JP2006170178A - Liquid pump and method for feeding liquid by liquid pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid pump and a method for feeding liquid by the liquid pump capable of continuously supplying and feeding liquid and accurately supplying and feeding liquid with removing babble or the like existing in liquid. <P>SOLUTION: This liquid pump consists of a plurality of pump main bodies connected to delivery flow passages via open close valves respectively and a tank supplying and feeding liquid to the pump man bodies. An outer diameter of a plunger of the pump main body is formed smaller diameter than an inner diameter of a syringe for supplied and fed liquid to flow in a gap part with the syringe via a suction flow passage from the tank, and a ring which is formed in larger diameter than an outer diameter of a plunger and smaller diameter than an inner diameter of the syringe is provided on a tip part of the plunger to eliminate babbles adhering on an inner wall of the syringe, and a plunger seal removing babble adhering on an surface of the plunger is provided in an opening part side of the syringe. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to, for example, a liquid pump suitable for precisely discharging a liquid with high accuracy in which bubbles are excluded as much as possible, which is used in analysis and research of chemicals, pharmaceuticals, etc., and a liquid feeding method using the liquid pump It is.

Conventionally, single-head double-acting pumps, single-head piston pumps, gear pumps, and the like have been used as liquid pumps used for precise discharge of liquids in the analysis and research of chemicals and pharmaceuticals.

In general, the single-head double-acting pump uses a first flow path connected to a flow path of a tank filled with liquid via a four-way switching valve, and sends liquid in one direction of the pump via a four-way switching valve. Liquid is discharged from the second flow path connected to the flow path and the flow path provided with the discharge port, and the four-way switching valve is switched at the stroke end of the pump, so that the flow path of the tank filled with liquid The liquid is supplied from the first flow path connected via the four-way switching valve and the flow path provided with the discharge port while the liquid flows in one direction of the pump through the second flow path connected via the one-way switching valve. The single-head piston pump closes the second check valve, opens the first check valve, operates the piston pump, and sends the liquid into the pump. Close the check valve, open the second check valve, and turn the piston pump That work will be configured to discharge from the discharge port of the liquid in the pump.

However, the single-head double-acting pump has a disadvantage that the flow of the liquid is stopped during the switching because it is necessary to switch the flow path through the four-way switching valve at the end of the stroke where the pump operates. Similarly, in the case of a single-head piston pump, there is a drawback that the flow of liquid discharge stops when the piston is sucked.

Therefore, as a configuration in which the flow of liquid discharge does not stop, the first pump body 102 (a configuration in which the ball screw 116 is rotationally driven by the motor 114 to move the plunger 112) and the second pump body 103 (the ball screw 117 is moved by the motor 115) And a first flow path 106 that connects the first tank 104 and the second tank 105 filled with liquid, and the first pump body 102 and the first tank 104. A second flow path 107 connecting the second pump body 103 and the second tank 105, a flow path 109 provided with a discharge port 108, and the first flow path 106 and the flow path 109, respectively. The first three-way switching valve 110 to be connected to each other, and the second three-way switching valve 1 to switch and connect the second flow path 107 and the flow path 109 respectively. Liquid pump 100 which is composed of one Metropolitan was considered (see FIG. 4).

The liquid pump 100 supplies liquid to the second pump main body 103 via the first pump main body 102 and the second flow path 107 via the first flow path 106 connected to the first tank 104 filled with liquid. In a state where the liquid is supplied, the first three-way switching valve 110 is switched to connect the flow path 109 provided with the discharge port 108 and the first flow path 106 to drive the plunger 112 of the first pump body 102. The supplied liquid is supplied to a fixed value and discharged at a fixed time, and then the second three-way switching valve 111 is switched according to a decrease in the discharge amount from the first pump body 102 to change the second pump body 103 The second flow path 107 and the flow path 109 provided with the discharge port 108 are connected to drive the second plunger 113 to feed and discharge the supplied liquid.
At this time, the discharge amount of the second pump body 103 is increased corresponding to the decrease of the discharge amount of the first pump body 102 so that the combined discharge amount becomes a quantitative value. After that, when the discharge amount from the first pump main body 102 becomes zero, the liquid is discharged with a fixed amount of liquid only by the second pump main body 103, and the first three-way switching valve 110 is switched to switch the first pump main body 102. The first flow path 106 and the flow path of the first tank 104 are connected to supply and feed liquid to the first pump body 102, and the first three-way switching is performed according to the decrease in the discharge amount from the second pump body 103. The valve 110 is switched to connect the first flow path 106 of the first pump main body 102 and the flow path 109 provided with the discharge port 108 to drive the plunger 112 of the first pump main body 102 to supply the supplied liquid. Deliver and discharge. At this time, the discharge amount of the first pump body 102 is increased corresponding to the decrease of the discharge amount of the second pump body 103 so that the combined discharge amount becomes a quantitative value.

