JP6880731B2 - Water storage tank and manufacturing method of water storage tank - Google Patents

Description

The disclosed embodiment relates to a water storage tank and a method for manufacturing the water storage tank.

Conventionally, in a resin water storage tank that stores wash water supplied to the toilet bowl body, a water storage unit that stores water (wash water) by pouring resin into a cavity formed by combining a cavity type and a core type. And a drainage port for discharging water are integrally formed (see, for example, Patent Document 1).

Further, in such a resin water storage tank, a flow path for guiding water from the inflow port at the upper end to the outflow port at the lower end of the drainage port is formed with a curved surface that expands outward as it goes upward. (See, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 11-21971 Japanese Unexamined Patent Publication No. 2016-37794

In recent years, the amount of water stored in the water storage tank has decreased due to water saving, and it has become difficult to obtain a high head pressure. Therefore, it is necessary to use the water stored in the water storage tank without loss, and a high seal is provided to prevent water leakage between the drain valve that opens and closes the drain port and the valve seat that the drain valve contacts when the valve is closed. Performance is required.

However, in the conventional water storage tank as described above, during molding, the resin fluidity in the valve seat portion is low, and molding defects such as a gas pool in which the resin does not spread and a so-called weld step in which a step remains at the resin confluence portion occur. It may occur on the molded surface. When such molding defects occur on the molded surface of the valve seat portion, the sealing performance may deteriorate.

One aspect of the embodiment is to provide a water storage tank and a method for manufacturing the water storage tank, which can suppress deterioration of sealing performance.

Water storage tank according to one embodiment of the implementation form, a reservoir for storing water, and a water outlet portion for discharging water stored in the water storage section is in the water storage tank made of resin formed integrally, the drainage The mouth portion has a valve seat portion that protrudes upward from the inner bottom surface of the water storage portion and is in contact with a drain valve that opens and closes the drainage port portion, and the inner peripheral surface of the drainage port portion is described from the lower end portion. It is a curved surface whose curvature increases outward toward the top of the valve seat portion, the water storage portion has a reinforcing rib on the outer peripheral portion of the drain port portion on the outer bottom surface, and the reinforcing rib is formed at the time of molding. It is characterized in that it is provided so as to avoid a portion where resins merge in the cavity.

According to this configuration, the inner peripheral surface of the drainage port is formed with a curved surface that extends outward from the lower end to the top of the valve seat, so that the resin fluidity toward the valve seat during molding of the water storage tank is formed. Is improved, and the resin can be poured smoothly. As a result, it is possible to suppress the occurrence of gas pools and weld steps in the valve seat portion, suppress the deterioration of the sealing performance, and realize high sealing performance in the valve seat portion. In addition, the strength of the bottom surface of the water storage tank can be increased by the reinforcing ribs. Further, by providing the reinforcing ribs so as to avoid the portion where the resin joins in the cavity when molding the water storage tank, it is possible to prevent the resin from being hindered from flowing.

Method for producing a water storage tank according to an aspect of an embodiment is a method for producing a water storage tank, said water storage tank, a water reservoir for storing water, water outlet for discharging water stored in the water storage section The drain port portion is made of resin integrally formed with the portion, and has a valve seat portion that projects upward from the inner bottom surface of the water storage portion and is in contact with a drain valve that opens and closes the drain port portion. The inner peripheral surface of the drainage port is a curved surface whose curvature increases outward from the lower end to the top of the valve seat, and the cavity type forming the outer peripheral surface of the water storage tank and the above. After combining with the core type forming the inner peripheral surface of the water storage tank, the resin is poured into the cavity through the gate hole arranged on the lower end side of the drain port portion.

According to such a manufacturing method, by arranging the gate hole for pouring the resin into the cavity on the lower end side of the drain port portion, the resin can be smoothly poured from the lower end portion to the valve seat portion at the time of molding the water storage tank. As a result, it is possible to suppress the occurrence of gas pools and weld steps in the valve seat portion, suppress the deterioration of the sealing performance, and realize high sealing performance in the valve seat portion.

Further, in the above-described method for manufacturing a water storage tank, the core mold is formed by combining a plurality of mold members, and the core mold is arranged so that a boundary portion between the mold members avoids the valve seat portion. And.

