Cleaning device and net cage
By designing a cleaning roller and drive structure for the net cage cleaning device, the problem of mesh clogging caused by marine organisms was solved, achieving uniform cleaning and water quality improvement, and enhancing water flow and cleaning effect in the aquaculture environment.
Patent Information
- Application Number
- CN202422985881.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-04
- Publication Date
- 2025-11-21
- Estimated Expiration
- 2034-12-04
AI Technical Summary
In existing technologies, after a period of use, marine organisms attach to aquaculture net cages, causing the mesh to become clogged, reducing dissolved oxygen levels and water quality, and affecting the health of fish.
A cleaning device is designed, including a cleaning roller and a drive structure. The cleaning roller moves along the side wall of the housing to achieve uniform cleaning. It is driven to move circumferentially by a first actuation structure and to move axially up and down by a second actuation structure to ensure uniform cleaning force.
It improves the flow of water inside and outside the net cage, enhances the cleaning effect, prevents marine organisms from attaching, improves water quality, and protects the health of fish.
Smart Images
Figure CN223571565U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present disclosure relates to the technical field of net cage cleaning, in particular, to a cleaning device and a net cage. BACKGROUND
[0002] In the prior art, after the net cage is used for a period of time, marine organisms such as algae and shellfish in seawater will be attached to the fishing net in a large area, causing the mesh to be blocked, hindering the exchange of seawater inside and outside the net cage, leading to a decrease in the dissolved oxygen content of seawater in the net cage and deterioration of water quality, and further causing diseases and death of the farmed fish. The prior art cleans the inside and outside sidewalls of the net cage by rubbing with a cleaning brush plate, which has a relatively long length, so that the pressure of the cleaning brush plate on the inside and outside sidewalls of the net cage is uneven, the cleaning force of the cleaning brush plate is small, and the cleaning effect is poor, thereby reducing the flow of water inside and outside the net cage. CONTENT OF THE UTILITY MODEL
[0003] The purpose of the present disclosure is to provide a cleaning device for a net cage to at least partially solve the technical problems existing in the related art.
[0004] In order to achieve the above-mentioned purpose, the present application provides a cleaning device for cleaning the box body of a net cage, comprising a cleaning roller and a driving structure;
[0005] The cleaning roller is adapted to be arranged on the sidewall of the box body, and the outer surface of the cleaning roller is adapted to abut against the sidewall surface of the box body.
[0006] The driving structure comprises a first actuating structure and a second actuating structure, the first actuating structure is connected with the cleaning roller and is used to drive the cleaning roller to move along the circumference of the box body, and the second actuating structure is connected with the cleaning roller and is used to drive the cleaning roller to move up and down along the axial direction of the box body.
[0007] Optionally, the first actuating structure comprises a first motor and a rotating frame,
[0008] The first motor is mounted on the box body.
[0009] The rotating frame is connected to the first motor, the cleaning roller is connected to the rotating frame, and the first motor is used to drive the rotating frame to rotate along the circumference of the box body, so that the cleaning roller can move along the circumference of the box body.
[0010] Optionally, the first motor is arranged at the bottom of the box body, one end of the rotating frame is connected with the first motor, and the other end of the rotating frame is buckled with the upper end of the sidewall of the box body.
[0011] Optionally, the second actuating structure comprises a reciprocating screw and a mounting member, the reciprocating screw is arranged in parallel to the side wall of the tank and connected to the rotating frame, and the reciprocating screw is arranged to move along the circumference of the tank with the rotating frame;
[0012] The reciprocating screw is threadedly connected with the mounting member to form a screw nut pair, and the cleaning roller is connected with the mounting member;
[0013] The driving structure further comprises a linkage assembly, the linkage assembly comprises a rotating member and a rotating member, the rotating member is sleeved on the reciprocating screw, the rotating member is mounted on the side wall of the tank and extends along the circumference of the tank, and the rotating member is in contact with the rotating member, and the rotating member is used to rotate the rotating member during the movement of the rotating member along the circumference of the tank with the rotating frame.
[0014] Optionally, the rotating member is a rack, and the rotating member is a gear, and the gear is engaged with the rack; or,
[0015] The rotating member is a friction strip, and the rotating member is a friction wheel, and the friction wheel is in frictional contact with the friction strip.
