JP2014137032A - Liquid supply device and method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid supply device which may inject a liquid without flowing the liquid through a valve after the liquid is lifted to a tank at a predetermined height by using an air pump.SOLUTION: A liquid supply device 1 includes: a liquid supply part 2 in which a liquid is stored; a liquid lifting tank 4 which is provided at a position higher than the liquid supply part; a liquid lifting pipe 3 where one end is inserted into the liquid in the liquid supply part and the other end is connected with the tank; an air pump 10 which decompresses the tank; and a liquid injection pipe 5 where one end is connected with the liquid lifting tank and the other end is open at a position lower than the one end. A liquid storage part 5c which bends downward is provided between the one end and the other end in the liquid injection pipe 5. The liquid is sealed in the liquid storage pipe 5c to allow the liquid storage pipe 5c to function as a valve.

Description

The present invention relates to a liquid supply apparatus and method for injecting a liquid at a low position to a high position using an air pump and then injecting the liquid to the outside.

Conventionally, a liquid pumping apparatus using a decompression type air pump (or vacuum pump) is known. In this pumping device, one end of a pumping pipe is inserted into a liquid source at a low position, the other end of the pumping pipe is connected to a tank provided at a high position, and the inside of the tank is decompressed by an air pump. The liquid from the liquid source is sucked up to the tank via the pumping pipe.

By the way, in order to inject the liquid to the outside after the liquid is sucked into the tank, it is necessary to newly connect an injection pipe to the tank. However, since it is necessary to seal the inside of the tank when the liquid is sucked into the tank, the inside of the liquid injection pipe must be sealed simultaneously with the suction. Therefore, it is necessary to provide an opening / closing valve in the liquid injection pipe.

FIG. 7 shows an example of an assumed liquid supply apparatus. In FIG. 7, reference numeral 100 denotes a liquid source provided at a low position, 101 denotes a pumping pipe having one end inserted into the liquid source 100, and 102 denotes a pumping tank provided at a high position. The other end of the pumping pipe 101 is connected to the side wall of the tank 102. An air pump 103 is attached to the upper wall portion of the tank 102, and the inside of the tank 102 is depressurized by driving the air pump 103. A liquid injection pipe 104 is connected to the bottom of the tank 102, and an opening / closing valve 105 is attached in the middle of the liquid injection pipe 104.

(A)-(c) of FIG. 8 shows operation | movement of the above-mentioned liquid supply apparatus. The on-off valve 105 is closed before the air pump 103 is driven. As a result, the inside of the tank 102 is sealed, so that the inside of the tank 102 is depressurized by driving the air pump 103, and the liquid in the liquid source 100 is sucked up through the pumping pipe 101. This state is shown in FIG.

When the air pump 103 is further driven, the liquid flows into the tank 102 through the pumping pipe 101. At this time, since the on-off valve 105 is closed, the liquid in the tank 102 does not leak outside. This state is shown in FIG.

When a predetermined amount of liquid has accumulated in the tank 102, the air pump 103 is stopped. Since the tank 102 is opened to the atmosphere by stopping the air pump 103, the liquid in the pumping pipe 101 returns to the liquid source 100. When the on-off valve 105 is opened in this state, the liquid in the tank 102 is poured out through the liquid injection pipe 104 as shown in FIG.

However, in such a liquid supply device, since the liquid contacts the on-off valve 105, when used for a long period of time, impurities in the liquid adhere to the on-off valve 105, and the valve sticks to achieve a desired on-off function. It may not be obtained. In particular, since the on-off valve 105 is required to have airtightness for blocking air and liquid-tightness for blocking liquid, it is difficult to maintain a good opening / closing function.

An object of the present invention is to provide a liquid supply apparatus and a method thereof that can inject liquid without using a valve after pumping into a tank having a predetermined height using an air pump.

In order to achieve the object, the first invention includes a liquid supply unit that stores liquid, a pumping tank provided at a position higher than the liquid supply unit, and one end in the liquid of the liquid supply unit. A pumping pipe inserted into the pumping tank, the other end connected to the pumping tank, an air pump for decompressing the tank, one end connected to the pumping tank, and the other end opened at a position lower than the one end. And a liquid supply device provided with a liquid-sealable liquid storage part bent downward between the one end and the other end.