According to this manufacturing method, when the core mold is formed by combining a plurality of mold members, protrusions (burrs) may occur at the boundary portion between the mold members on the molding surface, but the boundary portion between the mold members Is arranged so as to avoid the valve seat portion, so that it is possible to prevent burrs from being generated in the valve seat portion. As a result, deterioration of the sealing performance can be suppressed.

According to one aspect of the embodiment, deterioration of sealing performance can be suppressed.

FIG. 1 is a schematic explanatory view of a washing water tank device including a water storage tank according to the embodiment. FIG. 2A is a plan view of the drainage port portion. FIG. 2B is a cross-sectional view taken along the line AA in FIG. 2A. FIG. 3A is an explanatory diagram (No. 1) of the manufacturing process of the water storage tank. FIG. 3B is an explanatory diagram (No. 2) of the manufacturing process of the water storage tank. FIG. 3C is an explanatory diagram (No. 3) of the manufacturing process of the water storage tank. FIG. 4 is an explanatory diagram of another example of the manufacturing process of the water storage tank. FIG. 5A is an explanatory diagram (No. 1) of the resin flow at the drain port portion. FIG. 5B is an explanatory diagram (No. 2) of the resin flow at the drain port portion. FIG. 5C is an explanatory diagram (No. 3) of the resin flow at the drain port portion. FIG. 6A is an explanatory diagram (No. 1) of the resin flow in the modified example 1 of the drainage port portion. FIG. 6B is an explanatory diagram (No. 2) of the resin flow in the modified example 1 of the drainage port portion. FIG. 7A is an explanatory diagram (No. 1) of the resin flow in the modified example 2 of the drainage port portion. FIG. 7B is an explanatory diagram (No. 2) of the resin flow in the modified example 2 of the drainage port portion.

Hereinafter, embodiments of the water storage tank and the method for manufacturing the water storage tank disclosed in the present application will be described in detail with reference to the accompanying drawings. The present invention is not limited to the embodiments shown below.

<1. Washing water tank device ＞
First, with reference to FIG. 1, the outline of the washing water tank device 10 for accommodating the water storage tank 13 according to the embodiment will be described. FIG. 1 is a schematic explanatory view of a washing water tank device 10 including a water storage tank 13 according to an embodiment. Note that FIG. 1 shows a front sectional view of the washing water tank device 10 (and the water storage tank 13). Further, the washing water tank device 10 and the water storage tank 13 shown in FIG. 1 are examples, and the configuration of the washing water tank device 10 and the appearance of the water storage tank 13 are not limited to the illustrated examples.

Further, in FIG. 1, for convenience of explanation, a three-dimensional Cartesian coordinate system including a Z-axis whose positive direction is vertically upward is shown. Such a Cartesian coordinate system may also be illustrated in other figures. Further, in such a Cartesian coordinate system, the positive direction view of the X axis is defined as the "left side surface", the negative direction view of the X axis is defined as the "right side surface", and the positive direction view of the Y axis is defined as the "front surface". .. Therefore, the X-axis direction may be referred to as a left-right direction (also referred to as a horizontal direction), the Y-axis direction may be referred to as a front-back direction, and the Z-axis direction may be referred to as a vertical direction (also referred to as a vertical direction).

As shown in FIG. 1, the washing water tank device 10 includes an exterior tank 11 and a lid 12. Further, the washing water tank device 10 includes a water storage tank 13. The water storage tank 13 is provided in the outer tank 11 and stores water (washing water) to be supplied to the toilet bowl (toilet bowl main body) T. The water storage tank 13 will be described later with reference to FIGS. 2A and later.

The lid 12 is attached so as to cover the upper part of the exterior tank 11. The lid 12 together with the exterior tank 11 forms the appearance of the wash water tank device 10. The exterior tank 11 and the lid 12 are made of earthenware, for example.

Further, the washing water tank device 10 includes a water supply device 14, a drain valve device 15, and an operating device 16. The water supply device 14 supplies water supplied from an external water supply source (not shown) such as a water pipe into the water storage tank 13. The drain valve device 15 opens and closes the drain port 132 of the water storage tank 13. The drain valve device 15 will be described later. The operating device 16 operates the drain valve device 15.

