Drain socket, and siphon-type water closet provided with the same

Abstract

To provide a drain socket capable of forming a watertight area early to generate siphonage, and a siphon-type water closet provided with the same.SOLUTION: The drain socket 1 of the present invention comprises a vertical flow path 18 connected to a downstream end 12e of a drain trap pipeline 12 and forming a flow path extending in a vertical direction, and a flow path resistance section 24 provided on an upstream side in the vertical flow path, wherein the flow path resistance section includes a ramp 26 formed convexly and smoothly on an upstream side, a minimum diameter part 28 formed at an innermost end of the ramp, a projection 30 provided downstream of the minimum diameter part and protruding inward from a wall surface 18c of the vertical flow path, and an enlarged area 32 expanding the vertical flow path radially outward from the ramp toward a downstream side, and a flow path diameter D1 at an upstream end of the ramp is set to be larger than a flow path diameter D2 at the downstream end of the drain trap pipeline.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a drain socket and a siphon flush toilet equipped with it, and in particular to a drain socket that connects the drain trap pipe of a siphon flush toilet to an external drain pipe, and a siphon flush toilet equipped with it. [Background technology]

[0002] BACKGROUND ART Conventionally, drain sockets that connect the drain trap pipe of a siphon flush toilet to an external drain pipe are known, for example, from those described in Patent Documents 1 and 2. First, in the conventional drain socket described in Patent Document 1, an expanded flow path area that expands the flow path is provided upstream of the drain socket to which the outlet of the drain trap pipe of a siphon flush toilet is connected. Wastewater discharged from the outlet of the drain trap pipe temporarily accumulates in this expanded flow path area of the drain socket, inducing a siphon action. Furthermore, in the conventional drain socket described in Patent Document 2, multiple flow straightening plates are provided upstream of the enlarged flow path area of the internal flow path. The wastewater flowing down from the upstream side of the drain socket collides with the flow straightening plates before reaching the enlarged flow path area. This causes the wastewater to splash into the flow path after the collision, creating turbulence, and the flow path volume is reduced by the straightening plate, which has a synergistic effect, causing the flow path to fill up quickly, shortening the time until siphoning occurs. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-152534 [Patent Document 2] International Publication No. 2004 / 048708 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, with the trend toward water conservation in siphon flush toilets, an important issue has become how to increase the efficiency of the siphon action in the drain trap pipe and the drain socket downstream of it, while minimizing the amount of water wasted up until the siphon action occurs and ensuring that it occurs early. However, particularly in the case of drain sockets, if a flow path resistance portion or the like is provided in the drain socket in order to improve siphon activation, there is a problem in that there is a risk of clogging with filth.

[0005] Therefore, the present invention has been made to solve the problems and issues of the prior art mentioned above, and aims to provide a drain socket that can quickly form a watertight area and generate a siphon action, and a siphon-type flush toilet equipped with the same. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the present invention provides a drain socket that connects a drain trap pipe of a siphon type flush toilet to an external drain pipe, and has a vertical flow path that is connected to the downstream end of the drain trap pipe and forms a flow path that extends vertically, and a flow path resistance portion provided on the upstream side of this vertical flow path, the flow path resistance portion having a gently convex inclined portion formed on the upstream side, a narrowest diameter portion formed at the innermost end of the inclined portion, a protruding portion provided downstream of the narrowest diameter portion and protruding inward from the wall surface of the vertical flow path, and an expanding region that expands the vertical flow path radially outward from the inclined portion toward the downstream side, and is characterized in that the flow path diameter at the upstream end of the inclined portion is set to be larger than the flow path diameter at the downstream end of the drain trap pipe. In the present invention configured in this manner, when wastewater from the drain trap pipe of a siphon flush toilet is discharged into the vertical flow path of the drain socket, a watertight area can be formed early on in the flow path resistance section upstream within this vertical flow path, allowing the siphon action to occur. In addition, the inclined portion upstream of the flow path resistance portion is formed with a gentle convex slope, and the flow path diameter at the upstream end of the inclined portion is set to be larger than the flow path diameter at the downstream end of the drain trap pipe, so that drainage water from the drain trap pipe can be collected upstream within the vertical flow path of the drain socket, and a watertight area can be formed early. Furthermore, the protrusion of the flow path resistance portion can prevent waste from flowing in, while wastewater near the protrusion of the flow path resistance portion can flow along the protrusion due to the Coanda effect, thereby forming a watertight area in the flow path resistance portion early and generating a siphon action.

[0007] In the present invention, the downstream end of the expansion region preferably has an inner side that extends horizontally radially inward, or has an inner end that is provided with a turned portion that projects from the downstream side toward the upstream side. In the present invention configured in this manner, the wastewater flowing through the expansion area is collected at the downstream end of the expansion area along the protrusion due to the Coanda effect, and can then be guided toward the center of the flow path cross section by the return section, thereby more reliably forming a watertight area.

