CN110973045A

CN110973045A - Fish tank capable of automatically changing water

Info

Publication number: CN110973045A
Application number: CN202010004625.0A
Authority: CN
Inventors: 赵炳海; 许正
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-01-03
Filing date: 2020-01-03
Publication date: 2020-04-10

Abstract

The invention discloses a fish tank capable of automatically changing water, which belongs to the field of fish tanks and comprises a fish tank body and is characterized in that: the water tank, the floater, the water valve and the water pipe are also included; a floater is arranged in the water tank, is of a cup-shaped structure and comprises a side wall, a bottom plate, a pull rod, a vertical rod, a floater spring, a sealing ring, an ejector rod and a pressure relief device; the water valve comprises a first valve and a second valve; the first valve and the second valve are respectively provided with a series of openings, and the openings are respectively connected with different structures through water pipes; the first valve comprises a first valve body and a first valve core; the second valve comprises a second valve body, a second valve core and a valve body spring. Compared with the prior art have the characteristics that can trade water automatically.

Description

Fish tank capable of automatically changing water

Technical Field

The invention relates to a fish tank, in particular to a fish tank capable of automatically changing water.

Background

Many people like to breed fish, and the fish breeding brings pleasure to people and also needs certain labor for people, such as feeding, changing water and the like. The process of changing water is somewhat cumbersome relative to feeding: the waste water is pumped out and fresh water is added. Since tap water is disinfected by chlorine, it is not suitable for direct fish culture, and the tap water needs to be placed for one day in advance to volatilize the chlorine. Over time, these tedious tasks may reduce people's enjoyment of fish farming.

Disclosure of Invention

The technical task of the invention is to provide a fish tank capable of automatically changing water aiming at the defects of the prior art.

