy rain, sewage up to a certain amount of sewage in fine weather is led to a sewage treatment plant. Measures are taken. FIG. 5 is an explanatory view showing an example of the structure of the rainwater discharge chamber, where (a) is an explanatory plan view of the rainwater discharge chamber, and (b) is a sectional view taken along the line CC in (a). Normally, sewage flows from the junction pipe 32 through the rainwater discharge chamber 31 to the sewage outflow pipe 33 as indicated by the white arrow. The sewage outflow pipe 33 is connected to the sewage treatment plant. During heavy rain, as shown by the black arrows, sewage overflows from the overflow crest 34 and flows into the discharge pipe 35. The downstream end of the discharge pipe 35 leads to a river or the like. In addition, a bar screen 36 is appropriately installed for the purpose of removing the sewage residue after overflow. In FIG. 5, the bar screen 36 is installed in the rainwater discharge chamber 31, but may be installed in another chamber provided in the middle of the discharge pipe 35.

A flap gate is installed around the discharge outlet chamber (spout chamber 37) facing the river or the like to prevent the backflow of water from the river or the like. 6A and 6B are explanatory views showing an example of the structure of a conventional flap gate. FIG. 6A is a front explanatory view, and FIG. 6B is a side explanatory view. The sewage that has flowed into the discharge pipe 35 shown in FIG. 5 flows into the discharge chamber 37 through the discharge passage 38 and is discharged into a river or the like. The upper end of the flap gate 39 is rotatably attached around the support shaft 40 attached to the facility housing, and is normally positioned vertically by its own weight as shown by a solid line in FIG. 6B. The outlet of the discharge passage 38 is blocked. When there is a reverse flow of water from a river or the like, the sealing member 41 is pressed around the outlet of the discharge passage 38 by receiving the water pressure, and the watertight performance of the flap gate 39 is exhibited. Then, during heavy rain or the like, the sewage flowing through the discharge passage 38 opens and opens the flap gate 39 as indicated by the phantom line in FIG. 6B by the water pressure, and flows into the discharge chamber 37. As another conventional example of the flap gate 39, there is one provided with an actuator opening and closing device (see, for example, Patent Document 1).
Registered Utility Model No. 3011165

  The flap gate 39 is required to have a structure that can withstand a large reverse water pressure from a river or the like. Therefore, a reinforcing rib 39b such as a grooved steel is fixed to the steel plate 39a by welding or the like. However, the structure requiring the rib 39b has problems that the manufacturing cost of the flap gate 39 is high and the weight is greatly increased, so that it is difficult to handle it during transportation to the construction site or during installation. In addition, since the weight increases, for example, when sewage flows from the discharge passage 38, there is a restriction that it does not open unless a large water pressure is applied. In this case, a separate actuator opening / closing device or the like is provided. Measures may be taken, such as a structure that opens automatically.

  The present invention was created to solve the above-described problems, and provides a flap gate structure that can be manufactured at a low cost and easy to handle during transportation to and installation at the construction site. It is an object.

  In order to solve the above problems, the present invention is a structure of a flap gate for preventing backflow, the upper end of which is supported so as to be rotatable around a horizontal gate spindle, and a bar screen for catching residue is used as a water channel. When the flap gate is installed and subjected to water pressure due to the backflow, the plate member constituting the flap gate closes the opening portion of the bar screen in a state of being in contact with the downstream end face of each bar of the bar screen. The flap gate structure is characterized by the configuration.

  According to this flap gate structure, the plate member constituting the flap gate is in contact with the downstream end faces of the plurality of bars, so that the force due to the water pressure applied to the flap gate is distributed to the plurality of bars during reverse flow. Can effectively escape. Accordingly, for example, the flap gate can be constituted by only a single plate member without taking any special reinforcement measures for the flap gate.

  In the present invention, the bar screen is supported such that the upper end thereof is rotatable about a horizontal screen support shaft, the flap gate and the bar screen are connected by a connecting member, and the flap gate is in a normal flow state. When the flap gate starts to open and reaches a predetermined opening position, the flap gate opens while rotating the bar screen through the connecting member. The flap gate structure is characterized in that it has a different structure.

  According to this flap gate structure, a large amount of water can be discharged as an emergency when the water level rises abnormally with a simple structure.

  Moreover, in this invention, it was set as the structure of the flap gate characterized by installing the said flap gate and the bar screen in the upper part of the overflow dam of the rainwater discharge chamber in a combined sewer.