[0008] In the present invention, the flow path diameter of the narrowest diameter portion is preferably approximately the same as the flow path diameter of the downstream end of the drain trap pipe line. In the present invention configured in this manner, waste discharged from the downstream end of the drain trap pipe is discharged downstream from the narrowest diameter section, which has a flow path diameter approximately the same as the flow path diameter at the downstream end of the drain trap pipe, thereby preventing clogging with waste.

[0009] In the present invention, preferably, the inclined portion includes a convex curved surface whose inner side is connected to the most reduced diameter portion, and the center of the radius of curvature of this convex curved surface in a vertical plane view is located downstream of the most reduced diameter portion. In the present invention configured in this manner, the inside of the inclined portion includes a convexly curved surface connected to the most narrowed diameter portion, and the center of the radius of curvature of this convexly curved surface in a vertical view is located downstream of the most narrowed diameter portion.Therefore, a gentle convexly curved surface can be reliably formed on the connecting side of the inclined portion with the most narrowed diameter portion, and a watertight region can be secured upstream of the most narrowed diameter portion.

[0010] In the present invention, preferably, the flow path resistance portion comprises an inner flow path formed radially inward of the protrusion portion, and the flow path resistance portion comprises, from its upstream side to its downstream side, an expansion region in which the flow path cross-sectional area expands more than that of the inner flow path, a maximum cross-sectional area region in which the flow path cross-sectional area is maximum, and a contraction region in which the flow path cross-sectional area contracts from the maximum cross-sectional area region to the inner flow path, and the downstream end of the protrusion has a plurality of protrusions protruding downstream, and each of these plurality of protrusions defines the expansion region, the maximum cross-sectional area region, and the contraction region, respectively. In the present invention configured in this manner, the wastewater that flows from the downstream end of the drain trap pipe into the vertical flow path of the drain socket flows into the expanded area along the inclined part of the flow path resistance section due to the Coanda effect, and then passes through the maximum cross-sectional area and is discharged into the reduced area. On the other hand, most of the wastewater that flows from the downstream end of the drain trap pipe into the vertical flow path of the drain socket generally falls within the inner flow path, but even if some of the wastewater does enter the expanded area, it can be discharged into the reduced area along with the wastewater in the expanded area through the maximum cross-sectional area.

[0011] In the present invention, preferably, the plurality of protrusions each comprise a first protrusion and a second protrusion whose lower ends contact a portion of the wall surface of the enlarged region and the reduced region, and the first protrusion and the second protrusion are arranged radially spaced apart from each other so as to ensure a flow path in the maximum cross-sectional area region. In the present invention configured in this manner, the first and second protrusions of the multiple protrusions are arranged radially spaced apart from each other so as to ensure a flow area of the largest cross-sectional area, and therefore when wastewater flows through the expanded area along the inclined portion due to the Coanda effect and flows into the flow path of the largest cross-sectional area between the first and second protrusions of the multiple protrusions, the wastewater can be made watertight and then discharged into the reduced area.

[0012] In the present invention, preferably, the protrusions are a plurality of protrusions arranged at intervals in the circumferential direction within the vertical flow path, and the interval between adjacent protrusions among these multiple protrusions is set to 20 mm or less. In the present invention configured in this manner, the distance between adjacent protrusions among the multiple protrusions arranged at intervals circumferentially within the vertical flow path is set to 20 mm or less, so that, for example, waste larger than 20 mm will not become trapped between the protrusions, thereby preventing clogging with waste.

[0013] In the present invention, the member forming the reduced region is preferably a separate member independent of the members forming the enlarged region, the maximum cross-sectional area region, and the protrusion. In the present invention configured in this manner, the component forming the reduced area of the vertical area is a separate component independent of the components forming the expanded area, maximum cross-sectional area, and protrusion of the vertical flow path, which facilitates molding processes when manufacturing the drain socket, and allows for easy assembly by simply assembling the component forming the reduced area of the vertical flow path to the component forming the expanded area, maximum cross-sectional area, and protrusion of the vertical flow path.

[0014] In the present invention, the reduced area preferably has a rim portion that forms the flow path and that has a turned portion that projects from the downstream side toward the upstream side. In the present invention configured in this manner, when the wastewater flows through the expansion area along the slope due to the Coanda effect, flows into the flow path of the maximum cross-sectional area, and then flows into the contraction area, the wastewater can be made watertight and a siphon action can be generated.

