JPS5874881A - Liquid distributor - Google Patents

Abstract

PURPOSE:To prevent generation of liquid film, by providing an interlocking mechanism between a pair of tube compressing members and a tube squeezing pump in the manner such that the change of the volume in a tube is compensated by the displacement of the pump, and filling the top of a nozzle with liquid at the time of awaiting next operation. CONSTITUTION:Tube releasing motion of a first tube compressing member B and tube squeezing motion of a tube squeezing member D are interlocked with each other by an interlocking mechanism H. That is, at the time of awaiting next operation, the first tube compressing member B is retracted to a prescribed extent, and at the same time, the tube squeezing member D is moved forward through a distance corresponding to a displacement compensating the change of the volume in the tube caused by the retraction of the first tube compressing member B. Resultantly, liquid is filled at the top 4 of a nozzle, so that generation of liquid film can be prevented. Further, since the sample liquid to be metered is delivered only in the discharging direction, it is enabled to minimize pollution of the discharge passage and to keep the discharge rate of the sample liquid constant.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in liquid dispensers used in automatic biochemical analyzers and the like.

There are some types of liquid dispensers with ridges, but the one shown in Figure 1 has a pair of tubes tightened and fitted onto the elastic tube (1-K) by the opening/closing body (B) ( This is a dispenser that uses a round pump to press C) and a tube squeezing push piece Φ) at an intermediate position.

This dispenser operates as follows to intermittently dispense the liquid in the elastic tube (feL) and discharge it through the discharge path (2)K.
That is, Figure #1 (IL> shows the standby state immediately before discharging the liquid inside the elastic tube (4).This elastic tube body)
When discharging the liquid inside, while holding the first tube clamp (attached to the opening/closing body) in an open state, drive the tube squeezing push piece φ) in the direction of closing the elastic tube body). FIG. 1(1)) shows a state in the middle of discharging the liquid, and FIG. 1(C) shows a state when discharging is completed. When the discharge is completed, the first tube tightener holds the opening/closing body (0) in the closed state and the tube squeezing push piece (B) and the second tube tightening unit connects the opening/closing body (C') to the elastic tube (inclination). (See both figures in Figure 1).

As a result, the liquid in the liquid container (3) is sucked into the elastic tube body by the restoring force of the elastic tube.

When suction is completed, the second tube is tightened by the opening/closing body (C)
is driven in the direction of closing the elastic tube body), and the liquid is trapped inside the elastic tube body, as shown in FIG. After that, the first tube is tightened by the opening/closing body (B).
is driven in the direction of opening the elastic tube (A),
In the state shown in FIG. 1 (&), the next discharge is awaited. Thereafter, such operations are repeated to intermittently discharge the liquid between the first and second open/close positions to the dispensed liquid discharge path (2). Figure 2 shows the operation diagram of the opening/closing bodies (B) and (C) and the tube ladder emergency push piece (B) for tightening the tape. is the operating diagram of the opening/closing body), 1
Point M & indicates the operation diagram of the opening/closing body (C) for tightening the second chain, and the broken line indicates the operation diagram of the tube ironing push piece (D).

The operation of such a liquid dispenser is shown in Figure 1 (
When transitioning from the state e) to the state shown in FIG. 1(a)] mK, the tightened elastic tube (4) is released and its internal volume increases, and the dispensing liquid discharge path (2) Let the liquid inside recede slightly. For this reason, the following problems have arisen in conventional liquid dispensers. In other words, if the internal pressure of the nozzle (4) is pulled back due to the retreat of the liquid that has filled up to the nozzle tip (4), if the waiting time until the next discharge operation is long, the liquid that has adhered to the inner wall of the nozzle (4) will be removed from the nozzle (4). The liquid naturally flows down the inner wall and forms a liquid film (5) at the tip of the nozzle (4). Such sealing is caused by the fact that the inner diameter of the nozzle tip (4) is usually less than 11EII and by the surface tension of the adhering liquid, but when such a film (5) is formed, the inside of the nozzle (4) An air layer (6) is formed between the Shimotsuru liquid level and the exchanger (5), and this air layer (6) causes the exchanger (5) to rupture during the next discharge operation, causing the n to be scattered around. 〇In this case, when reaction tubes, etc. of circumferential MK@contact channels are arranged in a multi-channel automatic biochemical analyzer, this will have a negative effect.