[0016] Optionally, the cleaning roller comprises a rotating shaft and a cleaning roller body connected thereto, and the cleaning roller is mounted on the tank through the mounting member;
[0017] The driving structure further comprises a second motor, the second motor is connected to the mounting member and connected to the rotating shaft, and is used to drive the rotating shaft to rotate.
[0018] Optionally, two cleaning rollers are arranged, and the two cleaning rollers are located at the same position in the axial and circumferential directions of the tank;
[0019] The two cleaning rollers abut against the inner side wall and the outer side wall of the tank, respectively.
[0020] In the second aspect of the present disclosure, a net cage is provided, comprising a tank and the cleaning device described above.
[0021] Optionally, the net cage is a water culture net cage, and the tank comprises a lifting structure, the lifting structure is used to make the tank float or sink in the water area.
[0022] Optionally, the lifting structure comprises an air valve and a water valve,
[0023] The side wall of the tank is internally provided with a groove, the air valve is connected to the top of the groove and is adapted to communicate the groove with the atmosphere, and the water valve is connected to the bottom of the groove and is adapted to communicate the groove with the water area;
[0024] The culture box has a rising state and a falling state, in the rising state, the air valve is opened, and the recess is filled with air; in the falling state, the water valve is opened, and the recess is filled with liquid.
[0025] By the above technical solution, the cleaning roller is pressed on the side wall of the box body, and the first actuating structure is controlled to drive the cleaning roller to move along the circumference of the box body, and the second actuating structure is controlled to drive the cleaning roller to move up and down along the axis of the box body, so that the length of the cleaning roller can be set shorter, and the cleaning of the entire side wall of the box body can be completed, the length of the cleaning roller is shorter, the pressure distribution of the cleaning roller at each position of the box body is uniform, the cleaning force of the cleaning roller pressed on the side wall of the box body is better, the cleaning effect is better, and the flow of water in and out of the net cage is improved.
[0026] Other features and advantages of the present disclosure will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS
[0027] The accompanying drawings are included to provide a further understanding of the present disclosure and constitute a part of the specification, and are used together with the following specific embodiments to explain the present disclosure, but do not constitute a limitation on the present disclosure. In the drawings:
[0028] Figure 1 is a perspective view of a net cage provided by an exemplary embodiment of the present disclosure, wherein the mesh on the net cage is not shown;
[0029] Figure 2 is a cross-sectional view of a net cage provided by an exemplary embodiment of the present disclosure;
[0030] Figure 3 is Figure 2 is an enlarged view of part A in FIG. 1;
[0031] Figure 4 is Figure 2 is an enlarged view of part B in FIG. 1.
[0032] BRIEF DESCRIPTION OF DRAWINGS
[0033] 100, net cage, 10, box body, 11, side wall, 2, cleaning device, 20, cleaning roller, 21, rotating shaft, 22, cleaning roller body, 30, first actuating structure, 31, first motor, 32, rotating frame, 40, second actuating structure, 41, reciprocating screw, 42, mounting piece, 43, rotating piece, 44, rotating piece, 50, air valve, 60, water valve, 70, recess, 71, through hole, 80, second motor, 90, floating platform. DETAILED DESCRIPTION
[0034] The specific embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described and illustrated herein are merely intended to illustrate and explain the present disclosure, and are not intended to limit the present disclosure.
[0035] In the description of the present disclosure, it should be understood that the terms "upper", "lower", etc. indicate the orientation or positional relationship defined based on the direction of the drawing shown in the drawings, and are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, and a particular orientation configuration and operation, and therefore cannot be understood as a limitation on the present disclosure.
[0036] In the present disclosure, it should be noted that the terms "first", "second", etc. are used to distinguish one element from another element, and do not have sequentiality and importance. In addition, in the description with reference to the drawings, the same reference signs in different drawings represent the same elements.
[0037] In the description of the present disclosure, it should also be noted that, unless otherwise explicitly specified and limited, the terms "provided", "connected", "connected", "mounted" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrally connected; it can be directly connected, or it can be indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present disclosure can be understood according to the specific circumstances.