[0015] The present invention also provides a siphon flush toilet equipped with the above-mentioned drain socket. With this configuration, the present invention can provide a siphon flush toilet that can conserve water and increase siphon efficiency. [Effects of the Invention]

[0016] According to the drain socket of the present invention and a siphon flush toilet equipped with it, a watertight area can be formed early on, allowing the siphon action to occur. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a schematic side cross-sectional view of a siphon flush toilet equipped with a drain socket according to an embodiment of the present invention. [Figure 2] 2 is a partially enlarged cross-sectional view showing an upstream portion of an internal flow path of the drain socket according to the embodiment of the present invention shown in FIG. 1. FIG. [Figure 3] FIG. 10 is a bottom view of the inner member of the flow resistance portion of the drain socket according to one embodiment of the present invention. [Figure 4] 3 is a diagram showing a schematic view of the flow of drainage in the internal flow path of the drain socket according to the embodiment of the present invention shown in FIG. 2. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0018] A drain socket according to one embodiment of the present invention, and a siphon flush toilet equipped with the same, will now be described with reference to the accompanying drawings. First, FIG. 1 is a schematic side cross-sectional view of a siphon flush toilet equipped with a drain socket according to this embodiment. As shown in Figure 1, a siphon flush toilet 2 equipped with a drain socket 1 according to this embodiment comprises a ceramic toilet body 4 that is placed on the floor F, and a flush water supply device 6 installed behind it. The drain socket 1 also connects the toilet body 4 to a floor-side drain pipe D that is installed so as to extend from below the floor F upward. As a result, the flush toilet 2 of this embodiment is installed so that the bottom surface of the toilet body 4 is in contact with the floor surface F, making it a so-called "floor-mounted flush toilet," and the toilet body 4 is connected to a floor-side drain pipe D (floor-side drain pipe D) via the drain socket 1, so that wastewater discharged from the toilet body 4 is drained into the floor-side drain pipe D via the drain socket 1, making it a so-called "floor-side drainage system."

[0019] Next, as shown in Figure 1, the toilet body 4 comprises a bowl portion 8 for receiving waste, a rim portion 10 formed on the upper edge of the bowl portion 8, and a drain trap pipe 12 extending from an inlet portion 12a connected to the bottom of the bowl portion 8 to discharge waste within the bowl portion 8. As shown in FIG. 1, the drain trap pipe 12 has an ascending pipe 12c that rises from the downstream side of the inlet 12a to a rearward and upward top 12b, and a descending pipe 12d that descends rearward and downward from the top 12b of the ascending pipe 12c. Furthermore, as shown in FIG. 1, the toilet body 4 is provided with a rim spout 14 provided in the rim portion 10 and a jet spout 16 provided below and outside the bowl portion 8. Here, the rim spout 14 is directed toward the front inside the bowl portion 8, while the jet spout 16 is directed toward the inlet portion 12a of the drain trap pipe 12 at the rear thereof. As a result, the flushing water supplied from the flushing water supply device 6 to the toilet body 4 is discharged W1 (rim discharge W1) from the rim discharge port 114 into the bowl section 8, while the jet discharge port 16 is discharged W2 (jet discharge W2) to spray flushing water toward the inlet section 12a of the forward drain trap pipe line 12. As a result, the flush toilet 2 according to this embodiment is a so-called "siphon-type flush toilet" that uses the siphon action to suck up waste inside the bowl section 8 and discharge it all at once to the outside through the drain trap pipe 12. The flush toilet 2 of this embodiment employs a toilet flushing method known as "rim-jet flushing," in which the toilet is flushed with flush water (rim water W1, jet water W2) discharged from each of the rim spout 14 and jet spout 16, but this is not limited to this; it is also possible to omit the jet spout 16 and flush the toilet only with flush water (rim water W1) discharged into the bowl section 8 from only the rim spout 14, in other words, a toilet flushing method using "100% rim water discharge."

[0020] As shown in FIG. 1, the flush water supply device 6 employs a tank device that includes a water storage tank (not shown) that stores flush water supplied from a water supply source (not shown) such as a tap, and a pump (not shown) that pressure-feeds the flush water in the water storage tank (not shown) to the toilet body 4, but as the details of these are the same as those of conventional tank devices, explanations thereof will be omitted. The tank device may take the form of a so-called gravity-fed water storage tank, in which flush water stored in a water storage tank (not shown) is supplied to the toilet body 4 using gravity. Alternatively, a flush water supply device 6 other than a tank device may be a direct water pressure type or flush valve type that directly uses the water supply pressure of tap water to supply it directly to the toilet body 4.

[0021] Furthermore, the siphon-type flush toilet 2 of this embodiment may be a so-called tank-type flush toilet, in which flush water stored in a water storage tank (not shown) of the flush water supply device 6 is supplied to each of the rim spout 14 and jet spout 16 of the toilet body 4. Alternatively, the siphon flush toilet 2 of this embodiment may be a so-called hybrid flush toilet in which flush water supplied to the flush water supply device 6 under direct pressure from the water mains is supplied directly to the rim spout 14 of the toilet body 4, and flush water that is supplied to and stored in a water storage tank (not shown) of the flush water supply device 6 is supplied to the jet spout 16 of the toilet body by a pump (not shown).