The water supply device 14 starts water supply after the start of drainage by the drain valve device 15. The water supply device 14 supplies water so that the water level when the water storage tank 13 is full, that is, the water stop water level WL0 is at a constant position. Further, the water supply device 14 includes a water supply pipe 17, a float (also referred to as a float for a water supply device) 18, a water discharge pipe 19, and a water supply valve 21.

The water supply pipe 17 is connected to the water supply source described above. The float 18 is a float used for the water supply device 14. The water discharge pipe 19 communicates with the water supply pipe 17 and discharges wash water to the water storage tank 13. The water supply valve 21 is connected to the float 18 via, for example, a lever 20. Further, the water supply device 14 further includes, for example, a hand-washing water supply pipe 22 for supplying water to the hand-washing faucet 23 provided on the upper surface of the lid 12.

For example, the hand-washing faucet 23 discharges the hand-washing water to the hand-washing pot 12a provided on the upper surface of the lid 12 when the supply of the washing water to the toilet bowl main body T is started. Further, the water discharged from the hand-washing faucet 23 flows into the water storage tank 13 from the water spout 12b provided in the hand-washing pot 12a.

Further, below the lid 12, a water guiding member 25 for guiding the water flowing in from the spout 12b to the outside of the control cylinder 24 described later of the drain valve device 15 is provided. The operation device 16 includes an operation lever 26, a motor 27, and an operation button 28. When the operating lever 26 is rotated by a predetermined angle (for example, 90 degrees) to one side (for example, the front side in FIG. 1), the large cleaning is started. The operation button 28 has, for example, three buttons of large cleaning, small cleaning, and eco-small cleaning.

Further, when the operating lever 26 is rotated by a predetermined angle (for example, 90 degrees) to the other side (for example, the back side in FIG. 1), small cleaning is started. As described above, the operating lever 26 is a manual lever for operating the drain valve device 15.

When the button for general cleaning is pressed, the motor 27 rotates the operation lever 26 to one of the above (for example, toward the front). When the small cleaning button is pressed, the motor 27 rotates the operating lever 26 to the other side (for example, the back) described above. That is, the motor 27 operates the drain valve device 15 so that the large cleaning or the small cleaning is started.

The large cleaning and the small cleaning may be manually operated by the operation lever 26 or may be operated by the operation button 28. Further, for eco-friendly cleaning, the drain valve device 15 is operated by the motor 27, that is, when the user presses the operation button 28.

Further, a rotation transmission member 29 composed of a wire member, a universal joint, or the like is connected to the operation lever 26 and the motor 27. On the other end side of the rotation transmission member 29, a first pull-up member 30 and a second pull-up member 31 that swing around the rotation transmission member 29 as the rotation transmission member 29 rotates are attached. The upper end of the first ball chain 32 is attached to the tip of the first pulling member 30, and the upper end of the second ball chain 33 is attached to the tip of the second pulling member 31.

When the rotation transmission member 29 is rotated to one side (front side) of the first pulling member 30 and the second pulling member 31, the first pulling member 30 swings to one side and pulls up the first ball chain 32. On the other hand, when the rotation transmission member 29 is rotated to the other (back) side, the first pulling member 30 and the second pulling member 31 swing to the other side to pull up the first ball chain 32 and the second ball chain 33.

The drain valve device 15 includes a drain valve 34 and an overflow pipe 35. When the drain valve 34 is closed, the drain valve 34 closes the opening of the drain port portion 132 by contacting the top portion 137a (see FIGS. 2A and 2B) of the valve seat portion 137 provided in the water storage tank 13 from above. On the other hand, the drain valve 34 is pulled up when the valve is opened and is separated upward from the top 137a of the valve seat portion 137 to open the opening of the drain port portion 132.

