JPH0690215B2 - Dispensing nozzle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial field of application) The present invention relates to a dispensing nozzle used in, for example, an automatic biochemical analyzer.

(Prior Art) For example, an automatic chemical analyzer is used that uses serum collected from a human body as a sample, reacts it with a desired reagent, and measures the concentration of a specific component in the reaction solution by a colorimetric method for diagnosis. ing. This device dispenses a sample and a reagent to be measured into a reaction cell that moves inside a constant temperature bath to cause a reaction, and then causes light from a light source to enter the liquid to be measured, and It adopts a method in which the transmitted light is guided to an optical analysis means and the absorbance is measured.

One of the methods of dispensing reagents to the reaction cell adopted in this automatic biochemical analyzer is to install the reagent dispensing nozzle in the nozzle setting body above the reaction disk, and There is a method of discharging a reagent from a dispensing nozzle to a reaction cell when the reaction cell containing the corresponding sample passes through. This dispensing method has an advantage that the degree of freedom in setting items is large.

(Problem to be Solved by the Invention) However, in this dispensing method, when it is not necessary to discharge the reagent from the dispensing nozzle to the reaction cell, the reagent drops from the nozzle portion of the dispensing nozzle. There is. And since the dispensing nozzle is always above the reaction disk, that is, the reaction cell, if the reagent falls off from the dispensing nozzle, the reagent crawles into the sample in the reaction cell that does not require the reagent, and the sample remains as it is. There is a risk of being measured and making a false diagnosis.

The present invention has been made based on the above circumstances, and an object of the present invention is to provide a dispensing nozzle in which liquid does not drop.

[Object of the Invention] (Means and Actions for Solving the Problems) The inventor of the present invention has conducted various studies on drop-out of a dispensing nozzle in an automatic biochemical analyzer. As a result, it has been found that the shape of the nozzle opening of the conventional dispensing nozzle is a flat surface that is perpendicular to the nozzle axis direction, which may cause liquid dripping.

This point will be described. As shown in FIG. 14, in the dispensing nozzle, the tip portion of the nozzle body 1 is thinned to form the nozzle portion 2 so that the speed of the liquid discharged from the nozzle portion 2 is increased. In the injection nozzle 1, as shown in FIG. 14, the opening of the nozzle portion 2 is formed into a flat surface cut at a right angle to the axial direction of the nozzle body 1 for the purpose of improving the liquid drainage at the opening end of the nozzle portion 2. Is forming.

When the opening of the nozzle portion 2 of the dispensing nozzle has a flat surface as described above, the behavior of the discharge liquid when the liquid is discharged is as follows. Nozzle part 2 as shown in FIG.
Even if the liquid L discharged from is stopped, the liquid L flows by inertia as shown in FIG. 16, but finally the liquid L is torn off as shown in FIG. 17 and reverse as shown in FIG. Then, it is pulled toward the inside of the nozzle portion 2 and finally settles in a stationary state. In this process, when the shape of the opening of the nozzle portion 2 is a flat surface that is perpendicular to the axial direction, it is difficult for the liquid L to separate from the opening of the nozzle portion 2, and it takes time for the liquid L to separate from the opening of the nozzle portion 2. In addition, since the force is large and the force when the liquid is pulled toward the nozzle portion 2 is large, the liquid is not easily drained at the opening of the nozzle portion 2. When the opening of the nozzle portion 2 has a symmetric portion such as a small scratch or burr, the liquid is not easily drained. Therefore, when the liquid L is pulled toward the nozzle portion, as shown in FIGS. 19 and 20. At the opening end of the nozzle portion 2, the droplet easily goes around to the outside of the nozzle portion 2. Every time the liquid L is ejected from the nozzle portion 2, a droplet attached to the outside of the nozzle portion 2 grows, and the droplet cannot be held at a certain point. The droplets drop from the nozzle unit 2 and enter the sample inside the reaction cell.

From this, the inventor has studied the shape of the nozzle portion in which the liquid is easily drained at the nozzle portion and droplets are less likely to adhere to the outside of the nozzle portion. As a result of various experiments, by forming an inferior wedge-shaped part at the opening of the nozzle part of the dispensing nozzle toward the opening end, liquid is well drained at the nozzle part and droplets are less likely to adhere and grow outside the nozzle part. I found that.

