Drain device

Abstract

To provide a drain device superior in installation workability, and capable of effectively restraining falling-off of a strainer.SOLUTION: A drain device 10 includes a drain body 13 having a cylindrical part side 13d connected to a drainage pipe 3 and a plate part side 13d formed with an opening side 13c to which the cylindrical part side 13a is connected, a strainer 11 covering the opening side 13c, and a connection device 12 connecting the drain body 13 and the strainer 11. The connecting device 12 has plate springs 12g, 12h having end parts abutting on the inner peripheral surface of the cylinder part side 13d, and when force is imparted to the strainer 11 in the direction for separating from the cylinder part side 13d, friction force between the end parts of the plate springs 12g, 12h and the inner peripheral surface of the cylinder part side 12h is increased by increasing compression force in the longitudinal direction of the plate springs 12g,. 13d.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a drain device. [Background technology]

[0002] Waterproofing layers are installed on the roofs of buildings to prevent leaks and other damage. Drainage devices are also installed to drain rainwater and melted snow that accumulate on the waterproofing layers. The drainage devices are connected to drainage pipes installed inside and outside the building, and are configured to collect the water that accumulates on the waterproofing layers and drain it through the drainage pipes into rainwater manholes or other containers. Strainers are generally installed in the drainage devices to prevent foreign objects such as garbage from entering the drainage pipes.

[0003] However, waterproofing layers require periodic repairs to maintain their waterproofing function. One repair method is a total replacement method, in which the existing waterproofing layer is removed and a new one is installed.

[0004] On the other hand, a cheaper method than the total replacement method is the overlay method (or covering method), in which a new waterproof layer is laid on top of the existing waterproof layer while leaving it in place.With the overlay method, the waterproof function can be further improved by layering a new waterproof layer on top of the existing waterproof layer.

[0005] Regardless of which construction method is used, the drain device must be reinstalled before the waterproofing layer is laid, and in this case the drain body and drain pipe used in the existing drain device will be reused.

[0006] In such cases, a new drain system known as a retrofit double drain is installed after removing part of the existing drain system and connecting it to the existing drain pipe, simplifying the retrofit work and shortening the construction period.

[0007] Existing strainers are often fixed to the existing drain body with bolts or the like. During renovations, the bolts are removed so as not to interfere with the installation of a new drain device. In such cases, the problem arises of how to attach the strainer to the new drain device.

[0008] In response to this, Patent Document 1 proposes a technology in which a leaf spring that can be inserted into the drain outlet of a drain device is attached to a strainer (drain cap), and an anti-slip device is further provided on the leaf spring and pressed firmly against the inside periphery of the drain outlet, thereby providing a high anti-slip effect with the anti-slip device and effectively preventing the strainer from coming loose. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2022-177528 Summary of the Invention [Problem to be solved by the invention]

[0010] However, in the drain device of Patent Document 1, the tip of the leaf spring faces the back of the drain outlet, so there is a problem that the strainer is easily pulled out when a force in the pulling direction is applied to the strainer. In particular, in the event of strong winds, which have become more frequent in recent years due to global warming, simply providing an anti-slip device on the leaf spring may not be enough to prevent the strainer from coming out.

[0011] In response to this, one idea to improve the strainer's ability to prevent it from coming loose is to increase the thickness of the leaf spring, for example, to increase its elastic force and thereby increase the frictional force acting between the inner surface of the drain outlet and the leaf spring. However, because the worker must manually tighten the leaf spring to fit the inner diameter of the drain outlet when assembling the strainer, there is a concern that increasing the elastic force of the leaf spring may make it harder to assemble the strainer.

[0012] In view of the above-mentioned problems, an object of the present invention is to provide a drain device that is easy to install and can effectively prevent the strainer from falling off. [Means for solving the problem]

[0013] One of the representative drain devices of the present invention that solves the above problems is as follows: A drain body including a cylindrical portion connected to a drain pipe and a plate portion having an opening to which the cylindrical portion is connected; a strainer covering the opening; a connecting device that connects the drain body and the strainer, the coupling device includes a leaf spring having an end that abuts against an inner circumferential surface of the cylindrical portion, This is achieved by the fact that when force is applied to the strainer in a direction away from the tubular portion, the longitudinal compressive stress of the leaf spring increases, thereby increasing the friction force between the end of the leaf spring and the inner surface of the tubular portion. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a drain device that is easy to install and can effectively prevent the strainer from falling off. Problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a cross-sectional view showing a drain device according to a first embodiment attached to a rooftop. [Figure 2] FIG. 2 is an exploded perspective view of the drain device of the first embodiment. [Figure 3] FIG. 3 is a cross-sectional view showing an example of a drain device having a first leaf spring and a second leaf spring with different lengths. [Figure 4] FIG. 4 is a cross-sectional view of a drain device according to a first modified example. [Figure 5]FIG. 5 is a perspective view showing a strainer and a connecting device according to a second modified example. [Figure 6] FIG. 6 is a perspective view showing a connecting device according to a second modified example. [Figure 7A] FIG. 7A is a simplified bottom view of a connecting device according to a third modified example together with a drain body. [Figure 7B] FIG. 7B is a simplified bottom view of the connecting device according to the fourth modified example together with the drain body. [Figure 8] FIG. 8 is a cross-sectional view showing the drain device of the second embodiment attached to a rooftop. [Figure 9] FIG. 9 is an exploded perspective view of the drain device according to the second embodiment. [Figure 10] FIG. 10 is a simplified side view of a connecting device according to a first modified example of the second embodiment, viewed from the circular pipe side together with a drain body. [Figure 11] FIG. 11 is a simplified side view of a connecting device according to a second modified example of the second embodiment, viewed from the circular pipe side together with a drain body. [Figure 12] FIG. 12 is a diagram showing the results of a wind pressure resistance test in which the comparative example and the example were tested. [Figure 13] FIG. 13 is a diagram showing the results of a drainage test in which the comparative example and the example were tested. [Figure 14] FIG. 14 is a diagram showing the results of a pull-out test in which the comparative example and the example were tested. DETAILED DESCRIPTION OF THE INVENTION

[0016] [First embodiment] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Fig. 1 is a cross-sectional view showing a drain device of a first embodiment attached to a rooftop, with part of a strainer omitted. Fig. 2 is a perspective view showing the drain device of the first embodiment in an exploded state.

