CN218165217U

CN218165217U - Mop bucket

Info

Publication number: CN218165217U
Application number: CN202121203906.5U
Authority: CN
Inventors: 不公告发明人
Original assignee: Shaanxi Qianhua Suzi Intelligent Technology Co Ltd
Current assignee: Shaanxi Qianhua Suzi Intelligent Technology Co Ltd
Priority date: 2021-05-31
Filing date: 2021-05-31
Publication date: 2022-12-30
Anticipated expiration: 2031-05-31

Abstract

The utility model provides a mop bucket, which comprises a bucket body, a first water cavity, a water flow channel and a second water cavity. The first water cavity is arranged on the barrel body, and the water flow channel is communicated with the first water cavity and is used for enabling water in the first water cavity to flow into the barrel body; the second water cavity is communicated with the first water cavity, and water in the first water cavity can flow into the second water cavity, so that the water level in the first water cavity is lower than or level to the highest water storage point of the water flow channel. The utility model discloses set up the second water cavity on first water cavity, the second water cavity of setting up can reduce the water level height of clear water in the first water cavity, and the clear water of avoiding first water cavity overflows from the delivery port of rivers passageway, and then has avoided the extravagant problem of the water energy.

Description

Mop bucket

Technical Field

The utility model relates to the technical field of cleaning tools, in particular to mop bucket.

Background

The mop is an essential cleaning tool for cleaning in daily life, and the mop bucket is greatly convenient for people to clean the mop.

Currently, a mop bucket sold in the market comprises a bucket body, a water tank and a water flow channel, wherein the water flow channel is communicated with the water tank and is used for enabling water in the water tank to flow into the bucket body. However, since the highest point of water storage of the water tank is higher than the highest point of water storage of the water flow channel, when water is injected into the water tank so that the liquid level of water in the water tank is higher than the highest point of water storage of the water flow channel, the water can overflow from the water outlet of the water flow channel along the water flow channel, which causes waste of water energy.

SUMMERY OF THE UTILITY MODEL

For solving prior art, the mop bucket causes the extravagant technical problem of the water energy easily, the technical scheme of the utility model as follows:

the utility model provides a mop bucket, which comprises a bucket body, a first water cavity, a water flow channel and a second water cavity. The first water cavity is arranged on the barrel body, and the water flow channel is communicated with the first water cavity and is used for enabling water in the first water cavity to flow into the barrel body; the second water cavity is communicated with the first water cavity, and water in the first water cavity can flow into the second water cavity, so that the water level in the first water cavity is lower than or flush with the highest water storage point of the water flow channel.

The utility model provides a mop bucket has set up the second water cavity on first water cavity, from this, and the second water cavity can receive some clear water that comes from first water cavity to reduce the water level height in the first water cavity, make the water level in the first water cavity be less than or the parallel and level in the retaining peak of rivers passageway, can avoid the water of first water cavity to spill over from the delivery port of rivers passageway like this, and then avoided the extravagant problem of the water energy.

In one possible design, the highest water storage point of the second water cavity is lower than or flush with the highest water storage point of the water flow channel.

In one possible design, the second water chamber is disposed within the tub.

In one possible design, the first water chamber comprises a fixed water tank and a movable water tank; the fixed water tank is fixed set up in on the staving, rivers passageway with fixed water tank intercommunication, be equipped with the water inlet on the fixed water tank, remove water tank detachably install in water inlet department, work as remove water tank install in when water inlet department, the water accessible in the removal water tank the water inlet flows in fixed water tank.

In a possible design, the bottom of the movable water tank is provided with a water outlet which protrudes downwards and is inserted into the water inlet on the fixed water tank in a matching way; the bottom of moving water tank still is equipped with and is used for supporting moving water tank's supporting part, the bottom of supporting part be less than or the parallel and level in the bottom of delivery port, be equipped with the slot on the fixed water tank, the supporting part cooperation is inserted in the slot.

In one possible design, the movable water tank is provided with a handle groove for holding.

In one possible design, a water pumping device is arranged on the water flow channel, and the water pumping device is used for pumping the water in the first water cavity to the inner cavity of the barrel body.

