Seal member and drain valve device equipped with same

Abstract

To provide a seal member and a drain valve device equipped with the seal member that can suppress performance degradation due to deformation of the attached member while improving the positioning accuracy of the attached member when attaching other members to a ceramic water-related product.SOLUTION: There is provided a seal member (4) that is placed between a pottery water-related product (6) and other members (2) to ensure watertightness between them, comprising an annularly formed base (22), a positioning rib (18) that is formed on this base so as to extend in the circumferential direction and is not substantially deformed when used by being placed between the water-related product and other members, and at least one watertight rib (20) provided on the base, and formed on the circumferential side of the locating rib portion so as to extend circumferentially and to be more elastically deformed than the positioning rib when placed between the water-related product and other members.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a sealing member, and more particularly to a sealing member that is placed between a ceramic plumbing product and another member to ensure watertightness between them, and a drain valve device equipped with the sealing member. [Background technology]

[0002] In general, sealing members such as packings are placed at the joints between components of water-related products to ensure watertightness between the components. The sealing members are usually made of elastically deformable materials, and are sandwiched between the components and deformed a certain amount to adhere to the components and ensure watertightness. However, when the sealing members are elastically deformed by fastening the components together with screws, fastening metal fittings, etc., the relative positions between the components change depending on the fastening torque of the screws, etc., and there is a problem that the components cannot be positioned accurately. In addition, when multiple fastening metal fittings, etc. are fastened unevenly, the components that should be mounted perpendicular to the mounting surface may be mounted at an angle, and the expected performance may not be achieved. For this reason, when it is necessary to position the components relatively accurately, the amount of elastic deformation of the sealing members is controlled by specifying the fastening torque of the screws, etc.

[0003] Meanwhile, Japanese Patent Application Laid-Open Publication No. 2016-172985 (Patent Document 1) describes a drain valve device and a flush water tank device equipped with this drain valve device. This drain valve device is attached watertight to the bottom surface of the flush water tank, and a seal member is disposed between the drain valve device and the bottom surface of the flush water tank. In addition, a flange portion called a "return" is provided on the bottom of this drain valve device so as to surround the seal member, and the seal member can be elastically deformed by an appropriate amount by tightening the fixing metal fittings until this flange portion abuts against the bottom surface of the flush water tank. In addition, by attaching the drain valve device so that the flange portion abuts against the bottom surface of the flush water tank, the drain valve device can be positioned relatively accurately. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-172985 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in order to control the elastic deformation of the seal member by the tightening torque of the screws, fasteners, etc., it is necessary to tighten the screws using a torque wrench, etc. at the construction site, which reduces workability. In addition, the torque is not adequately controlled, which increases the probability of construction defects.

[0006] On the other hand, as in the drain valve device described in Patent Document 1, by providing a flange or the like that abuts against the mounting surface, it becomes unnecessary to manage the tightening torque, but there are cases where a flange or the like cannot be provided depending on the shape of the member. Furthermore, by attaching a member having a flange to a ceramic mounting surface, the attached member may be deformed, which may cause a decrease in performance. That is, the mounting surface of a ceramic plumbing product has undulations and irregularities of up to about 1 mm. For this reason, when a fixing bracket or the like is tightened so that the flange or the like abuts against such a mounting surface, the attached member may be locally deformed along the undulations of the mounting surface, which may cause a decrease in performance.

[0007] For example, when attaching a drain valve device to the bottom of a ceramic flush water tank, if the fixing bracket or the like is tightened so that the flange abuts against the bottom, the flange and the valve seat of the drain valve located nearby may be locally deformed along the undulations of the ceramic bottom. If the valve seat of the drain valve is locally deformed by attachment to the mounting surface in this way, there is a risk that the drain / stop performance of the drain valve device will be adversely affected.

[0008] Therefore, the present invention aims to provide a sealing member that can improve the positioning accuracy of a component to be attached when other components are attached to a ceramic plumbing product, while suppressing performance degradation due to deformation of the attached component, and a drain valve device equipped with the same. [Means for solving the problem]

[0009] In order to solve the above-mentioned problems, the present invention provides a sealing member that is placed between a ceramic bathroom product and other components to ensure watertightness between them, and is characterized by having a base formed in a circular ring shape, a positioning rib portion formed on the base so as to extend in a circumferential direction and that is not substantially deformed when placed between the bathroom product and other components and used, and at least one watertight rib portion formed on the base on the outer periphery of the positioning rib portion so as to extend in the circumferential direction and that is elastically deformed to a greater extent than the positioning rib portion when placed between the bathroom product and other components and used.

