Water stop structure and lid including the same

Abstract

To provide a water cut-off structure which can be easily attached to and detached from a conduit, and can maintain good sealing performance even when the inner diameter of the conduit is relatively large.SOLUTION: The lid 1 includes a first member 10 having a first external circumferential surface 17 and a first pressing surface 18, a second member 20 having a second pressing surface 28, an elastically deformable ring-shaped seal member 30 wound around the first external circumferential surface 17, and a moving mechanism 40 having a bolt 41 and a nut 42. The lid 1 is configured such that when the first pressing surface 18 and the second pressing surface 28 are brought close to each other by the moving mechanism 40, the sealing member 30 moves on at least one of the first pressing surface 18 and the second pressing surface 28 and is sandwiched between the first pressing surface 18 and the second pressing surface 28, so that the diameter of the sealing member 30 is increased.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a water-stopping structure and a lid equipped with the same. [Background technology]

[0002] For example, Patent Document 1 discloses a riser pipe buried underground, an outer frame (hereinafter referred to as the lid frame) provided at the upper end of the riser pipe, and a lid to be attached to the lid frame. When attempting to replace an existing lid with a lid of a different shape or size, a gap may occur between the lid and the lid frame. Therefore, Patent Document 1 proposes interposing a lid attachment adapter (hereinafter simply referred to as the adapter) between the lid and the lid frame.

[0003] When attaching a lid to a lid frame using the adapter, first apply adhesive to the inner circumferential surface of the lid frame, then use this adhesive to attach the adapter to the lid frame. Next, the lid is fitted into the adapter. This allows lids of different shapes or sizes to be attached to the lid frame.

[0004] According to the lid disclosed in Patent Document 1, the gap between the lid frame and the adapter is sealed with an adhesive, so that the watertightness between the lid frame and the adapter can be maintained well. However, because the adapter is glued to the lid frame, the adapter cannot be removed from the lid frame when inspecting the riser pipe, etc. The watertight structure disclosed in Patent Document 1 cannot be removed after the fact.

[0005] Patent Document 2 discloses a stop valve that ensures watertightness by elastically deforming a sealing member radially outward. This stop valve includes two flanges, a sealing member disposed between the flanges, and fastening means consisting of bolts and nuts that move the flanges toward or away from each other. When the bolts are tightened, the flanges move toward each other, and the sealing member is compressed by the flanges, elastically deforming radially outward and pressing against the inner circumferential surface of the pipe. This ensures watertightness through the sealing member. On the other hand, when the bolts are loosened, the flanges move away from each other, and the sealing member returns to its original shape, moving away from the inner circumferential surface of the pipe. This allows the stop valve to be easily removed from the pipe. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2023-94889 [Patent Document 2] Publication No. 7-4394 Summary of the Invention [Problem to be solved by the invention]

[0007] In the stop valve disclosed in Patent Document 2, when the inner diameter of the pipe is large, the gap between the sealing member and the inner peripheral surface of the pipe before bolt tightening is relatively large. However, there is a limit to the amount of elastic deformation of the sealing member radially outward when compressed in the axial direction of the pipe. Therefore, if the gap is large, there is a risk that the sealing performance will be reduced.

[0008] The present invention has been made in consideration of these points, and its purpose is to provide a water-stopping structure and a lid equipped with the same that can be easily attached to and removed from a pipeline and can maintain good sealing properties even when the inner diameter of the pipeline is relatively large. [Means for solving the problem]

[0009] The water-stopping structure of the present invention includes a first member having a first outer peripheral surface and a first pressing surface intersecting the first outer peripheral surface, a second member having a second pressing surface spaced from the first pressing surface, an elastically deformable ring-shaped seal member wrapped around the first outer peripheral surface and disposed between the first pressing surface and the second pressing surface, and a movement mechanism that moves the first member and the second member relative to each other so that the first pressing surface and the second pressing surface move toward or away from each other, wherein when the movement mechanism moves the first pressing surface and the second pressing surface toward each other, the seal member moves on at least one of the first pressing surface and the second pressing surface and is sandwiched between the first pressing surface and the second pressing surface, thereby expanding in diameter. Note that expanding the diameter of the seal member means that the outer diameter of the seal member increases.

