JP2000045952A - Fluid pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove impurities such as gases and foreign matters in the fluid, while removing bubbles from the fluid to be discharged from the discharge port. SOLUTION: A fluid pump 1 takes fluid into a pump chamber 2 through a suction port 3 by expanding capacity of the pump chamber 2 which is formed to variably change the capacity with a bellows 5, and discharges the fluid to the outside of the pump chamber 2 through a discharge port 4 by reducing the capacity of the pump chamber 2. A cavitation nozzle 11 is provided at the suction port 3 in order to remove gases included in the fluid as bubbles while the fluid is taken into the pump chamber 2 through the suction port 3. A bubble release port 14 is provided other than a discharge port 4 in order to release removed bubbles to the outside of the pump chamber 2 before discharging the fluid from the pump chamber 2 through the discharge port 4. A fluid-gas separator pipe 17 mounted to the discharge port 4 is projectingly disposed inward the pump chamber 2 having a fluid introduction hole 17a that introduces fluid only for separation of bubbles from the fluid to be discharged from the discharge port 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid pump for pumping and supplying a liquid used in various manufacturing industries such as a semiconductor manufacturing industry, a magnetic disk manufacturing industry, and a chemical industry. The present invention relates to a liquid pump for removing a gas or the like therein and supplying a liquid in a clean state under pressure.

[0002]

2. Description of the Related Art Conventionally, for example, in a manufacturing process of the semiconductor manufacturing industry, a chemical processing process using a chemical such as pure water, an organic solvent, a photoresist, and a developing solution has been frequently used. Here, the required processing dimensions of products manufactured through the above-mentioned chemical solution treatment process have tended to be further miniaturized in recent years. For this reason, if impurities such as gas and foreign matter are mixed in the chemical solution supplied to the chemical solution treatment process, there is a possibility that a shape defect or a characteristic defect may occur in the product. Therefore, it is necessary to remove impurities such as gas and foreign substances from the chemical solution in advance, and supply only a clean chemical solution to the chemical solution treatment process.

Accordingly, the applicant of the present application has previously described
Japanese Patent No. 45001 proposes a liquid supply apparatus capable of removing impurities such as gas and foreign matter from a liquid supplied to a chemical solution treatment process or the like. This device includes a liquid pump having a structure for sucking and discharging a liquid by utilizing a change in volume of a pump chamber. This liquid pump has a suction port, a discharge port, and a bubble removal port having an on-off valve function, and the suction port includes an orifice for defoaming. In this liquid pump, the suction port, the discharge port, and the bubble removing port are closed in a state in which the liquid is sucked into the pump chamber, and the volume in the pump chamber is expanded to make the pump chamber a negative pressure.

Therefore, according to this liquid pump, when the liquid is sucked into the pump chamber, the liquid is in a negative pressure state by the orifice provided at the suction port, and the micro gas dissolved in the liquid is removed. Foamed. Further, while the liquid is being sucked into the pump chamber, the suction port, the discharge port and the bubble removing port are closed, and the volume in the pump chamber is expanded to make the chamber a negative pressure. Exposed to Thus, the liquid sucked into the pump chamber is further degassed in vacuum. After that, open the air bubble removal port,
By reducing the volume of the pump chamber and pressurizing the chamber, bubbles accumulated in the pump chamber are removed to the outside of the pump chamber through the bubble removing port. Then, while reducing the volume of the pump chamber, by closing the bubble removing port and opening the discharge port, the liquid sucked into the pump chamber is discharged from the discharge port in a state where impurities such as gas and foreign matter have been removed. Will be done.

[0005]

However, in the above-described conventional liquid pump, bubbles generated by defoaming may collect around the discharge port. Therefore, when the discharge port is opened, the collected bubbles are not removed. There was a possibility that the liquid would flow out of the discharge port together with the liquid. On the other hand, when a large amount of air bubbles accumulate in the pump chamber, all of the air bubbles may not be completely removed from the air bubble removal port. In this case, the surplus air bubbles may be mixed into the liquid discharged from the discharge port, and the removal of the air bubbles from the liquid may be incomplete.

The present invention has been made in view of the above circumstances, and has as its object to remove impurities such as gas and foreign matter in a liquid and to reliably remove bubbles from the liquid discharged from a discharge port. It is an object of the present invention to provide a liquid pump capable of performing the above.