  According to the structure of this flap gate, the installation work of the flap gate in the combined sewer becomes easy.

  According to the present invention, the manufacturing cost of the flap gate is reduced, and handling of the flap gate during transportation to the construction site or attachment becomes easy.

  Hereinafter, the case where the flap gate to which the present invention is applied is installed in a rainwater discharge chamber of a combined sewer will be described. FIGS. 1 and 2 are a side view and a plan view, respectively, showing a rainwater discharge chamber and a flap gate to which the present invention is applied, and FIGS. 3 and 4 are diagrams for explaining the operation of the flap gate to which the present invention is applied. FIG.

  1 and 2, sewage flows from the merging passage 2 through the rainwater discharge chamber 1 to the sewage outflow passage 3 at a normal water level. The sewage outflow passage 3 leads to a sewage treatment plant. When the water level rises from the upper end of the overflow overflow 4 during heavy rain or the like, the flap gate 11 is opened by the water pressure, and the sewage flows into the discharge passage 5. The downstream end of the discharge passage 5 leads to a river or the like.

  In the present invention, when a bar screen 21 for catching residue is installed in a water channel and the flap gate 11 receives water pressure due to a backflow, the plate member constituting the flap gate 11 is provided downstream of each bar 22 of the bar screen 21. The main feature is that the opening portion 23 (FIG. 4) of the bar screen 21 is closed while being in contact with the side end face 22a.

  The bar screen 21 of the present embodiment is a so-called vertical pulling type screen in which a plurality of bars 22 are vertically arranged in parallel in the channel width direction. As shown in FIG. 4, each bar 22 is made of a flat member and is connected to each other by a connecting rod 24. As can be seen from FIG. 1, it is installed in an inclined shape so that the upper part is located upstream.

  A screen support shaft 26 is stretched horizontally between opposing side walls of the rainwater discharge chamber 1, and a cylindrical member 25 fixed over the upper end of each bar 22 is rotatably fitted to the screen support shaft 26. ing. That is, the bar screen 21 has a structure in which the upper end is supported so as to be rotatable around the screen support shaft 26 in the horizontal direction. Normally, the lower end of the bar screen 21 is in contact with the stepped side wall 4 a formed on the upper portion of the overflow dam 4 due to the weight of the bar screen 21.

  The upper end of the flap gate 11 is supported so as to be rotatable around the gate support shaft 12 in the horizontal direction. In the present embodiment, the hinge 13 is attached over the upper end of the flap gate 11 and the cylindrical member 25, and the rotation axis of the hinge 13 is used as the gate support shaft 12. The flap gate 11 is composed of a rectangular plate member, for example, a stainless steel plate. When the flap gate 11 is closed, the plate surface of the flap gate 11 is in contact with the downstream end face 22 a of each bar 22.

  In order to ensure the watertightness between the flap gate 11 and the bar screen 21 when the flap gate 11 is closed and subjected to water pressure due to the reverse flow, as shown in FIG. 27 is fixed, and on the side of the flap gate 11, a sealing member 14 made of a rubber material or the like is fixed over the entire four sides of the outer edge so as to be in close contact with the backing plate 27.

  Further, the flap gate 11 and the bar screen 21 are connected by a connecting member 15. The connecting member 15 is a member that connects the two while allowing the flap gate 11 to rotate relative to the bar screen 21, and a preferred example is a chain. The connecting member 15 has a function of transmitting the rotational force of the flap gate 11 to the bar screen 21 side after the flap gate 11 reaches a predetermined opening position.

  The operation of the present invention will be described. Normally, as shown in FIG. 1, the lower end of the bar screen 21 is in contact with the stepped side wall 4a of the overflow basin 4 due to its own weight, and the flap gate 11 is closed by its own weight. The plate surface of the gate 11 is in contact with the downstream end surface 22 a of each bar 22 of the bar screen 21. Therefore, even when the flap gate 11 receives water pressure due to the backflow from the river or the like, the plate of the bar screen 21 is opened with the plate member constituting the flap gate 11 in contact with the downstream end face 22a of each bar 22. The part 23 (FIG. 4) is closed.

