HK1139000B - Overflow device for water tank - Google Patents

Description

Overflow device for water tank

Technical Field

The present invention relates to an overflow device for a water tank for supplying water in the water tank such as a water tank for aquarium fish to an external device such as a filter device.

Background

When aquarium fish such as marine fish and freshwater fish are raised in a water tank, a filtering device is generally provided to keep the water in the water tank clean.

As a water tank filter device, there are known an underwater installation type filter device installed in a water tank and an out-of-tank installation type filter device installed outside the water tank, and the out-of-tank installation type filter device is suitable for being enlarged in size and can have excellent filtering performance as compared with the underwater installation type filter device.

Conventionally, an overflow device has been used to supply water in a water tank to an outside-tank installed filter device or to return water in the filter device to the water tank.

As shown in, for example, patent document 1 below, a conventional overflow device includes: an outer water storage part arranged along the outer surface of the side wall of the water tank; an inverted U-shaped siphon pipe arranged between the water storage parts inside and outside the water tank; and an overflow pipe disposed in the water storage part outside the tank. Further, water in the water tank is supplied to the outside water storage portion through the siphon tube based on a water level difference (water pressure difference) between the inside and outside water storage portions, and the water flows out through the overflow pipe and is supplied to the filtering device outside the tank.

Further, a discharge pump is provided in the filtering device outside the tank, and the water filtered by the filtering device is forcibly discharged (circulated) into the tank by the discharge pump.

However, in the conventional overflow device for a water tank disclosed in patent document 1, air is accumulated in an upper portion of the siphon tube in a stopped state, and the air needs to be discharged when the operation is started. Generally, an electric or manual suction pump is connected to an upper portion of the siphon tube via a suction pipe, and when the operation is started, the suction pump is operated to discharge air in the siphon tube.

Patent document 1: japanese Utility model registration No. 3018619 (FIG. 3)

However, in the conventional overflow device disclosed in patent document 1, since a suction pump needs to be provided to discharge air in the siphon tube, there is a problem that the structure becomes complicated and the cost increases in accordance with the provision of the suction pump.

Disclosure of Invention

The preferred embodiments of the present invention have been made in view of the above and/or other problems of the related art. The preferred embodiments of the present invention can significantly improve upon existing methods and/or apparatus.

An object of the present invention is to provide an overflow device for a water tank, which can solve the above-described problems of the prior art, and can simplify the structure and reduce the cost.

Other objects and advantages of the present invention will become apparent from the following preferred embodiments.

In order to achieve the above object, the present invention has the following constitutions.

An overflow device for a water tank, which supplies water in the water tank to an external device outside the water tank and supplies water in the external device to the water tank,

the overflow device for the water tank comprises:

an inverted U-shaped siphon tube, an inflow side end of which is disposed inside the water tank, and an outflow side end of which is disposed outside the water tank, and which guides water inside the water tank to the outside of the water tank according to a difference in water level between the inside and the outside of the water tank and supplies the water to an external device;

an inverted U-shaped discharge pipe, an inflow side end of which is disposed outside the water tank, and an outflow side end of which is disposed inside the water tank;

a water supply mechanism for supplying water from an external device, and allowing the water to flow into the discharge pipe from an inflow end of the discharge pipe and to be discharged from an outflow end of the discharge pipe;

a connecting pipe having one end connected to the upper part of the siphon pipe and the other end connected to the upper part of the discharge pipe,

the overflow device for a water tank is configured to suck water into the siphon pipe through the connecting pipe by a suction force generated by a flow of the water when the water is supplied to the discharge pipe by driving of the water supply mechanism.

The overflow device for a water tank as set forth in the preceding item 1,

a backflow preventing hole is arranged at the upper part of the discharge pipe,

when the water supply from the external device by the water supply mechanism is stopped, air is introduced into the discharge pipe from the backflow prevention hole, thereby preventing the backflow.

The overflow device for a water tank as set forth in the preceding item 2, wherein,

when the driving of the water supply mechanism is stopped, the air introduced into the discharge pipe from the backflow prevention hole is introduced into the siphon pipe through the connection pipe.

The overflow device for a water tank as set forth in any one of the preceding items 1 to 3,

the circumference of the connecting part of the connecting pipeline at the siphon pipe is composed of a Venturi tube,

said venturi tube having a suction aperture for connection with said connecting duct,

the water flow path around the pipe connecting hole in the water flow path in the venturi tube is formed narrower than the water flow path on the upstream side.

The overflow device for a water tank as set forth in the preceding item 4, wherein,

an inner circumferential groove which is continuous in the circumferential direction is provided on the inner circumferential surface of the venturi tube,

the inner circumferential groove communicates with the suction hole and is formed to be open to a downstream side.

According to the overflow device for a water tank of the invention [1], since the siphon tube is sucked through the connection pipe by the suction action by the flow of water when the water flows through the discharge pipe, it is not necessary to provide a suction pump for sucking and discharging the air in the siphon tube, and accordingly, the number of parts can be reduced, and simplification of the structure and reduction of the cost can be achieved.

According to the overflow device for a water tank of the invention [2], when the driving of the water supply mechanism is stopped due to a power failure or the like, air is introduced into the discharge pipe through the backflow prevention hole, and therefore, the water in the water tank can be prevented from flowing backward to the discharge pipe and being supplied to the external device.

According to the overflow device for a water tank of the invention [3], when the driving of the suction mechanism is stopped due to a power failure or the like, air is introduced into the middle upper portion of the siphon tube, and therefore, the water supply to the siphon tube can be stopped by the introduction of the air.

According to the overflow device for a water tank of the invention [4] [5], the suction effect on the siphon tube can be further improved.

Drawings

Fig. 1 is a perspective view showing a water tank system according to a first embodiment of the present invention.

Fig. 2 is a perspective view showing an overflow device applied to the water tank system of the first embodiment.

Fig. 3 is an exploded perspective view of the overflow device according to the first embodiment.

Fig. 4 is a side sectional view showing the overflow device of the first embodiment.

Fig. 5 is a perspective view showing a main part of the overflow device of the first embodiment.

Fig. 6 is a perspective view showing a filter device applied to the water tank system of the first embodiment in a state where functional parts units thereof are drawn out.

Fig. 7 is a front sectional view showing the filter device of the first embodiment.

Fig. 8 is a side sectional view showing the filter device of the first embodiment.

Fig. 9 is a perspective view showing a housing main body in the filter device of the first embodiment.