[0038] The present application provides a cleaning device 2 for cleaning the net cage body, such as Figures 1 to 4 As shown, it comprises a cleaning roller 20 and a driving structure, the cleaning roller 20 is adapted to be arranged on the side wall 11 of the cage body 10, and the outer surface of the cleaning roller 20 is adapted to abut the surface of the side wall 11 of the cage body 10, the driving structure comprises a first actuating structure 30 and a second actuating structure 40, the first actuating structure 30 is connected with the cleaning roller 20 and is used to drive the cleaning roller 20 to move along the circumference of the cage body 10, and the second actuating structure 40 is connected with the cleaning roller 20 and is used to drive the cleaning roller 20 to move up and down along the axial direction of the cage body 10.
[0039] Through the above technical solution, the cleaning roller 20 is pressed on the side wall 11 of the cage body 10, and the first actuating structure 30 controls the driving of the cleaning roller 20 to move along the circumference of the cage body 10, and the second actuating structure 40 drives the cleaning roller 20 to move up and down along the axial direction of the cage body 10, so that the length of the cleaning roller 20 can be set shorter, and the cleaning of the entire side wall 11 of the cage body 10 can be completed, the cleaning roller 20 with shorter length can make the pressure distribution of the cleaning roller 20 at each position of the cage body 10 uniform, and the cleaning force of the cleaning roller 20 pressed on the side wall 11 of the cage body 10 is better, so that the cleaning effect is better, and the flow of water in and out of the net cage 100 is improved.
[0040] In the present disclosure, the cleaning roller 20 is used to clean the side wall 11 of the box 10. The cleaning roller 20 is abutted against the side wall 11 of the box 10, so as to ensure the cleaning strength of the cleaning roller 20 when moving or rolling against the side wall 11 of the box 10. The cleaning roller 20 can move along the circumferential direction of the box 10, and can also move up and down along the axial direction of the box 10, that is, the cleaning roller 20 can clean the side wall 11 of the box 10, thereby ensuring the cleaning effect.
[0041] In the present disclosure, as shown in Figures 1 to 3 , the first actuating structure 30 can include a first motor 31 and a rotating frame 32. The first motor 31 is installed on the box 10, and the rotating frame 32 is connected to the first motor 31. The cleaning roller 20 is connected to the rotating frame 32. The first motor 31 is used to drive the rotating frame 32 to rotate along the circumferential direction of the box 10, so that the cleaning roller 20 can move along the circumferential direction of the box 10 with the rotating frame 32. In this way, the cleaning roller 20 can clean different positions on the side wall 11 of the box 10 in the circumferential direction.
[0042] Optionally, when the box 10 is in a cylindrical shape, as shown in Figure 2 , the rotating frame 32 can be arranged to rotate around the center of the bottom surface of the cylinder. The length of the rotating frame 32 along the radial direction of the cylinder is arranged to be slightly larger than the fixed length of the radius of the cylinder.
[0043] Optionally, when the box 10 is in a square tube or irregular tube shape, the rotating frame 32 can be arranged to rotate around the center of the bottom surface of the box 10. The length of the rotating frame 32 along the radial direction of the box 10 can be arranged as a controllable telescopic rod to adapt to the radial size of the tube.
[0044] In the present disclosure, as shown in Figure 2 , the first motor 31 can be arranged at the bottom of the box 10. One end of the rotating frame 32 can be connected to the first motor 31, and the other end of the rotating frame 32 can be buckled to the upper end of the side wall 11 of the box 10. In this way, the positions of the two ends of the rotating frame 32 are defined, and the stability of the rotating frame 32 during rotation is ensured.
[0045] Optionally, as shown in Figure 2 , the first motor 31 can be arranged at the center position of the bottom of the box 10. In this way, the rotating frame 32 is conveniently driven to rotate, and the force on the rotating frame 32 during rotation is uniform.