According to a second aspect of the present invention, there is provided a liquid supply unit storing liquid, a pumping tank provided at a position higher than the liquid supply unit, one end inserted into the liquid of the liquid supply unit, and the other end of the liquid supply unit A pumping pipe connected to the pumping tank, an air pump for reducing the pressure in the tank, and a liquid injection pipe having one end connected to the pumping tank and the other end opened at a position lower than the one end. The liquid injection pipe is provided with a liquid-sealable liquid storage part bent downward between the one end and the other end, and a liquid supply device is used, and the liquid storage part is liquid-sealed. The first step of depressurizing the pumped liquid tank by driving the air pump and pumping the liquid from the liquid supply part to the pumped liquid tank via the pumped liquid pipe, and the pumped liquid tank by stopping the air pump The inside is opened to atmospheric pressure, and due to the height difference between the liquid level in the pumping tank and the other end of the liquid injection pipe Providing a liquid supply method characterized by performing a second step of discharging the body from the other end of the liquid pouring tube, the.

The present invention provides the knowledge that by providing a liquid storage part sealed in the middle of the liquid injection pipe, the inside of the tank can be decompressed and the liquid can be discharged from the liquid injection pipe without providing an opening / closing valve in the liquid injection pipe. It is based on. That is, one end of the liquid injection pipe is connected to the pumping tank, and the other end is opened at a position lower than the one end. The liquid injection pipe is provided with a liquid storage portion bent downward between one end and the other end, and the liquid storage portion is sealed by allowing the liquid to flow into the liquid storage portion. Since the inside of the tank is hermetically sealed with the liquid storage part sealed, when the air pump is driven, the inside of the tank is depressurized and the liquid in the liquid supply part is sucked up to the tank via the pumping pipe. At this time, the liquid in the liquid storage part is also sucked up, but the liquid is continuously pumped into the tank by driving the air pump so that the liquid seal of the liquid storage part can be maintained. When the air pump is stopped after a predetermined amount of liquid has flowed into the tank, the pressure in the tank returns to atmospheric pressure, and the liquid in the pumped pipe returns to the liquid supply unit. On the other hand, the liquid in the tank is fed into the liquid injection pipe due to the height difference between the liquid level in the tank and the other end (exit) of the liquid injection pipe, and a predetermined amount of liquid is discharged from the other end of the liquid injection pipe. . Thereafter, the same liquid injection operation can be performed as the air pump is driven / stopped.

In the present invention, since the on-off valve is not provided in the liquid injection pipe, the cooperative operation between the air pump and the on-off valve is unnecessary, and liquid injection can be performed only by driving / stopping the air pump. That is, while the air pump is being driven, the liquid is stored in the tank, and the air pump is stopped to discharge the liquid in the tank. Accordingly, there is no problem that the inside of the tank becomes poorly sealed due to poor performance of the on-off valve or liquid leakage occurs.

The structure of the liquid storage unit is arbitrary as long as it stores a predetermined amount of liquid and has a cross-sectional shape that can be liquid-sealed. For example, a pipe line bent in a U-shape downward may be used, or a pipe line having an S-shape or a spiral shape may be used. The cross-sectional shape of the liquid storage part does not need to be constant, and a part thereof may be narrowed so that the liquid can be easily sealed.

The height h2 from the bottom surface of the liquid storage part to the connection part between the liquid injection pipe and the pumping tank is desirably larger than the height h0 that can be pumped by the air pump. If h2 <h0, when the air pump is driven to the maximum, the liquid in the liquid storage part may be sucked up to the tank side due to the negative pressure in the tank. The seal cannot be maintained. Therefore, even when the air pump is driven to the maximum by increasing the height from the bottom of the liquid storage part to the connection part between the liquid injection pipe and the pumping tank so that h2> h0, the liquid storage part The liquid seal can be maintained.