[0017] (Drain device configuration) First, with reference to FIG. 2, the configuration of the drain device 10 of this embodiment, which is for vertical pulling, will be described. In FIG. 2, the drain device 10 includes a strainer 11, a connecting device 12, and a drain body 13.

[0018] The strainer 11 comprises a top portion 11a, a plurality of vertical pillar portions 11b extending downward from the top portion 11a at equal angles to the axis and arranged circumferentially at predetermined intervals, intermediate connecting portions 11c connecting adjacent vertical pillar portions 11b at their intermediate positions, and lower end connecting portions 11d connecting adjacent vertical pillar portions 11b near their lower ends. An opening 11e is formed in the top portion 11a. A non-circular (e.g., rectangular) recess (not shown) is formed on the underside of the top portion 11a around the opening 11e.

[0019] The connecting device 12 includes a butterfly bolt 12a, a washer 12d, a connecting shaft 12f, a first leaf spring 12g, a second leaf spring 12h, and a screw 12c. The butterfly bolt 12a is a fastener consisting of a pair of wings and a bolt portion, and is assembled in an exposed state on the outside of the strainer 11, making it accessible to workers.

[0020] A threaded hole (not shown) is formed at the upper end of the connecting shaft body 12f, and the periphery of the threaded hole is formed in a non-cylindrical shape (for example, a rectangular cylindrical shape).

[0021] Four downwardly projecting protrusions 12b are formed at equal intervals around the periphery of the lower end of the connecting shaft 12f. The distance between adjacent protrusions 12b is approximately equal to the width of the first leaf spring 12g and the second leaf spring 12h. A screw hole (not shown) is also formed in the center of the lower end of the connecting shaft 12f.

[0022] The first and second metal leaf springs 12g and 12h have the same length and shape and each has a central through-hole 12k. Rubber or resin covering members 12i are attached to both ends of the first leaf spring 12g to cover the ends, and rubber or resin covering members 12j are attached to both ends of the second leaf spring 12h to cover the ends. The covering members 12i and 12j may entirely cover the first and second leaf springs 12g and 12h, or the covering members 12i and 12j may be omitted.

[0023] The drain body 13 is composed of a rectangular flat plate portion 13a, a recessed portion 13b formed in the center of the flat plate portion 13a, and a circular pipe (tubular portion) 13d connected to a circular opening 13c formed in the center of the recessed portion 13b. A spiral uneven portion is formed on the inner surface of the circular pipe 13d, and a corresponding spiral uneven portion 13e is also formed on the outer surface of the circular pipe 13d (not shown in the cross-sectional view, same below). Note that even if the inner surface of the circular pipe 13d does not have an uneven portion, the effect of preventing the coupling device 12 from being pulled out is ensured (the same applies to the following modified examples).

[0024] The connecting device 12 is pre-assembled to the strainer 11. Specifically, the assembly is performed by inserting a screw 12c through the central through-hole 12k of the first and second leaf springs 12g and 12h, which are assembled in a cross shape, and threading it into the threaded hole at the bottom of the connecting shaft 12f. This positions the first and second leaf springs 12g and 12h between the protrusions 12b at the bottom of the connecting shaft 12f. In a free state where no external force is applied to the first and second leaf springs 12g and 12h, the tips of the first and second leaf springs 12g and 12h point diagonally upward, as shown in FIG. 2. After assembly, the cross shape of the first and second leaf springs 12g and 12h is fixed by the protrusions 12b.

[0025] The upper end of this connecting shaft 12f is inserted from below the strainer 11 and engaged with the recessed portion on the underside of the top 11a. This aligns the opening 11e with the threaded hole at the upper end of the connecting shaft 12f, so that the bolt portion of the butterfly bolt 12a is threaded into the threaded hole through the opening 11e from above the strainer 11, with the washer 12d interposed between them. At this time, the engagement between the upper end of the connecting shaft 12f and the recessed portion on the underside of the top 11a prevents co-rotation, allowing the butterfly bolt 12a to be effectively screwed into the connecting shaft 12f. This completes the assembly of the connecting device 12 to the strainer 11.

[0026] (Installation of drain device) Next, with reference to FIG. 1, an installation mode of the drain device 10 of this embodiment will be described. The drain device 10 of this embodiment is installed after removing at least a part of an existing drain device that has been in use, for example, for repairing the waterproof structure. As preparation, the strainer and waterproof layer holder of the existing drain device, and if necessary, the surrounding waterproof layer, are removed.

[0027] At this time, as shown in Figure 1, a shallow dish-shaped drain base 2 with a hole 2a in the center and a drain pipe 3 connected to the hole 2a in the drain base 2 and extending downward from the vertical opening 1a in the waterproof base 1 remain on the waterproof base 1 (RC, PC, ALC, W, etc.) 1 placed on the roof of the building. For this reason, it is necessary to assemble a new drain device taking into consideration the existing drain device.

[0028] First, the drain body 13 is attached alone to the existing drain base 2. Here, the circular pipe 13d of the drain body 13 has an outer diameter smaller than the inner diameter of the drain pipe 3, so that the circular pipe 13d can be inserted into the inside of the drain pipe 3 and connected.

[0029] When the circular pipe 13d is inserted into the inside of the drain pipe 3, the recess 13b of the drain body 13 is located above the drain base 2. The recess 13b is formed to match the shape of the drain base 2, which is a shallow dish.

[0030] Meanwhile, the flat plate portion 13a of the drain body 13 is located on the upper surface of the waterproofing base 1 around the drain base 2. At this time, it is desirable to fix the lower surface of the flat plate portion 13a to the upper surface of the waterproofing base 1 using an adhesive sheet or adhesive. Furthermore, since the flat plate portion 13a is made of soft vinyl chloride, it is easily deformed, and even if the upper surface of the waterproofing base 1 is slightly uneven, it can be made to fit the upper surface, thereby increasing adhesion. The existing waterproof layer is indicated by the symbol 4.