The technical scheme for solving the technical problem is as follows: the utility model provides a can trade fish bowl of water automatically, includes the fish bowl, its characterized in that: the water tank, the floater, the water valve and the water pipe are also included; the two water tanks are arranged above the fish tank and comprise a first water tank and a second water tank; a floater is arranged in the water tank, is of a cup-shaped structure and comprises a side wall, a bottom plate, a pull rod, a vertical rod, a floater spring, a sealing ring, an ejector rod and a pressure relief device; the side wall is in a highly compressible elastic corrugated pipe structure, and the upper edge of the side wall is in an annular structure made of hard materials; the plurality of pull rods are uniformly distributed on the outer side of the side wall, the upper end of each pull rod is hinged with the upper edge of the side wall, the inner side surface of each pull rod is provided with a ratchet, the edge of the bottom plate protrudes outwards, the shape of the edge of the bottom plate is matched with the shape of a ratchet tooth groove, and the edge of the bottom plate can freely move upwards but cannot freely move downwards under the action of the ratchet and the edge of the bottom plate; the lower end of the pull rod inclines outwards; the upper wall of the water tank is provided with a vent hole and a guide hole at the position above the floater; the lower end of the vertical rod is fixed on the bottom plate of the floater, and the upper part of the vertical rod penetrates through the guide hole; the float spring is sleeved on the vertical rod; the sealing ring is positioned at the upper edge of the side wall; the pressure relief device is positioned on the upper edge of the side wall and comprises a pressure relief hole, a pressure relief spring, a piston and a deflector rod; the pressure relief hole is a horizontal through hole and penetrates through the inner side and the outer side of the upper edge of the side wall; the pressure relief hole is of a conical structure with a thin inner part and a thick outer part; the piston is positioned in the pressure relief hole, and the side wall of the piston is of a conical surface structure which is thin inside and thick outside and is matched with the pressure relief hole; in a natural state, the inner side end of the piston is exposed out of the pressure relief hole; the pressure relief spring is positioned in the pressure relief hole, the outer end of the pressure relief spring is fixed in the pressure relief hole, the inner end of the pressure relief spring is propped against the outer end of the piston, and the piston is propped outwards under the action of the pressure relief spring, so that the pressure relief hole can be sealed; the deflector rod is positioned below the inner side end of the piston, the outer side end of the deflector rod is hinged with the upper edge of the side wall or the main structure of the pressure relief device, the deflector rod is in a horizontal state in a natural state, a protruding structure is arranged on the upper side of the deflector rod, and the upper end of the protruding structure is positioned at the inner end of the piston; the top rod is positioned below the deflector rod, and the lower end of the top rod is fixed on the float bottom plate; the water tank is communicated with the water valve through a first water pipe; the fish tank is communicated with the water valve through a second water pipe; the water valve comprises a first valve and a second valve; the first valve and the second valve are respectively provided with a series of openings, and the openings are respectively connected with different structures through water pipes; the first valve comprises a first valve body and a first valve core, wherein the first valve body is of a hollow cylindrical structure, and a cylindrical cavity is formed inside the first valve body; the first valve core is positioned in the cavity of the first valve body, the first valve core is of a cylindrical structure, the two ends of the first valve core are thick, the middle of the first valve core is thin, the thick parts of the two ends of the first valve core are thick sections, the thin parts of the middle of the first valve core are thin sections, and the thick sections and the cavity of the first valve body form sealing; the first valve body is provided with five openings a, b, c, d and e, wherein the opening a is positioned at the left end of the first valve body, the opening c is positioned at the right end of the first valve body, the openings b, d and e are positioned on the side wall of the first valve body, the opening b is positioned in the middle of the side wall, the opening d and the opening e are respectively positioned at the positions of the middle part which is slightly right and the middle part which is slightly left, and the distance between the opening d and the opening e is greater than the length of the thin section of the first valve core; the ports d and e are thin ports, water flow can only pass through the ports d and e at a very slow speed, and the other ports are large ports, so that the water flow passing speed is high; when the first valve core is positioned at the left end, the port b and the port e are positioned at the thin section of the first valve core at the same time, so that the port b is communicated with the port e, the port d is positioned at the thick section of the right end of the first valve core, and the port d is blocked; when the first valve core is positioned at the right end, the port b is communicated with the port d, the port e is positioned at the thick section at the left end of the first valve core, and the port e is blocked; the port a is connected with the port g of the second valve, the port b is connected with a tap water pipe, the port c is connected with the port k of the second valve, the port d is connected with the second water tank, and the port e is connected with the first water tank; the second valve comprises a second valve body, a second valve core and a valve body spring; the second valve body is of a hollow cylindrical structure, and a cylindrical cavity is formed inside the second valve body; the two valve body springs are respectively positioned at the left end and the right end in the cavity of the second valve body; the second valve core is positioned in the cavity of the second valve body and between the two valve body springs; the second valve core is of a cylindrical structure, three thin sections are arranged in the middle of the second valve core, the other parts of the second valve core are four thick sections, and the thick sections and the cavity of the second valve body form sealing; the three sections are respectively a first section to a third section from left to right; twelve openings f, g and h … … q are arranged on the second valve body, wherein an opening f and an opening l are respectively positioned on the left end part and the right end part of the second valve body, the opening f and the opening l are thin openings, water flow can only pass through the opening f or the opening l at a very slow speed, and the other openings are large openings, so that the water flow passing speed is high; other openings are positioned on the side wall of the second valve body and are g, q, h, p, i, o, j, n, k and m from left to right, wherein g, q, h, p, i, o, j, n and m respectively form five pairs of openings, and each pair of openings are positioned on the same cross section of the second valve body; when the second valve core moves left and right, the thin sections are respectively positioned at different opening positions, when each pair of openings are positioned at the thin sections of the second valve core, the pair of openings are communicated with each other, and the openings positioned at the thick sections are blocked; when the second valve core moves to the right end, the first thin section is positioned at the g opening and the q opening, and the second thin section is positioned at the k opening and the m opening; when the second valve core moves to the left end, the second thin section is positioned at the g opening and the q opening, the third thin section is positioned at the k opening and the m opening, and other openings on the side wall are blocked; under the action of the valve body springs, when no pressure difference exists between the two ends of the second valve core, the two valve body springs are in natural lengths, the left end or the right end of the second valve core is abutted against one of the valve body springs, and the second thin section is positioned between the openings i and o and the openings j and n or between the openings i and o and the openings h and p; the three openings f, q and p are connected with a first water tank, the opening g is connected with an opening a of a first valve, the three openings h, i and j are connected with a fish tank, the opening k is connected with an opening c of the first valve, the three openings l, m and n are connected with a second water tank, and the opening o is connected with a drain pipe.