It is desirable that the height h3 from the bottom surface of the liquid storage part to the other end of the liquid injection pipe has a relationship of 2 × h3> h0 with respect to the height h0 that can be pumped by the air pump. By setting 2 × h3> h0 as described above, the liquid seal of the liquid storage part can be maintained even when the inside of the tank reaches the maximum negative pressure, and the external gas enters the tank through the bottom part of the liquid storage part. Inflow can be suppressed.

It is desirable that the connecting part between the pumping pipe and the pumping tank is higher than the connecting part between the liquid injection pipe and the pumping tank. In this case, when the air pump is stopped, the liquid in the tank is unlikely to return to the pumping pipe, and a lot of liquid flows into the liquid pouring pipe, so that the liquid injection amount can be increased. The inlet of the liquid injection pipe to the tank is preferably provided at the bottom of the tank. On the other hand, the connection port of the liquid pumping pipe to the tank is arbitrary as long as it is higher than the connection port of the liquid injection pipe.

The air pump preferably does not include a check valve and has a structure in which the suction port and the discharge port communicate with each other when not driven. Since a general vacuum pump has a check valve, the negative pressure in the tank is not immediately eliminated by the action of the check valve even after the air pump is stopped, and there is a time delay until the tank returns to atmospheric pressure. Occurs. For this reason, the liquid flows from the pumping pipe into the tank for a while, and the amount of the liquid flowing out from the liquid injection pipe increases by the time delay, resulting in a large amount of liquid injection. On the other hand, if an air pump that does not have a check valve is used, when the air pump is stopped, the tank instantaneously returns to atmospheric pressure, and the injection volume variation can be reduced.

The internal passage of the connecting portion between the liquid injection pipe and the pumping tank is preferably divided into two by a partitioning portion. In this case, since one of the internal passages is an air passage and the other is a liquid passage, the liquid in the tank and the gas in the liquid storage part can be easily replaced, and the gas can be prevented from flowing into the liquid storage part. That is, when gas enters the liquid storage part, the liquid mass in the liquid storage part, which is balanced with the pressure of the air pump, becomes lighter than when it is liquid-tight, and there is a possibility that the pumping efficiency may deteriorate. On the other hand, by dividing the internal passage of the connection part into two, the inflow of gas to the liquid storage part can be suppressed and the pumping efficiency can be increased.

It is desirable that one end portion of the liquid injection pipe is connected to the pumping tank in the horizontal direction, and the internal passage at one end portion of the liquid injection pipe is divided into two vertically by a partitioning portion. The connection structure of the liquid injection pipe to the pumping tank includes a method of connecting to the bottom wall of the tank in the vertical direction and a method of connecting to the bottom side wall of the tank in the horizontal direction. By dividing the internal passage into two parts, the height of the two passages is different, so that the liquid passes through the lower passage, the gas flows in preference to the higher passage, and the gas flows into the liquid storage part. Inflow suppression effect is increased.

As described above, according to the present invention, since the liquid storage portion sealed in the middle of the liquid injection pipe for injecting the liquid in the pumping tank to the outside is provided, the on-off valve is provided in the liquid injection pipe. There is no need to provide it, and there is no hindrance to the opening and closing operation even if it is used for a long time. Moreover, the structure is simple and can be configured at low cost. Furthermore, since the pumping / stopping to the tank and the liquid injection / stopping from the liquid injection pipe can be switched at the same time only by driving / stopping the air pump, control of the liquid injection amount is simplified.

It is the schematic of 1st Example of the liquid supply apparatus which concerns on this invention. It is sectional drawing of the piezoelectric micro blower which is an example of an air pump. It is operation | movement explanatory drawing of the liquid supply apparatus of 1st Example. It is the schematic of 2nd Example of the liquid supply apparatus which concerns on this invention. It is a cross-sectional view of the pumping tank of the liquid supply apparatus shown in FIG. It is the schematic of 3rd Example of the liquid supply apparatus which concerns on this invention. It is the schematic of an example of the liquid supply apparatus used as the premise of this invention. It is operation | movement explanatory drawing of the liquid supply apparatus shown in FIG.