Furthermore, when such a liquid dispenser is used in combination with a pulp-cut type measuring pulp (7) as shown in FIG. 5, there is a risk that the analysis accuracy of the analyzer will be reduced. As is well known, measuring pulp (7) Fi, a plurality of measuring parts aS-
) and a plate-shaped rotor (9) having −) of
0) t- stator aIJ having a common central axis (
), and the measuring part (8a) ω
b) Measure and dispense the sample α from the sample container α, and rotate the rotor (9) to connect the measuring part ω1)ωb) to the dispensing liquid discharge path (2). 2) is discharged together with the propellant. In this case, when the liquid in the dispensed liquid discharge channel (2) moves back as described above, the sample to be weighed also moves back along with it, resulting in contamination of the inner wall Ql of the channel by the sample to be weighed HK. (so-called carryover)
increases, deteriorating dispensing accuracy. In general, no matter how precisely the metering pulp (7) is processed, there may be an extremely small step αη at the boundary between the stator aυ and the rotor (9) as shown in FIG. Therefore, a small amount of sample α◆ remains at the corner of the step αη, but due to the reciprocating movement of the sample in the dispensing liquid discharge channel (2), the variation in the remaining amount increases, and the amount of sample α◆ to be measured increases. This causes errors in the discharge lid. As a result, the accuracy of sample analysis also decreases.

In view of the above-mentioned problems, this invention does not create an air layer and a liquid film that seals it at the tip of the nozzle, and eliminates the risk of affecting ζfLK even if there is a reaction tube of an adjacent channel around the nozzle tip. , even when used in conjunction with mourning and metering pulp.

The present invention aims to provide a new liquid dispenser that does not cause errors in the discharge lid of the sample to be measured.

That is, the present invention provides a dispensing device using a straining pump, which is equipped with a pair of opening/closing bodies for tightening the elastic tubes after flK, and a pushing piece for straining the tubes at an intermediate position thereof. In #IJ chain tightening, an interlocking adjustment mechanism is added between the two so that the pressure of the pump compensates for the change in the internal volume of the tube due to opening and closing of the opening/closing body. It is. Kof
1K allows the liquid in the dispensing liquid discharge path to flow only in the direction of discharge, preventing the formation and scattering of a liquid film at the tip of the nozzle that occurred in conventional devices, and using metering pulp in the front. If so, the metrological reproducibility may be omitted.

Hereinafter, a specific configuration of the present invention will be explained based on the drawings. This is a diagram showing the configuration of an embodiment of the liquid dispenser according to the invention of @Tatekake and Jin. In this figure, the elastic tube (in this figure) is disposed dripping onto the identification plate (towards), and one end of it is f
The other end of the i-liquid exclusive channel (1) K is connected to the dispensed liquid discharge channel (2).

For tightening the tube, the opening/closing bodies (B) and (C) and the tube-stretching push piece (c) are used to tighten the elastic tube body in a direction perpendicular to the fixing plate material ■ through this elastic tab (5). The plate cams (
1't) (1'2) (1'x) to cause intermittent reciprocating linear movement nλ → In other words, the first tube tightening is the opening/closing body (B) of the dispensing liquid discharge path of the elastic tube μ). The opening/closing body (C) is operated to open the tube from the outside under lateral pressure, and the opening/closing body (C) is operated to tighten the second tube.
When liquid is introduced (into the elastic tube), the opening/closing body (B) is operated alternately to open and open the elastic tube (k) from the outside.

The tube squeezing push piece @ is operated to open the WJl (on the elastic tube between the second opening and closing positions) flatly from the outside.