An n-shaped return bend is arranged at one end of the first water pipe, which is positioned in the water tank.

One end of the second water pipe connected with the fish tank is positioned at the depth of one third below the water surface of the fish tank.

Compared with the prior art, the automatic water changing device can automatically change water without manual operation.

Drawings

Fig. 1 is a schematic structural view of the present invention.

Fig. 2 is a schematic view of the structure of the water tank of the present invention.

Fig. 3 is a schematic view of the filled tank.

Fig. 4 is a schematic diagram of a tank after pressure relief.

Fig. 5 is a schematic view of a pressure relief device according to the present invention.

Fig. 6 is a schematic view of the first valve structure of the present invention.

Fig. 7 is a structural schematic diagram of the second valve when the second valve core moves to the right end.

Fig. 8 is a schematic view of the structure of the second valve in the natural state.

Detailed Description

The invention is further described with reference to the drawings and the detailed description.

As shown in fig. 1 to 8, the present invention includes a fish tank 2, a water tank 1, a float, a water valve, and a water pipe.

The number of the water tanks 1 is two, the water tanks include a first water tank 22 and a second water tank 23, and the two water tanks 1 are located above the fish tank 2. A floater is arranged in the water tank 1, and the floater is of a cup-shaped structure and comprises a side wall 13, a bottom plate 14, a pull rod 10, a vertical rod 6, a floater spring 5, a sealing ring 4, an ejector rod 15 and a pressure relief device 3. The side wall 13 is in a highly compressible elastic bellows structure, and the upper edge 9 of the side wall is in a ring structure made of hard materials. The pull rods 10 are uniformly distributed on the outer side of the side wall 13, the upper ends of the pull rods 10 are hinged with the upper edge 9 of the side wall, the inner side face of each pull rod 10 is provided with a ratchet 11, the edge of the bottom plate 14 protrudes outwards, the edge of the bottom plate 14 is matched with the tooth grooves of the ratchet 11 in shape, and the edge of the bottom plate 14 can move upwards freely but cannot move downwards freely under the action of the ratchet 11 and the edge of the bottom plate 14. The lower end of the drawbar 10 is inclined to the outside. When the bottom plate 14 is clamped on the pull rod 10 (as shown in fig. 3 and 4), after the float falls down, the pull rod 10 is pushed outwards by the lower wall of the water tank 1 after the pull rod 10 touches the lower wall of the water tank 1, so that the edge of the bottom plate 14 is separated from the ratchet 11, and the side wall 13 of the float is stretched and reset. The upper wall of the water tank 1 is provided with a vent hole 8 and a guide hole 7 at the position above the floater respectively. The lower end of the vertical rod 6 is fixed on a bottom plate 14 of the floater, the upper part of the vertical rod 6 penetrates through the guide hole 7, and the floater can only move up and down along the vertical direction under the action of the vertical rod 6 and the guide hole 7. The float spring 5 is sleeved on the vertical rod 6, and when the float is tightly attached to the upper wall of the water tank 1, the downward elastic force of the float bottom plate 14 is given under the action of the float spring 5. The sealing ring 4 is positioned on the upper edge of the side wall 13, when the floater props against the upper wall of the water tank 1, the inside and the outside of the floater are sealed through the action of the sealing ring 4, and the vent hole 8 is positioned inside the sealing ring 4, so that the inside of the water tank 1 and the outside air can be sealed.