[0022] Next, the drain socket 1 of this embodiment will be described in detail with reference to FIGS. 2 is a partially enlarged cross-sectional view of an upstream portion of an internal flow path of the drain socket according to the embodiment of the present invention shown in FIG. 1. FIG. First, as shown in Figures 1 and 2, the drain socket 1 connects the toilet-side drain outlet 12e of the toilet body 4 of the siphon flush toilet 2 to the floor-side drain outlet D0, which is the inlet of the floor-side drain pipe D. From upstream to downstream, this drain socket 1 is equipped with a vertical pipe 18, a connecting pipe 20, and a horizontal pipe 22, and these pipes 18, 20, and 22 form an internal flow path.

[0023] Next, as shown in Figure 2, the vertical pipeline 18 has its upstream end 18a (upper end 18a) connected to the outlet portion 12e of the drain trap pipeline 12 via a circular elastic seal connecting member M0 made of a rubber material or the like, thereby forming a vertical flow path 18 that extends entirely in the vertical direction. Furthermore, on the upstream side within the vertical flow path 18, a flow path resistance portion 24 is provided at a predetermined distance d1 downstream (downward) from the outlet portion 12e of the drain trap pipe line 12. Here, the flow path resistance portion 24 includes a generally annular inner member M1 and an outer member M2 provided on the outside of the inner member M1. Furthermore, the outer member M2 forms a part of the vertical flow path 18 upstream of the flow path resistance section 24, and also forms a part of the flow area downstream of the flow path resistance section 24, and is a separate member different from the inner member M1.

[0024] Furthermore, as shown in FIG. 1, the connecting pipeline 20 forms a flow path that extends vertically downward from an upstream end 20a (upper end 20a) connected to the downstream end 18b (lower end 18b) of the vertical pipeline 18 and then bends toward the horizontal downstream end 20b (front end 20b). As shown in Figure 1, the horizontal pipeline 22 has an upstream end 22a (rear end 22a) connected to the downstream end (front end 20b) of the connecting pipeline 20, and a downstream end 22b (lower end 22b) connected to the floor-side drain outlet D0, and forms a flow path that extends horizontally rearward from the upstream end 22a (rear end 22a) and then bends downward toward the downstream end 22b (lower end 22b) and the floor-side drain outlet D0. Here, as shown in Figures 1 and 2, the central axis A1 (drainage core A1) passing through the center O1 of the toilet side drain outlet 12e and extending vertically within the vertical pipe 18 is located a predetermined distance behind the central axis A2 (drainage core A2) passing through the center O2 of the floor side drain outlet D0 and extending vertically within the floor side drain pipe D, and the two centers O1, O2 are arranged eccentric to each other.

[0025] Next, the flow path resistance portion 24 of the drain socket 1 of this embodiment will be described in detail with reference to FIGS. FIG. 3 is a bottom view of the inner member of the flow resistance portion of the drain socket according to one embodiment of the present invention. As shown in Figures 2 and 3, the inner member M1 of the flow path resistance section 24 is a member that has, generally from the upstream side to the downstream side, an inclined section 26, a narrowest diameter section 28, a protruding section 30, and an enlarged region 32, and is formed into a generally cylindrical overall shape.

[0026] First, as shown in FIGS. 2 and 3, the inclined portion 26 is provided along the inner periphery of the upper rim portion 24a of the flow path resistance portion 24. Here, as shown in Figure 2, the flow path diameter D1 (diameter D1) at the upstream end 26a of the inclined portion 26 is set to be larger than the flow path diameter D2 (diameter D2) at the downstream end 12e (outlet portion 12e) of the drain trap pipe line 12 (D1>D2). Also, as shown in Figure 2, in a side view, the inclined portion 26 forms a gently sloping convex surface S1 extending from the upstream side (upper side) of the flow path resistance portion 24 toward the inner side in the flow path radial direction of the vertical flow path 18 (toward the center O3 of the upper edge portion 24a) and downstream side (lower side). Furthermore, as shown in Figure 2, the inclined surface S1 of the inclined portion 26 includes a convex curved surface S1 whose inside (more specifically, the lower end and innermost end) is connected to the narrowest diameter portion 28, and the center O4 of the curvature radius ρ1 of this convex curved surface S1 in a vertical view is located downstream (below) of the narrowest diameter portion 28.