[0010] In the present invention thus constructed, when the seal member is used between a ceramic plumbing product and another member, the positioning rib of the seal member is not substantially deformed, and the distance between the plumbing product and the other member is determined by the thickness of the positioning rib. On the other hand, when the seal member is used between a plumbing product and another member, the watertight rib formed on the outer periphery of the positioning rib is elastically deformed more than the positioning rib, and the watertight rib is in close contact with the surface of the plumbing product or the other member, ensuring watertightness.

[0011] According to the present invention configured as described above, since the positioning rib is not substantially elastically deformed, the position of the other member relative to the water-related product can be accurately determined without strictly controlling the fastening force between the water-related product and the other member. Furthermore, since the watertight rib is elastically deformed more than the positioning rib, and the deformation amount of the watertight rib is determined by the positioning rib, the watertight rib can be deformed by an appropriate amount, and watertightness between the water-related product and the other member can be reliably ensured. Furthermore, since the other member abuts against the ceramic water-related product via the positioning rib, local deformation of the other member due to direct abutment against the water-related product having undulations or the like can be suppressed.

[0012] In the present invention, the positioning rib portion is preferably formed so that its radial width is greater than that of the watertight rib portion. According to the present invention configured in this manner, the radial width of the positioning rib portion is formed wider than the radial width of the watertight rib portion, so that a positioning rib portion that is substantially undeformed and a watertight rib portion that undergoes greater elastic deformation than the positioning rib portion can be realized with a simple configuration.

[0013] In the present invention, the watertight rib portion is preferably formed to have a height greater than that of the positioning rib portion. According to the present invention thus configured, the height of the watertight rib is formed to be higher than the height of the positioning rib, so that when the positioning rib is in contact with a water-related product or other member, the watertight rib is elastically deformed by a predetermined amount, and watertightness can be reliably ensured. Also, the deformation amount of the watertight rib can be freely set by the height of the watertight rib.

[0014] In the present invention, the watertight rib portion is preferably formed so as to be inclined in the radial direction. According to the present invention configured in this manner, the watertight rib portion is formed so as to be inclined in the radial direction. Therefore, when the sealing member is placed between a water-related product and another component and used, the watertight rib portion is deformed so as to collapse, thereby increasing the contact area between the watertight rib portion and the water-related product or other component, and improving watertightness.

[0015] In the present invention, the watertight rib portion is preferably formed so as to be inclined radially inward. According to the present invention configured in this manner, the watertight rib portion is formed so as to incline radially inward. Therefore, when the seal member is placed between a plumbing product and another member, the watertight rib portion falls radially inward. This prevents the outer diameter of the seal member from expanding due to deformation of the watertight rib portion, and allows the seal member to be configured compactly.

[0016] In the present invention, preferably, a plurality of watertight ribs are provided, and the radial distance between the watertight ribs is narrower than the radial distance between the positioning rib and the watertight rib. According to the present invention configured as described above, by forming the radial interval between the positioning rib portion and the watertight rib portion relatively wide, it is possible to prevent the elastically deformed watertight rib portion from overlapping the positioning rib portion, which would result in a decrease in positioning accuracy. Also, by forming the radial interval between the watertight ribs relatively narrow, it is possible to configure the seal member compactly.

[0017] In the present invention, the positioning rib portion and the watertight rib portion are preferably formed on both sides of the base portion, respectively. According to the present invention configured in this manner, the positioning rib portion and the watertight rib portion are respectively formed on both sides of the base, so that the watertight rib portion can be brought into close contact with the water-related product and other components on both sides of the sealing member, thereby improving watertightness.

[0018] The present invention also relates to a drain valve device that is attached to a ceramic flushing water tank and is characterized in that it comprises a drain valve unit for opening and closing a drain outlet provided in the flushing water tank, and a sealing member of the present invention that is arranged between the drain valve unit and the flushing water tank. Effect of the Invention

[0019] According to the sealing member of the present invention and the drain valve device equipped with the same, when other components are attached to a ceramic plumbing product, it is possible to improve the positioning accuracy of the attached components while suppressing performance degradation due to deformation of the attached components. [Brief description of the drawings]