That is, the dispensing nozzle of the present invention is a dispensing nozzle in which the tip portion of the nozzle body is narrowed to form the nozzle portion, and the nozzle extends toward the opening of the nozzle portion toward the opening end of the nozzle portion in the opening of the nozzle portion. It is characterized in that it has a wedge-shaped portion which is inferior in quality.

According to this configuration, when the discharge of the discharge liquid is stopped, the liquid flows along the wedge-shaped portion and the liquid is smoothly drained, and the tension inside the nozzle portion after the liquid is drained is small. I think that the cutting will be better.

(Example) Hereinafter, the Example of this invention is described with reference to drawings.

An embodiment of the present invention will be described with reference to FIGS. 1 to 7.

1 and 2 show the structure of the dispensing nozzle.
In the figure, 1 is a cylindrical nozzle body made of metal,
The tip of the nozzle body 1 is formed into a cylindrical nozzle portion 2 by narrowing it down. The opening of the nozzle part 2 is formed by cutting out the opposing wall parts toward the center of the opening end to form a pair of cutout parts 3.
By forming 3, the pair of wedge-shaped portions 4 and 4 are formed in the opposing portions sandwiched by the pair of notches 3 and 3. As shown in FIG. 3, the pair of wedge-shaped portions 4 and 4 are inferior along the axial direction of the nozzle portion 2 and toward the opening end, and the angle A of the tip is set in the range of 30 ° to 90 °. Has been done.

The dispensing nozzle configured as described above is used, for example, in an automatic biochemical analyzer for injecting a reagent or sample and discharging it into a reaction cell for dispensing.

The dispensing nozzle is set vertically, and the liquid is supplied to the inside from the upper end opening of the nozzle body 1. The supplied liquid is the nozzle body 1
Inside the nozzle to enter the inside of the nozzle unit 2,
Is discharged downward from the opening. The liquid is discharged by the amount injected into the nozzle body 1, and the discharge is completed.

Here, the behavior of the liquid when the liquid discharge is stopped at the opening of the nozzle portion 2 will be described. Nozzle body 1 as shown in FIG.
The liquid L is being discharged from the opening of the nozzle portion 2 while the liquid L is being injected into the nozzle 2. Even after the injection of the liquid L into the nozzle body 1 is stopped, the liquid L flows by inertia, but as shown in FIG. 5, the liquid L is finally torn off and, conversely, pulled into the inside of the nozzle portion 2, As shown in FIG. 6 and FIG. 7, it finally falls inside the nozzle portion 2 in a stationary state. In this process, when the injection of the liquid L into the nozzle body 2 is stopped, the liquid L flows from the base end to the tip of the wedge-shaped portions 4 and 4 formed in the opening of the nozzle portion 2. Therefore, the liquid L
Is easily separated from the tips of the wedge-shaped parts 4 and 4, the time for the liquid L to separate from the opening of the nozzle part 2 is shortened, and the force when the liquid L is pulled toward the opening side of the nozzle part 2 is small.
Therefore, it can be said that the liquid is drained well at the opening of the nozzle portion 2.

Here, the difference in the effect due to the difference in the shape of the nozzle tip portion was examined using the reagent that is actually often used.

FIG. 8 shows the influence on the viscosity of the reagent solution. In this diagram, the horizontal axis indicates the viscosity of the reagent, and the vertical axis indicates the ratio (CV) of the variation in the ejection accuracy of the reagent from the nozzle tip. The discharge amount is 400μ. Line A in the figure shows the case of the nozzle of the present invention having a wedge-shaped portion in the opening, and line B shows the case of the conventional nozzle having a flat opening. FIG. 9 shows the influence on the specific gravity of the reagent solution. In this diagram, the horizontal axis shows the specific gravity of the reagent, and the vertical axis shows the ratio (CV) of variations in the ejection accuracy of the reagent from the nozzle tip. The discharge amount is 400μ. Line A in the figure shows the case of the nozzle of the present invention having a wedge-shaped portion in the opening, and line B shows the case of the conventional nozzle having a flat opening. From each of these diagrams, it can be seen that by adopting the nozzle of the present invention, the ejection accuracy can be significantly improved as compared with the conventional nozzle.

Next, an application example in which the dispensing nozzle of the present invention is used in an automatic biochemical analyzer will be described.