[0010] According to the water-stopping structure, after the first and second members are placed in the pipeline, the moving mechanism moves the first and second pressing surfaces closer to each other, causing the sealing member to expand in diameter. This allows for easy installation in the pipeline, and the gap between the first and second members and the pipeline is sealed by the sealing member. On the other hand, when the moving mechanism moves the first and second pressing surfaces away from each other, the sealing member contracts in diameter. This allows for easy removal of the first and second members from the pipeline. According to the water-stopping structure, when the sealing member expands in diameter, it not only elastically deforms radially outward but also moves on at least one of the first and second pressing surfaces. This allows for a relatively large amount of expansion of the sealing member. Therefore, good sealing performance can be maintained even when the inner diameter of the pipeline is relatively large.

[0011] The water-stopping structure may be configured such that when the first pressing surface and the second pressing surface are brought closer to each other by the moving mechanism, the sealing member moves on at least one of the first pressing surface and the second pressing surface, causing the posture of the cross-sectional shape of the sealing member to rotate by 45° or more.

[0012] This allows the seal member to move a relatively large distance, so that good sealing performance can be maintained even when the inner diameter of the pipe is relatively large.

[0013] When the direction in which the first pressing surface approaches the second pressing surface is defined as a first direction and the direction in which the second pressing surface approaches the first pressing surface is defined as a second direction, the first pressing surface may be a surface that is inclined with respect to the first direction so as to move radially inward of the sealing member as it moves in the first direction, and / or the second pressing surface may be a surface that is inclined with respect to the second direction so as to move radially inward of the sealing member as it moves in the second direction.

[0014] As a result, when the first pressing surface and the second pressing surface approach each other, the first pressing surface and / or the second pressing surface can effectively guide the change in position of the seal member so that the diameter of the seal member expands.

[0015] The cross-sectional shape of the seal member may have a constriction at a radially inner portion of the seal member.

[0016] As a result, when the seal member is sandwiched between the first pressing surface and the second pressing surface, the cross-sectional shape of the seal member is subjected to pressing forces from the first pressing surface and the second pressing surface, causing the seal member to bend radially inward at the constriction. Then, due to the repulsive force generated by the bending, the seal member moves on at least one of the first pressing surface and the second pressing surface, expanding in diameter. This facilitates movement of the seal member on the first pressing surface or the second pressing surface.

[0017] The cross-sectional shape of the sealing member may be gourd-shaped, having a first circular portion that contacts the first pressing surface, a second circular portion that contacts the second pressing surface, and a constriction formed between the first circular portion and the second circular portion.

[0018] This makes it easier for the seal member to move on the first pressing surface or the second pressing surface when the seal member is sandwiched between the first pressing surface and the second pressing surface.

[0019] The cross-sectional shape of the sealing member may be formed so that the center of one of the first circular portion and the second circular portion is located radially outward of the sealing member relative to the center of the other circular portion.

[0020] As a result, when the seal member is sandwiched between the first pressing surface and the second pressing surface, the radially outer circular portion of the first or second circular portion is more likely to move radially outward, thereby facilitating the radially outward movement of the seal member.

[0021] The diameter of the first circular portion and the diameter of the second circular portion may be different.

[0022] The water-stopping structure may be configured such that when the moving mechanism brings the first pressing surface and the second pressing surface closer to each other, the sealing member moves, and the circular portion having a larger diameter of the first circular portion and the second circular portion is positioned radially outward relative to the circular portion having a smaller diameter.

[0023] As a result, when the seal member expands in diameter, the circular portion having the larger diameter out of the first circular portion and the second circular portion is pressed against the inner circumferential surface of the pipeline, thereby further improving the sealing performance.

[0024] The first member and the second member may have a first bolt hole and a second bolt hole formed therein, respectively, extending in a direction in which the first pressing surface and the second pressing surface approach each other. The movement mechanism may have a bolt inserted into the first bolt hole and the second bolt hole, and a nut provided on the first member or the second member and engaged with the bolt.

[0025] This allows the diameter of the seal member to be expanded by rotating the bolt in a given direction, and the diameter of the seal member to be reduced by rotating the bolt in the opposite direction.