[0046] In the present disclosure, as shown in Figure 2 and Figure 3As shown, the second actuating structure 40 can include a reciprocating screw 41 and a mounting member 42, the reciprocating screw 41 is arranged parallel to the side wall 11 of the box 10, so that when the mounting member 42 moves along the axis direction of the reciprocating screw 41, the mounting member 42 can be always equidistant from each position of the side wall of the box 10. And connected to the rotating frame 32, and the reciprocating screw 41 is arranged to be able to move with the rotating frame 32 along the circumference of the box 10, the reciprocating screw 41 is threadedly connected with the mounting member 42 to form a screw nut pair, and the cleaning roller 20 is connected with the mounting member 42, that is, can reciprocate up and down on the reciprocating screw 41 along with the mounting member 42. The driving structure further includes a linkage assembly, the linkage assembly includes a rotating member 43 and a rotating member 44, the rotating member 43 is sleeved on the reciprocating screw 41, and the rotating member 44 is installed on the side wall 11 of the box 10 and extends along the circumference of the box 10, and the rotating member 44 is in contact with the rotating member 43, and the rotating member 44 is used for rotating the rotating member 43 in the process that the rotating member 43 moves along the circumference of the box 10 along with the rotating frame 32. In this way, the first actuating structure 30 can drive the reciprocating screw 41 of the second actuating structure 40 to move circumferentially when moving, and the reciprocating screw 41 can rotate itself through the linkage assembly, that is, the first actuating structure 30 can be linked with the second actuating structure 40, and the first actuating structure 30 can drive the rotation of the second actuating structure 40 when moving, so that the cleaning roller 20 can move up and down in the process of moving along the circumference of the box 10.
[0047] Among them, the reciprocating screw 41 refers to a special double-head screw design, that is, there are left-handed and right-handed thread grooves on one screw, and the leads of the two are the same. Allow the screw to keep the main shaft in a single rotation direction, realize the linear motion of the nut or moving part on the screw in the opposite direction through cooperation with two different rotation threads, or make a single part realize reciprocating motion through appropriate mechanism design. For example, the bidirectional threaded screw, in the present disclosure, the connection between the reciprocating screw 41 and the mounting member 42 can be set, and the rotation direction of the reciprocating screw 41 itself does not change, and the reciprocating motion of the mounting member 42 on the reciprocating screw 41 is completed.
[0048] In the present disclosure, the rotating member 43 on the linkage assembly is connected to the reciprocating screw 41, the rotating member 43 is sleeved on the reciprocating screw 41, and the rotating member 44 extends along the circumference of the side wall of the box 10, that is, when the rotating frame 32 moves along the circumference of the box 10, it drives the reciprocating screw 41 and the mounting member 42 to move along the circumference of the box 10, and at the same time, the rotating member 43 rotates to drive the reciprocating screw 41 to rotate itself, so that the mounting member 42 which forms a screw nut pair with the reciprocating screw 41 moves up and down, that is, the up and down movement of the cleaning roller 20 and the movement along the circumference of the box 10 are completed.
[0049] In the present disclosure, the rotating member 44 can be a rack, and the rotating member 43 can be a gear engaged with the rack, or the rotating member 44 can be a friction strip, and the rotating member 43 can be a friction wheel in frictional contact with the friction strip. In this way, when the rotating member 43 moves, the rotating member 44 can be rotated under the action of the rotating member 43.
[0050] Alternatively, the above functions can also be achieved by using a sprocket and a chain.
[0051] In the present disclosure, as shown in Figures 1 to 3 The cleaning roller 20 can include a rotating shaft 21 and a cleaning roller body 22 connected to each other, and the cleaning roller 20 is installed on the box body 10 through the mounting member 42. The driving structure further includes a second motor 80 connected to the mounting member 42 and connected to the rotating shaft 21 for driving the rotating shaft 21 to rotate. The cleaning roller itself forms rotation, and the cleaning roller 20 is in abutting friction with the side wall 11. The rotating cleaning roller 20 can simultaneously carry away part of the impurities, and better cleaning effect can be achieved.
[0052] In the present disclosure, as shown in Figure 3 Two cleaning rollers 20 can be provided, and the two cleaning rollers 20 are located at the same position in the axial and circumferential directions of the box body 10, and the two cleaning rollers 20 are respectively in abutting contact with the inner side wall 11 and the outer side wall 11 of the box body 10. In this way, a cleaning structure can be formed between the inner side wall 11 and the outer side wall 11 of the cleaning roller 20 to achieve better cleaning effect.