As shown in fig. 5, the pressure relief device 3 is located on the upper edge 9 of the side wall, and includes a pressure relief hole 18, a pressure relief spring 17, a piston 19, and a lever 20. The positional relationship "in" on the pressure relief device 3 means in the direction of the vertical rod 6 and "out" means in the direction of the outside of the float. The pressure relief hole 18 is a horizontal through hole and penetrates through the inner side and the outer side of the upper edge 9 of the side wall. The pressure relief hole 18 is a tapered structure with a thin inner part and a thick outer part. The piston 19 is positioned in the pressure relief hole 18, the side wall 13 of the piston 19 is in a tapered surface structure which is thin inside and thick outside and is matched with the pressure relief hole 18, so that the pressure relief hole 18 can be sealed, when the piston 19 moves towards the outer side end under the action of external force, a narrow gap is formed between the piston 19 and the pressure relief hole 18, and air on the inner side and the outer side of the float can slowly flow through the gap. In the natural state, the inner end of the piston 19 is exposed from the relief hole 18. The pressure relief spring 17 is located in the pressure relief hole 18, the outer end of the pressure relief spring 17 is fixed in the pressure relief hole 18, the inner end of the pressure relief spring 17 is pressed against the outer end of the piston 19, the piston 19 is pressed outwards under the action of the pressure relief spring 17, and therefore the pressure relief hole 18 can be sealed. The driving lever 20 is located below the inner side end of the piston 19, the outer side end of the driving lever 20 is hinged with the upper edge 9 of the side wall or the main structure of the pressure relief device 3, the driving lever 20 is in a horizontal state in a natural state, a protruding structure 21 is arranged on the upper side of the driving lever 20, and the upper end of the protruding structure 21 is located at the inner end of the piston 19. The push rod 15 is positioned below the shift lever 20, the lower end of the push rod 15 is fixed on the float bottom plate 14, when the push rod 15 moves upwards along with the float bottom plate 14, the upper end of the push rod 15 is pressed against the shift lever 20, the inner end of the shift lever 20 deflects upwards, the protruding structure 21 of the shift lever 20 is pressed against the piston 19, the piston 19 is pushed to move outwards, and a gap is formed between the piston 19 and the pressure relief hole 18.

Through the effect of the floater, after the water tank 1 is filled with water, the floater rises to block the vent hole 8 and the guide hole 7, so that the excessive water in the water tank 1 is prevented from overflowing from the vent hole 8 and the guide hole 7. After the water injection is stopped, the air in the water tank 1 is slowly exhausted under the action of the pressure relief device 3, the floater descends, and the vent hole 8 is exposed, so that the air inside and outside the water tank 1 can freely flow. The tap water contains chlorine and cannot be directly used for fish culture, and after a period of standing, chlorine in the water tank 1 is completely volatilized, so that the water is in a state suitable for fish culture until the water is discharged into the fish tank 2.

The specific working principle is as follows: after a certain amount of water is injected into the water tank 1, the floater rises to block the vent hole 8 and the guide hole 7 through the sealing ring 4; continuing to fill water into the water tank 1, gradually increasing the pressure in the water tank 1, compressing the float to a state shown in fig. 3 under the action of the pressure, wherein the upper end of the ejector rod 15 is abutted against the deflector rod 20 at the moment, and the deflector rod 20 pushes the piston 19 outwards, so that a narrow gap is formed between the piston 19 and the pressure relief hole 18, and because the pressure outside the float is high at the moment and the pressure inside the float is low, the air outside the float slowly enters the float from the gap of the pressure relief hole 18 and is discharged from the vent hole 8; after a period of time, the pressure in the water tank 1 slowly decreases until the pressure returns to the normal pressure; at the same time, the position of the bottom plate 14 of the float is fixed by the action of the pull rod 10, so that the float is kept in a compressed state; at the moment, the pressure difference between the inside and the outside of the floater disappears, the floater is pushed downwards under the action of the floater spring 5, and the water tank 1 is communicated with the outside in a state shown in figure 4; after the water in the water tank 1 is drained, the float falls down and falls on the lower wall of the water tank 1, the pull rod 10 is firstly contacted with the lower wall, the pull rod 10 inclines outwards, the lower end of the pull rod 10 is pushed to two sides through the lower wall, the pull rod 10 is opened, the float bottom plate 14 is released, and therefore the float can be restored until the water in the water tank 1 enters the water again, and the float floats and then is compressed again.