Problems to be solved by the invention

However, although the above-described conventional apparatus is suitable for supplying a constant amount of liquid, the liquid is supplied to each pump body by moving a plunger to move the syringe from the tip side (discharge port side). Since the liquid is fed into the syringe, when the liquid is fed into the syringe by retracting the plunger, the inside of the syringe becomes negative pressure, and the solvent in the liquid evaporates and is exposed as bubbles, or inside the syringe Bubbles are generated due to pressure difference and temperature difference. In addition, minute bubbles present in the liquid easily adhere to the inner wall surface of the syringe and the surface of the planer. If this is left as it is, the minute bubbles that are sequentially generated take in the next minute bubbles and gradually grow. For this reason, the configuration is not suitable for feeding a liquid with high accuracy in which bubbles are eliminated as much as possible.

In addition, if the bubbles are present in the liquid, the bubbles are very compressible with respect to the liquid, or the amount of bubbles present is not constant. The liquid cannot be supplied. Furthermore, turbulent flow due to minute irregularities in the flow path generates bubbles, and air and liquid are not sufficiently replaced at the time of the first liquid injection, and bubbles remain inside. In particular, in a liquid pump that switches between two pump bodies as described above, at the time of switching, the pump on the startup side starts supplying liquid from the low speed range, so even if there are a few bubbles, There is a problem that dripping occurs only in the flow rate of the liquid, which has a great influence on a chemical experiment or the like that requires a minute supply liquid.

Accordingly, the present invention provides a liquid pump capable of continuously supplying and feeding liquid in order to solve the above problems, and capable of feeding and feeding with high accuracy while eliminating bubbles and the like existing in the liquid, and the liquid pump It is an object of the present invention to provide a liquid feeding method according to the above.

Means for solving the problem

A first means for solving the problem of the present invention is a liquid comprising a plurality of pump bodies connected to a discharge flow path via open / close valves, and a tank for supplying and feeding liquid to the pump bodies. The outer diameter of the plunger of the pump body is formed smaller than the inner diameter of the syringe so that the liquid supplied and sent from the tank through the suction channel flows through the gap between the syringe and The tip of the plunger is provided with a ring that is larger than the outer diameter of the plunger and smaller than the inner diameter of the syringe to eliminate air bubbles adhering to the inner wall of the syringe, and on the opening side of the syringe. Is characterized in that a plunger seal for eliminating bubbles adhering to the surface of the plunger is provided.

According to the second means of the present invention, the plunger of one pump main body is operated to discharge the liquid from the syringe in order to discharge the liquid continuously from the discharge port, and the plunger of the other pump main body is moved in the reverse direction. A liquid feeding method by a liquid pump that operates and feeds liquid from a tank into a syringe, and when the liquid is fed by feeding a plunger to the pump body, the gap between the plunger and the syringe It is characterized in that the liquid is fed from the part and bubbles adhering to the inner wall of the syringe and the surface of the plunger are excluded.

Effects and effects of the invention

The operation of the present invention is to operate the plunger of one pump body to the discharge port side to discharge the liquid filled in the syringe and to operate the plunger of the other pump body in the reverse direction to operate the plunger and syringe. The liquid is supplied and fed from the tank into the syringe through the gap portion. When supplying and feeding liquid into the syringe, the tip of the plunger is attached to the inner wall of the syringe because a ring that is larger than the outer diameter of the plunger and smaller than the inner diameter of the syringe is provided. The ring scrapes off the air bubbles that are flowing, and since the plunger seal is provided on the opening side of the syringe, the air bubbles adhering to the surface of the plunger can be eliminated.

Then, according to the amount of liquid discharged from one pump body, the plunger is operated from the other pump body to gradually discharge the liquid to discharge a fixed amount, and the discharge of the liquid by one pump body ends. Then, a fixed amount of liquid is discharged only by the other pump body. Thereafter, the plunger of the other pump body is actuated to supply and feed liquid from the tank into the syringe through the gap between the plunger and the syringe. As described above, a certain amount of continuous liquid can be discharged by operating the plunger of each pump body.

Moreover, when supplying and feeding the liquid into the syringe, it can be supplied from the gap between the plunger and the syringe. A minute bubble can be easily made high by moving the plunger.

As described above, the liquid pump of the present invention can suppress the generation of bubbles as much as possible, and can eliminate the bubbles. Therefore, it is possible to supply a liquid with high accuracy and a chemical that requires a minute supply liquid. It can be used appropriately for experiments, material analysis, and micro-applications such as adhesives.