[0007]

According to a first aspect of the present invention, there is provided a liquid pump according to the first aspect of the present invention. A structure in which the liquid is sucked and the volume of the pump chamber is reduced to discharge the liquid from the discharge port to the outside of the pump chamber; and a structure in which the liquid is sucked from the suction port into the pump chamber through the suction port. A defoaming orifice for defoaming the gas dissolved in the liquid and a discharge port are provided separately from the discharge port, and before the liquid is discharged from the discharge port to the outside of the pump chamber, the defoamed bubbles are removed to the outside of the pump chamber. A liquid pump having a bubble removing port for removing air from the discharge port, and introducing only the liquid to separate bubbles from the liquid discharged from the discharge port. It purports to be provided with a liquid bubble separation tube having.

According to the structure of the present invention, when the volume of the pump chamber is expanded to suck the liquid from the suction port into the pump chamber, the liquid is in a negative pressure state by the defoaming orifice provided in the suction port. The gas dissolved in the liquid is defoamed. Then, in a state where a predetermined amount of liquid is sucked into the pump chamber, the suction port, the discharge port, and the bubble removing port are closed to further expand the volume of the pump chamber to make the pump chamber negative pressure, so that the pump chamber has a negative pressure. The liquid is exposed to negative pressure. Thus, the liquid in the pump chamber that has been defoamed by the defoaming orifice is further defoamed. Then, by opening the air bubble removal port, reducing the volume of the pump chamber and pressurizing the pump chamber,
Bubbles accumulated in the pump chamber are removed from the pump chamber through the bubble removing port. Thereafter, the bubble removing port is closed, the discharge port is opened, the volume of the pump chamber is further reduced, and the pump chamber is further pressurized, whereby the liquid is discharged from the discharge port to the outside of the pump chamber. Here, a liquid bubble separation tube is provided at the discharge port, and only the liquid is introduced from the liquid introduction hole, and bubbles are separated from the liquid discharged from the discharge port. Therefore, even if bubbles are collected around the discharge port, or even if a large amount of bubbles are generated beforehand and unremovable bubbles accumulate in the pump chamber, the bubbles may be generated in the liquid discharged from the discharge port. There is no mixing.

According to a second aspect of the present invention, there is provided a liquid pump according to the first aspect, wherein the pump chamber is formed of a telescopic bellows as a partition. It is intended.

According to the structure of the invention described above, the volume of the pump chamber is expanded and reduced by expanding and contracting the bellows in addition to the operation of the invention of the first aspect.

In order to achieve the above object, a liquid pump according to a third aspect of the present invention is the liquid pump according to the first or second aspect of the invention, wherein the liquid bubble separation pipe is vertically arranged downward from the discharge port. The lower end is closed, and the liquid introduction hole is opened horizontally or obliquely upward.

According to the structure of the invention, the lower end of the liquid bubble separation tube is closed, and the liquid introduction hole is opened in the liquid bubble separation tube horizontally or obliquely upward. Is difficult to enter the liquid introduction hole.

In order to achieve the above object, a liquid pump according to a fourth aspect of the present invention is the liquid pump according to the third aspect of the present invention, wherein the liquid bubble separation tube has an umbrella that extends outward immediately below the liquid introduction hole. It is intended to have a department.

According to the configuration of the present invention, in addition to the operation of the third aspect of the present invention, the bubbles which are going to float in the pump chamber due to the buoyancy are blocked by the umbrella portion, so that the bubbles are more likely to flow to the liquid introduction hole. It becomes difficult to enter.

In order to achieve the above object, a liquid pump according to a fifth aspect of the present invention is the liquid pump according to the first or second aspect of the invention, wherein the liquid bubble separation pipe is formed in a J-shape from the discharge port. It is intended that a liquid introduction hole is opened at a tip extending in a curved manner and pointing upward.

According to the structure of the invention described above, in addition to the function of the invention of claim 1 or 2, it is curved in a J-shape,
Since the liquid introduction hole is opened at the tip directed upward, it is difficult for bubbles that are going to float by buoyancy in the pump chamber to enter the liquid introduction hole.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] Hereinafter, a first embodiment of a liquid pump according to the present invention will be described in detail with reference to the drawings.