-1st Example-
FIG. 1 shows a first embodiment of a liquid supply apparatus according to the present invention. The device 1 is provided at a position higher than the liquid supply unit 2 provided at a low position, a vertical liquid pumping pipe 3 having one end inserted in the liquid L of the liquid supply unit 2, and the liquid supply unit 2. And a pumped liquid tank 4 having a sealed structure to which the other end of the pumped liquid pipe 3 is connected, and an air pump 10 for decompressing the inside of the tank 4. The liquid supply unit 2 of this embodiment is a liquid storage tank that opens upward, but may be a tank that is partially open to the atmosphere. The air pump 10 is provided on the upper wall portion of the tank 4 so as not to touch the liquid flowing into the tank 4. A liquid level sensor 8 is provided on the side wall of the tank 4, and the air pump 10 is controlled to stop when the liquid level in the tank 4 reaches the detection level of the liquid level sensor 8. The other end of the pumping pipe 3 is connected to the side wall of the tank 4, and the height h1 from the liquid level of the liquid supply part 2 to the other end of the pumping pipe 3 is the pumpable height of the air pump 10. h0 or less. In addition, the connection part with the tank 4 of the pumping pipe 3 is not restricted to a side wall part, but the liquid in the tank 4 does not flow back to the pumping pipe 3 before reaching the detection level of the liquid level sensor 8. It is preferable that the opening is higher than the detection level of the position sensor 8.

One end 5a of the liquid injection pipe 5 is connected to the bottom of the pumping tank 4, and the other end 5b of the liquid injection pipe 5 is open to the atmosphere at a position lower than the one end 5a. The connection part between the liquid injection pipe 5 and the tank 4 is not limited to the bottom part of the tank 4 as long as the connection part is lower than the connection part between the pumping pipe 3 and the tank 4. The liquid injection pipe 5 is provided with a liquid storage portion 5c that is bent downward and can be liquid-sealed between one end 5a and the other end 5b. Here, although the liquid storage part 5c is formed by the U-shaped pipe line of the same cross-sectional area as the liquid injection pipe 5, it is not limited to this. The height h2 from the bottom surface of the liquid storage part 5c to the connection part between the liquid injection pipe 5 and the liquid tank 4 is larger than the liquid pumpable height h0 of the air pump 10. Therefore, even if the air pump 10 is driven to the maximum, the liquid in the liquid storage part 5c is not all sucked up to the tank 4 side, and the liquid seal of the liquid storage part 5c can be maintained.

For example, assuming that the density of the liquid is ρ, the maximum negative pressure generated by the air pump 10 is P, and the gravitational acceleration is g, the pumpable height h0 by the air pump 10 is given by the following equation.
h0 = P / ρg
Therefore, for example, when the liquid is water and the maximum negative pressure generated by the air pump 10 is 2 kPa, the pumpable height h0 is about 20 cm.

As described above, the height from the liquid level of the liquid supply part 2 to the other end of the liquid pumping pipe 3 is h1, and the height from the bottom of the liquid storage part 5c to the connection part between the liquid injection pipe 5 and the liquid pumping tank 4 When h2 is h2, h1 and h2 are preferably set so as to satisfy the following expression.
h2>h0> h1

More preferably, if the height from the bottom surface of the liquid storage part 5c to the other end 5b of the liquid injection pipe 5 is h3, h3 should be set so as to satisfy the following expression.
h2> h3, 2 × h3> h0
By setting h2> h3 as described above, the liquid accumulated in the tank 4 can be poured out through the liquid injection pipe 5. Further, by setting 2 × h3> h0, even when the air pump 10 is driven and the inside of the tank 4 reaches the maximum negative pressure, the liquid seal of the liquid storage part 5c can be maintained, and the liquid storage part 5c It is possible to suppress the gas from flowing into the tank 4 through the bottom of the tank.

As the air pump 10, any known vacuum pump may be used. In this embodiment, a piezoelectric micro blower in which the suction port is connected to the tank 4 and the discharge port is opened to the atmosphere is used. The piezoelectric micro blower 10 is the same as that disclosed in, for example, Japanese Patent Application Laid-Open No. 2011-27079, and an example of the structure is shown in FIG. As shown in FIG. 2, the blower body 11 includes an inner case 12 and an outer case 13 that covers the outer side of the inner case 12 in a non-contact manner with a predetermined gap. The inner case 12 is accommodated in the outer case 13 with a predetermined gap, and the inner case 12 is elastically supported by the outer case 13 via a spring connecting portion 14. For this reason, when the inner case 12 vibrates in the vertical direction with the resonance drive of the diaphragm 15 described later, it has a function of suppressing leakage of the vibration to the outer case 13. An air inflow passage 17 is formed between the inner case 2 and the outer case 3.