[0031] Furthermore, a waterproof layer 5 is laid on the upper surfaces of the flat plate portion 13a and recessed portion 13b of the drain body 13 up to near the edge of the circular opening 13c. The waterproof layer 5 may be, but is not limited to, an asphalt waterproof layer, a sheet waterproof layer, or a coating waterproof layer. The thickness of the waterproof layer 5 varies depending on the material and construction method, but is approximately 1 mm to 15 mm.

[0032] After installing the waterproof layer 5, the strainer 11 incorporating the connecting device 12 is installed to cover the circular opening 13c. The worker grasps the ends of the first leaf spring 12g and the second leaf spring 12h facing diagonally upward with their hands so as to pinch them together (bring them closer together). This causes the first leaf spring 12g and the second leaf spring 12h to bend and elastically deform toward the connecting shaft 12f. Because the first leaf spring 12g and the second leaf spring 12h are relatively thin, the worker can easily pinch them. While maintaining this state, the first leaf spring 12g and the second leaf spring 12h are inserted into the circular pipe 13d from the side of the first leaf spring 12g and the second leaf spring 12h.

[0033] When the operator releases the first and second leaf springs 12g and 12h after their ends enter the circular tube 13d, the first and second leaf springs 12g and 12h return to their original position and contact the inner circumferential surface of the circular tube 13d, exerting elastic force. In this state, the upper ends of the first and second leaf springs 12g and 12h that contact the inner circumferential surface of the circular tube 13d face upward. The "facing of the ends" refers to the direction in which the longitudinal centerline extending through the ends of the leaf springs moves away from the ends. In other words, the direction from the vicinity of the upper ends of the first and second leaf springs 12g and 12h (i.e., the area below the upper ends) toward the upper ends includes at least a component that runs along the centerline of the circular tube 13d toward the strainer 11.

[0034] Immediately after insertion, as shown in Figure 1, the ends of first leaf spring 12g and second leaf spring 12h remain pointing diagonally upward, so even if strainer 11 is pushed downward, the frictional force between the ends of first leaf spring 12g and second leaf spring 12h and the inner surface of circular tube 13d does not increase, allowing the operator to push strainer 11 to the specified installation position with a relatively small amount of force. In a stationary state, a certain elastic force is generated in first leaf spring 12g and second leaf spring 12h, generating a certain frictional force between the ends and circular tube 13d.

[0035] As is clear from Figure 1, the waterproof layer 5 installed on the existing waterproof layer 4 is higher than the waterproof layer 5 installed on the upper surfaces of the flat plate portion 13a and the recessed portion 13b. Therefore, rainwater that drips onto the waterproof layer 5 flows toward the circular opening 13c and does not form pools. Furthermore, rainwater that passes through gaps between the vertical pillar portions 11b of the strainer 11 enters the circular opening 13c and is then drained through the drain pipe 3. At this time, debris and other particles in the rainwater are captured by the strainer 11.

[0036] For example, if strainer 11 is exposed to strong winds, an external force acts to pull connecting shaft 12f upward. If the central portions of first leaf spring 12g and second leaf spring 12h connected to connecting shaft 12f are displaced upward relative to circular tube 13d as strainer 11 moves, compressive force acts between both ends of first leaf spring 12g and second leaf spring 12h, increasing longitudinal compressive stress. This increases friction between the ends of first leaf spring 12g and second leaf spring 12h and circular tube 13d (or between covering members 12i and 12j, as the ends, and circular tube 13d). In other words, when force is applied to strainer 11 in a direction away from circular tube 13d, friction between the ends of first leaf spring 12g and second leaf spring 12h and the inner circumferential surface of circular tube 13d increases.

[0037] Even if the inner surface of circular pipe 13d is smooth, when force is applied to strainer 11 in a direction away from circular pipe 13d, the friction force between the ends of first leaf spring 12g and second leaf spring 12h and the inner surface of circular pipe 13d increases. However, if a spiral uneven portion is formed on the inner surface of circular pipe 13d in particular, the ends of first leaf spring 12g and second leaf spring 12h will get caught on the uneven portion, making them even less likely to come loose.

[0038] In addition, since the covering members 12i, 12j are formed on the ends of the first leaf spring 12g and the second leaf spring 12h, the frictional force between the first leaf spring 12g and the second leaf spring 12h and the circular tube 13d can be further increased.

[0039] After installing the drain device, it may be necessary to remove the strainer 11 for cleaning, inspection, etc. In such cases, the strainer 11 can be separated from the connecting shaft 12f by loosening and removing the butterfly bolt 12a, allowing an operator to inspect or clean the inside of the circular pipe 13d. Even after removing the strainer 11, the frictional force acting between the ends of the first and second leaf springs 12g and 12h and the inner surface of the circular pipe 13d prevents the first and second leaf springs 12g and 12h and the connecting shaft 12f from falling.

[0040] (Consideration of the length of the leaf spring) FIG. 3 is a cross-sectional view showing an example of a drain device having a first leaf spring 12g and a second leaf spring 12h with different lengths, but the waterproof base and the drain base are omitted.

[0041] 3(b), if the lengths of first leaf spring 12g and second leaf spring 12h are too short, the angle between first leaf spring 12g and second leaf spring 12h and the inner surface of circular tube 13d will approach a right angle. Therefore, when strainer 11 receives a force that tends to pull it out upward via connecting shaft 12f, first leaf spring 12g and second leaf spring 12h may be inverted, with their ends pointing downward. This reduces the friction between the ends of first leaf spring 12g and second leaf spring 12h and the inner surface of circular tube 13d, reducing the effectiveness of preventing strainer 11 from being pulled out.

[0042] 3(c), if the lengths of first leaf spring 12g and second leaf spring 12h are too long, the curved portions near the ends of first leaf spring 12g and second leaf spring 12h will come into contact with the inner circumferential surface of circular pipe 13d, and in some cases, the ends may lift off the inner circumferential surface of circular pipe 13d. Therefore, when strainer 11 is subjected to a force that tends to pull it out upward via connecting shaft 12f, first leaf spring 12g and second leaf spring 12h will be more likely to slide against the inner circumferential surface of circular pipe 13d, and the effect of preventing strainer 11 from being pulled out will be reduced.