In this embodiment, a liquid pump for supplying a chemical such as an organic solvent, a photoresist, and a developing solution in a chemical treatment process of semiconductor manufacturing will be described. Here, since the required processing dimensions of semiconductor products are extremely miniaturized, the inclusion of impurities such as gas and foreign substances in the chemical solution supplied to the chemical solution processing process may cause the semiconductor products to have defective shapes or defective characteristics. May occur, which is not preferable. Therefore, a liquid pump capable of removing impurities such as gas from a chemical solution in advance and supplying only a clean chemical solution to a chemical solution treatment process is used.

1 and 2 show the structure of the liquid pump 1 and the like. The liquid pump 1 draws a chemical solution from the suction port 3 into the pump chamber 2 by expanding the volume of the pump chamber 2 formed to have a variable volume, and reduces the volume of the pump chamber 2 to discharge from the discharge port 4. It has a structure in which a chemical solution is discharged out of the pump chamber 2. FIG. 1 shows a state where the volume of the pump chamber 2 is reduced most, and FIG. 2 shows a state where the volume of the pump chamber 2 is expanded most. In this embodiment, the pump chamber 2 is formed with the elastic bellows 5 as a partition. The bellows 5 is housed in a casing 6 constituting the liquid pump 1. The upper end of the bellows 5 is fixed and sealed to the upper part of the casing 6, and the lower end is closed by a bottom plate 7. The space between the casing 6 and the bellows 5 is a back room 8 of the pump chamber 2. By introducing a negative pressure into the back chamber 8, the bellows 5 expands and the volume of the pump chamber 2 expands. By introducing a positive pressure into the back chamber 8, the bellows 5 contracts and the volume of the pump chamber 2 is reduced. In this embodiment, a pressure line 9 for introducing a positive pressure and a negative pressure into the back chamber 8 is connected to the back chamber 8. A first on-off valve 10 is provided in the middle of the pressure line 9.

The suction port 3 is provided with a cavitation nozzle 11 as a defoaming orifice of the present invention.
The nozzle 11 is for defoaming a micro gas dissolved in the liquid medicine when the liquid medicine is sucked into the pump chamber 2 from the suction port 3. In this embodiment,
An inlet pipe 12 for introducing a drug solution into the inlet 3 is connected to the inlet 3. One end of the introduction pipe 12 is connected to a supply source such as a chemical tank. This introduction line 12
A second on-off valve 13 is provided in the middle of.

In this embodiment, the liquid pump 1
Has an air bubble removal port 14 provided separately from the discharge port 4. The bubble removing port 14 is for removing defoamed bubbles (including impurities such as foreign substances) to the outside of the pump chamber 2 before discharging the chemical solution from the discharge port 4 to the outside of the pump chamber 2. In this embodiment, a lead-out conduit 15 for leading bubbles from the bubble removing port 14 is connected to the bubble removing port 14. In the middle of the lead-out line 15, the third on-off valve 1
6 are provided.

In this embodiment, the liquid pump 1
Has a bubble separation tube 17 attached to the discharge port 4. The bubble separation pipe 17 is disposed so as to protrude from the discharge port 4 into the pump chamber 2. The bubble separation tube 17 has a plurality of liquid introduction holes 17a for introducing only a chemical solution to separate bubbles from the chemical solution discharged from the discharge port 4. In this embodiment, the liquid foam separation tube 17 extends vertically downward from the discharge port 4 and has a lower end closed. In the vicinity of the lower end, each of the liquid introduction holes 17a having a circular shape is opened in the horizontal direction. In this embodiment, the liquid foam separation tube 17 has a liquid introduction hole 17a at its lower end.
Has an umbrella portion 17b that extends outward immediately below the umbrella. In this embodiment, the shape of the liquid foam separation tube 17 is integrally formed. In this embodiment, a discharge pipe 18 for discharging a chemical solution from the discharge port 4 is connected to the discharge port 4. The outlet pipe 18 is connected to an apparatus (not shown) for a chemical solution processing process. A fourth on-off valve 19 is provided in the middle of the outlet pipe 18.