The plate cams (Fl) (E'2) (Fl) share their rotational axis @) so that they rotate together. 2) An interlocking adjustment machine 41 that interlocks the opening and closing movements of (C) and the push piece plow for breathing! ) is configured. The straining pump ψ) has an opening/closing body (B) (
C), a push piece for tube squeezing (C), this interlocking adjustment machine 115 (B), and a drive source (not shown) for rotating this plate cam.

This dispenser differs from conventional liquid dispensers in that the tube tightening of connection 1 suppresses the change in tube internal volume due to the opening of the opening/closing body (B) by the amount of suppression by the tube squeezing piece (C). In other words, as shown in FIG. 3 (IL), the first tube tightening is caused by the opening/closing body C.
When B) is opened even slightly, the opening and closing movements of both K are linked so that the amount of change in tube internal volume due to the opening is compensated for by the amount of suppression by the tube tightening push piece (4). The amount of change in the internal volume of the tape 1 due to the amount of pressure of the push piece (B) can be set to be equal to or greater than the amount of change in the internal volume of the tube.

In addition, the first tube tightening is performed through the interlocking movement of the opening movement of the opening/closing body (2) and the closing movement of the tube squeezing push piece (ID).

In this embodiment, the state shown in FIG. 3 (IL) is the standby state. That is, the first tube tightening is performed by opening the opening/closing body (gradient) by a predetermined amount, and at the same time by opening the tube tightening piece (1
)) moves in the closing direction by an amount of suppression that compensates for the amount of change in the tube internal volume due to the opening of the tube, and then stops. ko f'LK
Okay, the nozzle tip (4) is filled with liquid as shown in Figure 1 (I).
The formation of a liquid film (5) as shown in L) can be prevented. Further, when discharging the liquid from this state, the first tube tightening closes the opening/closing body (to) and the tube squeezing push piece (to). Also, when aspirating liquid, hold the first tube clamp (on the opening/closing body) in the closed position.
The tube-stretching push piece (B) and the second tube clamp open the opening/closing body (C). When the liquid is sucked, as shown in Figure 5(d)K, the second tube tightens to close the opening/closing body (B) to prevent backflow of the liquid during standby in Figure 5(a). let Thereafter, such operations are repeated, and suction and discharge are performed in the order of (a)→('b)→(0)→((1)→(IL)).

Since this invention is constructed as described above, the liquid is filled up to the nozzle tip during standby, so that it is possible to prevent the formation and scattering of a liquid film that seals the nozzle tip through an air layer. can. Therefore, there is a risk of contaminating the reaction tube of the surrounding WC instantaneous channel even if it exists.
There is no. In addition, when used in combination with Valve Caputo type metering pulp, the sample to be measured flows only in the forward direction of discharge, so contamination of the discharge channel is kept to a minimum and the discharge amount of the sample to be measured is kept constant. be able to.

Therefore, it is possible to maintain the accuracy of sample analysis at a constant level.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram showing the structure and operation of a conventional liquid dispenser, Figure 2 is a diagram showing the operation of the push piece for tightening the chain and tube in this liquid dispenser. 3
The figure is an explanatory diagram of the operation of the liquid dispenser according to Jin's invention, 1:
Figure g4 is cross section-1 showing the configuration when used in combination with the liquid dispenser tube metering valve (7) of one embodiment of this invention.
Figure 5 shows I'ti! It is a sectional view showing the structure of pulp (7). (M)...Elastic tubes (B) (C) - The opening and closing body for tightening the front and rear pair of tubes (B) - Push piece for chain ironing ■ - Shidoki pump (B) Interlocking adjustment mechanism Figure 1 (CI ) (b) (c) (d) (e) Figure 3

Claims (1)

[Claims] In a dispenser using a squeezing pump equipped with an opening/closing body and a push piece for squeezing the tube at an intermediate position, the tube tightening of the pair of front and rear elastic tubes is performed by opening/closing the opening/closing body. A liquid dispenser in which an interlocking vsm mechanism is added between the straining pump and the straining pump so that changes in internal volume are compensated for by the amount of suppression of the straining pump.