The overflow pipe 35 is provided so as to extend in the vertical direction. A drain valve 34 is attached to the lower end of the overflow pipe 35. The overflow pipe 35 is a sliding member that extends upward from the holding portion 35a that holds the drain valve 34 and is slidable in the vertical direction with respect to the control cylinder 24. When the flush water level in the water storage tank 13 exceeds the upper end of the overflow pipe 35 when the drain valve 34 is closed, the overflow pipe 35 allows the excess wash water to pass through the pipe and flows out to the drain port 132. Let me.

Further, the drain valve device 15 includes a control cylinder 24, a small tank 36, and a float 37. The control cylinder 24 is arranged above the drain port portion 132. The small tank 36 is arranged above the drainage port 132. A control cylinder 24 is arranged inside the small tank 36. The float 37 is arranged in the control cylinder 24 and moves up and down according to the water level in the control cylinder 24.

Further, the drain valve device 15 includes a switching valve 38. The switching valve 38 opens and closes an opening 39 provided on the side surface of the small tank 36. In the drain valve device 15, the amount of drainage is adjusted by a small tank 36, a switching valve 38, or the like.

<2. Water storage tank ＞
Next, the configuration of the water storage tank 13 (mainly the drain port portion 132) according to the embodiment will be described with reference to FIGS. 1, 2A and 2B. FIG. 2A is a plan view of the drainage port portion 132. FIG. 2B is a cross-sectional view taken along the line AA in FIG. 2A. Note that FIG. 2B is a front sectional view of the drain port portion 132.

As shown in FIG. 1, the water storage tank 13 has a water storage section 131, a drain port section 132, and a drainage channel section 133. The water storage unit 131 stores the water supplied from the above-mentioned water supply source. The drainage port 132 is a drainage port for water stored in the water storage section 131. The water discharged from the drain port portion 132 is supplied to the toilet bowl main body T as washing water. The water storage tank 13 is made of resin, and is integrally formed as a whole including the water storage portion 131, the drain port portion 132, and the drainage flow path portion 133.

The drainage port 132 is provided substantially in the center of the bottom surface of the water storage 131 in a plan view. As shown in FIGS. 2A and 2B, the drainage port 132 is formed in a cylindrical shape and has an opening 135 and an inner peripheral surface 136. The opening 135 is formed in the inner bottom surface 134a located on the inner peripheral surface side of the bottom surface of the water storage portion 131. The inner peripheral surface 136 is continuous downward from the opening 135 and projects toward the outer bottom surface 134b side of the water storage unit 131. Further, the drainage port portion 132 has a valve seat portion 137.

The valve seat portion 137 is provided on the peripheral edge of the opening 135, and projects upward from the inner bottom surface 134a of the water storage portion 131. A drain valve 34 (see FIG. 1) that opens and closes the opening 135 of the drain port 132 comes into contact with the annular upper end surface of the valve seat 137, that is, the top 137a, when the valve is closed.

The inner peripheral surface 136 of the drain port portion 132 has a curved surface 136b whose curvature increases outward from the lower end portion 136a to the upper end portion 137a of the valve seat portion 137 which is the upper end portion. In other words, the inner peripheral surface 136 of the drainage port 132 has a curved surface that expands outward as it goes upward. The outward direction is a direction away from the center O of the opening 135 of the drainage port 132 in a plan view.

Further, the curved surface 136b of the inner peripheral surface 136 of the drainage port 132 does not have a straight portion or an inwardly curved portion in a cross-sectional view because the curvature increases outward. That is, the curved surface 136b does not have a portion whose shape changes abruptly, for example, in a stepped shape. The lower end portion 136a of the inner peripheral surface 136 of the drainage port portion 132 is a position where the curved surface 136b starts.

The drainage flow path portion 133 is formed in a cylindrical shape and is continuous downward from the lower end portion 136a of the drainage port portion 132. The drainage flow path portion 133 is a flow path for discharging the water discharged from the drainage port portion 132 to the toilet bowl main body T side. Further, as shown in FIG. 1, the drainage flow path portion 133 serves as an attachment portion when the water storage tank 13 is attached to the outer tank 11 of the washing water tank device 10.

Further, as shown in FIG. 2B, the connecting portion 138 between the valve seat portion 137 and the inner bottom surface 134a of the water storage tank 13 is formed of a curved surface. Further, the water storage unit 131 has a reinforcing rib 139 on the outer bottom surface 134b side. The reinforcing rib 139 will be described later with reference to FIG. 5C.

