JPH0212598Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Application Field] This invention relates to a dispensing device for dispensing a specimen sample from a sample container and injecting it into a reaction tube in an automatic biochemical analyzer, etc., and in particular, to an improvement of its piping tube. [Prior Art] This type of dispensing device includes a dispensing nozzle that aspirates a sample contained in a sample container and discharges and injects the sample into a reaction tube;
A movement mechanism that moves the reaction tube and nozzle cleaning/drainage tank between positions, a syringe pump that aspirates and discharges the sample through the dispensing nozzle, as well as suctions and sends out pure water for cleaning the dispensing nozzle, and dispensing. It consists of a nozzle, a switching valve that switches the flow path between the pure water container and the syringe pump, and various piping tubes. When performing a dispensing operation using a dispensing device having such a configuration, each pipe is filled with pure water.
The suction and discharge of the sample is performed in the piping tube that connects the dispensing nozzle and the switching valve.The dispensing nozzle is cleaned after suctioning and dispensing one sample with pure water from the deionized water container using the syringe pump. After suctioning, the flow path is switched using a switching valve, and pure water is discharged from the nozzle tip into the cleaning/draining tank through the piping tube and the inside of the dispensing nozzle. By the way, the piping tube that connects the dispensing nozzle and the switching valve is made of a flexible material such as a Teflon tube. Conventionally, a straight Teflon tube was used to connect the dispensing nozzle with a slack. It was connected to the switching valve. [Problems that the invention aims to solve] Generally speaking, if the inner diameter of the piping tube connected to the dispensing nozzle is small, the flow path resistance will be large and it will take time to transfer the liquid, and it will also be large considering the same volume. When a sample is inhaled through a dispensing nozzle, the inner wall area of the tube that comes into contact with the sample is larger than that of a tube with an inner diameter, and therefore the sample tends to be diluted by the pure water adhering to the inner wall surface of the tube. However, if the inner diameter of the piping tube is small, the flow state of the liquid flowing inside it tends to be turbulent, and even if it becomes laminar flow, the difference in flow velocity between the center of the flow and the vicinity of the inner wall of the tube is small. In any case, the advantage is that it is relatively easy to clean the sample adhering to the inner wall surface of the piping tube, and the amount of cleaning water can be reduced. On the other hand, if the inner diameter of the piping tube is large, the flow path resistance is small, so it does not take much time to transfer the liquid, and the area of the tube inner wall that comes into contact with the sample is relatively small, so that the pure water adhering to the tube inner wall surface is The sample becomes less diluted. However, as the inner diameter of the piping tube becomes larger, the flow state of the liquid flowing inside the tube becomes laminar, and the flow velocity near the inner wall of the tube becomes slower than in the center of the flow. It has the disadvantage that it is difficult to wash and requires a large amount of washing water. As described above, conventional piping tubes have advantages and disadvantages depending on their inner diameter. Therefore, this invention was made in an attempt to provide a dispensing device that combines the advantages of each of these and is equipped with a piping tube that has a large inner diameter and is highly cleanable. [Means for solving the problem] This invention has a piping tube that connects the dispensing nozzle and the switching valve in the dispensing device, near the connection with the dispensing nozzle, for the pure water passing through it. The above object was achieved by constructing a spiral or meandering section to provide a turbulent flow effect. [Function] In the piping tube of the dispensing device according to this invention,
The flow state of the liquid flowing inside the pipe becomes turbulent even if the inner diameter of the piping tube is increased. In that case, since the inner diameter of the piping tube is large, the flow path resistance does not become so large. [Example] Hereinafter, an example of this invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of a dispensing device showing one embodiment of this invention. In the figure, dispensing nozzle 1
1 is reciprocated between the respective positions of the sample container 15, the reaction tube 17, and the nozzle cleaning/drainage tank 19 by the dispensing nozzle moving device 13. Furthermore, the dispensing nozzle 11 is also movable in the vertical direction, and sucks and separates the sample contained therein at the position of the sample container 15, and moves to the position of the reaction tube 17 to collect the sample. It is discharged and injected into the reaction tube 17. Further, the dispensing nozzle 11 is located at the nozzle cleaning/draining tank 19, and the pure water sent through the piping tube 21 causes the dispensing nozzle 11 to interact with the inner wall surface of the dispensing nozzle 11 and the piping tube 21. Wash away the sample adhering to the inner wall near the connection and discharge the drained liquid. Pure water is sent by the syringe pump 23, which is connected to the piping tube 2.
1 to the dispensing nozzle 11, and also to a pure water container 27 via a pure water suction tube 25. Then, flow path switching between the syringe pump 23, the dispensing nozzle 11, and the pure water container 27 is performed by a switching valve 29 such as a solenoid valve. As described above, during the dispensing operation, the piping tube 21 and the pure water suction tube 25 are filled with pure water, and the sample is sucked and discharged by the dispensing nozzle 11 and a part of the piping tube 21. In addition, when cleaning the sample adhering to the inner wall surface of the dispensing nozzle 11 and a part of the inner wall surface of the piping tube 21, after sucking pure water from the pure water container 27 via the pure water suction tube using the syringe pump 23, , switching valve 29
This is performed by switching the flow path using the syringe pump 23, sending pure water to the dispensing nozzle 11 side, and discharging the pure water from the dispensing nozzle 11. An example of a piping tube connecting the dispensing nozzle 11 and the switching valve 29 is shown in FIG. The piping tube is made of a flexible tube with chemical resistance, such as a Teflon tube, and is similar to the piping tube 21 shown in FIG.
is spirally wound near the connection part with the dispensing nozzle 11. To give an example of its dimensions, the outer diameter is 2.3mm,
The inner diameter is 1.5mm, which is larger than the commonly used tube (outer diameter 2.0mm, inner diameter 1.0mm). The diameter of the spiral portion is 8 mm, and the number of turns is about 10. Of course, these dimensions and the number of turns are not the gist of this invention, and a piping tube with appropriate dimensions and number of turns can be manufactured and used. When dispensing operation is performed by attaching this piping tube 21 to a dispensing device, when pure water is flowed inside the piping tube 21 to clean it, the pure water becomes turbulent in the spiral portion and is separated. The liquid reaches the injection nozzle 11 and is discharged from the tip of the dispensing nozzle 11. A dispensing device equipped with this spiral-shaped piping tube 21 and a conventional piping tube (thick type and thin type)
The following table shows the results of a comparative experiment with a dispensing device equipped with The values in parentheses in the table are as follows: After aspirating and discharging 340μ of phosphoric acid aqueous solution (sample) through the dispensing nozzle, use 900μ of pure water to clean the inner wall surface of the piping tube and dispensing nozzle. After washing, 340μ of pure water was sucked and discharged through a dispensing nozzle, and the phosphorus concentration of the discharged liquid was measured.Actually measured values are shown.

