JP3451014B2 - Nozzle device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nozzle device,
Particularly, it relates to a nozzle device suitable for sucking a small amount of liquid.

[0002]

2. Description of the Related Art In a nozzle device such as a dispensing device, a liquid (sample) is sucked by the nozzle and the liquid is discharged from the nozzle. Here, when suctioning the liquid,
The nozzle is positioned above the container, and the nozzle is pulled down from that state. At that time, liquid level detection is performed by utilizing air discharge from the nozzle tip, and liquid is sucked with the nozzle tip slightly inserted into the detected liquid level. At the time of suction, follow-up control is performed to lower the nozzle as the liquid level lowers. According to such control, the amount of liquid adhering to the outer surface of the nozzle can be reduced as much as possible, and problems such as liquid scattering and dispensing error during nozzle conveyance can be avoided.

By the way, ideally, it is possible to detect the liquid level when the nozzle descends until just before the bottom of the container. However, in reality, there are container positioning errors, nozzle positioning errors, nozzle molding errors (particularly when using a removable disposable chip), and it is not possible to perform liquid level detection immediately before the bottom of the container. difficult. In other words, considering the operating efficiency of the device, a certain speed is required for the nozzle descending speed in liquid level detection, and under such speed conditions, if the nozzle tip collides with the bottom surface of the container, the nozzle tip will be damaged. This is because there is a possibility that the nozzles may be damaged or the nozzle transport mechanism may be damaged. Further, in the conventional device, there is not much need for suction of the liquid that is present in a very small amount in the container, and therefore, it is not necessary to detect the liquid surface up to the vicinity of the bottom surface.

Therefore, the liquid level detection limit level is registered based on various conditions so that the above collision problem does not occur.
When the tip of the nozzle reached that height, the descending of the nozzle was forcibly stopped.

[0005]

In recent years, there is a case where a dispensing apparatus again dispenses a sample stored after the dispensing process. Generally, there are not many specimens remaining in the container, and for this reason, there is an increasing need to aspirate all the specimens remaining in the container and dispense them without waste. However, in the conventional device, control corresponding to such a request is not performed, and as described above, in order to avoid the collision of the nozzle tip with the bottom surface, the registered height (liquid level detection limit height ), The control for stopping the nozzle lowering is performed. As described above, the conventional device has a problem in that it is not possible to suck the liquid in the container when the amount of the liquid is very small.

The present invention has been made in view of the above conventional problems, and an object thereof is to provide an apparatus capable of efficiently sucking a small amount of liquid in a container. To do.

Another object of the present invention is to make it possible to almost completely suck the liquid present in the container.

[0008]

In order to achieve the above object, the present invention relates to a nozzle to which an air tube is connected and which sucks a liquid contained in a container, and a nozzle which descends from above the container. In this case, by continuously ejecting air from the nozzle tip opening and determining the pressure rise in the air tube due to the nozzle tip opening approaching or contacting the liquid surface, at a liquid level detection limit height or higher. The liquid level detecting means for detecting the liquid level and the nose when the liquid level is not detected above the liquid level detection limit height.
Contact control means for stopping the air ejection from the tip opening and further lowering the nozzle tip below the liquid level detection limit height to bring the nozzle tip into contact with the container bottom surface; and the nozzle tip contact with the container bottom surface. And a small amount suction control means for performing suction by positioning the nozzle tip at a predetermined height higher than that based on the height of the bottom surface of the container, and the tip surface of the nozzle is the bottom surface of the container when contacting the bottom surface of the container. Close to,
Suction of the liquid can row Ukoto therefrom by pulling the nozzle to the predetermined height, the nozzle lowering speed during liquid level detection
The nozzle descending speed at the time of contact with the bottom surface of the container is lower than the degree .

According to the above construction, when the nozzle is lowered from above the container, the liquid level is detected. In that case, if the liquid level is detected, suction control that follows the liquid level lowering is performed as in the conventional case, for example. On the other hand, when the liquid level cannot be detected even when the nozzle tip reaches the liquid level limit height, the nozzle is further lowered and the nozzle tip is brought into contact with the container bottom surface. That is, the bottom surface of the container is directly detected. Therefore, for example, if the nozzle is slightly pulled up from the bottom surface of the container to form a gap between the nozzle tip and the bottom surface of the container, and suction is performed in that state, almost all of the liquid existing in the container can be sucked. Is. In the above descent control,
Desirably, the nozzle descending speed at the time of contact with the bottom surface of the container is set to be lower than the nozzle descending speed at the time of detecting the liquid level. That is, the tip of the nozzle is damaged and the collision load is reduced. According to such speed switching, the processing speed can be improved as compared with the case where the liquid level is detected at a low speed from the beginning.