Next, the liquid pump 1 constructed as described above is used.
Will be described. First, in order to suck a chemical solution into the pump chamber 2, in the state shown in FIG. 1, the second opening / closing valve 13 corresponding to the suction port 3 is opened, and the third and third valves corresponding to the discharge port 4 and the bubble removing port 14 are opened. The on-off valves 16 and 19 of 4 are closed. Then, the first on-off valve 10 is opened, and a negative pressure is introduced into the back chamber 8 through the pressure line 9. As a result, the bellows 5 expands toward the state shown in FIG. 2 and the volume of the pump chamber 2 expands, and accordingly, a chemical solution is sucked into the pump chamber 2 through the introduction pipe 12 and the suction port 3. At this time, pump chamber 2
Since the chemical solution sucked into the inside is brought into a negative pressure state by the cavitation nozzle 11 provided in the suction port 3, impurities such as gas and foreign matter dissolved in the chemical solution are subjected to first defoaming to be bubbled. You.

Then, a predetermined amount of the drug solution is sucked into the pump chamber 2 and the second bubble is accumulated in a state in which bubbles generated by the first defoaming are accumulated.
Perform degassing. For this purpose, the on-off valves 13, 19, 16 corresponding to the suction port 3, the discharge port 4 and the bubble removing port 14 are closed, and a negative pressure is further introduced into the back chamber 8 to further expand the volume of the pump chamber 2. Then, the pressure inside the pump chamber 2 is reduced to a negative pressure.
As a result, the chemical in the pump chamber 2 is exposed to a negative pressure, and the chemical in the pump chamber 2 that has been defoamed by the cavitation nozzle 11 is further defoamed, and the gas and the like dissolved in the chemical become bubbles. Is done.

Thereafter, the third opening / closing valve 16 corresponding to the bubble removing port 14 is opened, and a positive pressure is introduced into the back chamber 8 through the pressure line 9. As a result, the bellows 5 contracts toward the state shown in FIG. 1 and the volume of the pump chamber 2 is reduced, so that the pump chamber 2 is pressurized. From the pump chamber 2 through the outlet pipe 15
It is removed outside.

Thereafter, the third on-off valve 16 corresponding to the air bubble removing port 14 is closed, and the fourth on-off valve 1 corresponding to the discharge port 4 is closed.
By opening 9 and introducing more positive pressure into the back chamber 8,
The volume of the pump chamber 2 is further reduced, and the pump chamber 2 is further pressurized. As a result, the liquid medicine is discharged from the discharge port 4 to the outside of the pump chamber 2 through the outlet pipe 18. Here, discharge port 4
Is provided with a liquid bubble separation tube 17, and its liquid introduction hole 17a
From the above, only the chemical is introduced into the separation pipe 17, and bubbles are separated from the chemical discharged from the discharge port 4.

Therefore, even if bubbles are gathered around the discharge port 4 or bubbles which cannot be removed due to generation of a large amount of bubbles at the time of defoaming are accumulated in the pump chamber 2, the bubbles are not removed. There is no mixing with the chemical discharged from the discharge port 4. Therefore, impurities such as gas and foreign matter in the chemical solution can be removed, and bubbles can be reliably removed from the chemical solution discharged from the discharge port 4. This makes it possible to supply only a clean chemical solution that does not contain any impurities such as gas to the apparatus for the chemical solution processing process.

In particular, in this embodiment, the lower end of the liquid bubble separation tube 17 is closed, and the liquid introduction hole 17a is opened in the horizontal direction. Also, bubbles in the liquid
Normally, there is a tendency to levitate right above according to the buoyancy. Therefore, it is difficult for air bubbles which are going to float in the pump chamber 2 by buoyancy to enter each liquid introduction hole 17a.
In this sense, bubbles can be reliably removed from the chemical solution discharged from the discharge port 4.

Further, according to this embodiment, the liquid bubble separation tube 17 is provided with an umbrella portion 17b which extends outward immediately below each liquid introduction hole 17a. Therefore, bubbles which are going to float in the pump chamber 2 by buoyancy are formed by the umbrella portion 17b.
, And it becomes more difficult for bubbles to enter each liquid introduction hole 17a. In this sense, the discharge port 4
Bubbles can be more reliably removed from the chemical solution discharged from the device than in the case where the umbrella portion 17b is not provided.

In the liquid pump 1 of this embodiment, since the volume of the pump chamber 2 is expanded and contracted by expanding and contracting the bellows 5, the pump chamber 2
Can be made relatively large. For this reason, the inhalation and discharge of the chemical solution and the defoaming and discharge of the chemical solution can be performed in a single inhalation and discharge process without excess or shortage.