[0053] The two cleaning rollers 20 are located at the same position in the axial and circumferential directions of the box body 10, which means that the two cleaning rollers 20 are located at corresponding positions on the inner side wall 11 and the outer side wall 11 of the box body 10. That is, the same position impurities can be cleaned at the same time, preventing impurities from being pushed from the outer side wall 11 to the inner side wall 11, or from the inner side wall 11 to the outer side wall 11, thereby reducing the difficulty of cleaning and ensuring the cleaning effect.
[0054] Here, two first actuating structures 30, two second actuating structures 40, and two second motors 80 can be provided, which can correspond to the two cleaning rollers 20 respectively, so as to control the movement or rotation of the two cleaning rollers 20.
[0055] In the second aspect of the present disclosure, a net cage 100 is provided, which includes a box body 10 and the above-mentioned cleaning device 2.
[0056] In the present disclosure, the net cage 100 is a water aquaculture cage, and the box body 10 includes a lifting structure for making the box body 10 float or sink in the water. The lifting structure can adjust the depth of the net cage 100 in the water to adapt to different requirements of the breeding conditions.
[0057] In the present disclosure, the lifting structure comprises the air valve 50 and the water valve 60, the side wall 11 of the box 10 is internally provided with the groove 70, the air valve 50 is connected to the top of the groove 70 and is adapted to communicate the groove 70 with the atmospheric environment, the water valve 60 is connected to the bottom of the groove 70 and is adapted to communicate the groove 70 with the water area, the net cage 100 has the rising state and the descending state, in the rising state, the air valve 50 is opened, the groove 70 is filled with air, in the descending state, the water valve 60 is opened, the groove 70 is filled with liquid. By setting the air valve 50 and the water pump, the submergence and the floating of the net cage 100 are controlled, and the depth of the net cage 100 in the water is adjusted.
[0058] Optionally, the side wall 11 of the net cage 100 can be partially provided as the floating platform 90, the floating platform 90 can be uniformly arranged along the circumference of the net cage 100 to ensure the stability of the rising and the descending of the net cage 100. In addition, the groove 70 described above can be arranged inside the floating platform 90, and the floating platform 90 is provided as a non-mesh structure, so that the groove 70 has the sealing property.
[0059] In the present disclosure, the side wall 11 of the net cage 100 can be provided as a mesh except the position of the floating platform 90, so that the water flows in and out, and the mesh of the net cage 100 is not shown in the illustration of the present disclosure.
[0060] Optionally, the air valve 50 can be provided as the air pump, when the net cage 100 is applied to the sea and needs to be submerged, the air pump responsible for discharging air is started to discharge the gas in the liquid cavity, the water pump for pumping in seawater is started, and then the seawater can be filled into the liquid cavity through the through hole 71 to increase the weight of the net cage 100 and facilitate the submergence of the net cage 100, when the net cage 100 needs to be floated, the air pump responsible for inhaling air is started to fill the gas into the liquid cavity, the water pump for discharging seawater is started, and then the seawater in the groove 70 is discharged from the groove 70 through the through hole to reduce the weight of the net cage 100 and facilitate the floating of the net cage 100.
[0061] When the inner side wall 11 and the outer side wall 11 of the box 10 need to be cleaned, the first motor 31 and the second motor 80 are started, the output shaft of the first motor 31 rotates to drive the rotating frame 32 to rotate and move along the circumference of the box 10, the cleaning roller 20 is installed on the rotating frame 32, so that the rotating frame 32 can drive the two cleaning rollers to move along the circumference of the box 10, thereby cleaning the impurities adhered to the side wall 11 of the net cage 100. Moreover, since the rotating member 43 is connected with the reciprocating screw rod 41, and the reciprocating screw rod 41 is connected with the rotating frame 32, the rotating frame 32 can drive the reciprocating screw rod 41 to move along the circumference of the box 10, thereby driving the rotating member 43 to move along the circumference of the box 10, so that the rotating member 43 and the driving member 44 are in contact, and the rotating member 43 moves on the driving member 44, the rotating member 43 rotates by itself, drives the screw rod to rotate by itself, and drives the cleaning roller 20 to move up and down along the circumference of the box 10. The cleaning roller can better clean the inner side wall 11 and the outer side wall 11 of the net cage 100, so as to ensure good water flow in the net cage 100.