[0020] [Figure 1] 1 is a full cross-sectional view of a drain valve device according to an embodiment of the present invention. [Diagram 2] 2 is a perspective view of a seal member according to an embodiment of the present invention; FIG. [Diagram 3] 2 is a full cross-sectional view of a seal member according to an embodiment of the present invention. [Figure 4] FIG. 2 is a partially enlarged cross-sectional view showing an enlarged cross-sectional shape of a seal member according to an embodiment of the present invention. [Diagram 5] 4 is a partially enlarged cross-sectional view showing a state in which the seal member according to the embodiment of the present invention is elastically deformed during actual use. FIG. [Figure 6] 11 is a graph showing the relationship between the tightening torque of the fixing metal fittings and the amount of squeezing of the sealing member when attaching the drain valve unit to the bottom surface of the flush water tank in a drain valve apparatus according to an embodiment of the present invention. [Figure 7] FIG. 4 is a cross-sectional view showing a cross-sectional shape of a sealing member according to a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Next, a seal member according to an embodiment of the present invention and a drain valve device including the seal member will be described with reference to the accompanying drawings. FIG. 1 shows a full cross-sectional view of a drain valve device according to an embodiment of the present invention.

[0022] As shown in Figure 1, a drain valve device 1 according to an embodiment of the present invention is made up of a drain valve unit 2 and a seal member 4. The drain valve device 1 is used by attaching it to the bottom surface 6 of a ceramic flush water tank provided in a flush toilet device (not shown), and watertightness is ensured by placing the seal member 4 between the drain valve unit 2 and the bottom surface 6. When flushing the bowl part (not shown) of the flush toilet device, the drain valve of the drain valve unit 2 is opened and flush water is discharged from the flush water tank.

[0023] The drain valve unit 2 has a main body portion 8 that is attached to the drain outlet 6a on the bottom surface 6 of the flush water tank, a valve body portion 10 that is arranged inside this main body portion 8 so that it can move vertically, and a drive mechanism 12 that drives this valve body portion 10. This drain valve unit 2 is configured to open and close the drain outlet 6a provided in the flush water tank by moving the valve body portion 10 vertically.

[0024] A generally cylindrical small diameter section 8a is provided at the lower end of the main body section 8, and this small diameter section 8a is arranged so as to extend into a drain port 6a provided in the bottom surface 6 of the flush water tank. Furthermore, a generally annular valve seat 8b that protrudes upward is formed at the upper edge of the small diameter section 8a. A valve body section 10 is seated on this valve seat 8b, and when the valve body section 10 is pulled up from the valve seat 8b by the drive mechanism 12, the drain valve device 1 is opened.

[0025] Additionally, a vertically extending overflow pipe 14 is provided on the side of main body 8, and the lower end of this overflow pipe 14 communicates with the inside of small diameter section 8a below (downstream side) of valve seat 8b. As a result, when the water level in the flush water tank becomes higher than the upper end of overflow pipe 14, the flush water in the flush water tank is discharged into the flush toilet (not shown), bypassing valve seat 8b.

[0026] Furthermore, a step 8c is provided at the bottom of the main body 8 so as to protrude radially outward from the small diameter portion 8a. The seal member 4 is disposed so as to surround the periphery of the small diameter portion 8a and be sandwiched between the step 8c and the bottom surface 6 of the flush water tank, ensuring watertightness. In other words, the seal member 4 is sandwiched between the bottom surface 6 of the flush water tank, which is a ceramic plumbing product, and the step 8c of the main body 8 of the drain valve unit 2, which is another component, ensuring watertightness therebetween.

[0027] Additionally, a fixing bracket 16 is attached to the inside of small diameter portion 8a of main body 8. This fixing bracket 16 is configured to engage with the underside of bottom surface 6 of the flush water tank, and by tightening fixing bracket 16, main body 8 of drain valve unit 2 is attracted to bottom surface 6 of the flush water tank, and drain valve unit 2 is fixed to the flush water tank. Additionally, sealing member 4 is elastically deformed by the tightening force of fixing bracket 16, and is sandwiched between the underside of step portion 8c of main body 8 and the upper surface of bottom surface 6 of the flush water tank, and is in intimate contact with these surfaces, ensuring watertightness.

[0028] Next, a sealing member according to an embodiment of the present invention will be described with reference to FIGS. Fig. 2 is a perspective view of the seal member, Fig. 3 is a full cross-sectional view of the seal member, Fig. 4 is a partially enlarged cross-sectional view showing the cross-sectional shape of the seal member, and Fig. 5 is a partially enlarged cross-sectional view showing the state in which the seal member is elastically deformed during actual use.

