Non-powered flap gate

Abstract

To provide a non-powered flap gate which prevents sedimentation and flooding of the rear area, does not cause the action of a weight to become a load factor in the opening and closing operation of a gate body, and is excellent in safety, economy and ease of construction. [Solution] In a non-powered flap gate, a door body 1 rotates around a connecting shaft 2 at the top as a hinge, and is equipped with a weight 3 that assists the opening and closing operation. Due to the eccentricity of the rotation axis C of the door body 1, when the weight 3 is not acting, the door body 1 is in a slightly open state, a convex portion 6 with a fan-shaped cross section is provided at the end of the connecting shaft 2, and a fan-shaped recessed portion 7 with a larger central angle than the convex portion 6 is provided inside the shaft fitting portion 5 on the weight 3 side, the convex portion 6 is loosely fitted into the recessed portion 7, and the weight 3 functions by the engagement between the convex portion 6 and the recessed portion 7, and when the convex portion 6 and the recessed portion 7 are not engaged during the opening and closing operation of the door body 1, the weight 3 does not become a load factor in the opening and closing operation of the door body 1. In this way, the weight 3 acts as a cam-type weight.

Description

[Technical Field]

[0001] This invention relates to a non-powered flap gate that is installed at a sluice gate and discharges water from a drainage channel into a river under normal conditions, but prevents backflow from the river into the drainage channel when the river floods. [Background technology]

[0002] At sluice gates that cross levees via culverts at the points where drainage channels join rivers, non-powered flap gates are sometimes installed, in which the gate body rotates on a hinged axis at the top, opening and closing automatically in response to changes in the water level. Under normal circumstances, the gate body opens slightly to discharge water from the drainage channel into the river, but in times of flooding, it prevents backflow from the river into the drainage channel. These flap gates are equipped with weights that assist the opening and closing action of the gate body (see Patent Documents 1 and 2 below). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-96122 [Patent Document 2] Japanese Patent Publication No. 2022-1698 Summary of the Invention [Problem to be solved by the invention]

[0004] Such non-powered flap gates have the major advantage of being unmanned and not requiring an operator, but they have issues with preventing sediment buildup and flooding of the rear area. Also, the action of the weight can become a load factor depending on the opening and closing stage of the gate body.

[0005] In addition to safety, other issues include the economics of installation, such as the cost of removing and dismantling the current equipment, and the feasibility of large-scale construction.

[0006] Therefore, the objective of this invention is to provide a non-powered flap gate that prevents sediment accumulation and flooding of the land behind it, does not cause the weight to become a load factor in the opening and closing operation of the gate body, and is therefore safe, economical, and easy to install. [Means for solving the problem]

[0007] In order to solve the above problems, this invention is a non-powered flap gate that is installed at a sluice gate where a drainage channel joins a river, and the gate body rotates around the upper connecting shaft as a hinge depending on the water level difference between the outside water level on the river side and the inside water level on the drainage channel side, and the gate body is equipped with a weight to assist its opening and closing operation. The rotation axis of the door body, which is the axis of the connecting shaft, is located forward, toward the river, from the center of gravity of the door body when the door body is in a fully closed state, and when the weight is not acting, the door body is in a slightly open state. An end of a connecting shaft that rotates integrally with the door body is fitted into a shaft hole of a shaft fitting portion on the base side of the weight so as to be relatively rotatable, A convex portion having a sectorial cross section centered on the rotation axis of the door body is provided at the end of the connecting shaft, and a sectorial recess having a larger central angle than the convex portion on the connecting shaft is provided inside the shaft hole on the weight side, and the convex portion on the connecting shaft is loosely fitted into the recess on the weight side, and the weight functions by the engagement between the convex portion and the recess, From the state in which the weight is not acting, until the inner water level rises by a predetermined level above the outer water level, the convex portion and the concave portion do not engage so that the weight does not become a load for rotating the door body in the opening direction, In addition, when the outer water level rises while the inner water level is low, the convex portion and the concave portion are equipped with a cam-type weight that does not engage with each other so that the weight does not become a load on the door body to rotate in the closing direction until the outer water level rises to a predetermined level (Configuration 1).

[0008] In addition, the non-powered flap gate of configuration 1 is equipped with a warning light that lights up to alert people in the surrounding area when the door body is closed (configuration 2).

[0009] In addition, in the non-powered flap gate of configuration 2, the warning lights are illuminated using electricity generated by a solar panel (configuration 3).

[0010] In addition, in the non-powered flap gate of any of configurations 1 to 3, a gate groove for corner dropping is provided upstream of the gate body in the drainage channel (configuration 4).

[0011] Alternatively, in the non-powered flap gate of any of configurations 1 to 3, the gate body is provided on the river side of an existing gate that cannot be operated unmanned (configuration 5). [Effects of the Invention]

[0012] In the non-powered flap gate of this invention, due to the eccentricity of the rotation axis relative to the center of gravity of the gate body, the gate body remains slightly open when the weight is not acting, so that inland water is expelled without accumulating in the drainage channel, reducing the risk of sediment accumulation causing problems with opening and closing the gate body or flooding the land behind it.