[0043] In response to this, as shown in Figure 3(a), by appropriately setting the lengths of the first leaf spring 12g and the second leaf spring 12h, the ends of the first leaf spring 12g and the second leaf spring 12h can be brought into contact with the inner surface of the circular tube 13d, ensuring sufficient frictional force and effectively preventing the strainer 11 from being pulled out.

[0044] According to the results of the inventors' investigations, it has been found that when the inner diameter of the circular tube 13d is a and the length of the first leaf spring 12g and the second leaf spring 12h is L, it is preferable that 1.2×a≦L≦3.0×a.

[0045] (First Modification) FIG. 4 is a cross-sectional view of a drain device 10A according to a first modified example, but the waterproof base and the drain base are omitted.

[0046] In the first modified example, multiple (e.g., four) connecting shafts 12Af are installed, and their upper ends are attached to the vertical column portion 11b of the strainer 11 with butterfly bolts 12a. The connecting shafts 12Af extend downward in parallel, and the lower end of each has the lower end of a single leaf spring 12Ag attached. Each leaf spring 12Ag is arranged with its upper end facing upward, and the upper end of the leaf spring 12Ag abuts against the inner circumferential surface of the circular tube 13d. A covering member 12Ai may be attached to the upper end of the leaf spring 12Ag. A member may be provided to connect adjacent connecting shafts 12Af to prevent the connecting shafts 12Af from tilting. The other configurations are the same as those of the first embodiment, so a description thereof will be omitted.

[0047] In the first modification, if strainer 11 is exposed to strong winds and an external force acts to pull connecting shaft 12Af upward, longitudinal compressive stress is generated in leaf spring 12Ag connected to connecting shaft 12Af, increasing the frictional force acting between leaf spring 12Ag and circular tube 13d. This effectively prevents strainer 11 from being pulled out.

[0048] (Second Modification) Fig. 5 is a perspective view showing the strainer 11 and a connecting device 12B according to a second modified example. Fig. 6 is a perspective view showing the connecting device 12B. The strainer 11 has the same configuration as that of the first embodiment described above.

[0049] The connecting device 12B of the second modified example does not have a connecting shaft, and the leaf springs 12Bg are directly attached to the strainer 11. More specifically, as shown in Fig. 6, the plurality of (three in this example) leaf springs 12Bg have a common shape, and each has an oblique side portion 12Bx, an arc-shaped portion 12By, and a connecting portion 12Bz that connects the lower end of the oblique side portion 12Bx to the lower end of the arc-shaped portion 12By. A covering member 12Bi may be attached to the upper end of the arc-shaped portion 12By.

[0050] When the upper ends of the oblique sides 12Bx are connected to the lower end connecting portion 11d of the strainer 11 using butterfly bolts, the connecting portions 12Bz intersect near the axis of the strainer 11, and the arc-shaped portions 12By face upward. As a result, the upper ends of the arc-shaped portions 12By face upward and abut the inner circumferential surface of the circular pipe 13d (see FIG. 1). The overlapping connecting portions 12Bz may be fixed together with bolts and nuts (not shown). Other configurations are the same as those of the first embodiment, and therefore description thereof will be omitted.

[0051] In the second modification, for example, if strainer 11 is exposed to strong winds and an external force acts on it, such that strainer 11 is pulled upward, longitudinal compressive stress is generated in arc-shaped portion 12By, increasing the frictional force acting between arc-shaped portion 12By and circular pipe 13d. This effectively prevents strainer 11 from being pulled out.

[0052] (Third Modification) 7A is a simplified bottom view of a connecting device 12C according to a third modified example, together with the drain body 13. In the first embodiment described above, the centers of the first leaf spring 12g and the second leaf spring 12h, which are crossed in a cross shape, are attached to the lower end of the connecting shaft body 12f, and both ends of the springs are in contact with the inner circumferential surface of the circular pipe 13d at a total of four locations.

[0053] In contrast, in the third modified example, the inner end of a leaf spring 12Cg consisting only of a curved portion is attached to the lower end of the connecting shaft body 12f. Here, three leaf springs 12Cg are arranged at equal intervals in the circumferential direction, and the outer ends of the leaf springs 12Cg point upward and abut the inner surface of the circular tube 13d at three points. The rest of the configuration is the same as in the first embodiment, so a description thereof will be omitted. The number of leaf springs 12Cg may be five or more, and the number of abutting points may be five or more. Furthermore, covering members may be provided on the ends of the leaf springs 12Cg.

[0054] In the third modification, for example, if strainer 11 is exposed to strong winds and an external force acts to pull connecting shaft 12f upward, longitudinal compressive stress is generated in leaf spring 12Cg, increasing the frictional force acting between leaf spring 12Cg and circular tube 13d, thereby effectively preventing strainer 11 from being pulled out.

[0055] (Fourth Modification) 7B is a simplified diagram of a connecting device 12D according to a fourth modified example, viewed from below together with the drain body 13. In the fourth modified example, the inner end of a leaf spring 12Dg consisting only of a curved portion is attached to the lower end of the connecting shaft 12f. Here, two leaf springs 12Dg are arranged 180 degrees out of phase with each other, and the outer ends of the leaf springs 12Dg point upward and abut the inner circumferential surface of the circular pipe 13d at two points. Other configurations are the same as those in the first embodiment, and therefore will not be described further.

[0056] For example, under conditions where the wind is determined to blow from a specific direction due to the structure of the building, if the leaf spring 12Dg is installed so that it is positioned in the specific direction as in the fourth variant, the strainer 11 can be effectively prevented from being pulled out even if the leaf spring 12Dg has two contact points.

[0057] [Second embodiment] Fig. 8 is a cross-sectional view showing the drain device 20 of the second embodiment attached to a rooftop, and Fig. 9 is an exploded perspective view showing the drain device 20 of the second embodiment.

[0058] (Drain device configuration) First, the configuration of the drain device 20 of this embodiment, which is for horizontal drawing, will be described with reference to FIGS. 8 and 9, the drain device 20 includes a strainer 21, a connecting device 22, and a drain body .

[0059] The strainer 21 includes a pair of strainer members 21a and 21b, and a pivot portion 21c that rotatably connects the pair of strainer members 21a and 21b.