The water tank 1 is communicated with the water valve through the water pipe 16, the n-shaped return bend 25 is arranged at one end, located in the water tank 1, of the water pipe 16, water in the water tank 1 can be discharged through the return bend 25 under the effect of the n-shaped return bend 25 when the water level in the water tank 1 is higher than the upper end of the return bend 25, and water in the water tank 1 cannot be discharged through the return bend 25 when the water level in the water tank 1 is lower than the upper end of the return bend 25. The fish tank 2 is communicated with the water valve through a second water pipe 24, and one end of the second water pipe 24 connected with the fish tank 2 is positioned at the one third depth below the water surface of the fish tank 2, so that one third of water in the fish tank 2 can be drained when water is changed.

The water valve comprises a first valve and a second valve. A series of openings are respectively arranged on the first valve and the second valve, and the openings are respectively connected with different structures through water pipes. As shown in fig. 6, the first valve includes a first valve body 26 and a first valve core 27, and the first valve body 26 is a hollow cylindrical structure and has a cylindrical cavity inside. The first valve core 27 is positioned in a cavity of the first valve body 26, the first valve core 27 is of a cylindrical structure, the two ends of the first valve core are thick, the middle of the first valve core is thin, the thick parts of the two ends are thick sections 28, the middle of the thin parts are thin sections 29, and the thick sections 28 and the cavity of the first valve body 26 form sealing. The first valve body 26 is provided with five openings a, b, c, d and e, wherein the opening a is positioned at the left end of the first valve body 26, the opening c is positioned at the right end of the first valve body 26, the openings b, d and e are positioned on the side wall of the first valve body 26, the opening b is positioned in the middle of the side wall, the opening d and the opening e are respectively positioned at the positions of the middle part which is inclined to the right and the middle part which is inclined to the left, and the distance between the opening d and the opening e is greater than the length of the first valve core thin section 29, so that the opening d and the opening e cannot be communicated. The diameter of the port d and the diameter of the port e are determined according to the size of the water tank and the water changing period, so that the water tank is filled in a water changing period; the other openings are large openings, and the water flow passing speed is high. As shown in fig. 6A, when the first valve core 27 is located at the left end, the b port and the e port are simultaneously located at the thin section 29 of the first valve core, so that the b port and the e port are communicated, the d port is located at the thick section 28 of the right end of the first valve core 27, and the d port is blocked; as shown in FIG. 6B, when the first valve core 27 is located at the right end, the port B is communicated with the port d, and the port e is located at the thick section 28 at the left end of the first valve core 27, and the port e is blocked. Wherein, the port a is connected with the port g of the second valve, the port b is connected with a tap water pipe, the port c is connected with the port k of the second valve, the port d is connected with the second water tank 23, and the port e is connected with the first water tank 22.

As shown in fig. 7 and 8, the second valve includes a second valve body 30, a second valve core 31, and a valve body spring 35. The second valve body 30 is a hollow cylindrical structure, and the interior of the second valve body is a cylindrical cavity. The two valve body springs 35 are respectively located at the left end and the right end of the cavity of the second valve body 30. The second valve core 31 is positioned in the cavity of the second valve body 30 and between the two valve body springs 35. The second valve core 31 is of a cylindrical structure, three thin sections are arranged in the middle of the second valve core 31, other parts are four thick sections, and the thick sections and the cavity of the second valve body 30 form sealing. For convenience of description, three sections are set as one-to-three