[0026] The lid of the present invention is a lid equipped with the water-stopping structure, wherein one of the first member and the second member is a lid body that is placed on a lid frame and covers the opening of the lid frame, and the other of the first member and the second member is positioned inside the lid frame.

[0027] The lid can be attached to a plurality of lid frames with different inner diameters. It is easy to attach and detach from the lid frame, and can maintain good sealing even when attached to a lid frame with a relatively large inner diameter.

[0028] The lid body may have a main lid having a pressure release hole formed therein, and a secondary lid covering the pressure release hole and slidably attached to the main lid. The secondary lid may be configured to open the pressure release hole of the main lid when the pressure inside the lid frame reaches or exceeds a predetermined value.

[0029] Pressure release lids tend to be installed in pipelines where relatively large internal pressures occur. Therefore, pressure release lids are required to have high watertightness. With this lid, when the sealing member expands in diameter, it not only elastically deforms radially outward, but also moves on at least one of the first and second pressing surfaces. Because the amount of expansion of the sealing member is relatively large, it can exhibit high watertightness. [Effects of the Invention]

[0030] According to the present invention, it is possible to provide a water-stopping structure and a lid equipped with the same that can be easily attached to and removed from a pipeline and can maintain good sealing properties even when the inner diameter of the pipeline is relatively large. [Brief explanation of the drawings]

[0031] [Figure 1] FIG. 2 is a plan view of the lid according to the embodiment. [Figure 2] 2 is a cross-sectional view of the lid taken along line II-II in FIG. 1, showing the state before the lid is sealed. [Figure 3] FIG. 10 is a plan view of the lid when the secondary lid is removed. [Figure 4] FIG. [Figure 5] FIG. [Figure 6] 10(a) to 10(c) are diagrams showing the movement and deformation of the seal member when pressed against the first pressing surface and the second pressing surface. [Figure 7] FIG. 2 is a view equivalent to FIG. 2 showing the state after the lid has been sealed. DETAILED DESCRIPTION OF THE INVENTION

[0032] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a plan view of a lid 1 according to the embodiment. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. As shown in Fig. 2, the lid 1 is attached to the upper end of a riser pipe 2 via a lid frame 3. The riser pipe 2 and the lid frame 3 form a pipeline.

[0033] The lid 1 comprises a first member 10, a second member 20, and an elastically deformable ring-shaped sealing member 30. The first member 10 and the second member 20 are constructed separately and then assembled together. The first member 10 is placed on the lid frame 3. The first member 10 is a lid body that covers the opening of the lid frame 3. The second member 20 is placed inside the lid frame 3. The second member 20 is configured to be movable up and down relative to the first member 10. The lid 1 is equipped with a movement mechanism 40 that moves the second member 20 up and down relative to the first member 10. Here, the first member 10 and the second member 20 are basically made of polyvinyl chloride resin, but there are no particular limitations on the materials used, and known resin materials such as plastic can be used.

[0034] In this embodiment, the lid 1 is a so-called pressure release lid. The lid 1 is configured to release the internal pressure when the internal pressure of the riser pipe 2 reaches or exceeds a predetermined value. The first member 10, which is the lid body, has a main lid 11 and a secondary lid 12. Figure 3 is a plan view of the lid 1 when the secondary lid 12 is removed. As shown in Figure 3, the main lid 11 has a cylindrical portion 13 in which an axial hole 13a is formed, and a plurality of arms 14 extending radially from the cylindrical portion 13. Pressure release holes 14a are formed between adjacent arms 14.

[0035] As shown in FIG. 1, the secondary lid 12 covers the pressure relief hole 14a. As shown in FIG. 2, the secondary lid 12 has a disk-shaped lid body 12a and a shaft 12b extending downward from the lid body 12a. The shaft 12b of the secondary lid 12 passes through the shaft hole 13a of the primary lid 11. The shaft 12b of the secondary lid 12 is slidably inserted into the shaft hole 13a of the primary lid 11. The secondary lid 12 is configured to be movable up and down relative to the primary lid 11. When the internal pressure of the riser pipe 2 exceeds a predetermined value, the secondary lid 12 rises due to the internal pressure. This opens the pressure relief hole 14a, releasing the internal pressure of the riser pipe 2. A stopper 15 is fixed to the lower end of the shaft 12b of the secondary lid 12 to prevent the shaft 12b from slipping out of the shaft hole 13a. When the secondary lid 12 rises due to the internal pressure of the riser pipe 2, the stopper 15 comes into contact with the cylindrical portion 13 of the primary lid 11, thereby preventing the secondary lid 12 from coming off the primary lid 11. A seal member 12c is provided on the outer periphery of the lid body 12a of the secondary lid 12. The primary lid 11 has a mounting portion 16 that is placed on the lid frame 3.