[0060] The strainer members 21a and 21b are formed, for example, by a mold, and have substantially rectangular grating portions 21d and 21e, respectively, and comb-tooth portions 21f and 21g extending at right angles from both sides of the grating portions 21d and 21e.

[0061] Grating portions 21d and 21e have a plurality of equally spaced bars, and comb teeth 21f and 21g also have a plurality of equally spaced comb teeth, which prevents foreign objects from passing through. The lengths of the comb teeth 21f and 21g from grating portions 21d and 21e gradually increase as they approach pivot portion 21c.

[0062] A plurality of short teeth 21h, 21i are alternately arranged and opposed to each other on the opposing side edges of the strainer members 21a, 21b.

[0063] The connecting device 22 has a butterfly bolt 22a, a washer 22d, a first connecting shaft 22f, a second connecting shaft 22m, a first leaf spring 22g, a second leaf spring 22h, and a screw 22c. The butterfly bolt 22a is assembled in an exposed state on the outside of the strainer 21 and is accessible to an operator.

[0064] The opposing proximal ends of the first connecting shaft 22f and the second connecting shaft 22m are pivotally connected to each other. The ends of the first connecting shaft 22f and the second connecting shaft 22m opposite the proximal ends are referred to as distal ends. A screw hole 22n is formed in the distal end of the first connecting shaft 22f.

[0065] Meanwhile, four protrusions 22b protruding toward the rear are formed at equal intervals in the circumferential direction on the outer periphery of the far end of the second connecting shaft 22m. The interval between adjacent protrusions 22b is approximately equal to the width of the first leaf spring 22g and the second leaf spring 22h. A screw hole (not shown) is formed in the center of the far end of the first connecting shaft 22f.

[0066] The first and second metal leaf springs 22g and 22h have the same length and shape and each has a central through-hole 22k. Rubber or resin covering members 22i are attached to both ends of the first leaf spring 22g to cover the ends, and rubber or resin covering members 22j are attached to both ends of the second leaf spring 22h to cover the ends. The covering members 22i and 22j may entirely cover the first and second leaf springs 22g and 22h, or the covering members 22i and 22j may be omitted.

[0067] The drain body 23 is formed by joining a vertical flat plate portion 23a, a horizontal flat plate portion 23b, and a circular pipe (tubular portion) 23d connected to a circular opening 23c formed at the lower end of the vertical flat plate portion 23a. A spiral uneven portion is formed on the inner surface of the circular pipe 23d, and a corresponding spiral uneven portion 23e is also formed on the outer surface of the circular pipe 23d. It is also possible to make only the vertical flat plate portion 23a and the horizontal flat plate portion 23b out of metal plate. It is also possible to ensure the effect of preventing the coupling device 12 from being pulled out even if the inner surface of the circular pipe 23d does not have an uneven portion formed thereon (the same applies to the following modified examples).

[0068] The connecting device 22 is pre-assembled to the strainer 21. Specifically, the assembly is performed by inserting a screw 22c through the central through-hole 22k of the first and second leaf springs 22g and 22h, which are assembled in a cross shape, and screwing it into the threaded hole at the distal end of the second connecting shaft 22m. This positions the first and second leaf springs 22g and 22h between the protrusions 22b at the distal end of the second connecting shaft 22m. In a free state where no external force is applied to the first and second leaf springs 22g and 22h, as shown in FIG. 2, the tips of the first and second leaf springs 22g and 22h face toward the first connecting shaft 22f. After assembly, the cross shape of the first and second leaf springs 22g and 22h is fixed by the protrusions 22b.

[0069] The distal end of first connecting shaft 22f connected to first connecting shaft 22f is inserted from the inside of strainer 21 so as to face the gap between central short tooth portions 21h, 21i. Then, from the outside of strainer 21, with washer 22d interposed, the bolt portion of butterfly bolt 22a is threaded into screw hole 22n through the gap between short tooth portions 21h, 21i. Because washer 22d has an outer diameter that does not allow it to pass through the gap between short tooth portions 21h, 21i, it is positioned outside short tooth portions 21h, 21i. In this way, connecting device 22 is assembled to strainer 21.

[0070] (Installation of drain device) Next, with reference to FIG. 8, an installation mode of the drain device 20 of this embodiment will be described. The drain device 20 of this embodiment is installed after removing at least a part of an existing drain device that has been in use, for example, for waterproofing repairs. As preparations, the strainer and waterproof layer holder of the existing drain device, and if necessary, the surrounding waterproof layer, are removed.

[0071] At this time, as shown in Figure 8, the waterproofing base (RC, PC, ALC, W, etc.) 1 placed on the side wall of the building roof will have a drain base 2 with a hole 2a formed therein, and a drain pipe 3 connected to the hole 2a of the drain base 2, which passes through the side wall from the horizontal opening 1a of the waterproofing base 1 and then extends downward, remaining. For this reason, it is necessary to assemble a new draining device taking into consideration the existing draining device.

[0072] First, the drain body 23 is attached alone to the existing drain base 2. Here, the circular pipe 23d of the drain body 23 has an outer diameter smaller than the inner diameter of the drain pipe 3, so the circular pipe 23d can be inserted into the inside of the drain pipe 3 to connect. When the circular pipe 23d is inserted into the inside of the drain pipe 3, the vertical flat plate portion 23a of the drain body 23 is positioned on the side of the waterproof base 1 around the drain base 2, and the horizontal flat plate portion 23b is positioned on the upper surface of the waterproof base 1 around the drain base 2.

[0073] At this time, it is desirable to fix the vertical flat plate portion 23a and the horizontal flat plate portion 23b to the waterproof base using an adhesive sheet or adhesive. Furthermore, since the vertical flat plate portion 23a and the horizontal flat plate portion 23b are made of soft vinyl chloride, even if the top surface of the waterproof base 1 is slightly uneven or even if the waterproof base 1 is not formed at a right angle, they can be made to blend in with the waterproof base 1, thereby increasing the degree of adhesion. The existing waterproof layer is indicated by the symbol 4.

[0074] Furthermore, a waterproof layer 5 is laid on the surfaces of the vertical flat plate portion 23a and the horizontal flat plate portion 23b of the drain body 23 up to near the edge of the circular opening 23c. The waterproof layer 5 may be, but is not limited to, an asphalt waterproof layer, a sheet waterproof layer, a paint film waterproof layer, etc. The thickness of the waterproof layer 5 varies depending on the material and construction method, but is approximately 1 mm to 15 mm.