[0027] Next, as shown in FIGS. 2 and 3, the narrowest diameter portion 28 is formed at the lower end and innermost end of the inclined portion 26. As shown in FIG. 2, the flow path diameter D3 (diameter D3) of the narrowest diameter portion 28 is approximately the same as the flow path diameter D2 (diameter D2) of the downstream end 12e (outlet portion 12e) of the drain trap pipe line 12 (D3≒D2). Furthermore, as shown in Figures 2 and 3, the protrusions 30 are provided downstream of the narrowest diameter section 28, and are formed in the shape of a thin plate protruding inward from the inner wall surface 18c of the vertical pipe 18, and multiple (e.g., 14) of them are provided at equal intervals in the circumferential direction.

[0028] 2 and 3, the expansion region 32 is a region that expands the vertical flow path 18 radially outward from the inclined portion 26 toward the downstream side. That is, due to this expansion region 32, the inner wall surface 18c of the vertical pipeline 18 is positioned more radially outward as it moves from the upstream side (upper side) to the downstream side (lower side). In addition, the downstream end 32a (lower end 32a) of the expansion region 32 has a return portion 34 whose inner side extends horizontally radially inward and whose inner end protrudes from the downstream side (lower side) toward the upstream side (upper side).

[0029] Next, as shown in FIGS. 2 and 3, the flow path resistance portion 24 of the vertical flow path 18 further includes an inner flow path 36 formed radially inward of the protruding portion 30 . As a result, the flow path resistance portion 24 of the vertical flow path 18 expands from the upstream side to the downstream side thereof by the flow path cross-sectional area C1 of the expansion region 32 compared to the flow path cross-sectional area C0 of the inner flow path . The flow resistance portion 24 of the vertical flow path 18 further includes a maximum cross-sectional area region 38 and a reduced area 40 . The maximum cross-sectional area region 38 is provided on the most downstream side (lower side) and outermost side of the expansion region 32, and is a region where the flow path cross-sectional area C2 is maximum.

[0030] Furthermore, the reduced area 40 is provided downstream of the maximum cross-sectional area area 38 and the inner flow path 36, and is an area in which the flow path cross-sectional area C3 is reduced from the flow path cross-sectional area C2 of the maximum cross-sectional area area 38 to the flow path cross-sectional area C0 of the inner flow path 36. The flow path cross-sectional area C3 of the contraction region 40 is a region that contracts from the flow path cross-sectional area C2 of the maximum cross-sectional area region 38 to the flow path cross-sectional area C0 of the inner flow path 36. In other words, the flow path cross-sectional area C3 of the contraction region 40 is set to be the same as the flow path cross-sectional area C0 of the inner flow path 36 (C3 = C0).

[0031] Next, as shown in FIGS. 2 and 3, the downstream end 30a (lower edge 30a) of each of the plurality (14) of protrusions 30 is formed in a shape that is generally concave upward in an arch shape. Furthermore, at the downstream end 30a (lower edge 30a) of each of these multiple (14) protrusions 30, multiple (two) first protrusions 42 (outer protrusions 42) and second protrusions 44 (inner protrusions 44) protruding downstream (downward) are provided at the outer end and inner end in the radial direction of the flow path, respectively. As a result, the plurality of (two) protrusions 42, 44 are arranged spaced apart from each other in the radial direction of the flow passage. Furthermore, the outer projections 42 define the outer edge of the maximum cross-sectional area region 38, and the inner projections 44 define the outer edges of the inner flow passage 36 and the contraction region 40. The projections 42, 44 also define the downstream region of the expansion region 32 between them.

[0032] Here, as shown in FIGS. 2 and 3, the lower end 42a of the first projection 42 (outer projection 42) is in contact with a part of the wall surface 32b on the downstream side (lower side) of the enlarged region 32. Furthermore, the lower end 44a of the second projection 44 (inner projection 44) is in contact with a part of the inner circumferential upper wall surface 40a of the reduced region 40. Furthermore, the first protrusion 42 (outer protrusion 42) and the second protrusion 44 (inner protrusion 44) of each protrusion 30 are arranged spaced apart from each other in the flow path radial direction, thereby ensuring a flow path 38a of the maximum cross-sectional area region 38 that connects the lower regions of adjacent protrusions 30 to each other in the circumferential direction.

[0033] Next, as shown in FIG. 3, a plurality of (14) protrusions 30 are arranged in the vertical flow path 18 at equal intervals in the circumferential direction. Here, the circumferential distance d2 between the inner ends of adjacent protrusions 30 among the plurality (14) of protrusions 30 is set to 20 mm or less. Moreover, the enlarged region 32, the maximum cross-sectional area region 38, and the protrusion 30 of the vertical flow passage 18 are integral with one another and are formed from the same inner member M1. On the other hand, the outer member M2 forms a reduced area 40 downstream of the inner member M1, and is an independent member that is different from the inner member M1. Furthermore, the reduced region 40 has a rim 40b that forms a flow path on the upstream side thereof, and forms a return portion 34 that projects from the downstream side toward the upstream side. As described above, this return portion 34 is formed so that the inside of the downstream end 32a (lower end 32a) of the expansion region 32 extends horizontally radially inward, and then its inner end protrudes from the downstream side (lower side) toward the upstream side (upper side).