A preferred aspect of the present invention is characterized in that it includes means for executing an error process when neither the liquid level nor the contact with the container bottom is detected.

In a preferred aspect of the present invention, the contact control means and the small amount suction control means stop the descending of the nozzle when the contact of the tip of the nozzle with the bottom surface of the container is detected, and thereafter, the nozzle is stopped. Is pulled up to position the tip of the nozzle at a height with a minute gap from the bottom surface to perform a suction operation. Desirably, the predetermined height is switched and controlled according to the type of the nozzle, and preferably, the predetermined height is switched and controlled according to the type of liquid to be sucked. More preferably, it includes a jamming sensor for detecting that the tip surface of the nozzle collides with the edge of the container, said nozzle tip is in contact with the container bottom Ru is determined based on the output of the jamming sensor.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a preferred embodiment of a nozzle device according to the present invention, and FIG. 1 is a conceptual diagram showing the overall structure thereof.

The nozzle 10 is a means for sucking and discharging the liquid 14 contained in the container 12. This nozzle 1
Reference numeral 0 indicates, for example, a metal nozzle or a resin-based disposable chip. As shown in the figure, in this example, the nozzle 10 is held vertically, and its tip end surface is in close contact with the bottom surface of the container when the bottom surface of the container is brought into contact with the bottom surface of the container.
Form a horizontal surface) . The nozzle 10 is held by a transport mechanism 16 so as to be able to move up and down. The transport mechanism 16 has a function of transporting the nozzle 10 in the vertical direction as well as a function of transporting the nozzle 10 in the horizontal direction. The jamming sensor 17 is a sensor that detects the collision when the tip of the nozzle 10 collides with, for example, the edge of the container 12. By the way, the impact force at the time of the collision is absorbed by an elastic member or the like provided inside the transport mechanism 16.

The nozzle 10 is connected to a dispensing pump 20 via an air tube 18. This dispensing pump 20
Is means for applying suction force and discharge force to the nozzle 10. A pressure detector 19 for detecting the pressure inside the air tube 18 is connected to the air tube 18.

In FIG. 1, the control unit 22 includes a nozzle 1
It is a means for controlling the transport of 0 and suction / discharge. Specifically, the control unit 22 controls the dispensing pump 20 and the transport mechanism 16. The detection signal from the jamming sensor 17 and the detection signal from the pressure detector 19 are input to the control unit 22, and the control unit 22 controls the transport mechanism 16 and the dispensing pump 20 based on these signals. ing.

The nozzle device shown in FIG. 1 is a device incorporated in, for example, a dispensing device. In such an application, the liquid 14 is, for example, serum or urine.

The nozzle device shown in FIG. 1 has a function of detecting the liquid surface when sucking the liquid.
In the present embodiment, the liquid level detection is executed by utilizing air ejection. That is, when the liquid 14 is sucked by the nozzle 10, the nozzle 10 is first pulled down by the transport mechanism 16. During the downward movement, the dispensing pump 20 is continuously driven, and a small amount of air is continuously discharged from the tip of the nozzle 10.
Then, at that time, the pressure inside the air tube 18 is monitored by the pressure detector 19, and the control unit 22 determines whether the pressure inside the air tube 18 increases due to the tip of the nozzle 10 coming close to or in contact with the liquid surface of the liquid 14. As a result, the height of the liquid surface is determined. this is,
This is a known technique.

In the apparatus according to the present embodiment, the lowering reference level 100 for liquid level detection is set. The lowering reference level 100 is set slightly above the bottom level 103 of the container in consideration of, for example, the positioning error of the container 12 and the positioning error of the nozzle 10. For example, the descending reference level 100 is set as a height about 5 mm above the theoretical bottom level 103. Of course, the lowering reference level 100 can be appropriately set according to various conditions. In any case, if the nozzle 10 is lowered to the theoretical bottom level 103, the tip of the nozzle 10 may collide with the bottom surface of the container 12 in some cases, thereby damaging the nozzle 10 or the container 12. In some cases, or excessive impact may be applied to the transport mechanism 16, and the lowering reference level 100 is set to prevent such a problem.