[0075] After installing the waterproof layer 5, the strainer 21 with the connecting device 22 assembled thereto is installed. When the worker grasps the ends of the first leaf spring 22g and the second leaf spring 22h with their hands so as to pinch them (bring them closer together), the first leaf spring 22g and the second leaf spring 22h bend and elastically deform toward the second connecting shaft 22m. Because the plate thicknesses of the first leaf spring 22g and the second leaf spring 22h are relatively thin, the worker can easily pinch the first leaf spring 22g and the second leaf spring 22h. While maintaining this state, the first leaf spring 22g and the second leaf spring 22h are inserted into the circular pipe 23d from the side of the first leaf spring 22g and the second leaf spring 22h.

[0076] At this time, since the first connecting shaft 22f and the second connecting shaft 22m are pivotable, the second connecting shaft 22m can be easily inserted into the circular pipe 23d together with the first leaf spring 22g and the second leaf spring 22h.

[0077] After the ends of the first leaf spring 22g and the second leaf spring 22h have entered the circular tube 23d, when the worker releases their hands, the first leaf spring 22g and the second leaf spring 22h return to their original shape, and the ends of the first leaf spring 22g and the second leaf spring 22h come into contact with the inner surface of the circular tube 23d, exerting an elastic force.

[0078] Immediately after insertion, the ends of first leaf spring 22g and second leaf spring 22h remain facing first connecting shaft 22f (circular opening 23c), so even if strainer 21 is pushed inward, the frictional force between the ends of first leaf spring 22g and second leaf spring 22h and the inner surface of circular tube 23d does not increase, allowing the operator to push strainer 21 to the specified installation position with a relatively small force. In a stationary state, a predetermined elastic force is generated in first leaf spring 22g and second leaf spring 22h, generating a predetermined frictional force between the ends and circular tube 23d.

[0079] The worker brings the strainer 21 close to the waterproof layer 5 to be installed, and rotates the strainer members 21a, 21b relatively via the pivot portion 21c to correspond to the angles of the vertical and horizontal planes, so that the comb tooth portions 21f and 21g abut against the waterproof layer 5 on the vertical flat plate portion 23a and horizontal flat plate portion 23b of the drain body 23.

[0080] As is clear from Figure 8, the waterproof layer 5 installed on the existing waterproof layer 4 is higher than the waterproof layer 5 installed on the upper surface of the vertical flat plate portion 23a. Therefore, rainwater that drips onto the waterproof layer 5 flows toward the circular opening 23c and does not form puddles. Furthermore, rainwater that passes through the gaps in the grating portions 21d, 21e or the comb-tooth portions 21f, 21g of the strainer 21 enters the circular opening 23c and is then drained through the drain pipe 3. At this time, debris and other particles in the rainwater are captured by the strainer 21 and do not enter the drain pipe 3.

[0081] For example, if strainer 21 is exposed to strong winds, an external force acts on first connecting shaft 22f to pull it outward. If the central portions of first leaf spring 22g and second leaf spring 22h connected to second connecting shaft 22m are displaced toward first connecting shaft 22f with respect to circular tube 23d as strainer 21 moves, a compressive force acts between both ends of first leaf spring 22g and second leaf spring 22h, increasing longitudinal compressive stress, and increasing the frictional force acting between the ends of first leaf spring 22g and second leaf spring 22h and circular tube 23d.

[0082] Even if the inner surface of circular pipe 23d is smooth, when force is applied to strainer 21 in a direction away from circular pipe 23d, the friction force between the ends of first leaf spring 22g and second leaf spring 22h and the inner surface of circular pipe 23d increases. However, if a spiral uneven portion is formed on the inner surface of circular pipe 23d in particular, the ends of first leaf spring 22g and second leaf spring 22h will get caught on the uneven portion, making them even less likely to come loose.

[0083] In addition, since covering members 22i, 22j are formed on the ends of first leaf spring 22g and second leaf spring 22h, the frictional force between them and circular tube 23d can be further increased.

[0084] After the drain device is installed, it may be necessary to remove strainer 21 for cleaning, inspection, etc. In such cases, strainer 21 can be separated from first connecting shaft body 22f by loosening and removing butterfly bolt 22a, allowing an operator to inspect and clean the inside of circular pipe 23d.

[0085] (First Modification) 10 is a simplified side view of the connecting device 22A according to the first modified example, viewed from the circular pipe 23d side, together with the drain body 23. In the second embodiment described above, the centers of the first leaf spring 22g and the second leaf spring 22h, which are crossed in a cross shape, are attached to the distal end of the second connecting shaft 22m, and both ends of the springs are in contact with the inner circumferential surface of the circular pipe 23d at a total of four locations.

[0086] In contrast, in the first modified example, only a leaf spring 22Ag is attached to the circular end of the second connecting shaft 22m. The leaf spring 22Ag has a configuration similar to that of the first leaf spring of the second embodiment, extending horizontally and curving toward the second connecting shaft 22m, abutting the inner circumferential surface of the circular tube 23d at two points. A covering member may also be provided on the end of the leaf spring 22Ag. The remaining configuration is the same as that of the first embodiment, and therefore a description thereof will be omitted.

[0087] In the first modified example, if strainer 21 is exposed to strong winds and an external force acts to pull out first connecting shaft 22f, longitudinal compressive stress in leaf spring 22Ag increases the frictional force acting between leaf spring 22Ag and circular pipe 13d, thereby effectively preventing strainer 21 from being pulled out. Note that in the case of a horizontal strainer 21, because it is less likely to swing up and down when exposed to strong winds, even leaf spring 22Ag, which contacts circular pipe 23d at two points, is effective.

[0088] (Second Modification) FIG. 11 is a simplified side view of a connecting device 22B according to a second modified example, together with the drain body 23, viewed from the circular pipe 23d side.