Further, since the discharge amount of the pump can be controlled while being finely adjusted, the discharge amount of a constant value can be easily controlled.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic explanatory view showing an embodiment of the liquid pump of the present invention, FIG. 2 is a schematic explanatory sectional view showing a plunger seal and a guide of the liquid pump, and FIG. FIG. 4 is a schematic graph showing a supply state, and FIG. 4 is a schematic explanatory view showing a conventional liquid pump.

The liquid pump 1 of the present invention includes a first pump main body 2 and a second pump main body 3 that are installed in a standing structure in a three-dimensional structure, and a first tank 4 and a second tank that are provided on the upper side and are filled with liquid. 5, a first flow path 6 that connects the first pump 2 and the first tank 4, a second flow path 7 that connects the second pump 3 and the second tank 5, and a discharge port 8. The flow path 9 is formed.

The first pump body 2 and the second pump body 3 are provided between the syringes 13 and 14 having discharge ports 11 and 12 provided at the distal ends thereof, and the syringes 13 and 14, and between the inner walls of the syringes 13 and 14. Planes provided on the side of the openings 17 and 18 of the syringes 13 and 14 and the plungers 15 and 16 formed to have a diameter B smaller than the diameters A and 13 of the syringes 13 and 14 so as to have a gap C that is sufficient and sufficient for the liquid to flow. It consists of jar sheet portions 19 and 20. On the distal end side of the plungers 15, 16, ring bodies 21, 22 formed with a diameter B smaller than the diameter A of the syringes 13, 14 and a diameter D larger than the diameter B of the plungers 15, 16 are provided. It is comprised so that the micro bubble adhering to syringe 13 and 14 inner wall may be scraped off by 16 moving.

Plunger drive mechanisms 23 and 24 for driving the plungers 15 and 16 in the vertical direction are provided on the rear end sides of the plungers 15 and 16.

The plunger seat portions 19 and 20 are fitted with fitting portions 25 and 26 formed in the shape of a stapler formed inside the openings 17 and 18, and the distal end side is fitted to the stapler of the fitting portions 25 and 26. The guide sleeves 27 and 28 are made of a soft material such as nylon and Teflon and are inserted into the guide sleeves 27 and 28. After inserting the plungers 15 and 16 into the guide sleeves 27 and 28, the guide sleeves 27 and 28 are moved backward. By configuring the fasteners 29 and 30 so as to be pressed more closely to the surfaces of the plungers 15 and 16, the liquid contact portion is prevented from accumulating air.

A first flow path 6 that connects the first tank 4 and the first pump body 2 and a second flow path 7 that connects the second tank 5 and the second pump body 3 are connected via open / close valves 31 and 32. The syringes 13 and 14 are connected to the vicinity of the female tapers on the fitting portions 25 and 26 side.

The flow path 9 provided with the discharge port 8 is connected to the discharge ports 11 and 12 of the syringes 13 and 14 via the open / close valves 33 and 34. The on-off valves 31 and 32 and the on-off valves 33 and 34 are configured to be individually opened and closed by electric drive or air drive.

The plunger drive mechanisms 23 and 24 and the opening and closing valves 31 and 32 and the opening and closing valves 33 and 34 are driven by a separate control panel (controller not shown).

The liquid pump 1 of the present invention is configured as described above. Next, the use of the liquid pump 1 will be described.

The driving conditions of the plunger drive mechanisms 23, 24, the open / close valves 31, 32, and the open / close valves 33, 34 are set in advance on the control panel, and the air bubbles in each flow path at the time of the first liquid supply are washed away at high speed. The first tank 4 and the second tank 5 are filled with a desired liquid.

Next, the opening / closing valve 31 provided in the flow path 9 on the supply liquid side of the first pump body 2 is closed along the setting, and the opening / closing valve 33 provided in the flow path 9 on the discharge liquid supply side is opened, The plunger 15 is pushed into the syringe 13 and moved to discharge a liquid having a volume equal to the cross-sectional area of the plunger 15 × the amount of pushing. At this time, the open / close valve 32 provided in the flow path 6 on the supply liquid side of the second pump body 3 is opened, the open / close valve 34 provided in the flow path 9 on the discharge liquid supply side is closed, and the plunger 16 is connected to the syringe. 14, the liquid of the volume of the cross-sectional area of the plunger 16 × the amount of pull-up is supplied and fed from the second tank 5.

After that, according to the decrease in the discharge amount from the first pump body 2, the second pump body 3 discharges and keeps the entire discharge amount constant, and when the discharge amount from the first pump body 2 ends, Only the second pump body 3 has a constant discharge amount.