[0034] Next, the operation of the drain socket 1 according to the present embodiment described above, and the siphon flush toilet 2 equipped with it, will be explained with reference to FIGS. FIG. 4 is a diagram schematically illustrating the flow of drainage water in the internal flow path of the drainage socket according to the embodiment of the present invention shown in FIG. First, as shown in Figures 1 to 4, with the drain socket 1 of this embodiment, when wastewater W3 from the drain trap pipe 12 of the siphon type flush toilet 2 is drained into the vertical flow path 18 of the drain socket 1, a watertight area can be formed early on in the flow path resistance section 24 on the upstream side within this vertical flow path 18, and a siphon action can be generated. In addition, the inclined portion 26 on the upstream side of the flow path resistance portion 24 is formed with a gentle convex slope, and the flow path diameter D1 (diameter D1) of the upstream end 26a of the inclined portion 26 is set to be larger than the flow path diameter D2 (diameter D2) of the downstream end 12e (outlet portion 12e) of the drain trap pipe line 12. This allows the drainage water W3 from the drain trap pipe line 12 to be collected on the upstream side within the vertical flow path 18 of the drain socket 1, allowing a watertight area to be formed early. Furthermore, the protrusion 30 of the flow path resistance portion 24 can prevent waste from flowing in, while the wastewater W3 near the protrusion 30 of the flow path resistance portion 24 can flow along the protrusion 30 due to the Coanda effect, thereby forming a watertight area in the flow path resistance portion 24 early on and generating a siphon action.

[0035] Next, according to the drain socket 1 of this embodiment, as shown in Figures 2 and 4, the downstream end 32a (lower end 32a) of the expanded area 32 has a return portion 34 whose inner side extends horizontally radially inward, and whose inner end protrudes from the downstream side (lower side) toward the upstream side (upper side). As a result, the wastewater W3 flowing through the enlarged area 32 of the flow path resistance section 24 is collected at the downstream end 32a of the enlarged area 32 along the protrusion 30 due to the Coanda effect, and can then be guided toward the center of the flow path cross section by the return section 34, thereby more reliably forming a watertight area.

[0036] Furthermore, according to the drain socket 1 of this embodiment, as shown in Figure 2, the flow path diameter D3 (diameter D3) of the narrowest diameter portion 28 is approximately the same as the flow path diameter D2 (diameter D2) of the downstream end 12e (outlet portion 12e) of the drain trap pipe line 12 (D3 ≒ D2). As a result, waste discharged from the downstream end 12e (outlet section 12e) of the drain trap pipe 12 is discharged downstream from the narrowest diameter section 28, which has a flow path diameter D3 (diameter D3) that is approximately the same as the flow path diameter D2 (diameter D2) of the downstream end 12e (outlet section 12e) of the drain trap pipe 12, thereby preventing clogging with waste.

[0037] Furthermore, according to the drain socket 1 of this embodiment, as shown in Figure 2, the inclined surface S1 of the inclined portion 26 includes a convex curved surface S1 whose inner side (more specifically, the lower end and innermost end) is connected to the narrowest diameter portion 28, and the center O4 of the curvature radius ρ1 of this convex curved surface S1 when viewed in a vertical plane is located downstream (below) of the narrowest diameter portion 28. This makes it possible to reliably form a gently sloping convex curved surface S1 on the connecting side of the inclined portion 26 with the narrowest diameter portion 28, and to ensure a watertight region on the upstream side of the narrowest diameter portion 28.

[0038] Furthermore, with the drain socket 1 of this embodiment, as shown in Figures 2 and 4, wastewater W3 that flows from the downstream end 12e (outlet section 12e) of the drain trap pipe 12 of the siphon flush toilet 2 into the vertical flow path 18 of the drain socket 1 flows into the enlarged area 32 along the inclined section 26 of the flow path resistance section 24 due to the Coanda effect, and then passes through the maximum cross-sectional area 38 and is discharged into the reduced area 40. On the other hand, most of the wastewater W3 that flows from the downstream end 12e (outlet section 12e) of the drain trap pipe 12 into the vertical flow path 18 of the drain socket 1 generally falls within the inner flow path 36, but even if some of the wastewater W3 does enter the expanded area 32, it can be discharged together with the wastewater W3 in the expanded area 32 through the maximum cross-sectional area 38 into the reduced area 40.