[0036] As shown in FIG. 3, first bolt holes 19 are formed in the main lid 11. Here, three first bolt holes 19 are formed. The first bolt holes 19 are formed at equal intervals around the center C1 of the lid 1. Here, the first bolt holes 19 are formed every 120° around the center C1 of the lid 1. However, the number of first bolt holes 19 is not particularly limited. The number of first bolt holes 19 may be two, or may be four or more.

[0037] 4 is a plan view of the second member 20. The second member 20 has a cylindrical portion 21 and a fastening portion 22 provided radially inward of the cylindrical portion 21. Here, three fastening portions 22 are formed. The fastening portions 22 are formed at equal intervals around the center C1 of the lid 1, in this case, every 120°. A second bolt hole 29 is formed in the fastening portion 22.

[0038] FIG. 5 is a cross-sectional view of the seal member 30. In this embodiment, the seal member 30 has a gourd-shaped cross section. That is, the cross-sectional shape of the seal member 30 has a substantially circular first circular portion 31, a substantially circular second circular portion 32, and radially inner and outer constrictions 33 formed between the first circular portion 31 and the second circular portion 32. The diameter D31 of the first circular portion 31 and the diameter D32 of the second circular portion 32 are different. Here, the diameter D31 of the first circular portion 31 is larger than the diameter D32 of the second circular portion 32. In this embodiment, the center C31 of the first circular portion 31 is located radially outward from the center C32 of the second circular portion 32. The distance between the center line C30 of the seal member 30 and the center C31 of the first circular portion 31 is longer than the distance between the center line C30 of the seal member 30 and the center C32 of the second circular portion 32. However, this is not particularly limited, and the distance between the center line C30 and the center C31 of the first circular portion 31 may be equal to the distance between the center line C30 and the center C32 of the second circular portion 32, or may be shorter than the distance between the center line C30 and the center C32 of the second circular portion 32. The dashed straight line L30 is a straight line that passes through the center C31 of the first circular portion 31 and the center C32 of the second circular portion 32. In this embodiment, the straight line L30 is not parallel to the center line C30 of the seal member 30, and is inclined with respect to the center line C30 of the seal member 30.

[0039] The material of the seal member 30 is not particularly limited, and various materials conventionally used for waterproof seal members can be suitably used. Rubber is usually used as the material for the seal member 30. In this embodiment, among rubbers, synthetic rubber is preferably used, and SBR (styrene butadiene rubber), NBR (acrylonitrile butadiene rubber), or EPDM (ethylene propylene diene rubber) is more preferably used.

[0040] As shown in FIG. 2 , the first member 10 has a first outer peripheral surface 17 and a first pressing surface 18 that intersects with the first outer peripheral surface 17. The first pressing surface 18 is formed on the upper side of the first outer peripheral surface 17 and is inclined with respect to a vertical line so as to extend radially inward as it extends downward. The second member 20 has a second pressing surface 28. The second pressing surface 28 is located below the first pressing surface 18. The second pressing surface 28 is inclined with respect to a vertical line so as to extend radially inward as it extends upward. The sealing member 30 is wrapped around the first outer peripheral surface 17 of the first member 10 and is disposed between the first pressing surface 18 and the second pressing surface 28. Here, the sealing member 30 is wrapped around the first outer peripheral surface 17 so that the first circular portion 31 contacts the first pressing surface 18 and the second circular portion 32 contacts the second pressing surface 28.