[0029] 2, the seal member 4 is a generally annular member, and in this embodiment, is disposed so as to surround the small diameter portion 8a of the main body 8 of the drain valve unit 2. In this embodiment, the seal member 4 is integrally molded from ethylene propylene diene rubber (EPDM) with a hardness of 50°.

[0030] 3, one positioning rib portion 18 extending circumferentially is formed on the inner peripheral side of the seal member 4, and two watertight rib portions 20 extending circumferentially are formed on the outer periphery of this positioning rib portion 18. The numbers of positioning rib portions 18 and watertight rib portions 20 can be set arbitrarily, and multiple positioning rib portions 18 may be provided, and one, or three or more watertight rib portions 20 may be provided.

[0031] 4, the seal member 4 is formed from a base 22 formed in a flat annular shape, a positioning rib portion 18 formed on the base 22 so as to extend in the circumferential direction, and a watertight rib portion 20 formed on the outer periphery of the positioning rib portion 18 so as to extend in the circumferential direction on the base 22. The positioning rib portion 18 is provided on both sides of the base 22, and is provided so as to protrude upward from the upper surface of the base 22 and is provided so as to protrude downward from the lower surface of the base 22. Similarly, the watertight rib portion 20 is also provided on both sides of the base 22, and two of the watertight ribs 20 are provided so as to protrude upward from the upper surface of the base 22 and are provided so as to protrude downward from the lower surface of the base 22. In addition, in this embodiment, the positioning rib portion 18 and the watertight rib portion 20 of the same shape are provided on both the upper and lower surfaces of the base 22, but the positioning rib portion 18 and the watertight rib portion 20 may be provided on only one of the surfaces, or the shape and arrangement of the ribs provided on both surfaces may be different.

[0032] In this embodiment, the seal member 4 is formed in a circular ring shape with an inner diameter Di of about 71.6 mm and an outer diameter Do of about 90.2 mm, as shown in FIG. 3. In this embodiment, the thickness Hb of the base 22 is about 4 mm, and the positioning rib 18 with a height Hp of 1.5 mm and two watertight rib 20 with a height Hs of about 2.5 mm are provided on the upper and lower surfaces of the base 22, respectively. Thus, in this embodiment, the height Hs of the watertight rib 20 from the base 22 is formed higher than the height Hp of the positioning rib 18 from the base 22. As an example, the thickness Hb of the base 22 can be set to about 4.0 mm to about 4.6 mm, the height Hp of the positioning rib 18 to about 1.5 mm to about 2.0 mm, and the height Hs of the watertight rib 20 to about 2.4 mm to about 2.7 mm.

[0033] With this structure, when the seal member 4 is compressed between the step 8c of the main body 8 and the bottom surface 6 of the flush water tank, first the watertight rib portion 20 is elastically deformed, and then the positioning rib portion 18 comes into contact with the step 8c and the bottom surface 6. Therefore, when used while being disposed between the step 8c and the bottom surface 6, the watertight rib portion 20 is elastically deformed to a greater extent than the positioning rib portion 18. In other words, the amount of displacement of the apex Pt of the watertight rib portion 20 in the compression direction (the vertical direction in FIG. 4) is greater than the amount of displacement of the upper surface of the positioning rib portion 18 in the compression direction.

[0034] In this embodiment, the width Wp of the positioning rib portion 18 at its base is about 3.7 mm, and the width Ws of each watertight rib portion 20 at its base is about 1.4 mm. Thus, in this embodiment, the width Wp of the positioning rib portion 18 in the radial direction of the seal member 4 is formed wider than the width Ws of the watertight rib portion 20 in the radial direction of the seal member 4. For this reason, the positioning rib portion 18 has a higher compression rigidity than each watertight rib portion 20, and is less likely to deform, and is not substantially deformed, when sandwiched between the step portion 8c of the main body portion 8 and the bottom surface 6 of the flush water tank. As an example, the width Wp of the positioning rib portion 18 can be set to about 3.3 mm to about 4.4 mm, and the width Ws of the watertight rib portion 20 can be set to about 1.3 mm to about 1.5 mm.