In one possible design, the water pumping device comprises a pump shell and an impeller, wherein the impeller is positioned in the pump shell and is rotationally connected with the pump shell; the water outlet part of the water pumping device is positioned on the pump shell, is arc-shaped and faces the inner cavity of the barrel body, so as to guide the flow of water pumped out of the pump shell.

In one possible design, the water pumping device comprises a pump shell and an impeller, wherein the impeller is positioned in the pump shell and is rotationally connected with the pump shell; the impeller is provided with blades, and the lower edges of the blades are inclined upwards along the direction away from the rotation axis of the impeller; the surface of the pump shell opposite to the lower edge of the blade is correspondingly inclined upwards.

In one possible design, the water storage maximum point of the first water chamber is higher than the water storage maximum point of the water flow channel.

Drawings

FIG. 1 is a schematic view of a mop bucket according to an embodiment of the present invention;

FIG. 2 is a schematic view of an embodiment of the present invention showing the mop bucket with the water tank removed;

FIG. 3 is a cross-sectional view of a mop bucket according to an embodiment of the present invention;

fig. 4 is a schematic view of an upper pump casing according to an embodiment of the present invention;

fig. 5 is a schematic view of a lower pump casing according to an embodiment of the present invention.

Reference numerals: 10. a barrel body; 11. a sprinkler head; 12. driving the rotating shaft; 20. a water pumping device; 21. a pump housing; 211. an upper pump casing; 212. a lower pump casing; 22. an impeller; 221. a blade; 222. a support shaft; 23. a water pumping part; 24. a water outlet part; 25. a water delivery pipe; 30. a first water chamber; 31. fixing the water tank; 311. a water inlet; 312. a slot; 32. moving the water tank; 321. a water outlet; 322. a support portion; 323. a handle buckling groove; 40. a second water chamber.

Detailed Description

The technical solution of the present invention will be described below with reference to the accompanying drawings. It is to be understood that the embodiments described are only some embodiments of the invention, and not all embodiments.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; may be mechanically connected, may be electrically connected or may be in communication with each other; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "side", "inner", "outer", "top", "bottom", and the like, indicate orientations or positional relationships based on installation, and are merely for convenience of description and simplicity of description, and do not indicate or imply that the device or element so referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present invention.

It should be noted that, in the embodiments of the present invention, the same reference numerals are used to indicate the same components or parts, and for the same parts in the embodiments of the present invention, only one of the parts or parts may be used as an example to be labeled with the reference numeral in the drawings.

In the following, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature.

As shown in fig. 1 and 2, the present embodiment provides a mop bucket including a bucket body 10, a first water chamber 30, a water flow passage, and a second water chamber 40. The first water cavity 30 is disposed on the barrel body 10, and the water flow channel is communicated with the first water cavity 30, so as to enable water in the first water cavity 30 to flow into the barrel body 10. The highest point of the water storage of the first water cavity 30 is higher than the highest point of the water storage of the water flow channel, the second water cavity 40 is communicated with the first water cavity 30, and the water in the first water cavity 30 can flow into the second water cavity 40, so that the water level in the first water cavity 30 is lower than or level with the highest point of the water storage of the water flow channel.

In this case, after the clean water is added into the first water cavity 30, the clean water enters the second water cavity 40 and then flows into the water flow channel; alternatively, the first water chamber 30 may be communicated with the second water chamber 40 and the water flow passage through two outlets, respectively, in which case, the clean water in the first water chamber 30 flows into the second water chamber 40 and the water flow passage simultaneously.

As shown in fig. 3, the dotted arrows indicate the meaning: the water flow trajectory. The end outlet of the water flow channel is used for connecting the sprinkler head 11, the highest point of water storage of the water flow channel can be the end outlet, or the water flow channel is arched, and the highest point of water storage is located at the arc top. The water flow channel can be a cavity, a pipeline, a pore channel, a diversion trench and other structures, or a combination of various structures.

In the prior art, the highest point of water storage of the water flow channel is generally lower than the highest point of water storage of the first water cavity 30, and when water is injected into the first water cavity 30 to enable the liquid level of water in the first water cavity 30 to be higher than the highest point of water storage of the water flow channel, the water can overflow from the water outlet of the water flow channel along the water flow channel, so that waste of water energy is caused.