Fig. 10 is a perspective view showing a functional component unit applied to the filter device of the first embodiment.

Fig. 11 is an exploded perspective view showing a functional component unit in the filter device of the first embodiment.

Fig. 12 is a front cross-sectional view showing a flow dividing plate portion of a water inlet portion in the filter device according to the first embodiment.

Fig. 13 is an exploded perspective view showing a filter unit in the filter device according to the first embodiment.

Fig. 14 is a sectional view showing a venturi tube of a discharge pipe in the overflow device of the first embodiment.

Fig. 15 is a cutaway perspective view showing the venturi tube of the first embodiment.

Fig. 16 is a perspective view showing an overflow device applied to a water tank system according to a second embodiment of the present invention.

Fig. 17 is a side sectional view showing an overflow device of the second embodiment.

Fig. 18 is a perspective view showing a main part of the overflow device of the second embodiment.

Fig. 19 is a sectional view showing a venturi tube according to a first modification of the present invention.

Fig. 20 is a sectional view of a venturi tube as a second modification of the present invention.

Detailed Description

< first embodiment >

Fig. 1 is a perspective view showing a water tank system according to a first embodiment of the present invention. As shown in the figure, the water tank system includes the following basic components: a water tank (1); an independent filtering device (2) which is arranged independently relative to the water tank (1); an overflow device (5) for flowing water (W) into and out of the water tank (1); an introduction hose (11) such as an introduction pipe for supplying water from the overflow device (5) to the filter device (2); and a discharge hose (12) such as a discharge pipe for supplying water from the filter device (2) to the overflow device (5).

< overflow apparatus >

As shown in fig. 1 to 4, the overflow device (5) includes an overflow tank (50) disposed across the upper end of the side wall of the water tank (1), and a siphon tube (55), a discharge tube (56), and a sound insulation cover (57) are assembled in the overflow tank (50).

The overflow tank (50) is formed by a resin molding product, and the resin molding product integrally comprises: a box-shaped water storage section (51) which is arranged along the inner surface of the side wall of the water tank (1) and has an open upper side; a box-shaped water storage part (52) arranged along the outer surface of the side wall of the water tank (1) and having an upper part opened; and a bridging connection part (53) which is arranged in a manner of being bridged between the upper end parts of the two water storage parts (51, 52) and is connected with the two water storage parts (51, 52).

A plurality of vertically long slit-shaped water passage holes (511) are arranged in parallel at predetermined intervals in the lateral direction on one wall portion of the in-tank water storage portion (51), and water (W) in the water tank flows into the in-tank water storage portion (51) through the water passage holes (511).

A discharge port (512) is provided at the lower end of one wall of the in-tank water reservoir (51), and a discharge nozzle (513) is attached to the discharge port (512).

The siphon pipe (55) is formed of a flat wide pipe member having an inverted U-shape or a downward コ -shape in side view, and has an inflow-side end portion disposed in the in-tank water storage section (51), a middle bent portion disposed on the bridging connection section (53), and an outflow-side end portion disposed in the out-tank water storage section (52). Thus, when the water level on the tank inside water reservoir part (51) side is higher than the water level on the tank outside water reservoir part (52) side in a state where the siphon pipe (55) is filled with water (W), the water (W) in the tank inside water reservoir part (51) is guided to the tank outside water reservoir part (52) side through the siphon pipe (55) by means of the air pressure difference.

A suction hole (555) is provided in the center of the upper surface of the middle bent portion (upper portion) of the siphon tube (55), and a water suction blocking mechanism (8) described later in detail is provided in the suction hole (555).

An introduction hose connection port 521 is provided at one end of the lower wall of the sump outer water storage portion 52, and an overflow pipe 54 having a predetermined height is provided on the upper surface of the lower wall of the water storage portion 52 corresponding to the connection port 521.

The inlet-side end of an introduction hose (11) made of a flexible hose is connected to the lower side of the introduction hose connection port (521). As described later, the outlet-side end of the introduction hose (11) is connected to the filter device (2), and the water (W) flowing out of the overflow device (5) is introduced into the filter device (2) through the introduction hose (11).

A sound insulation cover (57) is provided in the water storage section (52) outside the tank. The sound insulation cover (57) is formed in a water surface full-covering type, and can close four sides and the whole upper surface of the periphery of the area including the overflow pipe (54) on the water surface. A water passage notch part 571 is provided at the lower end of the peripheral side wall of the sound insulation cover 57, and water W stored in the water storage part 52 outside the tank flows into the sound insulation cover 57, that is, the overflow pipe 54 side, through the water passage notch part 571.

Further, air vent holes (572 ) are formed in the upper wall of the soundproof cover (57), and the inside of the soundproof cover (57) is maintained at atmospheric pressure by allowing air to enter and exit the inside of the soundproof cover (57) through the air vent holes.

A discharge hose connection port (523) is provided at the other end of the lower wall of the tank outer water storage part (52).

The discharge pipe (56) housed and arranged in the overflow tank (50) is formed in an inverted U shape or a downward コ shape, the inflow side end portion thereof is connected to a connection port (523) of the water storage portion (52) outside the tank, the intermediate bent portion thereof is arranged along the bridging connection portion (53), and the outflow side end portion thereof is connected to a discharge nozzle (513) at a discharge port (512) of the water storage portion (51) inside the tank.

As shown in FIGS. 3 and 5, a backflow prevention hole (561) is provided at the upper end of the inside-groove pipe portion of the discharge pipe (56). As described in detail later, the backflow prevention hole (561) prevents backflow of water (W) in the water tank from the discharge pipe (56) side to the filter device (2) side when the discharge pump (35) is suddenly stopped due to an accident or the like.

The outlet side end of the discharge hose (12) is connected to the lower side of the discharge hose connection port (523) of the overflow device (5) in a communicating manner, and the inlet side end of the discharge hose (12) is connected to the filter device (2) as described later. Further, water (W) discharged from the filter device (2) is introduced from the discharge hose connection port (523) into the overflow device (5) via the discharge hose (12), and the water is discharged from the discharge nozzle (513) into the water tank through the discharge pipe (56).

Furthermore, the upper middle connection part of the discharge pipe (56) is composed of a venturi tube (9).