[0035] Furthermore, in this embodiment, each watertight rib portion 20 is formed so as to be inclined toward the radial direction of the seal member 4. That is, in the radial cross section shown in FIG. 4, the apex Pt of each watertight rib portion 20 is located radially inward from the midpoint Pb of the base of the watertight rib portion 20, and the straight line connecting the apex Pt and the midpoint Pb is inclined radially inward, so that each watertight rib portion 20 is inclined radially inward. Also, since each watertight rib portion 20 is formed so as to have a height Hs greater than the width Ws at the base, as shown in FIG. 5, when the seal member 4 is disposed between the step portion 8c of the main body portion 8 and the bottom surface 6 of the flush water tank and compressed, the watertight rib portion 20 is bent and deformed so as to fall radially inward. In this way, since the watertight rib portion 20 is bent and deformed so as to fall radially inward, as shown in FIG. 5, in the actual use state, the contact area between the watertight rib portion 20 and the step portion 8c and the bottom surface 6 is widened, and the sealing performance can be improved. Furthermore, since the watertight rib portion 20 is deformed so as to fall radially inward, the outer diameter of the seal member 4 is not expanded due to the deformation of the watertight rib portion 20.

[0036] In this embodiment, as shown in Fig. 4, the radial interval Css between the watertight rib portions 20 is about 1.1 mm, and the radial interval Cps between the positioning rib portion 18 and the watertight rib portion 20 is about 1.7 mm. In this manner, the interval Css between the watertight rib portions 20 is narrower than the interval Cps between the positioning rib portion 18 and the watertight rib portion 20. Therefore, when the watertight rib portion 20 is bent and deformed radially inward, as shown in Fig. 5, the watertight rib portion 20 provided on the inner periphery side does not interfere with the positioning rib portion 18, and the bending deformation of the watertight rib portion 20 can be prevented from being hindered.

[0037] Next, with new reference to Figs. 6 and 7, the operation of the seal member according to the embodiment of the present invention and the drain valve device provided with the same will be described. Fig. 6 is a graph showing the relationship between the tightening torque of the fixing metal fitting 16 when attaching the drain valve unit 2 to the bottom surface 6 of the flush water tank and the amount of squeezing of the seal member 4. Fig. 7 is a cross-sectional view showing the cross-sectional shape of a seal member according to a comparative example.

[0038] First, when assembling the drain valve device 1 of the embodiment of the present invention, the sealing member 4 is positioned so as to surround the drain outlet 6a provided in the bottom surface 6 of the flush water tank. At this time, because the sealing member 4 of this embodiment has the same shape on both the upper and lower surfaces, the worker does not need to pay attention to which surface the sealing member 4 faces, and can perform the work easily.

[0039] Next, the drain valve unit 2 is placed in the drain outlet 6a in which the seal member 4 is placed. At this time, the drain valve unit 2 is placed on the bottom surface 6 so that the small diameter portion 8a of the main body portion 8 that constitutes the drain valve unit 2 is inserted into the drain outlet 6a. As a result, as shown in Figure 2, the seal member 4 is placed between the step portion 8c of the main body portion 8 that constitutes the drain valve unit 2 and the upper surface of the bottom surface 6 of the flush water tank.

[0040] Furthermore, by tightening the screws of the fixing bracket 16, the drain valve unit 2 is fixed to the bottom surface 6 of the flush water tank and watertightness is ensured between the drain valve unit 2 and the bottom surface 6. Note that in this embodiment, the drain valve unit 2 is fixed by tightening the screws of the fixing bracket 16, but the drain valve unit 2 can also be configured so that the small diameter portion 8a of the main body 8 penetrates the bottom surface 6 and is fixed by screwing a large diameter mounting nut (not shown) around the small diameter portion 8a.

[0041] 4, the watertight rib portion 20 of the seal member 4 is formed higher than the positioning rib portion 18, so when the fixing metal fittings 16 are not tightened, the tips of the watertight rib portions 20 respectively abut against the step portion 8c of the main body portion 8 and the bottom surface 6 of the flush water tank, but do not abut against the positioning rib portions 18. When the fixing metal fittings 16 are tightened from this state, the drain valve unit 2 is pulled towards the bottom surface 6 of the flush water tank, so first the watertight rib portion 20 of the seal member 4 is elastically deformed.

[0042] The solid line in Fig. 6 is a graph showing an example of the relationship between the tightening torque of the screw of the fixing metal fitting 16 and the amount of squeezing of the seal member 4 when the seal member 4 according to an embodiment of the present invention is used. The dashed and dotted line in Fig. 6 is a graph showing the relationship between the tightening torque and the amount of squeezing of a seal member according to a comparative example described later.