[0013] In addition, the convex portion on the connecting shaft, which forms the axis of rotation of the door body, is loosely fitted into the concave portion on the weight side, and the weight functions by engaging the convex portion with the concave portion, so the weight's function as an auxiliary power source does not become a load factor on the opening and closing operation of the door body.

[0014] Furthermore, if a warning light is installed that lights up using solar panel power when the gate is closed, people near the gate will be able to sense danger even if there is no external power supply in the event of a flood, thereby improving safety.

[0015] Furthermore, in order to respond to emergencies such as malfunction of the gate body, if a new gate is being constructed or an existing gate is being replaced, a gate groove for corner cutting can be installed, and if the existing gate is to be left in place, the existing gate can be utilized, making installation economical and enabling large-scale construction. [Brief explanation of the drawings]

[0016] [Figure 1] Installation structure diagram for new or replacement installation of the non-powered flap gate related to this invention [Figure 2] Installation structure diagram for adding the above non-powered flap gate while leaving the existing gate in place [Figure 3] Front view of the non-powered flap gate [Figure 4] FIG. 10 is a side view showing the outline of the operation of the same; [Figure 5] FIG. 10 is a side view showing the positional relationship between the center of gravity of the door body and the rotation axis of the same; [Figure 6] (a) is a cross-sectional view of the connecting shaft side and (b) is a cross-sectional view of the weight side of the connecting shaft side. [Figure 7] FIG. 10 is a schematic side view showing the opening and closing operation of the door body and the operating state of the weight; DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

[0018] This non-powered flap gate 11 is installed at a sluice gate that crosses a levee at the point where a drainage channel joins a river via a culvert. Figure 1 shows a schematic example of the installation structure when this non-powered flap gate 11 is installed as a new construction or replacement, and Figure 2 shows a schematic example of the installation structure when an existing gate 21 is left in place and an additional gate is installed.

[0019] As shown in Figures 3 and 4, the gate body 1 of this non-powered flap gate 11 rotates using the upper connecting shaft 2 as a hinge depending on the water level difference between the outside water level on the river side and the inside water level on the drainage channel side, and is equipped with two weights 3 on both sides above to assist the opening and closing operation.

[0020] The door body 1 rotates integrally with the connecting shaft 2 and is supported on the upper frame of the sluice gate by a hanging bracket 4. The end of the connecting shaft 2 is fitted into the shaft hole of the shaft fitting portion 5 on the base side of the weight 3 so as to be able to rotate relative to the shaft.

[0021] The rotation axis C of the door body 1, which is the axis of the connecting shaft 2, is located forward, towards the river, from the center of gravity G of the door body 1 when the door body 1 is fully closed. As shown in Figure 5, when the weight 3 is located directly above the rotation axis C of the door body 1 and does not act, the door body 1 is in a slightly open state.

[0022] This allows inland water to be removed without accumulating in the drainage channel, reducing the risk of sediment accumulation causing problems with opening and closing the gate body 1 or flooding the land behind it.

[0023] As shown in Figure 6(a), the end of the connecting shaft 2 is provided with a convex portion 6 having a sectorial cross section centered on the rotation axis C of the door body 1. Meanwhile, as shown in Figure 6(b), a sectorial recess 7 having a larger central angle than the convex portion 6 on the connecting shaft 2 is provided inside the shaft hole of the shaft fitting portion 5 on the weight 3 side. The convex portion 6 is loosely fitted into the recess 7, and the weight 3 functions through the engagement between the convex portion 6 and the recess 7. The weight 3 is attached to an engagement structure in which the convex portion 6 is loosely fitted into the recess 7 in this way, and is called a cam-type weight.

[0024] The position of the weight 3 from the rotation axis C can be adjusted by loosening the lock nut 8, so that the auxiliary force for the opening and closing operation can be set appropriately after the door body 1 is installed.

[0025] In a non-powered flap gate 11 having such a structure, when there is no difference between the inside water level and the outside water level, as shown in Figure 7(I), the convex portion 6 engages with one end face of the concave portion 7, causing the weight 3 to function, closing the door body 1 and pressing it against the watertight surface.

[0026] Also, as shown in Figure 7 (II), when the internal water level starts to rise while the external water level is low, the gate body 1 starts to open, and the weight 3 is positioned directly above the rotation axis C of the gate body 1, and the weight 3 is in a non-operating state. During this process, the weight 3 acts as a load against the rotation of the gate body 1 in the opening direction, but because the gate body 1 is eccentric as described above, the opening operation does not become heavy.

[0027] Subsequently, as the internal water level rises and the opening operation of the door body 1 progresses, the convex portion 6 and the concave portion 7 do not engage so that the weight 3 does not become a load on the door body 1 as it rotates in the opening direction, and the door body 1 rotates in the opening direction without receiving resistance from the weight 3.

[0028] Then, when the internal water level rises by a predetermined level relative to the external water level, the convex portion 6 engages with the other end face of the concave portion 7, as shown in Figure 7(III), and the weight 3 assists the movement of the door body 1 in the opening direction as it tilts, so that the door body 1 opens quickly and reliably, and when the internal water level rises further, the door body 1 becomes fully open, as shown in Figure 7(IV).