As shown in fig. 14 and 15, the venturi tube (9) is configured such that water (W) flows through a flow path inside the venturi tube, and negative pressure is generated in the suction hole (91). The periphery of the suction hole (91) in the water flow path of the venturi tube (9) is configured as a throttle water flow path (94) having a small diameter. A tapered surface (92) is formed between the inner peripheral surface of the throttle flow path (94) and the inner peripheral surface of the flow path (93) on the upstream side of the inner peripheral surface, and the inner diameter gradually decreases from the upstream side flow path (93) toward the throttle flow path (94). Thus, when the water introduced into the upstream side water flow path (93) passes through the tapered surface (92) and the throttle water flow path (94), the flow velocity increases, and a large suction force can be generated in the suction hole (91).

An inner circumferential groove (95) communicating with the suction hole (91) is formed continuously in the circumferential direction on the inner circumferential surface of the throttle water flow path (94) of the venturi tube (9). The inner peripheral groove (95) is open toward the downstream side, and as described later, air sucked from the suction hole (91) is smoothly sucked toward the downstream side along the inside of the venturi tube (9).

As shown in fig. 2, 4 and 5, one end of a connection pipe (8) is connected to the suction hole (555) of the siphon tube (55) of the overflow device (5) via a joint pipe (81). In addition, the other end of the connecting pipe (8) is connected in communication with a suction hole (91) of a venturi tube (9) in the discharge pipe (56). Thereby, the upper part in the siphon pipe (55) and the upper part in the discharge pipe (56) are communicated through the connecting pipe (8).

In the overflow device (5), as described in detail later, in a state where water is circulated, the siphon tube (55) is normally sucked from the discharge pipe (8) through the connection pipe (8), and water and air (bubbles) in the siphon tube (55) are sucked into the discharge pipe (56) through the suction pipe (8). When the driving of the discharge pump (35) to be described later is stopped due to a power failure or the like, air is introduced into the siphon tube (55), and the water supply (water suction) by the siphon tube (55) is immediately stopped.

As shown in fig. 2 and 3, in the overflow device (5), height adjusting screws (531 ) are provided on both sides of the bridging portion (53). The tips of the shaft portions of the screws 531, 531 are brought into contact with the upper end surface of the side wall of the water tub via a contact frame 532. Therefore, the height of the overflow device (5) relative to the water tank (1) is adjusted by adjusting the screwing amount of the screws (531 ), and the water level in the overflow device (5) can be adjusted.

In addition, in the overflow device (5), a vertical posture control screw (535) is arranged on the lower surface of the water storage part (52) outside the tank through a screw cylinder component (536). The head of the screw (535) is disposed in contact with the outer surface of the side wall of the sink. Therefore, the distance between the lower end of the water storage part (52) outside the water tank and the outer wall surface of the water tank is adjusted by adjusting the screwing amount of the screw (535), so that the horizontal posture of the overflow device (5) can be adjusted.

< filtration apparatus >

As shown in FIGS. 6 to 9, the filter device (2) is provided with a housing main body (21) having an opening at the upper end.

The front part of the housing main body (21) is configured as a functional component region (Z1), and a part on the rear side of the functional component region (Z1) is configured as a filter region (Z2).

A functional component unit (3) is provided in a functional component region (Z1) of the housing main body (21), and a filter unit (4) is provided in a filter region (Z2).

A guide projection (25) extending continuously in the vertical direction is formed on the inner surface of the side wall of the housing main body (21) so as to correspond to the space between the functional component region (Z1) and the filter region (Z2).

The functional component region (Z1) side in the upper end opening of the housing main body (21) is closed by an upper wall member (34) of a functional component unit (3) described later, and the filter region (Z2) side is closed by a housing cover (22).

In the first embodiment, the housing (20) is configured by the housing main body (21), the housing cover (22), and the upper wall member (34) of the functional component unit (3).

< functional component Unit >

As shown in FIGS. 6 to 11, the functional component unit (3) is provided with a unit frame (31), a discharge pump (35), a protein separator (6), various connection port members, and various piping.

The unit frame (31) is provided with: a base plate (311) which is provided on the bottom surface of the housing main body (21) and has a rectangular shape in plan view; three vertical frames (312) erected at three corners of the base plate (311); and an inlet chamber (32) provided above the vertical frame (312).

Further, the inlet chamber (32) has: an inlet chamber main body (33) supported at the upper end of the vertical frame (312); and an upper wall member (34) openably and closably attached to an upper end opening of the inlet chamber (33).

The inlet chamber main body (33) is disposed so that the upper end opening thereof corresponds to the upper end opening on the functional component region (Z1) side of the housing main body (21). Therefore, the upper wall member (34) that closes the upper end opening of the inlet chamber main body (33) also serves as a cover member (a part of the upper wall) of the housing main body (21).

The upper wall member (34) is provided with an introduction hose connection port (341), a discharge hose connection port (342), a protein separator attachment port (343), and a working port (344) for replacing wood stones.

The outlet side end of the inlet hose (11) connected to the overflow device (5) is connected to the inlet hose connection port (341) in a communicating manner, and the inlet side end of the outlet hose (11) connected to the overflow device (5) is connected to the outlet hose connection port (342) in a communicating manner.

A flow distribution plate (346) is provided on the introduction hose connection port (341) on the lower surface side of the upper wall member (34). As shown in fig. 12, the flow distribution plate (346) is provided with a chamber communication port (347) that communicates with the inlet chamber (32), and the inflow side end of a protein separator connection tube (67) described later is connected thereto. Further, a part of the water (W) introduced through the introduction hose (11) is introduced into the protein separator (6) through the protein separator connection pipe (67), and the remaining water (W) is introduced into the inlet chamber (32) through the chamber communication port (347).

A filtration region communication port (331) that communicates with the filtration region (Z2) is provided in the rear wall of the inlet chamber main body (33). Further, as described later, the water (W) introduced into the inlet chamber (32) through the introduction hose connection port (341) is introduced into the filtration zone (Z2) through the filtration zone communication port (331).

A discharge pump (35) is fixed to a base plate (311) of the unit frame (31). The lower end of a discharge pipe 351 is connected to the discharge port of the discharge pump 35 in a communicating manner, and the upper end of the discharge pipe 351 penetrates through the inlet chamber 32 and is connected to the discharge hose connection port 342 of the upper wall member 34 in a communicating manner. Further, the water (W) stored in the bottom of the housing main body (21) is sent to a discharge pipe (351) by a discharge pump (35), and the water (W) is supplied to the overflow device (5) through a discharge hose (12).

The lower end of the protein separator (6) is fixed to a base plate (311) of the unit frame (31), and the protein separator (6) has a separator main pipe (61) arranged vertically. The separator main pipe (61) has an upper end penetrating the inlet chamber (32) and is disposed above the upper wall member (34).