[Second Embodiment] Next, a second embodiment of the liquid pump according to the present invention will be described with reference to FIG. In the following embodiments including this embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted. Will be described respectively.

The liquid pump 31 of this embodiment differs from the liquid pump 1 of the first embodiment in the structure of the liquid bubble separation pipe 17. That is, in this embodiment, a plurality of elliptical liquid introduction holes 17a are opened obliquely upward near the lower end of the liquid bubble separation tube 17. Further, in this embodiment, a peripheral wall 17c that rises upward is provided on the peripheral edge of the umbrella portion 17b. The shape of such a liquid bubble separation tube 17 is integrally formed.

Therefore, according to this embodiment, since each liquid introduction hole 17a is opened obliquely upward, air bubbles are further formed in each liquid introduction hole as compared with the first embodiment. 17a. In addition, umbrella part 17b
The peripheral wall 17c provided in the hole functions to further restrict the intrusion of bubbles into the liquid introduction holes 17a. In this sense, bubbles can be more reliably removed from the chemical solution discharged from the discharge port 4.

[Third Embodiment] Next, a third embodiment of the liquid pump according to the present invention will be described with reference to FIG.

The liquid pump 41 of this embodiment differs from the liquid pump 1 of the first embodiment in the structure of the liquid bubble separation tube 20. That is, in this embodiment, the tube 2
The liquid foam separation tube 20 is formed by integrally joining the 1 and the cup 22. The tube 21 is provided with a rectangular liquid introduction hole 20a that opens in the horizontal direction. The cup 22 includes the umbrella portion 17b and the peripheral wall 17c described above.
It also has the function of

Therefore, the liquid pump 41 of this embodiment
Also, the same operation and effect as those of the liquid pump 31 of the second embodiment can be obtained.

[Fourth Embodiment] Next, a fourth embodiment of the liquid pump according to the present invention will be described with reference to FIG.

The liquid pump 51 of this embodiment differs from the liquid pumps 1, 31, and 41 of the first to third embodiments in the configuration of the liquid bubble separation tube 23. That is, in this embodiment, the liquid bubble separation tube 23 extends from the discharge port 4 in a curved shape in a J-shape, and its tip is directed upward. One liquid introduction hole 23a is opened at the tip directed upward. In this embodiment, the liquid bubble separation tube 2 is formed by simply bending a tube having both ends opened in a J-shape.
3 are formed.

Therefore, according to this embodiment, the liquid bubble separation tube 23 is curved in a J-shape, and the liquid introduction hole 23a is opened at the tip directed upward. It is difficult for air bubbles to float by the buoyancy into the liquid introduction hole 23a. Therefore, the discharge port 4
Air bubbles can be reliably removed from the chemical solution discharged from the apparatus. In particular, in this embodiment, since the tube is simply curved in a J-shape, the liquid bubble separation tube 23
Can be obtained relatively easily.

It should be noted that the present invention is not limited to the above-described embodiment, but can be carried out as follows without departing from the spirit of the invention.

In the above-described embodiment, the pump chamber 2 having a variable volume is formed by using the bellows 5 which can be expanded and contracted. However, the pump chamber having a variable volume is formed by using means such as a diaphragm in addition to the bellows 5. Can also. That is, the configuration of the present invention may be applied to a diaphragm type liquid pump.

[0042]

According to the first aspect of the present invention,
In a liquid pump capable of removing impurities such as gas and foreign matter from a liquid sucked into a pump chamber, the liquid pump is disposed so as to protrude from a discharge port into the pump chamber and separates bubbles from the liquid discharged from the discharge port. A liquid bubble separation tube having a liquid introduction hole for introducing only the liquid bubble is provided. This allows
Only the liquid is introduced from the liquid introduction hole of the liquid foam separation tube, and bubbles are separated from the liquid discharged from the discharge port. Therefore, bubbles accumulated in the pump chamber do not mix with the liquid discharged from the discharge port. As a result, impurities such as gas and foreign matter in the liquid can be removed, bubbles can be reliably removed from the liquid discharged from the discharge port, and only the clean liquid is supplied to the supply destination. It has the effect of being able to do it.