FIG. 11 shows a schematic configuration of the automatic biochemical analyzer. This device dispenses a sample and a reagent to be measured into a reaction cell that moves inside a constant temperature bath to cause a reaction, and then causes light from a light source to enter the liquid to be measured, and The transmitted light is guided to an optical analysis means to measure its absorption. That is, a plurality of reaction cells 11
Are supported by the support 12. A predetermined sample and a reagent are placed inside the reaction cell 11. Then, the light from the light source 13 is branched into a plurality of optical paths by the optical fiber 14 for light distribution,
The plurality of light-receiving optical fibers 15 respectively transmitted through the reagents of the reaction cell 11 enter the optical switch 16,
One optical path is selected by 16 and enters a diffraction grating 18 through a slit 17 and a condenser lens (not shown),
The detector 19 is configured to detect the amount of light of each wavelength that has been spectrally separated. According to this configuration, among the plurality of optical paths that have passed through the reaction cell, only one optical path is sequentially selected by the optical switch 16 and is incident on the diffraction grating, so that the photometric system can be simplified and the analyzer can be downsized. it can.

In order to dispense a reagent to the reaction cell 11 in this automatic biochemical analyzer, a reagent dispensing nozzle is installed in the noise setting body above the reaction disk, and a sample corresponding to a predetermined measurement item is placed. A method is adopted in which the reagent is discharged from the dispensing nozzle to the reaction cell when the reaction cell 11 is passed. FIG. 10 shows the mode of this dispensing.

In the dispensing nozzle of the present invention, the wedge-shaped portion formed in the opening of the nozzle portion can be easily formed in the form shown in the embodiment, but the present invention is not limited to this form, and is shown in FIGS.
As shown in the figure, various forms can be adopted.

EFFECT OF THE INVENTION As described above, according to the dispensing nozzle of the present invention, the opening of the nozzle portion has the wedge-shaped portion that extends in the axial direction of the nozzle portion and that is inferior toward the opening end of the nozzle portion. Good drainage during liquid discharge. Therefore, if the automatic biochemical analyzer is equipped to dispense a reagent to the reaction cell, the reagent will get wet from the nozzle opening to the reaction cell of the measurement item that does not require injection of the reagent and the reaction cell It is possible to prevent the occurrence of accidents that go inside and perform incorrect analysis.

Then, by forming the wedge-shaped portion formed in the nozzle portion opening at an angle in the range of 30 to 90 degrees, it is possible to secure the effect of making the liquid out of the nozzle portion opening favorable.

In addition, when the opposite portions of the nozzle opening are obliquely cut, and a pair of wedge-shaped portions are formed in the portions sandwiched by the cut-out portions, a wedge-shaped portion having a configuration with good liquid drainage effect is obtained. It can be easily formed.

[Brief description of drawings]

1 to 7 show an embodiment of the present invention, FIGS. 1 and 2 are views showing a dispensing nozzle, and FIG. 3 is an enlarged view of a wedge-shaped portion of a nozzle portion of the dispensing nozzle. FIGS. 4 to 7 are views for explaining the state when the liquid discharge is stopped at the nozzle portion opening of the dispensing nozzle, and FIGS. 8 and 9 are the dispensing nozzles shown in FIGS. 1 and 2. Diagram showing the results of testing the discharge accuracy using, Figure 10 and Figure 11 is an explanatory view showing a state in which the dispensing nozzle of the present invention is equipped in an automatic biochemical analyzer, Figure 12 and Figure 13 FIG. 14 is a view showing a nozzle portion opening of a dispensing nozzle of another embodiment, FIG. 14 is a view showing a conventional dispensing nozzle, and FIGS. 15 to 20 show a state at the time of stopping liquid discharge in the conventional dispensing nozzle. FIG. 1 ... Nozzle body, 2 ... Nozzle section, 4 ... Wedge section.

Claims (3)

[Claims] 1. A dispensing nozzle in which a tip portion of a nozzle main body is thinned to form a nozzle portion, and a wedge-shaped portion extending in the axial direction of the nozzle portion and sharpened toward an opening end of the nozzle portion is provided at an opening of the nozzle portion. Dispensing nozzle characterized by having. 2. The dispensing nozzle according to claim 1, wherein the wedge-shaped portion has an angle in the range of 30 to 90 degrees. 3. The dispensing nozzle according to claim 1, wherein the opposing portions of the nozzle portion opening are obliquely cut out, and a pair of wedge-shaped portions are formed in the portions sandwiched by the cutout portions.