<3. Manufacturing method of water storage tank ＞
Next, a method of manufacturing the water storage tank 13 according to the embodiment will be described with reference to FIGS. 3A to 3C. 3A to 3C are explanatory views of the manufacturing process of the water storage tank 13. 3A to 3C show a front cross section of the water storage tank 13 including the mold 40. As shown in FIGS. 3A to 3C, the mold 40 is used for injection molding of a resin and includes a cavity mold 41 and a core mold 42.

The cavity mold 41 is, for example, a mold on the fixed side and forms an outer peripheral surface of the water storage tank 13. The core mold 42 is, for example, a mold on the movable side that moves in contact with and separates from the mold on the fixed side, and forms an inner peripheral surface of the water storage tank 13. In such a mold 40, when the mold is closed by the cavity mold 41 and the core mold 42, the molten resin is poured into the cavity (cavity portion) 43 formed between the cavity mold 41 and the core mold 42 to form a molded product.

As shown in FIG. 3A, the cavity type 41 and the core type 42 are arranged to face each other. First, the core mold 42, which is a mold on the movable side, is moved in a direction close to the cavity mold 41, which is a mold on the fixed side, and the cavity mold 41 and the core mold 42 are combined. By combining the cavity type 41 and the core type 42, the cavity 43 (see FIG. 3B) is formed.

Next, as shown in FIG. 3B, melting is injected from a nozzle 45 of a molding machine (not shown) connected to the cavity mold 41 into the cavity 43 formed by combining the cavity mold 41 and the core mold 42. The resin is poured through the gate hole 44. The gate hole 44 is arranged on the lower end 136a side of the inner peripheral surface 136 of the drain port portion 132 of the water storage tank 13.

Next, as shown in FIG. 3C, when the resin in the cavity 43 is cooled and solidified, the core mold 42, which is a movable mold, is moved away from the cavity mold 41, which is a mold on the fixed side. The molded product (water storage tank 13) remaining in the cavity mold 41 is extruded by, for example, an extrusion pin, and is taken out from the cavity mold 41. As a result, the manufacturing process of the water storage tank 13 is completed.

As described above, according to the method for manufacturing the water storage tank 13 according to the embodiment, the gate hole 44 for pouring the resin into the cavity 43 is arranged on the lower end 136a side of the inner peripheral surface 136 of the drain port portion 132 to store water. When molding the tank 13, the resin can be smoothly poured from the lower end portion 136a to the valve seat portion 137. As a result, it is possible to suppress the occurrence of gas pools and weld steps in the valve seat portion 137, suppress the deterioration of the sealing performance, and realize high sealing performance in the valve seat portion 137.

Here, the core mold 42 may be formed by combining a plurality of mold members (also referred to as mold plates) 42a and 42b. FIG. 4 is an explanatory diagram of another example of the manufacturing process of the water storage tank 13. As shown in FIG. 4, when the core mold 42 is formed by combining a plurality of mold members 42a and 42b, the boundary portion (boundary line PL) between the mold members 42a and 42b when combined with the cavity mold 41 is a valve. The core mold 42 is arranged so as to avoid the seat portion 137.

As described above, according to another example of the method for manufacturing the water storage tank 13 according to the embodiment, when the core mold 42 is formed by combining a plurality of mold members 42a and 42b, the boundary portion between the mold members 42a and 42b is formed. By arranging the (boundary line PL) so as to avoid the valve seat portion 137, it is possible to prevent burrs from being generated in the valve seat portion 137. As a result, the valve seat portion 137 can be made into a good molded surface, and high sealing performance can be realized in the valve seat portion 137.

<4. Drainage port ＞
Next, with reference to FIGS. 5A to 5C, the resin flow at the drain port portion 132 at the time of manufacturing the water storage tank 13 according to the embodiment will be described. 5A to 5C are explanatory views of resin flow at the drain port portion 132. Note that FIG. 5A shows the front surface (partial cross section) of the drainage port 132. Further, FIG. 5B shows an enlarged portion B in FIG. 5A, and FIG. 5C shows a cross section taken along line CC in FIG. 5A.