  In contrast to the problem of water pressure due to backflow, the conventional flap gate structure requires a reinforcing rib, whereas in the present invention, the plate members constituting the flap gate 11 are connected to the downstream end faces 22a of the plurality of bars 22. Therefore, the force generated by the water pressure applied to the flap gate 11 can be dispersed to the plurality of bars 22 and effectively released. Thereby, the flap gate 11 can be comprised only from a single board | plate member, without taking special reinforcement measures to the flap gate 11. FIG. Therefore, the manufacturing cost of the flap gate 11 becomes low, and handling of the flap gate 11 at the time of conveyance to a construction site or attachment becomes easy.

  Next, a description will be given of a case where the amount of water from the merging passage 2 increases due to heavy rain or the like and the water level rises above the upper end of the overflow dam 4 during normal flow. When the rain water level is reached, the water pressure is applied to the plate surface of the flap gate 11 via the opening 23 (FIG. 4) of the bar screen 21, and when the flap gate 11 receives a water pressure higher than a predetermined value, first, FIG. As shown in (b), the flap gate 11 is pushed up and opened by the sewage. When the flap gate 11 reaches a predetermined opening position, the chain constituting the connecting member 15 is fully extended, and thereafter, the flap gate 11 passes through the chain as shown in FIG. The bar screen 21 is opened while being lifted and rotated.

  Since the lower end of the bar screen 21 is lifted up, of course, a part of the sewage residue in the sewage flows out of the gap between the lower end of the bar screen 21 and the upper end of the overflow dam 4 without being captured by the bar screen 21. Become. In this structure, when the flap gate 11 is subjected to water pressure that can pull up the bar screen 21, that is, when the water level rises abnormally, each bar 22 of the bar screen 21 is also a resistor against the water flow. Therefore, this is effective when it is desired to flow a large amount of sewage to the river without passing through the bar screen 21.

  When the bar screen 21 is closed, the edge of the bar screen 21 is in contact with a door stop (not shown) formed on the housing side of the rainwater discharge chamber 1. In order to ensure watertightness with the door stop, a seal member made of a rubber material or the like similar to the seal member 14 is fixed to the edge of the bar screen 21.

  The preferred embodiments of the present invention have been described above. The present invention is not limited to the embodiment described above, and can be modified as appropriate without departing from the spirit of the present invention. For example, although the bar screen 21 is movable in the described embodiment, it may be fixed. Further, when the bar screen 21 is rotated, an opening / closing device such as an actuator may be separately provided.

  In addition to the chain, the connecting member 15 may be a link arm that is normally folded and extends when the flap gate 11 is opened. Further, the bar screen 21 may be a so-called horizontal pulling type screen in which the bars 22 are arranged side by side in the vertical direction. Further, the bar screen 21 may be provided with a raking device. Moreover, this invention is applicable also to a river, an industrial waterway, etc. besides a sewer.

It is side explanatory drawing which shows a rainwater discharge chamber and the flap gate to which this invention is applied. It is plane explanatory drawing which shows a rainwater discharge chamber and the flap gate to which this invention is applied. It is operation | movement explanatory drawing of the flap gate to which this invention is applied. It is an external appearance perspective view of the flap gate to which this invention is applied. It is explanatory drawing which shows one structural example of a rainwater discharge chamber. It is explanatory drawing which shows one structural example of the conventional flap gate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rain water discharge chamber 4 Overflow cough 11 Flap gate 12 Gate spindle 15 Connecting member 21 Bar screen 22 Bar 22a Downstream end face 23 Opening part 26 Screen spindle

Claims (3)

It is a structure of a flap gate for preventing backflow, the upper end of which is supported so as to be rotatable around a horizontal gate spindle,
Install a bar screen in the water channel to catch the residue
When the flap gate receives water pressure due to the reverse flow, the plate member constituting the flap gate is configured to close the opening portion of the bar screen in a state of being in contact with the downstream end face of each bar of the bar screen. A flap gate structure characterized by that. The bar screen is supported such that the upper end thereof is rotatable around a horizontal screen support shaft,
The flap gate and the bar screen are connected by a connecting member,
When the flap gate receives a water pressure of a predetermined value or more during normal flow, the flap gate starts to open first and reaches a predetermined opening position. After that, the flap gate is connected to the bar screen via the connecting member. 2. The flap gate structure according to claim 1, wherein the flap gate is opened while being pivoted.   The structure of the flap gate according to claim 1 or 2, wherein the flap gate and the bar screen are installed on the upper part of the overflow basin of the rainwater discharge chamber in the combined sewer system.

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