[0041] The movement mechanism 40, which moves the second member 20 up and down relative to the first member 10, has a bolt 41 and a nut 42. The bolt 41 is inserted into the first bolt hole 19 of the first member 10 and the second bolt hole 29 of the second member 20. The nut 42 is fixed to the fastening portion 22 of the second member 20. Note that, as in this embodiment, the nut 42 and the fastening portion 22 of the second member 20 may be separate bodies, or the fastening portion 22 may constitute the nut 42. In other words, the nut 42 may be formed integrally with the fastening portion 22. The main cover 11 of the first member 10 is formed with a recess 19a into which the head 41a of the bolt 41 is inserted. The top surface of the main cover 11 and the top surface of the bolt 41 are flush with each other. However, the recess 19a is not necessarily required. As shown in FIG. 1 , the head 41a of the bolt 41 is formed with a hexagonal hole 41b.

[0042] When a hexagonal wrench (not shown) is inserted into the hole 41b of the bolt 41 and the hexagonal wrench is rotated clockwise as viewed from above, the bolt 41 rotates clockwise as viewed from above. Because the bolt 41 is engaged with the nut 42, when the bolt 41 is rotated clockwise (in other words, when the bolt 41 is tightened), the nut 42 moves upward. As a result, the second member 20 to which the nut 42 is fixed moves upward. Conversely, when the bolt 41 is rotated counterclockwise (in other words, when the bolt 41 is loosened), the nut 42 moves downward. As a result, the second member 20 to which the nut 42 is fixed moves downward. In this way, in the movement mechanism 40, the second member 20 can be moved up and down relative to the first member 10 by rotating the bolt 41.

[0043] When the second member 20 moves upward, the first pressing surface 18 and the second pressing surface 28 move closer to each other. When the second member 20 moves downward, the first pressing surface 18 and the second pressing surface 28 move away from each other. According to the lid 1 of this embodiment, when the movement mechanism 40 moves the first pressing surface 18 and the second pressing surface 28 closer to each other, the seal member 30 moves on at least one of the first pressing surface 18 and the second pressing surface 28 and is sandwiched between the first pressing surface 18 and the second pressing surface 28, thereby expanding the diameter of the seal member 30. Note that "expanding the diameter of the seal member 30" refers to an increase in the outer diameter of the seal member 30, and "reducing the diameter of the seal member 30" refers to a decrease in the outer diameter of the seal member 30. The outer diameter of the seal member 30 refers to the distance between the center of the ring of the seal member 30 (here, coincident with the center C1 of the lid 1) and the part of the seal member 30 farthest from the center of the ring.

[0044] Next, an example of a method for attaching the lid 1 will be described. First, as shown in FIG. 2, the lid 1 is placed on the lid frame 3. More specifically, the mounting portion 16 of the main lid 11 is placed on the lid frame 3. Next, the bolt 41 is tightened to move the second member 20 upward. As a result, as shown in FIG. 6(a), the second pressing surface 28 approaches the first pressing surface 18. As shown in FIG. 6(b), when the second pressing surface 28 approaches the first pressing surface 18, the sealing member 30 is pressed against the first pressing surface 18 and the second pressing surface 28. At this time, the first circular portion 31 of the sealing member 30 moves on the first pressing surface 18, and the second circular portion 32 moves on the second pressing surface 28, and the orientation of the cross-sectional shape of the sealing member 30 rotates by 45° or more, as shown in FIG. 6(c). The angle θ between the line L30 after the position change (a line passing through the center C31 of the first circular portion 31 and the center C32 of the second circular portion 32) and the line L30 before the position change (hereinafter also referred to as the position change angle) is 45° or greater. As described above, the position of the seal member 30 is changed by at least a portion of the seal member 30 sliding on the first pressing surface 18 and the second pressing surface 28. As a result, the first circular portion 31 of the seal member 30 moves radially outward. Furthermore, the seal member 30 is sandwiched between the first pressing surface 18 and the second pressing surface 28, causing the seal member 30 to elastically deform radially outward. This causes the seal member 30 to expand in diameter, and as shown in FIG. 7 , the gaps between the first and second members 10 and 20 and the lid frame 3 are sealed by the seal member 30. In this manner, the lid 1 can be easily attached to the lid frame 3, and sufficient watertightness can be ensured.