To solve the above problem, the second water chamber 40 is additionally arranged on the first water chamber 30 in this embodiment, and therefore, the second water chamber 40 can receive a part of the clean water from the first water chamber 30 to reduce the height of the water level in the first water chamber 30, so that the water level in the first water chamber 30 is lower than or flush with the highest point of the water storage of the water flow channel, and thus the water in the first water chamber 30 can be prevented from overflowing from the water outlet of the water flow channel, and the problem of water energy waste is avoided.

In one embodiment, as shown in fig. 3, the highest point of water impoundment of the second water chamber 40 is lower than or level with the highest point of water impoundment of the water flow channel.

In this embodiment, considering that the mop bucket has a compact overall structure, a reasonable design and a high space utilization rate, the second water chamber 40 does not need to be designed to be too large, and only the requirement of reducing the height of the water level of the clean water in the first water chamber 30 is required. Therefore, the highest point of water storage of the second water chamber 40 is lower than or flush with the highest point of water storage of the water flow channel, and preferably, the highest point of water storage of the second water chamber 40 is lower than the highest point of water storage of the water flow channel.

As shown in fig. 3, in one embodiment, the second water chamber 40 is disposed inside the tub 10.

The second water cavity 40 can be arranged inside or outside the barrel body 10, in the embodiment, in order to ensure the consistency of the appearance of the mop barrel, the phenomenon that the storage and the use are influenced by the appearance of the protrusion is avoided, the second water cavity 40 is arranged in the barrel body 10 to be hidden, and meanwhile, the appearance of the mop barrel is ensured to be attractive.

As shown in fig. 2 and 3, in one embodiment, the first water chamber 30 includes a fixed water tank 31 and a movable water tank 32. The fixed water tank 31 is fixedly arranged on the barrel body 10, the water flow channel is communicated with the fixed water tank 31, a water inlet 311 is formed in the fixed water tank 31, the movable water tank 32 is detachably arranged at the water inlet 311, and when the movable water tank 32 is arranged at the water inlet 311, water in the movable water tank 32 can flow into the fixed water tank 31 through the water inlet 311.

The first water chamber 30 and the tub 10 may be an integrated structure, and water may be injected into the first water chamber 30 through an external water pipe. First water cavity 30 still can be for the components of a whole that can function independently structure in staving 10, and as shown in this embodiment specifically, divide first water cavity 30 into fixed water tank 31 and removal water tank 32, rivers passageway and fixed water tank 31 intercommunication, fixed water tank 31 can be dismantled with removal water tank 32 and be connected, carries out the moisturizing for fixed water tank 31 through removal water tank 32. From this, it is more nimble when moisturizing first water cavity 30, need not wholly carry or move staving 10, can directly dismantle removal water tank 32 from staving 10 and carry out the moisturizing.

Optionally, the water replenishing and discharging of the movable water tank 32 can be carried out through one opening, and the movable water tank is disassembled and assembled in a manner similar to the replacement of a purified water bucket. The water replenishing and discharging of the movable water tank 32 can also be entered and exited from two ports, a openable water tank cover is arranged at the top of the movable water tank 32 for replenishing water, and a water outlet 321 which protrudes downwards is arranged at the bottom of the movable water tank 32 and is used for communicating with the water inlet 311 of the fixed water tank 31.

As shown in fig. 2 and 3, in one embodiment, the bottom of the movable water tank 32 is provided with a water outlet 321 protruding downwards, and the water outlet 321 is inserted into the water inlet 311 of the fixed water tank 31; the bottom of the movable water tank 32 is further provided with a supporting portion 322 for supporting the movable water tank 32, the bottom end of the supporting portion 322 is lower than or flush with the bottom end of the water outlet 321, the fixed water tank 31 is provided with an insertion slot 312, and the supporting portion 322 is inserted into the insertion slot 312 in a matching manner.