[0089] In the second modified example, the inner end of a leaf spring 22Bg consisting only of a curved portion is attached to the circular end of the second connecting shaft 22m. Here, three leaf springs 22Bg are arranged at equal intervals in the circumferential direction, and the outer ends of the leaf springs 22Bg point upward and abut the inner surface of the circular tube 23d at three points. The rest of the configuration is the same as in the first embodiment, so a description thereof will be omitted. The number of leaf springs 22Bg may be five or more, and the number of abutment points may be five or more. Furthermore, a covering member may be provided on the end of the leaf spring 22Bg.

[0090] In the second modification, for example, if strainer 21 is exposed to strong winds and an external force acts to pull out first connecting shaft 22f, longitudinal compressive stress is generated in leaf spring 22Bg, increasing the frictional force acting between leaf spring 22Bg and circular pipe 23d, thereby effectively preventing strainer 21 from being pulled out.

[0091] (Comparative test between comparative examples and examples) The comparative tests carried out by the present inventors will be described below. The inventors conducted a wind pressure resistance test and a drainage test, comparing Example 1 with Comparative Examples 1 and 2. The strainer and connecting shaft body were the same for Example 1 and Comparative Examples 1 and 2, and only the leaf spring was different. Specifically, the following is the result.

[0092] Example 1 Example 1 has the same basic configuration as the first embodiment shown in Figures 1 and 2. Specifically, the height of the strainer 11 is 170 mm, the length of the connecting shaft 12f is 335 mm, and the lengths of the first and second leaf springs 12g and 12h are 260 mm and 0.8 mm, respectively. The first and second leaf springs 12g and 12h are entirely covered by covering members 12i and 12j.

[0093] (Comparative Example 1) In Comparative Example 1, the first leaf spring 12g and the second leaf spring 12h were attached to the connecting shaft 12f (length 170 mm) in the opposite direction to Example 1, and the resin covering members 12i and 12j were removed from the tips of the first leaf spring 12g and the second leaf spring 12h. The shape of the strainer 11 is slightly different from that of Example 1, but the effect on the wind pressure resistance test is thought to be negligible.

[0094] (Comparative Example 2) In Comparative Example 2, the first leaf spring 12g and the second leaf spring 12h were attached to the connecting shaft 12f (length 195 mm) in the opposite direction to Example 1, and the first leaf spring 12g and the second leaf spring 12h were entirely covered with covering members 12i and 12j. The shape of the strainer 11 was the same as in Example 1.

[0095] (Drain body) For comparison, three types of drain bodies were prepared by changing the outer diameter of a circular pipe (made of soft vinyl chloride) with a spirally uneven portion, and a wind pressure resistance test was conducted by attaching Comparative Examples 1 and 2 and Example 1 to each. Specifically, the outer diameters of the circular pipe to which the leaf spring was attached were 139 mm (nominal diameter 140), 113 mm (nominal diameter 115), and 87 mm (nominal diameter 90).

[0096] (wind pressure resistance test) The wind pressure resistance test was conducted by an external testing organization. The strainer of each test specimen was irradiated with air from a fan and the condition was observed. The test air speed was gradually increased from 0 to 60 m / s, and after reaching 60 m / s it was held for 1 minute. The opening dimensions of the fan outlet were 1400 mm x 1400 mm, and the distance from the fan outlet to the test specimen was 1550 mm.

[0097] (Test results) Figure 12 shows the results of the wind pressure resistance test. When the strainer was lifted up by the pressure of the wind blown out from the blower, the distance from the ground to the bottom of the strainer was measured and recorded as "float," with the maximum value (mm) recorded. Note that if the maximum amount of lift exceeded 75 mm, it meant that the strainer had been blown away.

[0098] According to the test results in Fig. 12, the amount of floating increases as the nominal diameter of the drain body increases in both Example 1 and Comparative Examples 1 and 2. This is presumably because the frictional force between the tip of the leaf spring and the inner surface of the circular pipe decreases as the nominal diameter of the drain body increases.

[0099] Furthermore, regardless of the nominal diameter of the drain body, the amount of floating is greater in Comparative Example 1 than in Comparative Example 2. This is presumably because Comparative Example 2 has a covering member attached to the tip of the leaf spring, while Comparative Example 1 does not, and therefore the frictional force between the resin and the circular pipe (Comparative Example 2) is higher than the frictional force between the metal and the circular pipe (Comparative Example 1).

[0100] Furthermore, Example 1 showed a smaller amount of floating than Comparative Example 2, regardless of the nominal diameter of the drain body. This is because in Comparative Example 2, the tip of the leaf spring faces the back of the circular pipe, whereas in Example 1, the tip faces the strainer, increasing the frictional force between the leaf spring and the circular pipe when the strainer is exposed to strong winds. From the above, it was found that Example 1 has superior wind pressure resistance compared to Comparative Examples 1 and 2.

[0101] (Drainage test) The inventors attached Example 1 and Comparative Examples 1 and 2 to the same drain body and conducted a drainage test.

[0102] (Test results) The results of the drainage test are shown in Figure 13. The vertical axis in Figure 13 is the drainage rate (L / s). The drainage rate of Example 1 is lower than that of Comparative Example 2, but is equivalent to that of Comparative Example 1. Note that the values ​​of the drainage test are likely to vary depending on the shape of the test tank, the conditions of the base, and the drain diameter.

[0103] (pull-out test) The inventors further conducted a pull-out test on Examples 1 and 2 and Comparative Example 2. Example 1 is the same as Example 1 used in the above test, and the length of the leaf spring was set to 260 mm. On the other hand, Example 2 is the same as Example 1, except that the length of the leaf spring was set to 310 mm.

[0104] As described above, Comparative Example 2 has a configuration similar to that of Example 1, except that the first leaf spring 12g and the second leaf spring 12h are attached to the connecting shaft body 12f in the opposite directions.

[0105] (Drain body) For Examples 1 and 2 and Comparative Example 2, as in the wind pressure resistance test, three types of drain bodies (with uneven portions on the inner circumferential surface of the circular pipe 13d) with different nominal diameters were prepared, and Examples 1, 2, and Comparative Example 2 were attached to each, and the strainer pull-out force was gradually increased using a universal testing machine, and the pull-out force when the strainer was pulled out was measured. The results are shown in Figure 14(a). Furthermore, a drain body with a nominal diameter of 95 (without any unevenness on the inner peripheral surface of the circular pipe 13d) was prepared, and Example 1 and Comparative Example 2 were attached to each of them. The strainer pull-out force was gradually increased using a universal testing machine, and the pull-out force when the strainer was pulled out was measured. The results are shown in Figure 14(b).