[0045] Furthermore, the lid 1 can be easily removed from the lid frame 3. To remove the lid 1, the bolt 41 is loosened to move the second member 20 downward. This causes the second pressing surface 28 to move away from the first pressing surface 18, and the sealing member 30 returns to its original shape as shown in Figures 6(c) -> (b) -> (a). This causes the sealing member 30 to contract in diameter. Therefore, the lid 1 can be easily removed from the lid frame 3 by lifting it up.

[0046] As described above, according to this embodiment, after the lid 1 is placed on the lid frame 3, tightening the bolt 41 to move the first pressing surface 18 and the second pressing surface 28 closer to each other causes the diameter of the sealing member 30 to expand. This seals the gap between the first member 10, the second member 20, and the lid frame 3. This allows the lid 1 to be easily attached to the lid frame 3. On the other hand, loosening the bolt 41 to move the first pressing surface 18 and the second pressing surface 28 away from each other causes the diameter of the sealing member 30 to contract. This allows the lid 1 to be easily removed from the lid frame 3. According to this embodiment, when the diameter of the sealing member 30 expands, the sealing member 30 not only elastically deforms radially outward but also moves on at least one of the first pressing surface 18 and the second pressing surface 28. This allows the sealing member 30 to expand by a relatively large amount. Therefore, good sealing performance can be maintained even when the inner diameter of the lid frame 3 is relatively large.

[0047] According to this embodiment, when the first pressing surface 18 and the second pressing surface 28 are brought closer to each other by tightening the bolt 41, the sealing member 30 moves on at least one of the first pressing surface 18 and the second pressing surface 28, causing the orientation of the cross-sectional shape of the sealing member 30 to rotate by 45° or more. Because the movement amount of the sealing member 30 is relatively large, good sealing performance can be maintained even when the inner diameter of the lid frame 3 is relatively large.

[0048] According to this embodiment, the first pressing surface 18 is a surface that slopes radially inward as it goes downward, and the second pressing surface 28 is a surface that slopes radially inward as it goes upward. As a result, when the first pressing surface 18 and the second pressing surface 28 are brought closer to each other by tightening the bolt 41, the first pressing surface 18 and the second pressing surface 28 can effectively guide the change in position of the seal member 30.

[0049] 5 , the cross-sectional shape of the seal member 30 has a constriction 33 formed in a radially inner portion of the seal member 30. When the seal member 30 is wrapped around the first outer peripheral surface 17 and is not pressed by the first pressing surface 18 and the second pressing surface 28, the cross-sectional shape of the seal member 30 has a constriction 33 formed in a radially inner portion of the seal member 30. The cross-sectional shape of the seal member 30 is gourd-shaped, having a first circular portion 31 in contact with the first pressing surface 18, a second circular portion 32 in contact with the second pressing surface 28, and a constriction 33 formed between the first circular portion 31 and the second circular portion 32. As a result, when the seal member 30 is sandwiched between the first pressing surface 18 and the second pressing surface 28, the cross-sectional shape of the seal member 30 is subjected to pressing forces from the first pressing surface 18 and the second pressing surface 28, and is initially bent radially inward at the constriction 33 (see FIG. 6(b)). Thereafter, the first circular portion 31 of the seal member 30 is subjected to a repulsive force generated by the bending, and the seal member 30 expands in diameter. According to this embodiment, such deformation of the seal member 30 can promote radially outward movement of the seal member 30.

[0050] According to this embodiment, in the cross-sectional shape of the seal member 30, the center C31 of the first circular portion 31 is located radially outward from the center C32 of the second circular portion 32 (see FIG. 5). Therefore, when the seal member 30 is sandwiched between the first pressing surface 18 and the second pressing surface 28, the first circular portion 31 is likely to move radially outward. This can promote movement of the seal member 30 on the first pressing surface 18 and the second pressing surface 28.