A tapered tube (62) having a diameter that decreases upward is connected to the inside of the upper end of the separator main tube (61), and a protein separator cup (63) is provided so as to cover the upward tapered portion of the tapered tube (62). The cup (63) is provided with an outlet (631) for discharging organic contaminants such as proteins stored in the cup as will be described later.

The protein separator connecting pipe (67) is disposed to penetrate the upper portion of the separator main pipe (61), and as described above, a part of the water (W) branched by the flow dividing plate (346) in the chamber upper wall member (34) is introduced into the separator main pipe (61) of the protein separator (6) via the connecting pipe (67).

In the protein separator (6), the lower end of the separator main pipe (61) is connected to the lower end of the inclined pipe (64). The inclined pipe (64) is arranged to extend obliquely upward from the lower end of the separator main pipe (61), and the upper end thereof penetrates the inlet chamber (32) and communicates with the work port (344) for replacing wood stones, which is connected to the upper wall member (34).

The inclined tube (64) is fitted with closing members (651, 652) at the upper and lower ends thereof. In addition, a hard air supply pipe (65) is arranged in the inclined pipe (64) in a penetrating way in a way of penetrating both the sealing members (651, 652). The front end of the air supply pipe (65) is arranged corresponding to the lower end of the separator main pipe (61).

A wooden stone (66) as an air bubble generation means is disposed at the lower end of the separator main pipe (61), and the wooden stone (66) is connected to the front end of the air supply pipe (65) in a communicating manner. The wooden stone (66) has an elongated cylindrical shape having a diameter smaller than the inner diameter of the inclined tube (64), and can penetrate the inclined tube (64). Therefore, the air supply pipe (65) is pulled out from the inclined pipe (64), so that the wooden stones (66) and the air supply pipe (65) can be taken out from the main separator pipe (61) to the outside through the inclined pipe (64). Conversely, when the wooden stone (66) is attached to the front end of the air supply pipe (65), the wooden stone (66) can be disposed at a predetermined position below the separator main pipe (61) by inserting the wooden stone (66) and the air supply pipe (65) together into the inclined pipe (64) from the upper end of the inclined pipe (64).

Thus, the wooden stone (66) can be put in and taken out without troublesome operations such as disassembling other components.

The wooden stone (66) has a large number of pores, and a large number of air bubbles are generated from the wooden stone (66) by supplying air to the wooden stone (66) through the air supply pipe (65) in a state where the wooden stone (66) is immersed in the stored water (W) in the separator main pipe (61). Organic contaminants such as proteins in water are attached to the bubbles thus generated, float up, and are transported upward. The protein discharged upward rises in the separator main pipe (61), is discharged from the upper end of the tapered tube (62), is collected in the protein separator cup (63), and is discharged to the outside through the discharge port (631).

The lower end of the peripheral wall of the main separator pipe (61) in the protein separator (6) is connected to the lower end of an overflow pipe (68) in communication therewith, and the upper end of the overflow pipe (68) is disposed below the inlet chamber (32) in the filtration zone (Z1). Thus, when the water (W) supplied into the separator main pipe (61) is stored at a predetermined amount or more, the water is discharged into the housing (20) outside the protein separator (6) through the overflow pipe (68).

In the functional component unit (3) configured as described above, the planar shapes of the inlet chamber (32) and the base plate (311) are formed so as to correspond to the top cross-section of the functional component region (Z1) in the housing main body (21). Then, in a state where the functional component unit (3) is assembled, the unit (3) is configured to be insertable into and extractable from the functional component region (Z1) of the case main body (21) through the upper end opening portion thereof. In addition, during the insertion and extraction operation, the inlet chamber (32) of the unit (3) and both rear end side portions of the base plate (311) are locked with and guided by the guide projections (25) provided on the inner side surface of the housing main body (21), and the insertion and extraction operation of the unit (3) can be smoothly performed. In addition, when the unit (3) is stored, the inlet chamber (32) of the unit (3) and both rear end sides of the base plate (311) are positioned and locked to the guide projections (25), and thus the entire unit (3) is disposed in the housing main body (21) in an appropriate state.

In the embodiment, the functional component unit (3) can be inserted into and removed from the housing main body (21) regardless of whether or not the filter unit (4) described later is housed in the housing main body (21).

< filtration Unit >

As shown in fig. 8 and 13, the filter unit (4) is composed of a lower layer tub (41), an intermediate layer tub (42), a water dispersion plate (43), a curtain plate (44), and a groove member (45).

The tub (41, 42) has a box shape with an open upper end, a plurality of water spray holes (411, 421) are formed in a bottom wall, and water (W) supplied into the tub (41, 42) is injected downward through the water spray holes (411, 421).

A spacing projection (211) is formed on the bottom surface of the housing main body (21) on the side of the filtration region (Z2), and the lower-stage tub (41) is placed on the spacing projection (211). Thus, the lower-stage tub (41) is housed in the filter region (Z2) of the casing main body (21) with a substantial gap formed between the lower-stage tub and the bottom surface of the filter region (Z2) of the casing main body (21).

The middle layer barrel (42) is placed above the lower layer barrel (41) and accommodates a filtering area (Z2) arranged in the housing main body (21).

The water-scattering plate (43) has a box shape with a shallow bottom with an open upper end, and a plurality of water-scattering holes (431) are arranged on the bottom wall. In addition, a spacing projection (432) is formed on the bottom surface of the water dispersing disc (43).

The water-dispersing tray (43) is placed above the middle-layer barrel (42) and accommodates a filter area (Z2) disposed in the housing main body (21).

The curtain plate (44) is formed corresponding to the inner circumference shape of the water dispersion plate (43), and is provided with a plurality of water dispersion holes (441).

The curtain plate (44) is placed on the spacing projection (432) of the water dispersion plate (43). Thus, the curtain plate (44) is accommodated in the water-dispersing tray (43) in a proper state with a gap formed between the curtain plate and the bottom surface of the water-dispersing tray (43).

The trough member (45) has a trough shape with an upper part opened, and a plurality of water spray holes (451) are formed on the bottom wall. The front end (end on the functional component region side) of the groove member (45) is open, and the rear end is closed.

The trough member (45) is placed on the water dispersion tray (43) via a curtain plate (44) in a state where the open end of the trough member corresponds to the filtration region communication port (331) of the inlet chamber (32) of the functional component unit (3).