sections

32, 33, 34 from left to right. Twelve openings f, g and h … … q are arranged on the second valve body 30, wherein an opening f and an opening l are respectively positioned at the left end part and the right end part of the second valve body 30, the opening f and the opening l are thin openings, water flow can only pass through the opening f or the opening l at a very slow speed, the opening and closing of each opening are controlled by the movement of the second valve core 31 in the second valve, the movement speed of the second valve core depends on the diameters of the opening f and the opening l, therefore, the diameters of the opening f and the opening l can meet the requirement that the movement speed of the second valve core 31 is slow enough, the opening time of each opening is long enough, and the openings can pass through the required water quantity; the other openings are large openings, and the water flow passing speed is high. The other openings are positioned on the side wall of the second valve body 30 and are g, q, h, p, i, o, j, n, k and m from left to right, wherein g, q, h, p, i, o, j, n and m respectively form five pairs of openings, and each pair of openings is positioned on the same cross section of the second valve body 30. When the second valve core 31 moves left and right, the thin sections are respectively positioned at different opening positions, when each pair of openings are positioned at the thin sections of the second valve core 31, the pair of openings are communicated with each other, and the openings positioned at the thick sections are blocked. As shown in fig. 7, when the second valve element 31 moves to the right, the first thin section 32 is located at two openings g and q, and the second thin section 33 is located at two openings k and m; when the second valve core 31 moves to the left end, the second thin section 33 is located at two openings g and q, the third thin section 34 is located at two openings k and m, and other openings on the side wall are blocked. Through the action of the valve body springs 35, when there is no pressure difference between the two ends of the second valve core 31, the two valve body springs 35 are in natural length, at this time, the left end or the right end of the second valve core 31 abuts against one of the valve body springs 35, and at this time, the second thin section 33 is located between the openings i and o and the openings j and n, or between the openings i and o and the openings h and p. The three openings f, q and p are connected with a first water tank 22, the opening g is connected with an opening a of a first valve, the three openings h, i and j are connected with a fish tank 2, the opening k is connected with an opening c of the first valve, the three openings l, m and n are connected with a second water tank 23, the opening o is connected with a drain pipe, and the drain pipe is connected with an indoor drain pipe or a waste water bucket and the like and is used for draining waste water in the fish tank 2.

The working principle of the invention is as follows: as shown in fig. 6A, when the first valve core 27 is located at the left end, the port b is communicated with the port e, tap water slowly enters the first water tank 22 from the port b through the port e, and after a long period of time, for example, one day or several days, the first water tank 22 is filled; after the water tank is filled, the pressure in the first water tank 22 is gradually increased to the pressure of tap water, so that water flow can enter the second valve through the f port, the second valve core 31 is pushed to slowly move rightwards under the action of water pressure until the second valve core moves to the rightmost end, as shown in fig. 7, the g port and the q port on the second valve are communicated at the moment, water in the first water tank 22 enters the first valve from the a port through the g port from the q port, the first valve core 27 is pushed to move rightwards under the action of water pressure, the b port is communicated with the d port, and tap water slowly enters the second water tank 23 from the b port through the d port; after a period of time, the pressure in the first water tank 22 is gradually released under the action of the pressure relief device 3, so that the pressures at the left and right ends of the second valve core 31 are balanced, the second valve core 31 is pushed to slowly move leftwards to the position shown in fig. 8 under the action of a right valve body spring 35, and the second thin section 33 is positioned between the openings i and o and the openings j and n; after a long period of time, the second water tank 23 is filled, the water pressure in the second water tank 23 rises, the water in the second water tank 23 enters the second valve through the port I, and the second valve core 31 is pushed to move leftwards slowly under the action of pressure; when the second valve core 31 moves to the middle position, the second thin section 33 is positioned at the position of the port i and the port o, the port i is communicated with the port o, and water in the fish tank 2 enters the drain pipe through the port i and is drained through the port o; the second valve core 31 continues to move leftwards slowly, when the second thin section 33 moves to the position of the h port and the p port, the h port is communicated with the p port, at the moment, the water in the first water tank 22 is kept still for a long time, chlorine in the water is fully discharged, and the water in the first water tank 22 enters the fish tank 2 from the p port through the h port, so that the process of changing the water in the fish tank 2 is realized; the second valve core 31 continues to move leftwards slowly, when the second thin section 33 moves to the position of the g port and the q port, the third thin section 34 is located between the k port and the m port, the g port is communicated with the q port, the k port is communicated with the m port, water in the second water tank 23 enters the first valve from the c port through the k port from the m port, the first valve core 27 is pushed to move leftwards, the b port is communicated with the e port, and tap water slowly enters the first water tank 22 through the e port. Through the repeated process, the function of automatically changing water in the fish tank 2 is realized.