[0051] According to this embodiment, the diameter D31 of the first circular portion 31 is larger than the diameter D32 of the second circular portion 32. When the first pressing surface 18 and the second pressing surface 28 are brought closer to each other by tightening the bolt 41, the posture of the sealing member 30 is changed, and the first circular portion 31, which has a larger diameter, moves radially outward relative to the second circular portion 32, which has a smaller diameter. When the sealing member 30 expands in diameter, the first circular portion 31, which is the circular portion with a larger diameter, is pressed against the inner circumferential surface of the lid frame 3 (see FIG. 7 ), thereby enabling a higher sealing performance than when the second circular portion 32, which is the circular portion with a smaller diameter, is pressed against the inner circumferential surface of the lid frame 3.

[0052] The configuration of the movement mechanism 40 is not particularly limited as long as it can move the first pressing surface 18 of the first member 10 and the second pressing surface 28 of the second member 20 toward and away from each other. In this embodiment, the movement mechanism 40 includes a bolt 41 inserted into the bolt hole 19 of the first member 10 and the bolt hole 29 of the second member 20, and a nut 42 provided on the second member 20. The diameter of the seal member 30 can be expanded by rotating the bolt 41 clockwise, and the diameter of the seal member 30 can be reduced by rotating the bolt 41 counterclockwise. According to this embodiment, the operation of expanding and reducing the diameter of the seal member 30 is easy. Therefore, the lid 1 can be easily attached and removed.

[0053] The first member 10 is a lid body that is placed on the lid frame 3 and covers the opening of the lid frame 3, and the second member 20 is disposed inside the lid frame 3. The lid 1 according to this embodiment can be attached to a plurality of lid frames 3 with different inner diameters. The lid 1 according to this embodiment is easy to attach and detach from the lid frame 3, and can maintain good sealing even when attached to a lid frame 3 with a relatively large inner diameter. For example, when the lid 1 according to this embodiment is attached to replace an existing lid attached to the lid frame 3, even if the diameters of the existing lid and the lid 1 differ, the lid 1 can be attached while maintaining sufficient sealing. The lid 1 according to this embodiment can be attached to replace an existing lid without being subject to significant dimensional constraints.

[0054] The lid 1 according to this embodiment is a pressure release lid that automatically opens when the internal pressure increases. Pressure release lids tend to be installed in pipelines where relatively large internal pressures are generated. For this reason, pressure release lids are required to have relatively high watertightness. According to the watertight structure according to this embodiment, when the seal member 30 expands in diameter, the seal member 30 not only elastically deforms radially outward, but also moves on the first pressing surface 18 and the second pressing surface 28. Because the seal member 30 expands in diameter by a relatively large amount, it can exhibit high watertightness. Therefore, the watertight structure according to this embodiment is particularly suitable for pressure release lids.

[0055] Although one embodiment of the present invention has been described above, the embodiment is merely an example, and the present invention can be embodied in various other forms.

[0056] Although the lid 1 according to the embodiment is a pressure release lid, the lid according to the present invention is not limited to a pressure release lid. The lid 1 does not have to include the sub-lid 12. For example, the first member 10 may have a single lid body.

[0057] The installation location of the lid according to the present invention is not limited to the upper end of the vertically extending riser pipe 2. The lid according to the present invention may be attached to the tip of a pipe extending horizontally, for example.

[0058] Furthermore, the application of the water stop structure according to the present invention is not limited to lids, and the water stop structure according to the present invention can be used for purposes other than lids.

[0059] In the above embodiment, the position change angle θ (see FIG. 6(c)) of the seal member 30 when the first pressing surface 18 and the second pressing surface 28 are brought closer to each other is 45° or more, but the position change angle θ is not particularly limited. The position change angle θ of the seal member 30 may be less than 45°.

[0060] In the above embodiment, both the first pressing surface 18 and the second pressing surface 28 are inclined surfaces, but the first pressing surface 18 or the second pressing surface 28 may be a flat surface extending in the radial direction.

[0061] In the above embodiment, the constrictions 33 are formed on both the inner and outer radial sides of the seal member 30, but the constrictions 33 may be formed only on the inner radial side. Also, the constrictions 33 are not necessarily required. The constrictions 33 may be absent. The cross-sectional shape of the seal member 30 is not limited to a gourd shape.

[0062] In the above embodiment, the diameter D31 of the first circular portion 31 is larger than the diameter D32 of the second circular portion 32, but the diameter D31 of the first circular portion 31 may be equal to the diameter D32 of the second circular portion 32 or may be smaller than the diameter D32 of the second circular portion 32.