In addition, a tongue piece (452) for guiding water extending forward is formed at the front end of the bottom wall of the groove member (45). The tongue piece (452) is inserted through the filtration region communication port (331) and locked to the inlet chamber (32) in the functional component unit (3). Thus, the water (W) stored in the inlet chamber (32) is guided by the tongue piece (452) and smoothly supplied to the groove member (45) through the communication port (331).

The filter unit (4) configured as described above is configured such that the respective components (41) to (45) can be inserted into and extracted from the upper end opening of the housing main body (21) on the side of the filter region (Z2).

The top view shapes of the barrels (41, 42) and the water-dispersing disk (43) are formed corresponding to the top view cross-sectional shape of the filtering area (Z2) in the housing main body (21). Therefore, when these components (41-43) are inserted into and pulled out of the filtering area (Z2) of the housing main body (21), the front side both sides of the barrels (41, 42) and the water-dispersing disk (43) are locked on and guided by the guide projection (25) arranged on the inner side surface of the housing (21), thereby the insertion and pulling out of the components (41-45) can be performed with high precision. In addition, under the state that each component (41-45) is contained, the front two sides of the barrels (41, 42) and the water dispersion plate (43) are positioned and locked on the guide projection (25), thereby each component (41-45) is configured in the shell main body (21) in a proper state.

In the first embodiment, the components (41-45) of the filter unit (4) can be inserted into and removed from the housing main body (21) regardless of whether the functional component unit (3) is housed in the housing main body (21).

The housing cover (22) is openably and closably attached to an upper end opening of the housing main body (21) on the side of the filter region (Z2) via a gasket (not shown).

Further, as described above, the housing cover (22) and the upper wall member (34) of the functional component unit (3) are attached to the housing main body (21) to form the housing (20), and the interior of the housing (20) is opened to the atmosphere. For example, an atmosphere communication port (221) is formed in the housing cover (22), and air enters and exits the housing (20) through the communication port (221), whereby the housing (20) is opened to the atmosphere.

In fig. 1, reference numeral 352 denotes a power cord of the discharge pump (35), and reference numeral 655 denotes an air supply mechanism for supplying air to the wooden stone (66) through the air supply pipe (65).

< operation of Water tank System >

In the water tank system configured as described above, before the actual start of operation, operation preparation is performed as follows.

In preparation for operation, first, as shown in FIG. 8, filter materials (71-73) are provided in a filter device (2). At this time, a filtering material (71) such as a biological ring (siporax) for propagating anaerobic filtering bacteria is stored in the lower layer barrel (41) of the filtering unit (4) for biological filtration. In addition, a filtering material (72) such as a bionic ball (bionic ball) for propagating aerobic filtering bacteria is stored in the middle layer barrel (42) for biological filtration. In addition, a filter material (73) such as Wool fiber (Wool) or activated carbon is housed in the water distribution tray (43) through a curtain plate (44) to perform physical filtration.

The overflow device (5) is provided on the side wall of the water tank (1) so as to straddle the upper end of the side wall as described above. At this time, the water reservoir (51) in the overflow device (5) is immersed in the water (W) in the water tank to a predetermined position, and the water (W) in the water tank flows in through the water passage hole (511) and is retained in the water reservoir (51) in a predetermined amount.

In addition, a physical filtration material (not shown) such as sponge is also housed in the in-tank water storage section (51) of the overflow device (5).

Furthermore, hoses (11, 12) are arranged between the filter device (2) and the overflow device (5). That is, the inlet-side end of the inlet hose (11) is connected in communication with the inlet hose connection port (521) of the overflow device (5), and the outlet-side end is connected in communication with the inlet hose connection port (341) of the filter device (2). The inflow-side end of the discharge hose (12) is connected to the discharge hose connection port (342) of the filter device (2) in a communicating manner, and the outflow-side end is connected to the discharge hose connection port (523) of the overflow device (5) in a communicating manner.

Water (W) is injected into an outer water storage part (52) of an overflow device (5) provided on the side wall of the water tank to a position slightly lower than the water level of an inner water storage part (51). A sound insulation cover (57) is provided in the tank outside water storage part (52) so as to seal the entire periphery of the overflow pipe (54).

In addition, after a predetermined amount of water (W) is injected into the housing (20) of the filter device (2), the operation of the water tank system is started. That is, the discharge pump (35) of the filter device (2) is driven, and air is supplied to the wood stones (66) of the protein separator (6).

Thus, first, in the housing (20) of the filter device (2), water (W) is fed to the discharge pipe (351) by the discharge pump (35), and the water (W) is supplied to the discharge pipe (56) of the overflow device (5) through the discharge hose (12). The water (W) supplied to the discharge pipe (56) is discharged from the discharge nozzle (513) into the water tank (1).

When water (W) thus flows through the venturi tube (9) in the discharge pipe (56), negative pressure is generated around the suction hole (91) of the venturi tube (9), and the negative pressure is supplied to the connection pipe (8). Further, by this suction action, air in the siphon tube (55) is sucked and discharged into the discharge pipe (56) through the connection pipe (8). Thus, when air in the siphon tube (55) is pumped out and the siphon tube (55) is filled with water (W), water supply by the siphon tube (55) is started. That is, a suction action (siphon phenomenon) is generated in the siphon pipe (55) due to a difference in water level between the water tank (1) and the outer water reservoir part (52) of the overflow device (5), and water (W) in the water tank is supplied from the inner water reservoir part (51) to the outer water reservoir part (52) through the siphon pipe (55). The water (W) flows into an overflow pipe (54) and is supplied into a housing (20) of the filter device (2) through an introduction hose (11).

In the present embodiment, since the water flow path around the suction hole (91) in the venturi tube (9) of the discharge pipe (56) is formed as the throttle water flow path (94) having a small inner diameter, the flow velocity of the water (W) is increased in the throttle water flow path (94), and thus a sufficient negative pressure can be generated around the suction hole (91). Therefore, a sufficient negative pressure can be supplied to the connecting duct (8), and the air in the siphon tube (55) can be reliably discharged through the connecting duct (8). Therefore, water can be reliably supplied by the siphon pipe (55).

In the present embodiment, since the inner circumferential surface of the venturi tube (9) is formed with an inner circumferential groove (95) that communicates with the suction hole (91) and is open toward the downstream side, the air and water (W) sucked from the suction hole (91) smoothly flow from the open portion of the inner circumferential groove (95) to the downstream side along the flow of the water (W). Therefore, the suction action of the venturi tube (9) can be further enhanced, and the air in the siphon tube (55) can be more reliably sucked. Thus, the siphon pipe (55) can be used to supply water more reliably.