The inner case 12 is formed in a U-shaped cross section with an opening at the bottom, and the diaphragm 15 is fixed so as to close the opening of the inner case 12, and the first blower chamber 16 is formed between the inner case 12 and the diaphragm 15. Is formed. The vibration plate 15 has a unimorph structure in which a piezoelectric element 15a made of, for example, piezoelectric ceramic is attached to a central portion of a diaphragm 15b made of a thin elastic metal plate, and is vibrated by applying a voltage of a predetermined frequency to the piezoelectric element 15a. The entire plate 15 is resonantly driven in a bending mode. In this example, the piezoelectric element 15a is fixed to the surface of the diaphragm 15b opposite to the first blower chamber side.

A first wall portion 12 a is provided at a portion of the inner case 12 that constitutes one wall surface of the first blower chamber 16 and faces the diaphragm 15. It is preferable that the first wall portion 12a is formed of a thin elastic metal plate and the first wall portion 12a is excited accordingly when the vibration plate 15 is driven to resonate in a predetermined mode. A first opening portion 12 b that communicates the inside and the outside of the first blower chamber 16 is formed at a portion of the first wall portion 12 a that faces the center portion of the diaphragm 15. A second wall portion 13b is provided at a portion of the outer case 13 that faces the first wall portion 12a, and a second opening portion 13c is provided at a center portion of the second wall portion 13b, that is, a portion that faces the first opening portion 12b. Is formed. The second opening 13c serves as an air outlet. A predetermined inflow space 17a is formed between the first wall portion 12a and the second wall portion 13b, and this space 17a constitutes a part of the inflow passage 17 described above. The inflow space 17a has a role of guiding the air introduced from the inflow passage 17 to the vicinity of the first opening 12b and the second opening 13c.

A third wall 19 for forming a second blower chamber 18 with the diaphragm 15 is provided on the lower surface side of the outer case 13, that is, on the side opposite to the first blower chamber 16 with the diaphragm 15 in between. It has been. A third opening 19 a that communicates the outside with the second blower chamber 18 is formed at the center of the third wall portion 19. The third opening 19a serves as an air inlet. The volume of the second blower chamber 18 and the opening area of the third opening 19 a are set so that a pseudo resonance space can be formed with the vibration of the diaphragm 15. The second blower chamber 18 and the inflow passage 17 are connected to each other. Therefore, the air that has flowed into the second blower chamber 18 through the third opening 19 a is supplied to the inflow space 17 a through the inflow passage 17.

When an AC voltage having a predetermined frequency is applied to the piezoelectric element 15a, the diaphragm 15 is driven to resonate in the primary resonance mode or the tertiary resonance mode, and thereby the volume of the first blower chamber 16 changes periodically. When the volume of the first blower chamber 16 increases, the air in the inflow space 17a is sucked into the first blower chamber 16 through the first opening 12b, and conversely, when the volume of the first blower chamber 16 decreases, The air in the first blower chamber 16 is discharged to the inflow space 17a through the first opening 12b. Since the diaphragm 15 is driven at high frequency, the high-speed / high-energy air flow discharged from the first opening 12b to the inflow space 17a passes through the inflow space 17a and is discharged from the second opening 13c. . At this time, the surrounding air in the inflow space 17a is discharged from the second opening 13c while entraining the surrounding air, so that a continuous air flow from the inflow passage 17 toward the inflow space 17a occurs, and the air from the second opening 13c It is discharged continuously as a jet. The air flow is indicated by arrows in FIG. In particular, if the first wall portion 12a is excited along with the resonance drive of the diaphragm 15, the discharge flow rate can be dramatically increased.