In this embodiment, optionally, the water outlet 321 of the movable water tank 32 is provided with a valve, the water inlet 311 of the fixed water tank 31 is provided with a push rod, when the water outlet 321 is inserted into the water inlet 311, the push rod pushes the valve core upwards to open the water outlet 321, so that the movable water tank 32 is communicated with the fixed water tank 31, and when the movable water tank 32 is detached, the valve core blocks the water outlet 321 downwards to seal the bottom of the movable water tank 32.

In addition, in order to ensure the connection strength between the movable water tank 32 and the fixed water tank 31 and prevent the movable water tank 32 from tipping over to one side, a socket structure, such as a supporting portion 322 and a slot 312, is added on the connection surface between the movable water tank 32 and the fixed water tank 31, in one embodiment, the supporting portion 322 is arranged at the bottom of the movable water tank 32, the slot 312 is arranged on the fixed water tank 31, and the supporting portion 322 is inserted into the slot 312 in a matching manner to connect the two. In another embodiment, the supporting portion 322 and the slot 312 can be interchangeably disposed on the base, that is, the slot 312 is disposed on the bottom of the movable water tank 32, and the supporting portion 322 is disposed on the fixed water tank 31.

Further, the downward extension length of the supporting portion 322 is limited, and the stress strength can be further refined, specifically: when the bottom end of the supporting portion 322 is flush with the bottom end of the water outlet 321, the supporting portion 322 and the water outlet 321 support the movable water tank 32 together, so as to prevent the movable water tank 32 from falling down after being detached; when the bottom end of the supporting portion 322 is lower than the bottom end of the water outlet 321, the supporting portion 322 supports the movable water tank 32 to prevent the movable water tank 32 from falling down after being detached.

As shown in fig. 2, in one embodiment, the moving water tank 32 is provided with a grip groove 323 for holding.

In order to facilitate the user to easily hold the portable water tank 32 by hand when the portable water tank 32 is detached, transported, or refilled, a grip groove 323 is formed on the surface of the portable water tank 32.

In one embodiment, as shown in fig. 3, a water pumping device 20 is disposed on the water flow passage, and the water pumping device 20 is used for pumping water in the first water chamber 30 to the inner cavity of the tub 10.

As mentioned above, the outlet at the end of the water channel is used to connect the sprinkler head 11, and the water pumping device 20 is added to the water channel to increase the flow rate of the clean water, so that the clean water has a certain impact strength to be sprayed out from the sprinkler head 11, thereby realizing the function of flushing the mop head.

As shown in fig. 3, 4 and 5, in one embodiment, the water pumping device 20 includes a pump casing 21 and an impeller 22, the impeller 22 is located in the pump casing 21 and is rotatably connected to the pump casing 21; the water outlet 24 of the water pumping device 20 is located on the pump casing 21, and the water outlet 24 is curved and faces the inner cavity of the barrel 10 to guide the water pumped out of the pump casing 21.

In this embodiment, the pumping device 20 includes a pump housing 21 and an impeller 22, and is classified into an electric water pump or a manual rotary water pump according to a driving mode of the impeller 22. The electric water pump is a motor driving the impeller 22 to rotate, and the manual rotary water pump is a manual rotary water pump driving the impeller 22 to rotate by pressing down the mop rod.

Specifically, the manual rotary water pump is: the barrel body 10 is provided with a driving rotating shaft 12, the driving rotating shaft 12 can slide along the axial direction of the barrel body, the lower end of the driving rotating shaft 12 can be connected with the impeller 22 in a matched mode, the upper end of the driving rotating shaft can be connected with the mop rod in a matched mode, and when a user uses the electric mop, the mop rod is manually pressed down to drive the driving rotating shaft 12 to rotate, so that the impeller 22 rotates.

In this embodiment, the impeller 22 can be driven by the driving shaft 12 to rotate in the pump casing 21, and the circumferential fixing manner of the impeller 22 and the driving shaft 12 is as follows: keys and keyways, polygonal prisms and corresponding polygonal prism grooves. The driving shaft 12 moves downwards to connect with the impeller 22, and then the mop rod drives the driving shaft 12 and the impeller 22 to rotate, thereby performing the function of the water pumping device 20.