[0063] In the above embodiment, when the sealing member 30 expands in diameter, the circular portion with the larger diameter (first circular portion 31) of the first circular portion 31 and the second circular portion 32 is positioned radially outward from the circular portion with the smaller diameter (second circular portion 32), but the circular portion with the smaller diameter may also be positioned radially outward from the circular portion with the larger diameter. [Explanation of symbols]

[0064] 1 lid 3 Lid frame 10 First member 11 Parent lid 12 child cover 14a Pressure relief hole 17 First outer surface 18 First pressing surface 19 First bolt hole 20 Second member 28 Second pressing surface 29 Second bolt hole 30 Sealing material 31 1st circle section 32 2nd circle section 33 Waistline 40 Moving mechanism 41 volts 42 Nut

Claims

1. a first member having a first outer peripheral surface and a first pressing surface intersecting the first outer peripheral surface; a second member having a second pressing surface spaced from the first pressing surface; an elastically deformable ring-shaped seal member wrapped around the first outer peripheral surface and disposed between the first pressing surface and the second pressing surface; a movement mechanism that moves the first member and the second member relatively so that the first pressing surface and the second pressing surface move toward or away from each other, A water-stopping structure configured such that when the first pressing surface and the second pressing surface are brought closer to each other by the moving mechanism, the sealing member moves on at least one of the first pressing surface and the second pressing surface and is sandwiched between the first pressing surface and the second pressing surface, thereby expanding the diameter of the sealing member.

2. 2. The water-stopping structure according to claim 1, wherein when the first pressing surface and the second pressing surface are brought closer to each other by the moving mechanism, the sealing member moves on at least one of the first pressing surface and the second pressing surface, thereby rotating the posture of the cross-sectional shape of the sealing member by 45° or more.

3. When a direction in which the first pressing surface approaches the second pressing surface is defined as a first direction, and a direction in which the second pressing surface approaches the first pressing surface is defined as a second direction, The water-stopping structure described in claim 1, wherein the first pressing surface is a surface inclined with respect to the first direction so as to move radially inward of the sealing member as it moves in the first direction, and / or the second pressing surface is a surface inclined with respect to the second direction so as to move radially inward of the sealing member as it moves in the second direction.

4. The water stopping structure according to claim 1 , wherein the cross-sectional shape of the seal member has a constriction on a radially inner portion of the seal member.

5. 2. The water-stopping structure according to claim 1, wherein the cross-sectional shape of the sealing member is gourd-shaped, having a first circular portion that contacts the first pressing surface, a second circular portion that contacts the second pressing surface, and a constriction formed between the first circular portion and the second circular portion.

6. The water-stopping structure described in claim 5, wherein the cross-sectional shape of the sealing member is formed so that the center of one of the first circular portion and the second circular portion is located radially outward of the sealing member relative to the center of the other circular portion.

7. The water stopping structure according to claim 5 , wherein the diameter of the first circular portion and the diameter of the second circular portion are different.

8. The water-stopping structure described in claim 7, wherein when the moving mechanism brings the first pressing surface and the second pressing surface closer to each other, the sealing member moves, and the circular portion having a larger diameter of the first circular portion and the second circular portion is positioned radially outward relative to the circular portion having a smaller diameter.

9. a first bolt hole and a second bolt hole extending in a direction in which the first pressing surface and the second pressing surface approach each other are formed in the first member and the second member, respectively; The water-stopping structure described in claim 1, wherein the moving mechanism includes a bolt inserted into the first bolt hole and the second bolt hole, and a nut provided on the first member or the second member and engaged with the bolt.

10. A lid equipped with the water stopping structure according to any one of claims 1 to 9, one of the first member and the second member is a lid body that is placed on a lid frame and covers an opening of the lid frame; The other of the first member and the second member is disposed inside the lid frame.

11. The lid body has a main lid having a pressure release hole formed therein, and a sub lid covering the pressure release hole and slidably attached to the main lid, The lid according to claim 10, wherein the secondary lid is configured to open the pressure release hole of the primary lid when the pressure inside the lid frame reaches or exceeds a predetermined value.

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