By the action of the invention, tap water is used as power, the automatic water changing function of the fish tank is realized, and the water does not need to be changed periodically and manually. Does not depend on electric power, is energy-saving and environment-friendly, and can be used in occasions without electricity.

It should be noted that while the invention has been described in detail with respect to specific embodiments thereof, it will be apparent to those skilled in the art that various obvious changes can be made therein without departing from the spirit and scope of the invention.

Claims

1. The utility model provides a can trade fish bowl of water automatically, includes the fish bowl, its characterized in that: the water tank, the floater, the water valve and the water pipe are also included; the two water tanks are arranged above the fish tank and comprise a first water tank and a second water tank; a floater is arranged in the water tank, is of a cup-shaped structure and comprises a side wall, a bottom plate, a pull rod, a vertical rod, a floater spring, a sealing ring, an ejector rod and a pressure relief device; the side wall is in a highly compressible elastic corrugated pipe structure, and the upper edge of the side wall is in an annular structure made of hard materials; the plurality of pull rods are uniformly distributed on the outer side of the side wall, the upper end of each pull rod is hinged with the upper edge of the side wall, the inner side surface of each pull rod is provided with a ratchet, the edge of the bottom plate protrudes outwards, the shape of the edge of the bottom plate is matched with the shape of a ratchet tooth groove, and the edge of the bottom plate can freely move upwards but cannot freely move downwards under the action of the ratchet and the edge of the bottom plate; the lower end of the pull rod inclines outwards; the upper wall of the water tank is provided with a vent hole and a guide hole at the position above the floater; the lower end of the vertical rod is fixed on the bottom plate of the floater, and the upper part of the vertical rod penetrates through the guide hole; the float spring is sleeved on the vertical rod; the sealing ring is positioned at the upper edge of the side wall; the pressure relief device is positioned on the upper edge of the side wall and comprises a pressure relief hole, a pressure relief spring, a piston and a deflector rod; the pressure relief hole is a horizontal through hole and penetrates through the inner side and the outer side of the upper edge of the side wall; the pressure relief hole is of a conical structure with a thin inner part and a thick outer part; the piston is positioned in the pressure relief hole, and the side wall of the piston is of a conical surface structure which is thin inside and thick outside and is matched with the pressure relief hole; in a natural state, the inner side end of the piston is exposed out of the pressure relief hole; the pressure relief spring is positioned in the pressure relief hole, the outer end of the pressure relief spring is fixed in the pressure relief hole, the inner end of the pressure relief spring is propped against the outer end of the piston, and the piston is propped outwards under the action of the pressure relief spring, so that the pressure relief hole can be sealed; the deflector rod is positioned below the inner side end of the piston, the outer side end of the deflector rod is hinged with the upper edge of the side wall or the main structure of the pressure relief device, the deflector rod is in a horizontal state in a natural state, a protruding structure is arranged on the upper side of the deflector rod, and the upper end of the protruding structure is positioned at the inner end of the piston; the top rod is positioned below the deflector rod, and the lower end of the top rod is fixed on the float bottom plate; the water tank is communicated with the water valve through a first water pipe; the fish tank is communicated with the water valve through a second water pipe; the water valve comprises a first valve and a second valve; the first valve and the second valve are respectively provided with a series of openings, and the openings are respectively connected with different structures through water pipes; the first valve comprises a first valve body and a first valve core, wherein the first valve body is of a hollow cylindrical structure, and a cylindrical cavity is formed inside the first valve body; the first valve core is positioned in the cavity of the first valve body, the first valve core is of a cylindrical structure, the two ends of the first valve core are thick, the middle of the first valve core is thin, the thick parts of the two ends of the first valve core are thick sections, the thin parts of the middle of the first valve core are thin sections, and the thick sections and the cavity of the first valve body form sealing; the first valve body is provided with five openings a, b, c, d and e, wherein the opening a is positioned at the left end of the first valve body, the