Further, the mop pole has interior pole and the outer pole that cup joints each other, is equipped with the drive structure that can turn into the linear motion of outer pole the rotary motion of interior pole between the interior, outer pole, and the user reciprocates outer pole so that the mop head of connecting on interior pole accomplishes the rotary motion in the mop bucket, can drive pivot 12 when interior pole is rotatory simultaneously and rotate, and drive pivot 12 drives the water pump again, takes out the clear water to the water jet through the water pump in order to wash the mop head.

The working principle of the water pumping device 20 in this embodiment is as follows: the water pumping device 20 is similar to the working principle of the centrifugal pump in the prior art, and works by utilizing the centrifugal force generated by water due to the rotation of the impeller 22, before the water pumping device 20 is started, the pump shell 21 and the water pumping part 23 are filled with water, then the rotating shaft drives the impeller 22 and the water to do high-speed rotation motion, the water is thrown to the outer edge of the impeller 22 under the action of the centrifugal force and enters the water outlet part 24 of the water pumping device 20 through the pipeline of the pump shell 21, the center of the impeller 22 of the water pumping device 20 forms vacuum after being thrown out under the action of the centrifugal force, the water outside the water pumping part 23 is pressed into the pump shell 21 under the action of atmospheric pressure, and the impeller 22 continuously rotates, so that the water continuously flows in and out under the action of the impeller 22, and the purpose of water conveying is achieved.

3-5, in this embodiment, the water outlet 24 is located on the pump housing 21, and the water outlet 24 is curved and faces the inner cavity of the barrel 10 to guide the water pumped out of the pump housing 21.

As mentioned above, according to the operation principle of the water pumping device 20, water is thrown to the outer edge of the impeller 22 by the centrifugal force and flows out through the water outlet portion 24 of the pump housing 21, the clear water flies out along the tangential direction of the circumference at the moment of being thrown out, in order to guide the clear water upwards and reduce the frictional resistance of the clear water in the water outlet portion 24, the water outlet portion 24 is designed to be an upward arc-shaped structure, the water outlet portion 24 is communicated with the water spraying head 11 through the water pipe 25, and the outflowing clear water is sprayed out from the water spraying head 11 after passing through the water outlet portion 24 and the water pipe 25 in sequence.

As shown in fig. 3-5, in one embodiment, the water pumping device 20 includes a pump housing 21 and an impeller 22, the impeller 22 is located in the pump housing 21 and is rotatably connected to the pump housing 21; the impeller 22 has blades 221, and the lower edges of the blades 221 are inclined upward as being away from the rotation axis of the impeller 22; the surface of the pump casing 21 opposite to the lower edge of the vane 221 is also inclined upward.

According to the operation principle of the water pumping device 20, water is thrown to the outer edge of the impeller 22 under the action of centrifugal force and flows out through the water outlet portion 24 of the pump shell 21, so that the contact area between the outer edge of the impeller 22 and clean water directly determines the adhesion between clean water and the impeller 22 and the difficulty of throwing the clean water out, the smaller the contact area is, the smaller the adhesion of the clean water is, i.e. the clean water is more easily thrown out by the impeller 22, and meanwhile, the problem of guiding after the clean water is thrown out is also considered, i.e. the clean water is required to flow into the inner cavity of the barrel 10 above after being pumped out.

In summary, the lower edge of the blade 221 of the impeller 22 is inclined upward as being away from the rotation axis of the impeller 22, the cross section of the end of the blade 221 is gradually reduced, so that the contact area between the blade 221 and the clean water is correspondingly reduced, the adhesion force of the clean water to the blade 221 is smaller, the clean water is more easily thrown upward, and the working efficiency of the water pumping device 20 is improved.

In order to further improve the working efficiency of the water pumping device 20, the situation that the gap between the pump shell 21 and the blade 221 is irregular due to large or small gaps is avoided, the flowing disorder of the clean water in the pump shell 21 is prevented, the surface of the pump shell 21, which is opposite to the lower edge of the blade 221, is correspondingly inclined, the gap between the pump shell 21 and the blade 221 is regular, the clean water is regular when flowing in the pump shell 21, the occurrence of the turbulent flow situation is avoided, the frictional resistance of the water flow is reduced, and the working efficiency of the water pumping device 20 is improved.