As shown in FIGS. 5A and 5B, at the time of manufacturing the water storage tank 13, the molten resin sent from the nozzle 45 of the molding machine passes through the gate hole 44 to the inner peripheral surface 136 of the drain port portion 132. It flows into the cavity 43 (see FIG. 3B) from the lower end 136a side. As described above, the inner peripheral surface 136 of the drain port portion 132 is a curved surface 136b whose curvature increases outward from the lower end portion 136a to the top portion 137a of the valve seat portion 137.

Therefore, as shown in FIG. 5B, the molten resin 50 that has flowed through the gate hole 44 has the top portion 137a of the valve seat portion 137 along the cavity shape that forms the curved surface 136b of the inner peripheral surface 136 of the drain port portion 132. Flows smoothly toward. When the molten resin 50a heading toward the top portion 137a of the valve seat portion 137 reaches the top portion 137a of the valve seat portion 137, the molten resin 50a changes its direction and flows toward the inner bottom surface 134a side of the water storage portion 131. In this case, since the connecting portion 138 between the valve seat portion 137 and the inner bottom surface 134a of the water storage tank 13 is a curved surface, the molten resin 50b smoothly flows toward the inner bottom surface 134a side.

As described above, according to the water storage tank 13 according to the embodiment, the inner peripheral surface 136 of the drain port portion 132 is formed with a curved surface extending outward from the lower end portion 136a to the top portion 137a of the valve seat portion 137. When molding the water storage tank 13, the fluidity of the resin toward the valve seat portion 137 is improved, and the resin can be smoothly poured. As a result, it is possible to suppress the occurrence of gas pools and weld steps in the valve seat portion 137, suppress the deterioration of the sealing performance, and realize high sealing performance in the valve seat portion 137.

Further, according to the water storage tank 13 according to the embodiment, since the connecting portion 138 between the valve seat portion 137 and the inner bottom surface 134a of the water storage portion 131 is a curved surface, the water storage portion is formed from the valve seat portion 137 when the water storage tank 13 is formed. The resin fluidity toward the bottom surface side of 131 is improved, and the resin can be poured smoothly. As a result, it is possible to suppress the occurrence of gas pools and weld steps in the valve seat portion 137, suppress the deterioration of the sealing performance, and realize high sealing performance in the valve seat portion 137.

As shown in FIG. 5C, the water storage portion 131 has a plurality of reinforcing ribs 139 on the outer peripheral portion of the drain port portion 132 on the outer bottom surface 134b. The reinforcing rib 139 has a convex shape protruding downward from the outer bottom surface 134b of the water storage portion 131, and extends in the surface direction on the outer bottom surface 134b. Further, the reinforcing rib 139 is provided so as to avoid the portion P where the molten resin 50c joins in the cavity 43 (see FIG. 3B) when the water storage tank 13 (see FIG. 3B) is formed. In other words, the reinforcing rib 139 is not provided in the portion P where the molten resin 50c joins.

As described above, according to the water storage tank 13 according to the embodiment, the strength of the bottom surface of the water storage tank 13 can be increased by the reinforcing rib 139. Further, by providing the reinforcing rib 139 so as to avoid the portion P where the molten resin 50c merges in the cavity 43 during molding, it is possible to prevent the molten resin 50c from being hindered from flowing.

In the above embodiment, the plurality of reinforcing ribs 139 have a linear shape arranged in parallel in the bottom view, but the present invention is not limited to this, and for example, the reinforcement ribs 139 are arranged along the radial direction from the center of the drain port portion 132 in the bottom view. May be extended. Further, the reinforcing rib 139 is not limited to a linear shape, and may have a curved shape when viewed from the bottom surface, for example.

<5. Deformation example of drainage port 1>
Next, a modified example 1 (drainage port portion 232) of the drainage port portion will be described with reference to FIGS. 6A and 6B. 6A and 6B are explanatory views of the resin flow in the modified example 1 (drainage port portion 232) of the drainage port portion. Note that FIG. 6A shows the front surface (partial cross section) of the drainage port portion 232. Further, FIG. 6B shows an enlarged portion D in FIG. 6A. Further, in the first modification, the same or equivalent parts as the water storage tank 13 according to the above-described embodiment are designated by the same reference numerals, and the description thereof is omitted.