On the other hand, the water (W) introduced into the housing (20) by the water supply of the siphon (55) is split by the splitting plate (346) at the introduction hose connection port (341), most of the water (W) is introduced into the inlet chamber (32) through the chamber communication port (347), and the remaining part of the water (W) is introduced into the separator main pipe (61) of the protein separator (6) through the protein separator connection pipe (67).

The water (W) introduced into the protein separator (6) is freed of proteins contained in the water. That is, a wooden stone (66) is disposed in the water introduced into and retained in the separator main pipe (61), and a large amount of air bubbles are generated from the wooden stone (66). The protein in the water is attached to the bubbles, floats, is sequentially discharged upward, and gradually rises in the main pipe (61) of the separator. The thus-raised protein-bearing bubbles are discharged from the upper end of the tapered tube (62), collected in the protein separator cup (63), and discharged to the outside from the discharge port (631). Thus, only the protein was drained and removed from the water.

The water (W) from which the proteins have been removed is discharged into the outer casing (20) outside the protein separator (6) through an overflow pipe (68) of the protein separator (6).

On the other hand, water (W) introduced into the inlet chamber (32) is supplied to the groove member (45) of the filtration zone (Z2) through the filtration zone communication port (331).

The water supplied to the groove member (45) flows through the groove member (45), and at the same time, the water is dispersed and dripped from the plurality of water spray holes (451) and supplied to the filter material (73) of the water spray tray (43) in a state of being dispersed over substantially the entire area of the filter material (73) of the water spray tray (43).

Water (W) supplied to a filter material (73) such as wool fibers or activated carbon in the water scattering disk (43) is physically filtered by the filter material (73), and then dispersed and dropped from a plurality of water scattering holes (431) in the water scattering disk (43) by the curtain plate (44) and supplied to the filter material (72) in the middle layer tub (42) in a state of being dispersed over substantially the entire region of the filter material (72) in the middle layer tub (42).

Water (W) supplied to a filter medium (72) such as a bio-ball in the middle layer barrel (42) is biologically filtered by aerobic filter bacteria attached to the filter medium (72), and then dispersed and dropped from the plurality of water spray holes (421) and supplied to the filter medium (71) in the lower layer barrel (41) in a state of being dispersed over substantially the entire area of the filter medium (71) in the lower layer barrel (41).

Water (W) supplied to a filter material (71) such as a bio-ring of the lower-layer tub (41) is biologically filtered by anaerobic filter bacteria attached to the filter material (71), and then supplied to the bottom of the casing (20) through the plurality of water spray holes (511).

The water (W) thus filtered flows from the filter region (Z2) to the function part region (Z1), is sent from there to the discharge pipe (351) by the discharge pump (35), and is supplied into the water tank (1) in the same manner as described above.

Thus, water (W) is continuously circulated between the water tank (1) and the filter device (2), and the water (W) in the water tank (1) is filtered by the filter device (2) and is kept clean all the time.

On the other hand, in the normal operation of the water tank system, in the overflow device (5), water and air in the siphon tube (55) are always sucked into the discharge pipe (56) through the connection pipe (82) by a suction action generated by the circulation of water in the discharge pipe (56). Thus, water can be stably supplied through the siphon pipe (55).

< effects of Water tank System >

In the water tank system of the first embodiment, even if the discharge pump (35) is suddenly stopped due to an unexpected event such as a power failure, the water (W) in the water tank can be prevented from flowing back in the discharge pipe (56) and being supplied to the filter device (2), and the water (W) in the water tank can be prevented from being supplied to the filter device (2) through the siphon pipe (55).

That is, when the discharge pump (35) stops sending water to the discharge hose (12), the water (W) in the discharge hose (12) flows backward toward the filter device (2) due to gravity, and the water (W) in the water tank is sucked and attempts to flow backward to the inverted U-shaped discharge pipe (56) in the overflow device (5), but in the first embodiment, since the backflow prevention hole (561) is formed at the upper end portion of the pipe portion inside the water tank of the discharge pipe (56), when the water (W) attempts to flow backward through the discharge pipe (56), air is introduced into the discharge pipe (56) from the backflow prevention hole (561), and therefore, the water (W) in the water tank is prevented from flowing backward into the discharge pipe (56), and can be prevented from flowing backward toward the filter device (2). In addition, when the discharge pump (35) stops under the condition that the backflow preventing hole (561) does not exist, the water in the discharge hose (12) flows backwards, and simultaneously, the water (W) in the water tank is sucked into the discharge pipe (56) due to the siphon phenomenon and flows backwards to the filtering device (2).

In addition, even if the discharge pump (35) is stopped, if no measure is taken, the water (W) in the water tank is sucked from a siphon (55) of the overflow device (5) and is supplied into the filter device (2) through the introduction hose (11). In contrast, in the present embodiment, since the siphon tube (55) and the discharge tube (56) are connected via the connection pipe (8), the water supply by the siphon tube (55) can be blocked. That is, when the discharge pump (35) is stopped, air is introduced into the discharge pipe (56) as described above, and therefore the air is introduced into the siphon pipe (55) through the backflow preventing hole (561), the discharge pipe (56), and the connection pipe (8). The air introduced in this way separates water (W) flowing into the side pipe section and water (W) flowing out of the side pipe section of the siphon tube (55). Therefore, the water (W) in the water tank can be prevented from being sucked by the siphon pipe (55), and the water supply by the siphon pipe (55) can be stopped quickly.

Thus, in the first embodiment, even if the discharge pump (35) is suddenly stopped due to a power failure or the like, the water (W) in the water tank can be prevented from flowing back through the discharge hose (12), and the supply of the water (W) by the siphon tube (55) can be automatically and rapidly stopped. Therefore, the adverse conditions caused by the backflow or excessive water supply from the water tank to the filtering device (2), such as water overflow and water leakage, can be prevented, and the operation reliability can be further improved.

In the first embodiment, even if the water supply to the siphon tube (55) and the discharge tube (56) is stopped due to a power failure, the power failure is canceled, and the discharge pump (35) is energized again to automatically return to the normal state.