[0062] The preferred embodiments of the present disclosure are described in detail above with reference to the drawings, but the present disclosure is not limited to the specific details in the above-described embodiments. Within the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.
[0063] In addition, it should be noted that various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction, and the present disclosure will not describe various possible combinations again.
[0064] In addition, various different embodiments of the present disclosure can also be combined in any appropriate manner, as long as they do not deviate from the idea of the present disclosure, and they should also be considered as disclosed by the present disclosure.
Claims
1. A cleaning device for cleaning the body of a wire mesh cage, characterized in that, Includes cleaning rollers and drive structure; The cleaning roller is adapted to be disposed on the side wall of the housing, and the outer surface of the cleaning roller is adapted to abut against the side wall surface of the housing; The driving structure includes a first actuation structure and a second actuation structure. The first actuation structure is connected to the cleaning roller and is used to drive the cleaning roller to move circumferentially along the housing. The second actuation structure is connected to the cleaning roller and is used to drive the cleaning roller to move up and down along the axial direction of the housing.
2. The cleaning device according to claim 1, characterized in that, The first actuation structure includes a first motor and a rotating frame. The first motor is mounted on the housing; The rotating frame is connected to the first motor, and the cleaning roller is connected to the rotating frame. The first motor is used to drive the rotating frame to rotate around the circumference of the box, so that the cleaning roller can move around the circumference of the box.
3. The cleaning device according to claim 2, characterized in that, The first motor is located at the bottom of the housing, one end of the rotating frame is connected to the first motor, and the other end of the rotating frame is fastened to the upper end of the side wall of the housing.
4. The cleaning device according to claim 2, characterized in that, The second actuation structure includes a reciprocating lead screw and a mounting component. The reciprocating lead screw is arranged parallel to the side wall of the housing and connected to the rotating frame. The reciprocating lead screw is configured to move circumferentially along the housing with the rotating frame. The reciprocating lead screw is threadedly connected to the mounting component to form a lead screw and nut pair, and the cleaning roller is connected to the mounting component; The drive structure also includes a linkage component, which includes a rotating component and an actuating component. The rotating component is sleeved on the reciprocating screw, and the actuating component is installed on the side wall of the housing and extends circumferentially along the housing. The actuating component contacts the rotating component, and the actuating component is used to rotate the rotating component as the rotating frame moves circumferentially along the housing.
5. The cleaning device according to claim 4, characterized in that, The actuating component is a rack, and the rotating component is a gear, wherein the gear meshes with the rack; or... The actuating component is a friction strip, the rotating component is a friction wheel, and the friction wheel is in frictional contact with the friction strip.
6. The cleaning device according to claim 1, characterized in that, The cleaning roller includes a connected rotating shaft and a cleaning roller body, and the cleaning roller is mounted to the housing by a mounting component; The drive structure also includes a second motor, which is connected to the mounting component and to the rotating shaft, for driving the rotating shaft to rotate.
7. The cleaning apparatus according to any one of claims 1-6, characterized in that, Two cleaning rollers are provided, and the two cleaning rollers are located at the same position in both the axial and circumferential directions of the housing; The two cleaning rollers respectively abut against the inner and outer walls of the housing.
8. A wire mesh cage, characterized in that, It includes a housing and the cleaning device according to any one of claims 1-7.
9. The cage according to claim 8, characterized in that, The cage is an aquaculture cage, and the cage body includes a lifting structure, which is used to make the cage body float or sink in the water.
10. The wire mesh cage according to claim 9, characterized in that, The lifting structure includes an air valve and a water valve. The side wall of the box is provided with a groove, the air valve is connected to the top of the groove and is adapted to connect the groove with the atmospheric environment, and the water valve is connected to the bottom of the groove and is adapted to connect the groove with the water area; The cage has an ascending state and a descending state. In the ascending state, the air valve is opened and air is filled into the groove. In the descending state, the water valve opens, and liquid fills the groove.