〔effect〕

This invention is constructed and operates as explained above. According to the dispensing device according to this invention, the inner diameter of the piping tube can be increased, so that the flow path resistance is reduced and the dispensing The nozzle can aspirate and discharge the sample as well as send out the cleaning water in a relatively short time. In addition, the area of the inner wall of the tube that comes into contact with the sample when inhaling the sample is relatively small, and the dilution of the sample caused by pure water adhering to the inner wall of the tube is reduced, making it possible to prevent a drop in dispensing accuracy. can. Even if the inner diameter of the piping tube is increased, a turbulent flow occurs when the liquid flows through the spiral portion, so that the degree of cleaning is high and the amount of cleaning water is small. This invention makes it possible to provide a dispensing device with the various advantages described above using an extremely simple mechanism.

[Brief explanation of the drawing]

FIG. 1 shows a schematic configuration diagram of a dispensing device which is an embodiment of this invention, and FIGS. 2 and 3 each show an example of a piping tube used in the dispensing device according to this invention. FIG. 11...Dispensing nozzle, 13...Dispensing nozzle moving device, 15...Sample container, 17...Reaction tube, 19
...Nozzle cleaning/drainage tank, 21, 21'...Piping tube, 23...Syringe pump, 27...Pure water container, 29...Switching valve.

Claims (1)

[Scope of utility model registration request] A dispensing nozzle that is movable between the positions of a sample container, a reaction tube, and a cleaning tank, and that sucks and separates a sample contained in a sample container and discharges and injects the sample into a reaction tube; and this dispensing nozzle. and a pure water container via a switching valve, and suction and discharge of the sample by a dispensing nozzle, suction of deionized water from the deionized water container and delivery of deionized water to the dispensing nozzle. a syringe pump that performs this, and a piping tube that connects the dispensing nozzle and the switching valve, and a turbulent flow is applied to the pure water passing through the piping tube near the connection between the piping tube and the dispensing nozzle. 1. A dispensing device characterized by comprising a spiral portion or a meandering portion for giving the same amount of water.