[0029] On the other hand, as shown in Figure 7(V) or (VI), when the inside water level is low and the outside water level rises, the convex portion 6 and the concave portion 7 do not engage so that the weight 3 does not become a load on the door body 1 to rotate in the closing direction until the outside water level rises to a predetermined level, and the door body 1 rotates in the closing direction without receiving resistance from the weight 3.

[0030] As shown in Figure 7 (VII), when the outside water level rises to a high level and the weight 3 passes directly above the rotation axis C of the door body 1, the weight 3 assists the movement of the door body 1 in the closing direction as it tilts, so that the protrusion 6 engages with one end face of the recess 7, and the weight 3 functions, reliably closing the door body 1 and pressing it firmly against the watertight surface. This state is maintained even if the outside water level drops and becomes equal to the inside water level.

[0031] In this way, in the non-powered flap gate 11, the convex portion 6 on the connecting shaft 2 side, which is the rotation axis C of the door body 1, is loosely fitted into the concave portion 7 formed inside the shaft hole of the shaft fitting portion 5 on the weight 3 side, and the weight 3 functions by the engagement between the convex portion 6 and the concave portion 7, so the function of the weight 3 as an auxiliary power source does not become a load factor in the opening and closing operation of the door body 1.

[0032] As shown in Figures 1 and 2, this non-powered flap gate 11 is equipped with a warning light 9, such as a rotating light, on the embankment that lights up to alert people in the vicinity when the gate body 1 is closed. The warning light 9 is illuminated using electricity generated by a solar panel 10 attached to the top of its support pole.

[0033] Therefore, even if there is no external power supply in the event of a flood, people near the sluice gate can sense the danger, ensuring safety.

[0034] As shown in Figure 1, when this non-powered flap gate 11 is installed as a new gate or to replace an existing gate, if a gate groove 20 for a stop gate is installed upstream of the gate body 1 in the drainage channel, in the event of a malfunction such as the gate body 1 not operating during a flood, an emergency response can be made by using the stop gate to prevent external water from flowing from the river into the land behind.

[0035] Furthermore, as shown in Figure 2, if the existing gate 21 is left in place and this non-powered flap gate 11 is added, in the event of a malfunction such as the gate body 1 not working during a flood, an emergency response is possible by using the existing gate 21 to prevent external water from flowing from the river into the hinterland. Therefore, by using existing facilities, installation is economical and large-scale construction is also possible.

[0036] In this document, the term "culvert" includes what is commonly called a culvert or gate.

[0037] Furthermore, the term "rivers" refers to various waterways downstream of a sluice gate, and the term "drainage channels" refers to various waterways upstream of a sluice gate. [Explanation of symbols]

[0038] 1 Door body 2 connection shaft 3 weight 4 Hanging bracket 5 Shaft fitting part 6 Convex part 7 recess 8 Lock nuts 9 Warning light 10. Solar Panels 11 Non-powered flap gate 20 Gate groove 21 Existing gate C Rotation axis G center of gravity

Claims

1. This is a non-powered flap gate that is installed at a sluice gate where a drainage channel joins a river, and the gate body rotates around the upper connecting shaft as a hinge depending on the water level difference between the outside water level on the river side and the inside water level on the drainage channel side, and the gate body is equipped with a weight that assists the opening and closing operation. The rotation axis of the door body, which is the axis of the connecting shaft, is located forward, toward the river, from the center of gravity of the door body when the door body is in a fully closed state, and when the weight is not acting, the door body is in a slightly open state. An end of a connecting shaft that rotates integrally with the door body is fitted into a shaft hole of a shaft fitting portion on the base side of the weight so as to be relatively rotatable, A convex portion having a sectorial cross section centered on the rotation axis of the door body is provided at the end of the connecting shaft, and a sectorial recess having a larger central angle than the convex portion on the connecting shaft is provided inside the shaft hole on the weight side, and the convex portion on the connecting shaft is loosely fitted into the recess on the weight side, and the weight functions by the engagement between the convex portion and the recess, From the state in which the weight is not acting, until the inner water level rises by a predetermined level above the outer water level, the convex portion and the concave portion do not engage so that the weight does not become a load for rotating the door body in the opening direction, Furthermore, the non-powered flap gate is characterized by being equipped with a cam-type weight that does not engage with the convex portion and the concave portion so that the weight does not become a load on the rotation of the gate body in the closing direction when the external water level rises while the internal water level is low, until the external water level rises to a predetermined level.

2. 2. A non-powered flap gate according to claim 1, further comprising a warning light that emits light to alert people in the vicinity when the gate body is closed.

3. 3. A non-powered flap gate according to claim 2, wherein the warning light is illuminated by electricity generated by a solar panel.

4. 4. A non-powered flap gate according to claim 1, wherein a gate groove for corner cutting is provided upstream of the gate body in the drainage channel.

5. 4. A non-powered flap gate according to claim 1, wherein the gate body is provided on the river side of an existing gate that cannot be operated unmanned.

Images