Then, the open / close valve 31 provided in the flow path 6 on the supply liquid supply side of the first pump body 2 is opened, the open / close valve 33 provided in the flow path 9 on the discharge liquid supply side is closed, and the plunger 15 is connected to the syringe 13. Then, the liquid is pulled up and moved to supply liquid into the syringe 13. By repeating the above, it is possible to discharge liquid continuously.

When supplying and feeding liquid into the syringes 13 and 14, the liquid is supplied along the inner walls of the syringes 13 and 14 through the gap C between the plungers 15 and 16 and the inner walls of the syringes 13 and 14. In addition, since temperature rise and pressure change during supply can be suppressed as compared with conventional direct supply, generation of bubbles can be suppressed. Further, when the plungers 15 and 16 are lifted and moved up to the vicinity of the plunger sheet portions 19 and 20, minute bubbles in the liquid adhering to the surfaces of the plungers 15 and 16 are guided to the plunger sheet portions 19 and 20. The sleeves 27 and 28 are surely removed by close contact, and air bubbles adhering to the inner walls of the syringes 13 and 14 are removed so as to be scraped off by the rings 21 and 22 provided on the distal ends of the plungers 15 and 16. .

Further, when the liquid is supplied and fed into the syringes 13 and 14, the bubbles in the liquid rise and gather to the upper side (plunger sheet portions 19 and 20 side) of the syringes 13 and 14. In this bubble removal method, the open / close valves 31 and 32 and the open / close valves 33 and 34 are set in the same manner as in the liquid supply state. When the plungers 15 and 16 are pushed into the syringes 13 and 14 in this state, the bubbles are passed through the flow paths 6 and 7. Are discharged into the first tank 4 and the second tank 5 through the open / close valves 31 and 32, and float in the first tank 4 and the second tank 5 to be released into the atmosphere. Therefore, when the next liquid is supplied and fed into the syringes 13 and 14, the bubbles are not sucked again.

The pushing amount of the plungers 15 and 16 into the syringes 13 and 14 is an experimental value or detection of the internal pressure of the syringes 13 and 14 because the amount of air bubbles is indefinite, the plunger driving mechanism 23, It is determined by detecting a load on 24 motors (not shown).

Thus, according to the present invention, not only the liquid is continuously discharged, but also the bubbles can be reliably removed, and the liquid with high accuracy can be discharged.
Therefore, it can provide from a micro flow rate to a high-speed flow pump.

By completely eliminating bubbles in the liquid, a flow rate along the control curve can be obtained, and a continuous flow without a seam is possible even though the pump is a dual pump.

Since the bubbles in the syringe can be eliminated only by the movement of the plunger and the opening / closing valve on the liquid supply / feeding side, there is no adverse effect on the pump side during discharge.

Since the outer peripheral surface of the plunger and the inner wall of the syringe are not in contact with each other, it can be used even with liquids (eg liquids with liquid crystal spacers, epoxy resin glass particles, etc.) after coarse particles. The range is also wide.

In the above embodiment, the number of pump bodies is two, but in the present invention, the number of pump bodies is not limited to two, and may be two or more.

These are schematic explanatory drawings which show one Example of the liquid pump of this invention. FIG. 3 is a schematic cross-sectional view showing a plunger seal and a guide of a liquid pump. Is a schematic graph showing the supply state at the start of the liquid pump. FIG. 6 is a schematic explanatory view showing a conventional liquid pump.

Explanation of symbols

1 Liquid pump

Claims (2)

A liquid pump comprising a plurality of pump bodies respectively connected to a discharge passage through open / close valves and a tank for supplying and feeding liquid to the pump body, and an outer diameter of a plunger of the pump body is The liquid supplied and sent from the tank through the suction channel is formed to have a diameter smaller than the inner diameter of the syringe so as to flow through the gap with the syringe, and is attached to the inner wall of the syringe at the tip of the plunger. A plunger that is larger than the outer diameter of the plunger and smaller than the inner diameter of the syringe is provided to eliminate air bubbles, and on the opening side of the syringe, the plunger that eliminates air bubbles adhering to the plunger surface A liquid pump characterized in that a seal is provided. In order to discharge liquid continuously from the discharge port, the plunger of one pump body is operated to discharge the liquid from inside the syringe, and the plunger of the other pump body is operated in the reverse direction to liquid from the tank in the syringe. Liquid feeding method using a liquid pump that feeds and feeds the liquid, and when the plunger is operated to feed and feed the liquid to the pump body, the liquid is fed from the gap between the plunger and the syringe and the syringe A liquid feeding method using a liquid pump, wherein bubbles adhering to the inner wall and the surface of the plunger are eliminated.

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