[0039] Furthermore, according to the drain socket 1 of this embodiment, as shown in Figures 2 to 4, the first protrusions 42 and second protrusions 44 of the multiple protrusions 42, 44 of each protrusion 30 are arranged at a distance from each other in the flow path radial direction so that each secures a flow area (flow path 38a) of the maximum cross-sectional area 38.Therefore, when the drainage water W3 flows through the expanded area 32 along the inclined portion 26 due to the Coanda effect and flows into the flow path 38a of the maximum cross-sectional area 38 between the first protrusion 42 and the second protrusion 44, the drainage water W3 can be made watertight and then discharged into the reduced area 40.

[0040] Furthermore, according to the drain socket 1 of this embodiment, as shown in Figure 3, within the vertical flow path 18, the circumferential spacing d2 between the inner ends of adjacent protrusions 30 in multiple (14) protrusions 30 is set to 20 mm or less. This prevents waste larger than, for example, 20 mm from getting caught between the protruding portions 30, thereby preventing clogging with waste.

[0041] Furthermore, according to the drain socket 1 of this embodiment, as shown in Figure 2, the outer member M2 of the flow path resistance portion 24 that forms the reduced area 40 of the vertical flow path 18 is a separate member independent of the inner member M1 of the flow path resistance portion 24 that forms the expanded area 32, maximum cross-sectional area 38, and protrusion 30 of the vertical flow path 18. This makes it easier to carry out molding processes etc. when manufacturing the drain socket 1, and it can be easily assembled by simply assembling the outer member M2 of the flow path resistance section 24, which forms the reduced area 40 of the vertical flow path 18, to the inner member M1 of the flow path resistance section 24, which forms the expanded area 32, maximum cross-sectional area 38, and protrusion 30 of the vertical flow path 18.

[0042] Furthermore, according to the drain socket 1 of this embodiment, as shown in Figures 2 and 4, in the reduced area 40, the rim portion 40b that forms the flow path on the upstream side forms a return portion 34 that protrudes from the downstream side toward the upstream side. Therefore, when the wastewater W3 flows through the expansion area 32 along the inclined portion 26 due to the Coanda effect, flows into the flow path 38a of the maximum cross-sectional area area 38, and then flows into the contraction area 40, the wastewater W3 can be made watertight, and a siphon action can be generated.

[0043] Furthermore, a siphon flush toilet 2 equipped with a drain socket 1 according to this embodiment can improve siphon efficiency while also saving water.

[0044] Furthermore, the siphon flush toilet 2 equipped with the drain socket 1 of this embodiment described above is a "floor-standing flush toilet" and has been described as having a "floor-side drainage system," but it can also be applied to other types of siphon flush toilets. For example, another type of siphon flush toilet may be a so-called "wall-hung flush toilet" in which the bottom surface of the toilet body 4 is positioned above and spaced apart from the floor surface F, and the rear end of the toilet body 4 is fixed to the wall surface behind it, and may also be in the form of a "floor-side drainage system." Alternatively, for these siphon-type flush toilets, instead of adopting the "floor-side drainage system," a so-called "wall-side drainage system" may be adopted, in which wastewater discharged from the toilet body 4 passes through the drain socket 1 and is drained into a wall-side drain pipe (not shown) that is installed so as to extend forward from the back side of the wall behind the toilet body 4. [Explanation of symbols]