By the way, in the conventional nozzle device,
When the liquid level cannot be detected even when the tip of the nozzle 10 reaches the lowering reference level 100, the nozzle 10 is pulled up assuming that there is no liquid 14 in the container 12. However, in reality, as described above, some liquid 14 may remain on the bottom of the container 12.

In particular, when re-dispensing is performed, there is a demand to suck all of such a small amount of liquid 14. Therefore, in the present embodiment, as will be described later in detail, the nozzle 10 that has reached the descending reference level 100 is pulled down more slowly, the tip of the nozzle 10 is brought into contact with the bottom surface of the container 12, and the actual bottom detected thereby is detected. Efficient suction of a small amount of liquid is realized by performing suction at a position where the nozzle 10 is slightly lifted above the level 103.
FIG. 3 shows the state of the nozzle at that time, and FIG. 3A shows the state in which the tip of the nozzle 10 is in contact with the bottom surface of the container 12. (B) has a bottom level of 10
A pulling level 102 is shown, which is a small distance from 3.

By the way, when the bottom of the container 12 is not actually detected when the nozzle 10 is lowered in order to bring the tip of the nozzle 10 into contact with the bottom surface of the container 12,
That is, the tip of the nozzle 10 is at the error determination level 104
If it reaches, error processing is executed as described above.

Next, the operation of the apparatus according to this embodiment will be described with reference to FIG.

In S101, the container 1 for sucking the liquid
2, the nozzle 10 is positioned above the nozzle 10.
Is pulled down at a predetermined speed. At the same time, as described above, the liquid level detection by air ejection is started. S1
In 02, it is determined whether or not the liquid level is detected.
Specifically, the output of the pressure detector 19 is monitored by the control unit 22, and the liquid level is determined by comparing the pressure value with a predetermined value. Here, when the liquid level is not detected, the descending reference level 10
It is determined whether the tip of the nozzle 10 has reached 0.
If the tip of the nozzle 10 has not reached that level, the process of S102 is repeatedly executed.

Here, if the liquid level is detected while the nozzle 10 is descending, the descending of the nozzle 10 is stopped in S104, and at the same time, the ejection of air related to the liquid level detection is also stopped. Then, in S105, suction is started by the nozzle 10, and in S106, follow-up lowering control for lowering the nozzle 10 as the liquid surface lowers is executed. In S107, it is determined whether or not the liquid 10 has been sucked by the nozzle 10 by a predetermined amount.

In S108, when a predetermined amount of the liquid 14 has been sucked, the suction is stopped and the lowering of the nozzle 10 is also stopped. In S109, the nozzle 10 is pulled up and the necessary dispensing operation is executed.

On the other hand, if it is determined in S103 that the liquid surface is not detected even when the nozzle 10 is lowered and it is determined that the tip of the nozzle 10 has reached the lowering reference level 100, in this embodiment, the nozzle 10 is determined in S110. Is stopped, and at the same time, air discharge related to liquid level detection is stopped. Then, in step S111, the nozzle 10 is pulled down at a lower descending speed than the descending speed of the nozzle 10. In this case, a speed is set such that the above-mentioned various problems do not occur even if the tip of the nozzle 10 comes into contact with the bottom surface of the container 12.

In S112, it is determined whether the tip of the nozzle 10 has reached the error determination level 104. If it is determined that the tip of the nozzle 10 has reached the error determination level 104, error processing is executed in S113. It
That is, the absence of the container 12 or the liquid 14 is output to the user as an alarm message.

On the other hand, when the tip of the nozzle 10 has not reached the error determination level 104, it is determined in S114 whether the tip of the nozzle 10 has reached the bottom surface of the container 12. Specifically, this is the jamming sensor 17
It is determined based on the output of. If the tip of the nozzle 10 contacts the bottom surface of the container 12, the transport mechanism 1
The pressing force at that time is absorbed by the elastic member in the conveyance mechanism 16 by 6, and the stop of the nozzle 10 is directly detected by the jamming sensor 17. It is possible to detect that the tip of the nozzle 10 is in contact with the bottom surface of the container 12 by using the jamming sensor 17 that has been conventionally provided.