That is, when the discharge pump (35) is driven, the water in the filter device (2) is forcibly discharged into the water tank through the discharge hose (12) and the discharge pipe (56). When water flow is generated in the discharge pipe (56) in this way, as described above, negative pressure is supplied to the connection pipe (82) from the venturi tube (9) side of the discharge pipe (56). Thus, air within the siphon tube (55) is drawn in and expelled through the connecting duct (82) by the suction effect. When the air is discharged in this way and the entire area in the siphon tube (55) is filled with water, the water (W) in the water tank is sucked by the siphon tube (55) and supplied to the filter device (2).

When the power failure is released, the normal state is automatically restored, so that a troublesome restoration operation is not required, and adverse effects due to the power failure or the like when no person is present can be prevented.

In addition, in the present embodiment, since the air in the siphon pipe (55) is discharged by the venturi tube (9) provided in the discharge pipe (56), it is not necessary to provide a dedicated suction pump for sucking and discharging the air in the siphon pipe (55), and accordingly, the number of components can be reduced, and simplification of the structure and reduction of cost can be achieved.

In the filtration device (2) according to the first embodiment, the interior of the housing (20) is accurately divided into the functional component region (Z1) and the filtration region (Z2), and the functional component unit (3) is detachably housed in the functional component region (Z1), so that the functional component unit (3) can be easily detached, and maintenance inspection and repair of the pump (35), the protein separator (6), and the like constituting the unit (3) can be easily performed. Further, the functional component unit (3) includes a pump power cord and various pipes in addition to the inlet hose connection port (341), the outlet hose connection port (342), the protein separator attachment port (343), the working port for replacing wood stones (344), and the like, so that these components and parts can be easily maintained and inspected.

In particular, since the discharge pump (35) is more likely to be deteriorated or damaged than other components, the maintenance inspection of the pump (35) can be easily performed as described above, and the convenience of use of the filter device (2) can be remarkably improved.

In addition, in the filter device (2) according to the first embodiment, the wood stones (66) of the protein separator (6) can be easily replaced. That is, since the upper end of the inclined pipe (64) connected to the lower end of the separator main pipe (61) is opened to the upper surface of the upper wall member (34) of the functional component unit (3), and the wooden stone (66) with the air supply pipe (65) is inserted from the upper end opening of the inclined pipe (64) and disposed at a predetermined position of the separator main pipe (61), the wooden stone (66) and the air supply pipe (65) can be taken out together by pulling out the air supply pipe (64) from the upper end opening of the inclined pipe (64). Thus, the wooden stones (66) can be easily taken out and replaced without detaching the main pipe (61) of the separator or disassembling other components. Particularly, since the wooden stone (66) is replaced at a fast time due to clogging or the like, the replacement work of the wooden stone (66) can be easily performed as described above, and the usability of the filter device (2) can be further improved.

In addition, in the filter device (2) of the first embodiment, since the inlet chamber (32) is provided in the housing (20), the water (W) from the water tank (1) is temporarily stored in the chamber (32), and the water (W) is supplied from the chamber (32) to the filter region (Z2), the water (W) can be stably supplied to the filter region (Z2), and the filtering performance can be improved.

In addition, in the filter device (2) according to the first embodiment, since the housing (20) is open to the atmosphere and the upper portion in the housing (20) is in contact with the air, the filter device can filter the air by the aerobic filter bacteria, and the filtering performance can be further improved.

In addition, in the filtering device (2) of the first embodiment, as the filtering materials (71-73), wool fibers or activated carbon for physical filtering, bio-balls for aerobic bacteria filtering, and bio-rings for anaerobic bacteria filtering are used, and different types of filtering are sequentially performed, so that water (W) in the water tank can be reliably filtered by a dry and wet method, cleanness can be kept, and the inside of the water tank can be maintained in an optimum environment for ornamental fish and the like.

In addition, in the filter device (2) of the first embodiment, the filter regions (Z2) are formed by laminating different types of filter materials (71-73), and water (W) is caused to pass through the filter materials (71-73) in sequence from above, so that the water (W) can reliably pass through the filter materials (71-73) by natural falling, and the filter performance can be more reliably improved.

Further, according to the overflow device (5) in the water tank system of the first embodiment, it is possible to avoid adverse effects on the surroundings due to suction noise generated when water (W) is sucked from the overflow pipe (54). That is, in the ordinary overflow pipe (54), when water (W) is sucked from the upper end thereof, air and water are irregularly entrained together, and thus entrainment sound (suction sound) of air is generated. In contrast, according to the overflow device (5) of the first embodiment, since the sound-proof cover (57) is attached to the tank outside water storage unit (52), and the four side surfaces and the entire upper surface of the area above the water surface around the overflow pipe (54) are sealed by the sound-proof cover (57), even if suction sound of the overflow pipe (54) occurs, the suction sound is blocked by the sound-proof cover (57), and the suction sound can be sealed inside the cover (57). Since the suction sound can be blocked and prevented from being diffused to the outside in this way, the suction sound does not adversely affect the surroundings, and the occurrence of a problem of suction sound can be reliably prevented.

< second embodiment >

Fig. 16 to 18 are views showing an overflow device (5) in a water tank system according to a second embodiment of the present invention. As shown in these figures, in the overflow device (5) of the second embodiment, a suction pump (80) is used as an auxiliary means when sucking and discharging air in the siphon tube (55).

That is, in the venturi tube (9) of the siphon tube (55) and the discharge tube (56) in the overflow device (5), suction holes (555, 91) are provided as described above.

A first connection part of a T-shaped pipe joint (86) with three connection parts communicated with each other is communicated and connected with a suction hole (555) of the siphon pipe (55). In addition, one end of a suction pipe 81 is connected to a second connection part of the T-shaped pipe joint 86 in a communicating manner, and an auxiliary suction pump 80 is connected to the other end of the suction pipe 81. One end of a connecting pipe 8 is connected to a third connecting portion of the T-shaped pipe joint 86 in a communicating manner, and the other end of the connecting pipe 8 is connected to a suction hole 91 of a venturi tube 9 in the discharge pipe 56 in a communicating manner.

In the second embodiment, the other configurations are the same as those of the first embodiment, and therefore the same or corresponding portions are given the same reference numerals, and overlapping descriptions are omitted.

In the overflow device (5), at the start of operation, water (W) is supplied to the discharge pipe (351), the discharge hose (12), and the discharge pipe (56) of the overflow device (5) by the discharge pump (35), and is discharged into the water tank (1).

