JPH07134131A - Automatic dispensing device - Google Patents

Abstract

PURPOSE:To make the collecting pressure of a nozzle and a nozzle chip constant by a control circuit by use of a spring provided on the vertically moving mechanism of the nozzle chip and a detector to allow the stable collection of the nozzle chip, and narrow the horizontally moving range to make a device conformable to the doubling of the nozzle. CONSTITUTION:An X-driving base 29 has a dispensing nozzle 4 pressed by a spring 30 and a spring contraction sensor 31, and at the collection of a nozzle chip 3, the collecting pressure is made constant by driving a constant pulse X-driving pulse motor 15 by a Z-motor control circuit 32 after the detection of the spring contraction sensor 31. Thus, a nozzle chip rack 2 is controlled for movement, whereby the mechanism can be minimized, and an easy device manufacture at low cost can be performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nozzle collecting technique for an automatic pipetting device for pipetting a liquid by using a disposable nozzle tip.

[0002]

2. Description of the Related Art An automatic dispenser for dispensing a liquid sample such as a serum or a reagent from a container such as a test tube to another container is used for dispensing each liquid sample in order to prevent contamination between the liquid samples. Replace nozzle tip automatically. Therefore, unused nozzle chips are mounted on the nozzle chip rack, and the nozzle chip rack is installed in the moving range of the mechanism for moving the nozzle horizontally and vertically. A plurality of nozzle tip racks are installed in consideration of nozzle tip replenishment so that the nozzle tips can be set in the nozzle tip rack from which the nozzle tips have not been collected.

The nozzle is mounted on the nozzle tip rack by moving the nozzle onto the nozzle tip rack by the horizontal movement mechanism moving in the XY directions and lowering the nozzle on the target nozzle tip by the vertical movement mechanism. After mounting, the nozzle with the nozzle tip is moved up again, moved horizontally on the liquid sample, sucked down, and again discharged into the target container for dispensing. The used nozzle tip is discarded by the tip remover at the tip discarding position to prepare for the next nozzle sampling.

To collect the nozzle tip, the nozzle is lowered by a vertical movement mechanism by a predetermined amount to fit the nozzle into the nozzle tip. At this time, the nozzle is connected to the vertical movement mechanism by a spring, and pressure is applied to the nozzle tip against the inset to enable sampling of the nozzle tip.

When the nozzle tip is not set in the nozzle tip rack, the nozzle does not touch the nozzle tip even if the nozzle tip is lowered by a certain amount by the vertical movement mechanism, the spring does not contract, and the sensor for detecting the contraction of the spring detects the nozzle tip. It is detected that there is no such thing, it moves again to the next position, and the nozzle tip is taken.

[0006]

As described above, in the conventional apparatus, the vertical movement mechanism moves the nozzle downward by a certain amount to collect the nozzle tip. The distance has to be accurately manufactured or adjusted, and the mechanism becomes complicated, and high-precision processing is required.

Further, in order to install a plurality of nozzle tip racks, it is necessary to enlarge the horizontal movement range of the nozzles, which makes it difficult to maintain the levelness of the nozzle tips, and high precision machining is required to maintain the horizontality between the nozzle tips. Was needed.

The object of the present invention is to make it possible to easily make a horizontal movement mechanism by moving a plurality of nozzle tip racks to reduce the horizontal movement range of the nozzles to the same extent as in the case of one nozzle tip rack. To do. Furthermore, since it is difficult to secure the vertical position accuracy of the nozzle tip by the nozzle tip moving mechanism, the sensor for detecting the contraction of the spring of the nozzle and the vertical movement mechanism control circuit are used to adjust the top dead center of the nozzle vertical moving mechanism and the nozzle sampling height. Even if the vertical distance is relatively rough, the nozzle tip can be accurately collected.

[0009]

A vertical movement mechanism for a nozzle is driven by an actuator such as a pulse motor that can control the movement distance, and a control circuit controls the movement distance and the movement speed. The moving distance is set to be longer from the top dead center of the nozzle in consideration of the variation in height accuracy from the nozzle tip sampling position. Further, by inputting the signal of the sensor for detecting the contraction of the spring of the nozzle to the interrupt input of the vertical movement mechanism control circuit, it is detected that the nozzle touches the nozzle tip. Since the contraction amount of the spring and the insertion pressure for the nozzle to press the nozzle tip are almost proportional, it is appropriate that the nozzle picks the nozzle tip from the interrupt input from the detector when the nozzle touches the nozzle tip. If the vertical movement mechanism of the nozzle is lowered by an amount equivalent to a certain pressure, the nozzle does not move in the vertical direction while it is inserted in the nozzle tip, only the spring contracts and the nozzle always keeps the nozzle tip at a certain and appropriate level. It can be collected at various pressures. As a result, even if the height of the nozzle tip and the height of the top dead center of the mechanism for moving the nozzle in the vertical direction fluctuate to some extent, the amount of contraction of the spring can be made constant and proper nozzle tip collection can be performed.

Further, if the signal of the sensor for detecting the contraction of the spring of the nozzle is not input to the control circuit of the vertical movement mechanism of the nozzle, it means that the nozzle is below the nozzle tip sampling position and there is no nozzle tip. Can be detected by the same detector.

By thus roughening the height accuracy of the nozzle tips, even if a plurality of nozzle tip racks are mounted on a moving mechanism such as a rotating mechanism, it is possible to reliably collect the nozzle tips with a relatively simple mechanism. Even if the horizontal movement range of the nozzle is reduced to one nozzle chip rack, the nozzle chips on all the nozzle chips can be collected by moving the nozzle chip rack.