As shown in FIGS. 6A and 6B, in the first modification, the drain port portion 232 has a valve seat portion 237 having a flat upper end surface. In the drain port portion 232, the flat surface of the valve seat portion 237 increases the contact area of the drain valve 34 (see FIG. 1) with the valve seat portion 237 when the valve is closed, so that the sealing performance is improved.

Further, also in the modification 1 (drainage port portion 232), the molten resin sent from the nozzle 45 of the molding machine at the time of manufacturing the water storage tank 13 passes through the gate hole 44 to the lower end portion 236a side of the inner peripheral surface 236. Flows into the cavity 43 (see FIG. 3B). The inner peripheral surface 236 of the drainage port portion 232 has a curved surface 236b whose curvature increases outward from the lower end portion 236a to the top portion 237a of the valve seat portion 237, similarly to the drainage port portion 132 described above.

Therefore, as shown in FIG. 6B, the molten resin 50 that has flowed through the gate hole 44 has the top portion 237a of the valve seat portion 237 along the cavity shape that forms the curved surface 236b of the inner peripheral surface 236 of the drain port portion 232. Flows smoothly toward. When the molten resin 50d toward the top portion 237a of the valve seat portion 237 reaches the top portion 237a of the valve seat portion 237, the molten resin 50d changes its direction and flows toward the inner bottom surface 134a side of the water storage portion 131.

As described above, according to the modified example 1 (drainage port portion 232), the inner peripheral surface 236 of the drainage port portion 232 is formed by a curved surface extending outward from the lower end portion 236a to the top portion 237a of the valve seat portion 237. Therefore, when the water storage tank 13 is molded, the resin fluidity toward the valve seat portion 237 is improved, and the resin can be smoothly poured. As a result, it is possible to suppress the occurrence of gas pools and weld steps in the valve seat portion 237, suppress the deterioration of the sealing performance, and realize high sealing performance in the valve seat portion 237.

<6. Deformation example of drainage port 2>
Next, a modified example 2 (drainage port portion 332) of the drainage port portion will be described with reference to FIGS. 7A and 7B. 7A and 7B are explanatory views of the resin flow in the modified example 2 (drainage port portion 332) of the drainage port portion. Note that FIG. 7A shows the front surface (partial cross section) of the drainage port portion 332. Further, FIG. 7B shows an enlarged portion E in FIG. 7A. Further, also in the modified example 2, the same or equivalent parts as the water storage tank 13 according to the above-described embodiment are designated by the same reference numerals, and the description thereof is omitted.

As shown in FIGS. 7A and 7B, in the second modification, the drainage port portion 332 has a valve seat portion 337 whose upper end surface protrudes upward and is curved. In the modified example 2 (drainage port portion 332), the molten resin sent from the nozzle 45 of the molding machine at the time of manufacturing the water storage tank 13 passes through the gate hole 44 from the lower end portion 336a side of the inner peripheral surface 336 to the cavity. It flows into 43 (see FIG. 3B). The inner peripheral surface 336 of the drainage port portion 332 has a curved surface 336b whose curvature increases outward from the lower end portion 336a to the top portion 337a of the valve seat portion 337, similarly to the drainage port portion 132 described above.

Therefore, as shown in FIG. 7B, the molten resin 50 that has flowed through the gate hole 44 has the top portion 337a of the valve seat portion 337 along the cavity shape that forms the curved surface 336b of the inner peripheral surface 336 of the drain port portion 332. Flows smoothly toward. When the molten resin 50e heading toward the top portion 337a of the valve seat portion 337 reaches the top portion 337a of the valve seat portion 337, it changes its direction and flows toward the inner bottom surface 134a side of the water storage portion 131. In this case, the molten resin 50e flows smoothly toward the inner bottom surface 134a because the valve seat portion 337 and the connecting portion 338 between the valve seat portion 337 and the inner bottom surface 134a of the water storage tank 13 are curved surfaces.