Further, water is communicated through a venturi tube (9) in the discharge pipe (56), whereby negative pressure is supplied to the connection pipe (8), and simultaneously negative pressure is supplied to the suction pipe (81) by the auxiliary suction pump (80). Thus, air in the siphon pipe (55) is sucked and discharged through the connecting pipe (8) and the suction pipe (81). When the entire area in the siphon tube (55) is filled with water (W) in this manner, water supply from the siphon tube (55) is started.

In the second embodiment, even when the discharge pump (35) is suddenly stopped due to an unexpected event such as a power failure, the water (W) in the water tank can be prevented from flowing back through the discharge pipe (56) and being supplied to the filter device (2), and the water (W) in the water tank can be prevented from being supplied to the filter device (2) through the siphon pipe (55).

That is, when the water supply to the discharge hose (12) by the discharge pump (35) is stopped and the water (W) attempts to flow backward in the discharge pipe (56), air is introduced into the discharge pipe (56) from the backflow prevention hole (561), so that the water (W) in the water tank is prevented from being sucked into the discharge pipe (56) and can be prevented from flowing backward toward the filter device (2).

When air is introduced into the discharge pipe (56), the air is introduced into the siphon pipe (55) through the backflow prevention hole (561), the discharge pipe (56), and the connection pipe (8). Thus, the water (W) in the inflow side pipe section and the water (W) in the outflow side pipe section of the siphon pipe (55) are separated, and the water supply by the siphon pipe (55) is rapidly stopped.

Thus, in the second embodiment, even when the discharge pump (35) is suddenly stopped due to a power failure or the like, the water (W) in the water tank can be prevented from flowing back in the discharge hose (12), and the supply of the water (W) by the siphon tube (55) can be automatically and rapidly stopped.

In the second embodiment, when the power failure is released, the discharge pump (35) and the auxiliary suction pump (80) are again energized, and the operation is automatically returned to the normal operation state as in the case of the operation start.

< modification example >

In the above embodiment, the venturi tube (9) formed with the inner circumferential groove (95) is used, but the present invention is not limited thereto, and as shown in fig. 19, a venturi tube (9) not provided with an inner circumferential groove may be used.

In the above embodiment, the venturi tube (9) in which the inner peripheral surface between the throttle flow path (94) and the upstream flow water path (93) is formed as the tapered surface (92) is used, but the present invention is not limited to this, and as shown in fig. 20, the venturi tube (9) in which the curved surface (921) is formed between the throttle flow water path (94) and the upstream flow water path (93) may be used.

In the above embodiment, the case where the drain pipe (35) and the protein separator (6) are included in the functional component unit (3) of the water tank filter device (2) has been described as an example, but the present invention is not limited thereto, and the protein separator may not be included in the functional component unit (3). The functional unit (3) of the present invention may include a heater, a blower, a cooler, and the like for adjusting the water temperature.

Further, in the overflow device (5) in the above-described embodiment, the in-tank water reservoir section (51) is provided in the water tank (1), and the water (W) in the water tank is supplied from there to the out-tank water reservoir section (52) via the siphon tube (55).

In the above embodiment, the case where the present invention is applied to the overflow device in which the overflow pipe (54) is provided in the tank outer water storage unit (52) has been described as an example, but the present invention is not limited thereto, and the present invention can be applied to the following overflow device: water (W) discharged from the filter device is temporarily stored in a water storage part provided in the tank, and the water (W) is supplied from the water storage part into the water tank through an overflow pipe.

The present application claims priority of application No. 2006-228892, which was applied in japan on 8/25/2006, and the disclosure of which directly constitutes a part of this application.

The terms and expressions which have been employed herein are used as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding any equivalents of the features disclosed and described herein, it being recognized that various modifications are possible within the scope of the invention claimed.

This invention can be embodied in many different forms and this disclosure should be considered to provide examples of the principles of the present invention, which are to be understood as not limiting the invention to the preferred embodiments described and/or illustrated herein, which are described in connection with a number of illustrative embodiments.

Although several illustrative embodiments of the present invention have been described herein, the present invention is not limited to the various preferred embodiments described herein, but includes all equivalent elements, modifications, deletions, combinations (e.g., combinations of features relating to various embodiments), improvements, and/or alterations as would be understood by those skilled in the art based on this disclosure. The limitations of the claims are to be interpreted broadly based on the language employed in the claims, and not limited to examples described in the present specification or procedures of the application, but rather, should be interpreted to mean that such examples are nonexclusive.

Industrial applicability

The overflow device for a water tank of the present invention can be applied to a water tank facility for supplying water in a water tank such as a water tank for aquarium fish to a filter device or the like.

Claims (3)

1. An overflow device for a water tank, which supplies water in the water tank to an external device outside the water tank and supplies water in the external device to the water tank,

the overflow device for the water tank comprises:

an inverted U-shaped siphon tube, an inflow side end part of which is arranged in the water tank, an outflow side end part of which is arranged outside the water tank, and which guides water in the water tank to the outside of the water tank according to a water level difference between the inside and the outside of the water tank and supplies the water to an external device;

an inverted U-shaped discharge pipe having an inflow side end disposed outside the water tank and an outflow side end disposed inside the water tank;

a water supply mechanism for supplying water from an external device, and allowing the water to flow into the discharge pipe from an inflow side end of the discharge pipe and to be discharged from an outflow side end of the discharge pipe;

a connecting pipe, one end of which is connected with the upper part of the siphon pipe and the other end is connected with the upper part of the discharge pipe,

the overflow device for a water tank is configured to suck water into the siphon pipe through the connecting pipe by a suction force generated by the flow of water when the water is supplied to the discharge pipe by the driving of the water supply mechanism,

the circumference of the connecting part of the connecting pipeline at the siphon pipe is composed of a Venturi tube,

the venturi tube has a suction hole connected to the connection pipe,

a water flow path around the pipe connecting hole in the water flow path in the venturi tube is formed narrower than a water flow path on an upstream side of the pipe connecting hole,

an inner circumferential groove which is continuous in the circumferential direction is provided on the inner circumferential surface of the venturi tube,

the inner circumferential groove communicates with the suction hole and is formed to be open to a downstream side.

2. The overflow device for a sink according to claim 1,

a backflow preventing hole is arranged at the upper part of the discharge pipe,

when the water supply from the external device by the water supply mechanism is stopped, air is introduced into the discharge pipe from the backflow preventing hole, thereby preventing backflow.

3. The overflow device for a sink according to claim 2,

when the driving of the water supply mechanism is stopped, the air introduced into the discharge pipe from the backflow prevention hole is introduced into the siphon pipe through the connection pipe.