[0043] As shown by the solid line in Fig. 6, when the screws of the fixing bracket 16 are tightened and the tightening torque exceeds T1 [N m], the crushing amount [mm] of the seal member 4 begins to increase rapidly. In other words, when the tightening torque exceeds T1 [N m], each watertight rib portion 20 of the seal member 4 begins to bend and deform so as to fall radially inward, and the increment in the crushing amount relative to the increment in the tightening torque becomes large. In this way, since each watertight rib portion 20 is configured to bend and deform, it is possible to set the compression stiffness (compressive force [N] applied to the seal member 4 / crushing amount [mm] of the seal member 4) to a relatively small value even if the seal member 4 is made of a material with high hardness.

[0044] Next, when the tightening torque reaches T2 [N·m], which is greater than T1, the amount of crushing does not increase significantly even if the tightening torque increases. That is, when the fixing metal fittings 16 are tightened to the tightening torque T2, the watertight rib portion 20 is sufficiently elastically deformed, so that the watertight rib portion 20 comes into close contact with the step portion 8c and the bottom surface 6 of the flush water tank, ensuring watertightness. Furthermore, when the tightening torque reaches T2 or more, as shown in FIG. 5, in addition to each watertight rib portion 20, the positioning rib portion 18 also comes into contact with the step portion 8c of the main body portion 8 and the bottom surface 6 of the flush water tank. Here, the positioning rib portion 18 is formed wider than the watertight rib portion 20 and is compressed and deformed, so that the compressive rigidity is greater than that of the watertight rib portion 20. For this reason, when the tightening torque exceeds T2 and the positioning rib portion 18 comes into contact with the step portion 8c and the bottom surface 6, even if the tightening torque is increased, the seal member 4 is not substantially deformed, and the increase in the amount of crushing relative to the increase in the tightening torque becomes extremely small. On the other hand, when the positioning rib portion 18 is in contact, the increase in the amount of crushing becomes extremely small, so that the watertight rib portion 20 also does not elastically deform any further. In this way, the amount of elastic deformation of the watertight rib portion 20 is largely determined by the positioning rib portion 18, so the amount of elastic deformation of the watertight rib portion 20 can be easily set to an appropriate amount, and watertightness can be reliably ensured.

[0045] That is, as shown in FIG. 6, even if the torque is further increased after exceeding the torque T2, the amount of crushing of the seal member 4 increases only slightly. The usable tightening torque of the seal member 4 of this embodiment is from T2=6 [N·m] to T3=14 [N·m], and by fixing with a tightening torque within this range, watertightness between the drain valve unit 2 and the bottom surface 6 of the flush water tank can be reliably ensured. Here, the increment in the amount of crushing of the seal member 4 when the tightening torque is increased from T2 to T3 is δ1 [mm], as shown in FIG. 6. In other words, in the drain valve device 1 of this embodiment, by tightening the fixing metal fitting 16 with a tightening torque within the usable range of T2 to T3 [N·m], the drain valve unit 2 can be positioned with respect to the bottom surface 6 with a positional accuracy of within δ1 [mm]. This positioning accuracy δ1 [mm] is sufficient for the flatness of the bottom surface 6 of a ceramic flush water tank.

[0046] In this embodiment, the compressive rigidity of the seal member 4 in the region of the tightening torque T2 or more is about 0.3 [N / mm], the crush amount δ1 of the seal member 4 in the range of the tightening torque T2 to T3 [N·m] is only about 0.8 [mm], and the positioning rib portion 18 of the seal member 4 is not substantially deformed. In this way, according to the seal member 4 of this embodiment, the crush amount δ1 of the seal member 4 can be sufficiently small within a sufficiently wide range of usable tightening torque. Therefore, it is possible to position the drain valve unit 2 with respect to the bottom surface 6 with sufficient accuracy without strict tightening torque management in a state where the drain valve unit 2 is not in direct contact with the bottom surface 6. In addition, the step portion 8c of the main body portion 8 of the drain valve unit 2 is fixed to the bottom surface 6 of the flush water tank via the seal member 4 and is not in direct contact with the bottom surface 6, so that even if there is local unevenness on the bottom surface 6, deformation of the step portion 8c due to the unevenness can be suppressed.

[0047] Preferably, the compression stiffness of the seal member 4 in the region of the tightening torque T2 or more is set to about 0.3 [N / mm] or more, and the crush amount δ1 of the seal member 4 within the usable tightening torque range is set to about 4.0 [mm] or less. Also, preferably, the compression stiffness of the seal member 4 in the region of the tightening torque T2 or more where the positioning rib portion 18 starts to elastically deform is set to about 1.5 to about 3.0 times the compression stiffness in the region of the tightening torque less than T2 where only the watertight rib portion 20 elastically deforms. This allows the seal member 4 to achieve a good balance between the sealing performance and the positioning performance.