opening c is positioned at the right end of the first valve body, the openings b, d and e are positioned on the side wall of the first valve body, the opening b is positioned in the middle of the side wall, the opening d and the opening e are respectively positioned at the positions of the middle part which is slightly right and the middle part which is slightly left, and the distance between the opening d and the opening e is greater than the length of the thin section of the first valve core; the ports d and e are thin ports, water flow can only pass through the ports d and e at a very slow speed, and the other ports are large ports, so that the water flow passing speed is high; when the first valve core is positioned at the left end, the port b and the port e are positioned at the thin section of the first valve core at the same time, so that the port b is communicated with the port e, the port d is positioned at the thick section of the right end of the first valve core, and the port d is blocked; when the first valve core is positioned at the right end, the port b is communicated with the port d, the port e is positioned at the thick section at the left end of the first valve core, and the port e is blocked; the port a is connected with the port g of the second valve, the port b is connected with a tap water pipe, the port c is connected with the port k of the second valve, the port d is connected with the second water tank, and the port e is connected with the first water tank; the second valve comprises a second valve body, a second valve core and a valve body spring; the second valve body is of a hollow cylindrical structure, and a cylindrical cavity is formed inside the second valve body; the two valve body springs are respectively positioned at the left end and the right end in the cavity of the second valve body; the second valve core is positioned in the cavity of the second valve body and between the two valve body springs; the second valve core is of a cylindrical structure, three thin sections are arranged in the middle of the second valve core, the other parts of the second valve core are four thick sections, and the thick sections and the cavity of the second valve body form sealing; the three sections are respectively a first section to a third section from left to right; twelve openings f, g and h … … q are arranged on the second valve body, wherein an opening f and an opening l are respectively positioned on the left end part and the right end part of the second valve body, the opening f and the opening l are thin openings, water flow can only pass through the opening f or the opening l at a very slow speed, and the other openings are large openings, so that the water flow passing speed is high; other openings are positioned on the side wall of the second valve body and are g, q, h, p, i, o, j, n, k and m from left to right, wherein g, q, h, p, i, o, j, n and m respectively form five pairs of openings, and each pair of openings are positioned on the same cross section of the second valve body; when the second valve core moves left and right, the thin sections are respectively positioned at different opening positions, when each pair of openings are positioned at the thin sections of the second valve core, the pair of openings are communicated with each other, and the openings positioned at the thick sections are blocked; when the second valve core moves to the right end, the first thin section is positioned at the g opening and the q opening, and the second thin section is positioned at the k opening and the m opening; when the second valve core moves to the left end, the second thin section is positioned at the g opening and the q opening, the third thin section is positioned at the k opening and the m opening, and other openings on the side wall are blocked; under the action of the valve body springs, when no pressure difference exists between the two ends of the second valve core, the two valve body springs are in natural lengths, the left end or the right end of the second valve core is abutted against one of the valve body springs, and the second thin section is positioned between the openings i and o and the openings j and n or between the openings i and o and the openings h and p; the three openings f, q and p are connected with a first water tank, the opening g is connected with an opening a of a first valve, the three openings h, i and j are connected with a fish tank, the opening k is connected with an opening c of the first valve, the three openings l, m and n are connected with a second water tank, and the opening o is connected with a drain pipe.

2. An aquarium capable of automatically changing water according to claim 1, which is characterized in that: an n-shaped return bend is arranged at one end of the first water pipe, which is positioned in the water tank.

3. An aquarium capable of automatically changing water according to claim 1, which is characterized in that: one end of the second water pipe connected with the fish tank is positioned at the depth of one third below the water surface of the fish tank.