As shown in fig. 3-5, in one embodiment, the impeller 22 is mounted inside the pump housing 21 by a support shaft 222. The support shaft 222 is fixed in the pump housing 21, and the center of the impeller 22 overlaps the tip of the support shaft 222. Preferably, a ball is further provided between the impeller 22 and the support shaft 222 to reduce the rotational resistance between the impeller 22 and the support shaft 222.

As shown in fig. 3-5, in one embodiment, the pump casing 21 includes an upper pump casing 211 and a lower pump casing 212, the upper pump casing 211 interfacing with the lower pump casing 212. The corresponding positions of the upper pump shell 211 and the lower pump shell 212 are provided with a buckle and a clamping groove, so that the upper pump shell 211 and the lower pump shell 212 can be quickly assembled and connected.

Optionally, the upper pump casing 211 and the lower pump casing 212 may also be connected by a socket structure, bonded by an adhesive, or the like.

The above description is only for the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art can easily think of the changes or substitutions within the technical scope of the present invention, and all should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A mop bucket is characterized by comprising a bucket body (10), a first water cavity (30), a water flow channel and a second water cavity (40);

the first water cavity (30) is arranged on the barrel body (10), and the water flow channel is communicated with the first water cavity (30) and is used for enabling water in the first water cavity (30) to flow into the barrel body (10); the second water cavity (40) is communicated with the first water cavity (30), and water in the first water cavity (30) can flow into the second water cavity (40) so that the water level in the first water cavity (30) is lower than or flush with the highest water storage point of the water flow channel.

2. The mop bucket of claim 1, wherein the highest point of water storage of the second water cavity (40) is lower than or flush with the highest point of water storage of the water flow channel.

3. The mop bucket of claim 1, wherein the second water chamber (40) is disposed within the bucket body (10).

4. The mop bucket according to claim 1, wherein the first water chamber (30) comprises a stationary water tank (31) and a moving water tank (32);

fixed water tank (31) fixed set up in on staving (10), the rivers passageway with fixed water tank (31) intercommunication, be equipped with water inlet (311) on fixed water tank (31), movable water tank (32) detachably install in water inlet (311) department, work as movable water tank (32) install in when water inlet (311) department, the water accessible in movable water tank (32) water inlet (311) flow in fixed water tank (31).

5. The mop bucket according to claim 4, characterized in that, the bottom of the moving water tank (32) is provided with a water outlet (321) projecting downwards, the water outlet (321) is inserted into the water inlet (311) on the fixed water tank (31) in a matching way;

the bottom of removal water tank (32) still is equipped with and is used for supporting part (322) of removal water tank (32), the bottom of supporting part (322) be less than or the parallel and level in the bottom of delivery port (321), be equipped with slot (312) on fixed water tank (31), supporting part (322) cooperation is inserted in slot (312).

6. The mop bucket according to claim 4, characterized in that the moving water tank (32) is provided with a catching groove (323) for holding.

7. The mop bucket according to claim 1, wherein a water pumping device (20) is disposed on the water flow passage, and the water pumping device (20) is used for pumping the water in the first water cavity (30) to the inner cavity of the bucket body (10).

8. The mop bucket according to claim 7, wherein the water pumping device (20) comprises a pump housing (21) and an impeller (22), the impeller (22) being located in the pump housing (21) and being rotatably connected to the pump housing (21);

the water outlet part (24) of the water pumping device (20) is positioned on the pump shell (21), and the water outlet part (24) is arc-shaped and faces towards the inner cavity of the barrel body (10) so as to guide the flow of water pumped out of the pump shell (21).

9. The mop bucket according to claim 7, wherein the water pumping device (20) comprises a pump housing (21) and an impeller (22), the impeller (22) being located in the pump housing (21) and being rotatably connected to the pump housing (21);

the impeller (22) is provided with a blade (221), and the lower edge of the blade (221) is inclined upwards along the direction away from the rotation axis of the impeller (22);

the surface of the pump shell (21) opposite to the lower edge of the blade (221) is correspondingly inclined upwards.

10. The mop bucket of claim 1, wherein a highest point of water storage of the first water cavity (30) is higher than a highest point of water storage of the water flow channel.