[0048] Next, as a comparative example, the operation of a conventional seal member 30 having a cross-sectional shape shown in FIG. 7 will be described. 7, the sealing member 30 according to the comparative example is a roughly annular member, and is disposed so as to surround the small diameter portion 8a of the main body 8 of the drain valve unit 2. The sealing member 30 is also integrally molded from styrene-butadiene rubber (SBR) with a hardness of 35°.

[0049] As shown in FIG. 7, the sealing member 30 according to the comparative example is composed of a base 32 and three rib portions 34 extending downward from the base 32. The three rib portions 34 extend around the circumference of the sealing member 30 and abut against the upper surface of the bottom surface 6 of the flush water tank below the sealing member 30. These three rib portions 34 have isosceles triangular cross sections of the same height and contact the bottom surface 6 of the flush water tank simultaneously. In addition, no rib is provided on the upper surface of the base 32, and the base 32 directly contacts the upper step 8c. In other words, by providing the rib portions 34 on the side of the ceramic bottom surface 6, which has a low flatness, the surface of the bottom surface 6 and the sealing member 30 are sufficiently closely attached to ensure watertightness.

[0050] Next, the dashed line in Figure 6 is a graph showing an example of the relationship between the tightening torque of the screw of the fixing metal fitting 16 and the crushing amount of the seal member 30 when a comparative seal member 30 is used. As shown by the dashed line in Figure 6, in the seal member 30 of the comparative example, the crushing amount increases at a substantially constant rate as the tightening torque increases. Also, in the seal member 30 of the comparative example, watertightness can be ensured at a tightening torque of T2 [N·m], and the tightening torque range for use is between T2 and T3 [N·m].

[0051] The amount of crushing δ2 of the seal member 30 in the usable tightening torque range T2 to T3 is about 1.7 mm. Therefore, when the seal member 30 according to the comparative example is used, even if the drain valve unit 2 is attached with a tightening torque within the usable range that ensures watertightness, the attachment position of the drain valve unit 2 varies within a maximum range of about 1.7 mm. In order to improve the positioning accuracy of the drain valve unit 2 using the seal member 30 according to the comparative example, it is necessary to manage the tightening torque of the fixing metal fitting 16 and to manage the amount of compressive deformation of the seal member 30. That is, since the seal member 30 according to the comparative example does not have the positioning rib portion 18 like the seal member 4 according to the embodiment of the present invention, the compressive rigidity is low in the usable tightening torque range, the attachment position varies widely, and the drain valve unit 2 cannot be positioned with sufficient accuracy.

[0052] According to the seal member 4 of the embodiment of the present invention, the positioning rib portion 18 is not substantially elastically deformed, so the position of the drain valve unit 2 relative to the flush water tank can be accurately determined without strictly controlling the tightening force between the flush water tank, which is a plumbing product, and the drain valve unit 2, which is another member. Furthermore, the watertight rib portion 20 is elastically deformed more than the positioning rib portion 18, and the amount of deformation of the watertight rib portion 20 is determined by the positioning rib portion 18, so the watertight rib portion 20 can be deformed an appropriate amount, and watertightness between the flush water tank and the drain valve unit 2 can be reliably ensured. Furthermore, because the drain valve unit 2 abuts against the flush water tank via the positioning rib portion 18, localized deformation of the drain valve unit 2 due to direct abutment against a flush water tank that has undulations, etc., can be suppressed.

[0053] Furthermore, according to the sealing member 4 of this embodiment, the radial width of the positioning rib portion 18 is formed wider than the radial width of the watertight rib portion 20 (Figure 4), so that the positioning rib portion 18 that is substantially undeformed and the watertight rib portion 20 that is elastically deformed more than the positioning rib portion 18 can be realized with a simple configuration.

[0054] Furthermore, according to the seal member 4 of this embodiment, the height Hs of the watertight rib portion 20 is formed higher than the height Hp of the positioning rib portion 18 (FIG. 4), so that when the positioning rib portion 18 is in contact with the flush water tank or the drain valve unit 2, the watertight rib portion 20 is reliably elastically deformed a predetermined amount, thereby reliably ensuring watertightness. Also, the amount of deformation of the watertight rib portion 20 can be freely set by the height of the watertight rib portion 20.