Since the micro blower (air pump) 10 having the above-described structure does not include a check valve, the suction port 19a and the discharge port 13c communicate with each other when not driven. Therefore, when the driving of the air pump 10 is stopped, the inside of the pumping tank 4 and the pumping pipe 3 are instantaneously returned to the atmospheric pressure, and the liquid remaining in the pumping pipe 3 is not pumped, and the liquid supply unit 2 Can be returned to. As a result, the amount of pumped liquid can be easily controlled.

-Description of operation-
Next, an example of the operation of the liquid supply apparatus 1 having the above configuration will be described with reference to FIG. First, as shown in FIG. 1, priming water L is supplied to the liquid injection pipe 5 in advance, and the liquid storage part 5c is sealed. When the air pump 10 is driven from this state, the inside of the tank 4 is depressurized, and the inside of the pumped liquid pipe 3 and the liquid injection pipe 5 connected to the tank 4 is also depressurized. Therefore, the liquid L in the liquid supply unit 2 is sucked up into the pumping pipe 3, and at the same time, the liquid (priming water) L stored in the liquid storage unit 5c is also sucked up to the tank side. This state is shown in FIG.

When the driving of the air pump 10 is continued, the inside of the tank 4 is further depressurized, and the liquid in the liquid supply unit 2 is sucked up into the tank 4 through the pumping pipe 3, and part of the liquid in the liquid storage unit 5 c is also in the tank 4. And then merges in the tank. This state is shown in FIG.

When the liquid level in the tank 4 reaches the detection level of the liquid level sensor 8, the driving of the air pump 10 is stopped. At this time, since the air pump 10 is not provided with a check valve and has a structure in which the suction port and the discharge port communicate with each other when not driven, the pressure in the tank 4 instantaneously returns to the atmospheric pressure. Therefore, as shown in FIG. 3C, the residual liquid in the pumping pipe 3 flows down to the liquid supply unit 2 due to its own weight, and at the same time, the liquid in the tank 4 flows out to the liquid injection pipe 5. Since the other end (outlet) 5b of the liquid injection pipe 5 is at a position lower than the one end (inlet) 5a, all the liquid in the tank 4 is poured out from the other end 5b. Since no valve is provided in the middle of the liquid injection pipe 5 from the tank 4 to the other end 5b, the liquid in the tank 4 is smoothly poured out. Then, it returns to the state of FIG.

As a specific example of the liquid supply apparatus 1, the inner diameter of the pumping pipe 3 is 6 mmφ, the inner diameter of the liquid injection pipe 5 is 6 mmφ, the height of the tank is 10 cm, the diameter of the tank is 10 cmφ, the maximum negative pressure of the air pump 10 is 2 kPa, air When the flow rate when the back pressure of the second opening 13c of the pump 10 is 0 is 1 L / min, h1 = 15 cm, h2 = 25 cm, h3 = 15 cm, liquid injection is performed by driving the air pump 10 for 60 seconds. 100 ml of water could be injected from the other end 5 b of the tube 5.

-Second Example-
4 and 5 show a second embodiment of the liquid supply apparatus according to the present invention. In this apparatus 20, the same parts as those of the apparatus 1 of the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

In this embodiment, one end 21 a of the liquid injection pipe 21 is connected to the bottom of the tank 4 in the vertical direction, and the internal passage of one end (connection part) 21 a of the liquid injection pipe 21 is divided into two by the partition plate 22. Has been. One passage partitioned by the partition plate 22 is an air flow passage 23 and the other is a liquid flow passage 24.

Thus, since one of the connection portions 21a of the liquid injection pipe 21 becomes an air hole, the liquid in the tank 4 and the gas in the liquid injection pipe 21 are easily replaced, and the gas does not easily flow into the liquid injection pipe 21. . That is, when gas enters the liquid storage part 21b, the “weight / cross-sectional area” of the liquid storage part 21b that balances with the pressure of the air pump 10 becomes lighter than that when the liquid is liquid-tight. In FIG. 3B, the pumping efficiency may be deteriorated, but in the present embodiment, this can be suppressed and the pumping efficiency can be improved.