When such a detection is made, the nozzle 10 is pulled up slightly in S115. For example, the nozzle is pulled upward by 1 mm. This is because if the tip of the nozzle 10 is in close contact with the bottom surface of the container 12, suction cannot be performed efficiently. In S115,
In the state where the nozzle 10 is slightly lifted,
In S116, the nozzle 10 sucks a predetermined amount of liquid. However, when the liquid remaining in the container is less than the predetermined amount, the tip of the nozzle 10 is
Since it is close to the bottom surface of the nozzle 2, almost all the liquid is in the nozzle 1.
Can be aspirated into 0 and will be aspirated. S
At 117, the nozzle 10 is pulled up and the necessary dispensing operation is continuously executed.

Therefore, according to the above embodiment, there is an advantage that a small amount of the liquid remaining near the bottom of the container 12 can be efficiently sucked and the dispensing speed can be increased. Incidentally, for example, the pull-up amount in S115 may be switch-controlled in accordance with the type of the nozzle 10 or the type of sample. Further, similarly to this, the descending reference level 100 may be selected according to the dispensing condition.

[0032]

As described above, according to the present invention,
Even when a small amount of liquid is present in the container, such liquid can be efficiently sucked. According to the present invention, it is possible to almost completely suck the liquid existing in the container.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a preferred embodiment of a nozzle device according to the present invention.

FIG. 2 is a flowchart showing the operation of the apparatus.

FIG. 3 is a diagram showing a state in which a nozzle is pulled up.

[Explanation of Codes] 10 Nozzle, 12 Container, 14 Liquid, 16 Conveying Mechanism, 17 Jamming Sensor, 19 Pressure Detector, 20
Dispensing pump, 22 control.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-55-39029 (JP, A) JP-A-8-15276 (JP, A) JP-A-7-151768 (JP, A) JP-A-6- 242126 (JP, A) JP 11-271322 (JP, A) Actually open 58-54558 (JP, U) Actually open 7-41464 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01N 35/00-35/10 G01N 1/00-1/44 JISST file (JOIS)

Claims (6)

(57) [Claims] 1. A nozzle connected to an air tube for sucking a liquid contained in a container, and when lowering the nozzle from above the container, continuously ejecting air from a nozzle tip opening, When the nozzle tip opening approaches or contacts the liquid surface, the air tube
A liquid level detecting means for detecting the liquid level above the liquid level detection limit height by determining the pressure rise in the tube, and when the liquid level detection is not performed above the liquid level detection limit height, Stop the air discharge from the nozzle tip opening
Stop, and further lower the nozzle tip below the liquid level detection limit height to bring the nozzle tip into contact with the bottom surface of the container, and a height of the bottom surface of the container after the nozzle tip contacts the bottom surface of the container. A small amount suction control means for positioning the nozzle tip at a predetermined height higher than that and performing suction, the tip end surface of the nozzle comes into close contact with the container bottom surface when contacting the container bottom surface, given the height pulling the nozzle can row Ukoto suction of the liquid, when the container bottom abutment than the nozzle lowering speed during liquid level detection Bruno
Nozzle device characterized by a lower descent speed . The apparatus of claim 2 according to claim 1 Symbol mounting, nozzle device, characterized in that it comprises means for executing error processing if not made any detection of contact of the detection and the container bottom of the liquid surface . 3. A device according to claim 1 or 2, wherein said abutment control means and the small amount suction control means, a nozzle lowering is stopped when the contact of the nozzle tip to the container bottom is detected, After that, the nozzle device is pulled up to position the tip of the nozzle at the predetermined height with a minute gap from the bottom surface to perform a suction operation. 4. The nozzle device according to claim 3 , wherein the predetermined height is switch-controlled according to the type of the nozzle. 5. The nozzle device according to claim 3 , wherein the predetermined height is controlled to be switched according to the type of liquid to be sucked. 6. The jamming sensor according to claim 1, further comprising a jamming sensor that detects that a tip end surface of the nozzle collides with an edge of the container, and that the tip end of the nozzle contacts a bottom surface of the container. The nozzle device is characterized by being determined based on the output of the nozzle device.