[0045] 1. Drainage socket according to one embodiment of the present invention 2. Siphon-type flush toilet 4 Toilet body 6 Cleaning water supply device 8 Toilet bowl 10 Rim of toilet bowl body 12 Toilet body drain trap pipe 12a Inlet of drain trap pipe 12b Top of drain trap line 12c Drain trap pipe riser 12d Downstream pipe of drain trap pipe 12e Outlet of drain trap pipe, downstream end of drain trap pipe 14 Rim Spout 16 Jet Spout 18 Vertical pipe line of drain socket (vertical flow path) 18a Upstream end (upper end) of the vertical pipe (vertical flow path) of the drain socket 18b Downstream end (bottom end) of the vertical pipe (vertical flow path) of the drain socket 18c Inner wall surface of the vertical pipe (vertical flow path) of the drain socket 20 Drainage socket connecting pipe, first bent flow path 20a Upstream end (top end) of the drain socket connection pipe 20b Downstream end (front end) of the drain socket connection pipe 20c Vertical inner wall of the drain socket connection pipe 22 Horizontal pipe for drain socket 22a Upstream end (rear end) of horizontal drainage socket pipe 22b Downstream end (bottom end) of horizontal pipe of drain socket 24 Flow resistance 24a Upper rim 26 Slope 26a Upstream end of the slope 28 Most reduced diameter part 30 Protrusion 30a downstream end of the protrusion, lower edge of the protrusion 32 Expanded Area 32a Downstream end and bottom end of the expansion area 32b Downstream (lower) wall of the expansion area (wall of the expansion area) 34 Return part 36 Inner flow path 38 Maximum cross-sectional area 38a Flow path with maximum cross-sectional area 40 Reduced area 40a: Inner upper wall surface of the reduction area (wall surface of the reduction area) 40b Rim of reduced area 42 1st process, lateral process 42a Lower end of first protrusion, lower end of outer protrusion 44 Second process, medial process 44a Lower end of second protrusion, lower end of inner protrusion A1 Central axis of the toilet drain outlet, central axis of the vertical flow path, drain core A2 Center axis of the inlet of the floor-side drain pipe, drain core C0 Channel cross-sectional area of inner channel C1 Cross-sectional area of the expansion region C2: Maximum cross-sectional area of the flow path C3 Cross-sectional area of the narrowed region D Floor side drain pipe D0 Floor drain pipe inlet, floor drain outlet D1: Flow path diameter at the upstream end of the slope D2: Flow path diameter at the downstream end of the drain trap pipe D3: Diameter of the narrowest part of the flow passage d1 Predetermined distance d2 Circumferential distance between the inner ends of the protrusions F Floor M0 Elastic seal connecting member M1 Inner member of flow resistance part M2 Outer member of flow resistance part O1 Center of toilet drain O2 Center of floor drain pipe inlet O3 Center of the inner periphery of the upper lip of the flow path forming member O4 Center of curvature radius S1 Gently inclined surface, convex curved surface W1 Rim Spout W2 Jet Water Spout W3 Drainage ρ1 Radius of curvature of a convex curved surface in a vertical view ρ2 Radius of curvature of the downward bend of the first bend in the connecting pipe

Claims

1. A drain socket that connects the drain trap pipe of a siphon-type flush toilet to an external drain pipe, A vertical flow path that is connected to the downstream end of the drain trap pipe and forms a flow path that extends in a vertical direction; a flow path resistance portion provided on the upstream side of the vertical flow path, the flow path resistance portion includes an inclined portion formed in a gently convex shape on the upstream side thereof, a diameter-reduced portion formed at the innermost end of the inclined portion, a protruding portion provided on the downstream side of the diameter-reduced portion and protruding inward from a wall surface of the vertical flow path, and an expanding region that expands the vertical flow path radially outward from the inclined portion toward the downstream side, A drain socket characterized in that the flow path diameter at the upstream end of the inclined portion is set to be larger than the flow path diameter at the downstream end of the drain trap pipe.

2. A drain socket as described in claim 1, wherein the downstream end of the expanded area has an inner side that extends horizontally radially inward, or an inner end that has a turned portion that protrudes from the downstream side toward the upstream side.

3. 2. The drain socket according to claim 1, wherein the flow path diameter at the narrowest diameter portion is substantially the same as the flow path diameter at the downstream end of the drain trap pipe line.

4. A drain socket as described in claim 1, wherein the inclined portion includes a convex curved surface whose inner side is connected to the narrowest diameter portion, and the center of the radius of curvature of this convex curved surface in a vertical view is located downstream of the narrowest diameter portion.

5. the flow path resistance portion includes an inner flow path formed radially inward of the protrusion portion, the flow path resistance portion includes, from the upstream side to the downstream side thereof, an expanding region in which the flow path cross-sectional area is expanded more than that of the inner flow path, a maximum cross-sectional area region in which the flow path cross-sectional area is maximum, and a contracting region in which the flow path cross-sectional area is contracted from the maximum cross-sectional area region to the inner flow path, The drain socket of claim 1, wherein the downstream end of the protrusion has a plurality of protrusions protruding downstream, each of the plurality of protrusions defining the enlarged region, the maximum cross-sectional area region, and the reduced region.

6. A drain socket as described in claim 5, wherein the plurality of protrusions each include a first protrusion and a second protrusion whose lower ends contact a portion of the wall surface of each of the enlarged area and the reduced area, and the first protrusion and the second protrusion are arranged radially spaced apart from each other to ensure a flow path in the maximum cross-sectional area.

7. A drain socket as described in claim 5, wherein the protrusions are multiple protrusions arranged at intervals circumferentially within the vertical flow path, and the spacing between adjacent protrusions among these multiple protrusions is set to 20 mm or less.

8. 6. The drain socket of claim 5, wherein the member forming the reduced area is a separate member from the members forming the enlarged area, the maximum cross-sectional area, and the protrusion.

9. 6. The drain socket according to claim 5, wherein the reduced area has a rim portion that forms the flow path and that has a turn-back portion that projects from the downstream side toward the upstream side.

10. A siphon flush toilet equipped with the drain socket according to any one of claims 1 to 9.

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