[0055] Furthermore, according to the sealing member 4 of this embodiment, the watertight rib portion 20 is formed so as to be inclined in the radial direction (Figure 4), so that when the sealing member 4 is compressed between the flush water tank and the drain valve unit 2, the watertight rib portion 20 is deformed so as to collapse, and the contact area between the watertight rib portion 20 and the flush water tank or the drain valve unit 2 is enlarged (Figure 5), thereby improving watertightness.

[0056] Furthermore, according to the sealing member 4 of this embodiment, the watertight rib portion 20 is formed so as to incline radially inward, so that when the sealing member 4 is compressed between the flush water tank and the drain valve unit 2, the watertight rib portion 20 collapses radially inward (Figure 5), so that the outer diameter of the sealing member 4 is not expanded due to deformation of the watertight rib portion 20, and the sealing member 4 can be configured compactly.

[0057] Furthermore, according to the seal member 4 of this embodiment, by forming the radial interval Cps between the positioning rib portion 18 and the watertight rib portion 20 relatively wide, it is possible to prevent the elastically deformed watertight rib portion 20 from overlapping the positioning rib portion 18, which would result in a decrease in positioning accuracy. Furthermore, by forming the radial interval Css between the watertight rib portions 20 relatively narrow, the seal member 4 can be configured compactly.

[0058] Furthermore, according to the sealing member 4 of this embodiment, the positioning rib portion 18 and the watertight rib portion 20 are formed on both sides of the base 22, so that the watertight rib portion 20 can be brought into close contact with the flush water tank and the drain valve unit 2, respectively, on both sides of the sealing member 4, thereby improving watertightness.

[0059] Although the embodiment of the present invention has been described above, various modifications can be made to the above-mentioned embodiment. In particular, in the above-mentioned embodiment, the sealing member is disposed between the bottom surface of the ceramic flush water tank and the drain valve unit, but the sealing member of the present invention can be disposed between any ceramic plumbing product and other components, such as between a washbasin, which is a ceramic plumbing product, and a piping, which is another component. In addition, the "other components" do not necessarily have to be made of resin or metal, and may be made of ceramic. [Explanation of symbols]

[0060] 1 Drain valve device 2 Drain valve unit (other parts) 4. Sealing material 6. Bottom of the cleaning water tank (ceramic plumbing products) 6a Drain 8 Main body 8a Small diameter section 8b Valve seat 8c Stepped section 10 Valve body 12 Drive mechanism 14 Overflow pipe 16 Fixing bracket 18 Positioning rib 20 Watertight rib section 22 Base 30 Sealing material 32 Base 34 Rib section

Claims

1. A sealing member that is placed between a ceramic water-related product and another component to ensure watertightness between them, A base portion formed in a circular ring shape; a positioning rib portion formed on the base portion so as to extend in a circumferential direction and which is not substantially deformed when the positioning rib portion is disposed between the plumbing product and the other member; At least one watertight rib portion is formed on the base portion so as to extend in a circumferential direction on the outer peripheral side of the positioning rib portion, and when the water supply product is disposed between the water supply product and the other member and used, the watertight rib portion is elastically deformed more than the positioning rib portion; having The positioning rib portion and the watertight rib portion are formed on both sides of the base portion, A sealing member characterized in that, when the sealing member is compressed between a water-related product and another member, the compression rigidity of the sealing member when the positioning rib portion begins to elastically deform is 1.5 to 3.0 times the compression rigidity of the sealing member when only the watertight rib portion is elastically deformed.

2. 2. The seal member according to claim 1, wherein the radial width of said positioning rib portion is formed wider than the radial width of said watertight rib portion.

3. 3. The seal member according to claim 1, wherein the watertight rib portion is formed to have a height greater than a height of the positioning rib portion.

4. 4. The seal member according to claim 1, wherein the watertight rib portion is formed so as to be inclined in a radial direction.

5. 5. The seal member according to claim 4, wherein said watertight rib portion is formed so as to be inclined radially inward.

6. The seal member according to any one of claims 1 to 5, wherein a plurality of the watertight rib portions are provided, and a radial distance between the watertight rib portions is formed narrower than a radial distance between the positioning rib portion and the watertight rib portion.

7. A drain valve device for use in a ceramic flush water tank, a drain valve unit for opening and closing a drain outlet provided in the flush water tank; a seal member according to any one of claims 1 to 6, which is disposed between the drain valve unit and the flush water tank; A drain valve device comprising:

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