As described above, according to the modified example 2 (drainage port portion 332), the inner peripheral surface 336 of the drainage port portion 332 is formed with a curved surface extending outward from the lower end portion 336a to the top portion 337a of the valve seat portion 337. Therefore, when the water storage tank 13 is molded, the resin fluidity toward the valve seat portion 337 is improved, and the resin can be smoothly poured. As a result, it is possible to suppress the occurrence of gas pools and weld steps in the valve seat portion 337, suppress the deterioration of the sealing performance, and realize high sealing performance in the valve seat portion 337.

Further, according to the modification 2 (drain port portion 332), since the valve seat portion 337 and the connecting portion 338 between the valve seat portion 337 and the inner bottom surface 134a of the water storage portion 131 are curved surfaces, when the water storage tank 13 is formed. , The resin fluidity from the valve seat portion 337 toward the bottom surface side of the water storage portion 131 is improved, and the resin can be smoothly poured. As a result, it is possible to suppress the occurrence of gas pools and weld steps in the valve seat portion 337, suppress the deterioration of the sealing performance, and realize high sealing performance in the valve seat portion 337.

Further effects and variations can be easily derived by those skilled in the art. For this reason, the broader aspects of the invention are not limited to the particular details and representative embodiments expressed and described as described above. Therefore, various modifications can be made without departing from the spirit or scope of the general concept of the invention as defined by the appended claims and their equivalents.

10 Washing water tank device 11 Exterior tank 12 Lid 12a Hand wash bowl 12b Water spout 13 Water storage tank 14 Water supply device 15 Drain valve device 16 Operating device 17 Water supply pipe 18 Float for water supply device 19 Water discharge pipe 20 Lever 21 Water supply valve 22 Hand wash water supply pipe 23 Hand wash curan 24 Control cylinder 25 Water guide member 26 Operation lever 27 Motor 28 Operation button 29 Rotation transmission member 30 1st pulling member 31 2nd pulling member 32 1st ball chain 33 2nd ball chain 34 Drain valve 35 Overflow pipe 35a Holding part 36 Small tank 37 Float 38 Switching valve 39 Opening 40 Mold 41 Cavity type 42 Core type 43 Cavity 44 Gate hole 45 Nozzle 131 Water storage part 132 Drainage port part 133 Drainage flow path part 134a Internal bottom surface 134b External bottom surface 135 Opening 136 Inner peripheral surface 137 Valve seat part 137a Top part 138 Connection part 139 Reinforcing rib O Center P Resin confluence part PL Boundary line T Toilet bowl (toilet bowl body)
WL0 Water level

Claims (3)

In a resin water storage tank in which a water storage unit for storing water and a drainage port for discharging water stored in the water storage unit are integrally formed.
The drainage port is
It has a valve seat portion that protrudes upward from the inner bottom surface of the water storage portion and is in contact with a drain valve that opens and closes the drain port portion.
The inner peripheral surface of the drainage port is
It is a curved surface whose curvature increases outward from the lower end to the top of the valve seat.
The water storage section
It has a reinforcing rib on the outer peripheral portion of the drainage port on the outer bottom surface.
The reinforcing rib
A water storage tank characterized in that it is installed avoiding the part where the resin joins in the cavity during molding. It is a manufacturing method of a water storage tank.
The water storage tank
It is made of resin in which a water storage unit for storing water and a drainage port for discharging water stored in the water storage unit are integrally formed.
The drainage port is
It has a valve seat portion that protrudes upward from the inner bottom surface of the water storage portion and is in contact with a drain valve that opens and closes the drain port portion.
The inner peripheral surface of the drainage port is
It is a curved surface whose curvature increases outward from the lower end to the top of the valve seat.
After combining the cavity type that forms the outer peripheral surface of the water storage tank and the core type that forms the inner peripheral surface of the water storage tank, a resin is formed in the cavity through a gate hole arranged on the lower end side of the drainage port. A method of manufacturing a water storage tank, which is characterized by pouring water. The water storage tank according to claim 2 , wherein the core mold is formed by combining a plurality of mold members, and the core mold is arranged so that the boundary portion between the mold members avoids the valve seat portion. Production method.

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