According to the second aspect of the present invention, in the configuration of the first aspect of the present invention, the pump chamber is formed of a telescopic bellows as a partition. Therefore, in addition to the functions and effects of the first aspect of the present invention, since the volume of the pump chamber is expanded and reduced by expanding and contracting the bellows, it is possible to make the volume change of the pump chamber relatively large. Become. As a result, liquid inhalation and discharge,
The defoaming and discharge of the liquid can be performed in one suction / discharge step without excess and deficiency, respectively.

According to the third aspect of the present invention, in the first or second aspect of the present invention, the liquid supply hole extends vertically downward from the discharge port, the lower end thereof is closed, and the liquid introduction hole extends in the horizontal direction. Alternatively, a liquid foam separation tube that is opened obliquely upward is provided. Therefore, it is difficult for air bubbles to float in the pump chamber to enter the liquid introduction hole. In this sense,
It is possible to remove impurities such as gas and foreign matter in the liquid, and to reliably remove bubbles from the liquid discharged from the discharge port.

According to a fourth aspect of the present invention, in the configuration of the third aspect of the present invention, the liquid bubble separation tube is provided with an umbrella portion extending outward immediately below the liquid introduction hole. Therefore, in addition to the function and effect of the third aspect of the present invention, air bubbles that are going to float in the pump chamber are blocked by the umbrella portion, and it is more difficult for air bubbles to enter the liquid introduction hole. In this sense, there is an effect that bubbles can be more reliably removed from the liquid discharged from the discharge port as compared with the case where there is no umbrella portion.

According to a fifth aspect of the present invention, in the first or second aspect of the present invention, a liquid introduction hole is provided at a tip which extends in a J-shape from the discharge port and is directed upward. Is provided with a liquid foam separation tube. Therefore, it is difficult for air bubbles to float in the pump chamber to enter the liquid introduction hole. In this sense, it is possible to remove impurities such as gas and foreign matter in the liquid, and to reliably remove bubbles from the liquid discharged from the discharge port.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a structure of a liquid pump according to a first embodiment.

FIG. 2 is a sectional view showing the structure of the liquid pump.

FIG. 3 is a cross-sectional view illustrating a structure of a liquid pump according to a second embodiment.

FIG. 4 is a cross-sectional view illustrating a structure of a liquid pump according to a third embodiment.

FIG. 5 is a cross-sectional view illustrating a structure of a liquid pump according to a fourth embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 liquid pump 2 pump chamber 3 suction port 4 discharge port 5 bellows 11 cavitation nozzle 14 bubble removal port 17 liquid foam separation tube 17 a liquid introduction hole 17 b umbrella section 20 liquid foam separation tube 20 a liquid introduction hole 23 liquid foam separation tube 23 a liquid introduction hole 31 liquid Pump 41 Liquid pump 51 Liquid pump

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3H003 AA02 AC04 BG00 CC00 3H077 AA01 CC03 CC07 DD09 DD13 EE25 FF14 FF23 FF46 4D011 AA16

Claims (5)

[Claims] 1. A pump chamber having a variable volume is expanded to expand a volume of the pump chamber, thereby sucking a liquid into the pump chamber from a suction port, and reducing the volume of the pump chamber to discharge a liquid from the discharge port to the outside of the pump chamber. A defoaming orifice provided at the suction port for defoaming a gas dissolved in the liquid when the liquid is sucked into the pump chamber from the suction port; and A liquid pump provided with an outlet and having a bubble removing port for removing the defoamed bubbles to the outside of the pump chamber before discharging the liquid from the discharge port to the outside of the pump chamber; A liquid bubble separation tube protruding from the discharge port into the pump chamber and having a liquid introduction hole for introducing only the liquid for separating the bubbles from the liquid discharged from the discharge port. A liquid pump comprising: 2. The liquid pump according to claim 1, wherein the pump chamber is formed by using a stretchable bellows as a partition. 3. The liquid pump according to claim 1, wherein the liquid foam separation tube extends vertically downward from the discharge port,
A liquid pump, wherein a lower end is closed and the liquid introduction hole is opened horizontally or obliquely upward. 4. The liquid pump according to claim 3, wherein the liquid bubble separation tube has an umbrella portion that extends outward immediately below the liquid introduction hole. 5. The liquid pump according to claim 1, wherein the liquid foam separation pipe extends in a J-shape from the discharge port, and the liquid introduction hole is opened at a tip directed upward. A liquid pump.