-Third Example-
FIG. 6 shows a third embodiment of the liquid supply apparatus according to the present invention. In this apparatus 30, the same parts as those of the apparatus 1 of the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

In this embodiment, one end 31 a of the liquid injection pipe 31 is connected to the bottom of the tank 4 in the horizontal direction, and the internal passage of the connection part 31 a of the liquid injection pipe 31 is divided into two vertically by a partition plate 32. Yes. The upper side of the partition plate 32 is an air flow path 33 and the lower side is a liquid flow path 34.

Since the two divided internal passages have different heights, the liquid flows in preference to the lower liquid flow passage 34 and the gas flows into the higher air flow passage 33. Therefore, in comparison with the second embodiment, the inflow of gas to the liquid storage part 31b can be further suppressed, and the pumping efficiency is improved.

The present invention is not limited to the above embodiment. For example, in the above-described embodiment, the height h2 from the bottom surface of the liquid storage part 5c of the liquid injection pipe 5 to the connection part between the liquid injection pipe 5 and the tank 4 is larger than the height h0 that can be pumped by the air pump 10. However, it is not limited to this. That is, if the air pump 10 is turned ON / OFF at a timing at which the gas at the outlet 5b of the liquid injection pipe 5 and the inside of the tank 4 do not communicate with each other, even if h2 ≦ h0, the liquid storage part 5c. It is possible to maintain the liquid seal.

DESCRIPTION OF SYMBOLS 1 Liquid supply apparatus 2 Liquid supply part 3 Pumping pipe 4 Pumping liquid tank 5 Injection pipe 5a One end (inlet)
5b The other end (exit)
5c Liquid storage part 8 Liquid level sensor 10 Air pump (micro blower)
13c Discharge port 19a Suction port

Claims (8)

A liquid supply unit storing liquid;
A pumping tank provided at a position higher than the liquid supply unit;
A pumping pipe having one end inserted into the liquid in the liquid supply unit and the other end connected to the pumping liquid tank;
An air pump for depressurizing the tank;
A liquid injection pipe having one end connected to the pumping tank and the other end opened at a position lower than the one end;
The liquid supply apparatus, wherein the liquid injection pipe is provided with a liquid-sealable liquid storage portion bent downward between the one end and the other end. The height h2 from the bottom surface of the liquid storage part to the connection part between the liquid injection pipe and the pumping tank is larger than a height h0 that can be pumped by the air pump. The liquid supply apparatus as described. The height h3 from the bottom surface of the liquid storage part to the other end of the liquid injection pipe is as follows with respect to the height h0 that can be pumped by the air pump: 2 × h3> h0
The liquid supply device according to claim 2, wherein: The connection part of the said pumping pipe and the said pumping tank is higher than the connection part of the said liquid injection pipe and the said pumping tank, The any one of Claims 1 thru | or 3 characterized by the above-mentioned. Liquid supply device. 5. The liquid supply apparatus according to claim 1, wherein the air pump does not include a check valve, and the suction port and the discharge port communicate with each other when the air pump is not driven. 6. The liquid supply apparatus according to claim 1, wherein an internal passage of a connection portion between the liquid injection pipe and the pumping tank is divided into two by a partition portion. One end of the liquid injection pipe is connected to the pumping tank in a horizontal direction, and an internal passage at one end of the liquid injection pipe is vertically divided into two by the partition part. The liquid supply apparatus according to claim 6. A liquid supply unit storing liquid;
A pumping tank provided at a position higher than the liquid supply unit;
A pumping pipe having one end inserted into the liquid in the liquid supply unit and the other end connected to the pumping liquid tank;
An air pump for depressurizing the tank;
A liquid injection pipe having one end connected to the pumping tank and the other end opened at a position lower than the one end;
Using the liquid supply device provided with a liquid-sealable liquid storage portion bent downward between the one end and the other end of the liquid injection pipe,
In a state in which the liquid storage part is sealed, a first step of reducing the pressure in the pumping tank by driving the air pump and pumping the liquid from the liquid supply part to the pumping tank through the pumping pipe;
By stopping the air pump, the inside of the pumping tank is opened to atmospheric pressure, and the liquid is discharged from the other end of the liquid injection pipe due to the height difference between the liquid level in the liquid pumping tank and the other end of the liquid injection pipe. And a second step of causing the liquid to flow out.

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