[0106] In the pull-out test results shown in Figure 14, if the strainer did not come out even when the pull-out force exceeded 80 N, the pull-out test was stopped to prevent damage to the part, and the pull-out force in that case was set to 80 N or more.

[0107] (Test results) The results shown in Figure 14(a) indicate that, under conditions where the circular pipe has an uneven portion, both Examples 1 and 2 require a pulling force that is 1.3 times greater than that of Comparative Example 2 to pull out the strainer. Furthermore, the results shown in Figure 14(b) indicate that, under conditions where the circular pipe does not have an uneven portion, Example 1 requires a pulling force that is 2 times greater than that of Comparative Example 2 to pull out the strainer. This proves that this example can exert a sufficiently high pulling force even under conditions where the circular pipe does not have an uneven portion. Furthermore, based on the above test results, similar effects are expected for the second embodiment.

[0108] The present invention is not limited to the above-described embodiment and can be modified in various ways. For example, the drain device of this embodiment has been described as being installed during renovation, but it can also be installed at the time of new construction. The present invention also includes drain devices in which the tip of the leaf spring is bent into a U-shape and faces the back. Furthermore, while a wing bolt is threaded into the threaded hole of the connecting shaft to attach the strainer, a bolt may be provided on the connecting shaft and protrude from the strainer, and a fastener such as a wing nut or knurled nut may be manually threaded onto the bolt by an operator.

[0109] This specification includes the disclosure of the following inventions. (First aspect) A drain body including a cylindrical portion connected to a drain pipe and a plate portion having an opening to which the cylindrical portion is connected; a strainer covering the opening; a connecting device that connects the drain body and the strainer, the coupling device includes a leaf spring having an end that abuts against an inner circumferential surface of the cylindrical portion, When a force is applied to the strainer in a direction away from the cylindrical portion, the longitudinal compressive stress of the leaf spring increases, thereby increasing the friction force between the end of the leaf spring and the inner surface of the cylindrical portion. A drain device characterized by:

[0110] (Second aspect) The end of the leaf spring that contacts the inner circumferential surface of the cylindrical portion faces the opening side. The drain device of the first aspect, characterized in that:

[0111] (Third aspect) the connecting device has a connecting shaft connected to the leaf spring, The connecting shaft is detachably connected to the strainer by a fastener exposed to the outside of the strainer. The drain device according to the first or second aspect,

[0112] (Fourth aspect) The longitudinal center of the leaf spring is connected to the end of the connecting shaft body, and both ends of the leaf spring abut on the inner circumferential surface of the cylindrical portion. A drain device according to a third aspect, characterized in that:

[0113] (Fifth aspect) The leaf spring is detachably connected to the strainer by a fastener exposed on the outside of the strainer. The drain device according to the first or second aspect,

[0114] (Sixth aspect) The drain device is for vertical pulling, and there are two or more contact points between the end of the leaf spring and the inner circumferential surface of the cylindrical portion. The drain device according to any one of the first to fifth aspects, characterized in that:

[0115] (Seventh aspect) The drain device is for horizontal pulling, and the end of the leaf spring and the inner circumferential surface of the cylindrical portion have two or more contact points. The drain device according to any one of the first to sixth aspects, characterized in that:

[0116] (Eighth aspect) Both ends of the leaf spring abut on the inner circumferential surface of the cylindrical portion, The cylindrical portion is a circular tube, and when the inner diameter of the circular tube is a and the length of the leaf spring is L, 1.2 × a ≦ L ≦ 3.0 × a. The drain device according to any one of the first to seventh aspects, characterized in that: [Explanation of symbols]

[0117] 1. Waterproofing base 2 Drain base 3 Drain pipe 4 Existing waterproofing layer 5 Waterproof layer 10, 20 Drain device 12f Connecting shaft body 12g, 12Ag, 12Bg, 12Cg, 12Dg First leaf spring 12h Second leaf spring 22f First connecting shaft 22m 2nd connecting shaft 22g 1st leaf spring 22h Second leaf spring 22Ag, 22Bg leaf springs 11, 21 Strainer 12, 22 Coupling device 13, 23 Drain body

Claims

1. A drain body including a cylindrical portion connected to a drain pipe and a plate portion having an opening to which the cylindrical portion is connected; a strainer covering the opening; a connecting device that connects the drain body and the strainer, the coupling device includes a leaf spring having an end that abuts against an inner circumferential surface of the cylindrical portion, When a force is applied to the strainer in a direction away from the cylindrical portion, the longitudinal compressive stress of the leaf spring increases, thereby increasing the friction force between the end of the leaf spring and the inner surface of the cylindrical portion. A drain device characterized by:

2. The end of the leaf spring that contacts the inner circumferential surface of the cylindrical portion faces the opening side. The drain device according to claim 1 .

3. the connecting device has a connecting shaft connected to the leaf spring, The connecting shaft is detachably connected to the strainer by a fastener exposed to the outside of the strainer. The drain device according to claim 1 .

4. The longitudinal center of the leaf spring is connected to the end of the connecting shaft body, and both ends of the leaf spring abut on the inner circumferential surface of the cylindrical portion. The drain device according to claim 3 .

5. The leaf spring is detachably connected to the strainer by a fastener exposed on the outside of the strainer. The drain device according to claim 1 .

6. The drain device is for vertical pulling, and the end of the leaf spring and the inner circumferential surface of the cylindrical portion have two or more contact points. The drain device according to claim 1 .

7. The drain device is for horizontal pulling, and the end of the leaf spring and the inner circumferential surface of the cylindrical portion have two or more contact points. The drain device according to claim 1 .

8. Both ends of the leaf spring abut on the inner circumferential surface of the cylindrical portion, The cylindrical portion is a circular tube, and when the inner diameter of the circular tube is a and the length of the leaf spring is L, 1.2 × a ≦ L ≦ 3.0 × a is satisfied. The drain device according to any one of claims 1 to 7.

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