In order to further improve the processing capacity, a single horizontal moving mechanism is provided with a plurality of nozzles, each of which is provided with a vertical moving mechanism and its control circuit, and the nozzle chip sampling timing is shifted, thereby providing a nozzle chip rack and a nozzle chip rack. Even if there is some play in the rotating mechanism and deflection occurs, only the top dead center of the nozzle and the height at which the tip is taken change only here, and the above means makes it possible to take an appropriate nozzle just like an individual nozzle. .

[0013]

[Operation] A nozzle tip rack moving mechanism such as a rotating mechanism having a plurality of nozzle tip racks each having a nozzle tip mounted collects nozzle chips for one rack of the nozzle tip rack located within the movement range of the horizontal movement mechanism of the nozzles. The control circuit determines that the nozzle tip rack is finished, and moves the nozzle tip rack so that the next nozzle tip rack is located within the movement range of the horizontal movement mechanism of the nozzle. The nozzle tip is sampled by the vertical movement mechanism of the nozzle, and the sample liquid is sucked using the mechanism for sucking and discharging the liquid into the nozzle tip,
Dispense into another container and automatically perform dispensing operation. Since one or more sample liquids and containers to be dispensed are sent by being loaded into one sample rack by an automatic transport system, the dispensing position can be within a limited range, and the nozzle for the dispensing position The horizontal movement range of s may be a very small range. Further, as described above, when the nozzle tip rack is moved by the mechanism for moving the nozzle tip rack to collect the nozzle tips, the nozzle horizontal movement mechanism of the automatic dispensing apparatus using the disposable tips can be realized. A mechanism for horizontally moving in the XY directions is difficult to manufacture with high precision when the moving range is large, and the cost increases, but the nozzle tip rack moving mechanism allows the nozzle horizontal moving mechanism to be small and easily realized at low cost.

The vertical moving mechanism of the nozzle and the nozzle are contracted in the vertical direction by the spring, and the detector for detecting the contraction of the spring controls when the nozzle lowered by the control circuit touches the nozzle tip and the spring contracts. The interrupt input of the circuit is controlled so that the nozzle touches the nozzle tip and then descends a certain distance and then stops. As a result, the nozzle tip and the nozzle are pressed by the same pressure due to the same contraction amount of the spring even if there is a slight error in the height direction, so that the nozzle tip works stably.

In order to further improve the processing capacity, when two nozzles are used, two nozzles and their respective vertical moving mechanisms must be provided on the same horizontal moving mechanism, so that the two nozzles simultaneously form a nozzle tip. The force applied to the horizontal movement mechanism of the nozzle and the nozzle tip rack and its movement mechanism is doubled between the case of going to pick up and the case of going to pick up only one side, but there is also a difference in the vertical distance due to deflection, The detector and the control circuit push the spring with the same pressure due to the same contraction amount of the spring, and act to stably collect the nozzle tip. In addition, the control circuit controls the vertical movement mechanism of the two nozzles with a time lag, thereby eliminating the interference of the detector output due to the deflection when the respective springs are contracted, and more stably collecting the nozzle tip. To work.

[0016]

An embodiment of the present invention will be described below with reference to the drawings.

When serum or urine, which is a liquid sample, is analyzed and measured using a plurality of analyzers, an automatic transportation system is introduced for the purpose of preventing infection and labor saving in transportation. In addition, in order to perform efficient analytical measurement using multiple analyzers, an automatic pipetting device should be installed on the transfer line of the automatic liquid sample transfer system so that the liquid sample can be divided into several containers and analyzed and measured simultaneously. Incorporate.

As shown in FIGS. 1 and 2, the pre-dispensing transport unit 2
A test tube 18 containing serum or urine that is a liquid sample is set in the suction source sample rack 17a sent from No. 4 and stopped at the dispensing position of the dispensing unit 26 by the suction source sample line 9. In addition, the discharge destination container A sample cup 27
a. Discharge destination container A sample rack 17b with discharge destination container B sample cup 27b and discharge destination container B sample rack 17c similarly stopped at the dispensing position by the discharge destination container A line 10 and the discharge destination container B line 11. To do. The three sample racks are stopped at the same coordinates with respect to the X direction in the device for dispensing the sample rack. Since the length of the sample rack is about 100 mm, it must be moved in order to dispense the liquid sample serum or urine from the test tube 18 to the discharge destination container A sample cup 27a and the discharge destination container B sample cup 27b. Dispensing nozzle 4a
・ 4b movement range in X direction is 100mm, which is equivalent to this distance.
It's enough. On the other hand, a disposable nozzle tip 3 is used for the liquid suction part in order to prevent contamination of liquid samples such as serum and urine between individuals. The nozzle tip 3 is mounted on the nozzle tip rack 2, and the nozzle tip rack 2 is set on the nozzle tip rack rotating mechanism 1 and rotated by 90 degrees by the turntable drive motor 22 and the gears 23a and 23b. By setting the distance in the X direction at the position where the nozzle chips 3 of the nozzle chip rack 2 can be collected to be about 100 mm, which is almost the same as the length of the sample rack, the moving distance of the dispensing nozzles 4a and 4b in the X direction, that is, the size of the X drive base 5 is set. The height can be set to about 100 mm, which enables the Y-movement 8 to be held by the Y-moving rail 14 on only one side.

The X drive base 5 is connected to the Y drive belt 13 and moved by the Y drive motor 7 on the Y moving rail 14 in the Y direction to the position of the nozzle tip rack 2. As shown in FIG. 3, the Z drive base 29 connected to the Z drive belt 28 is lowered by the Z drive pulse motor 15 to collect the nozzle chips 3. When the dispensing nozzle 4 is inserted into the nozzle tip 3, the dispensing nozzle 4 stops descending, and the dispensing nozzle 4 rises relative to the Z drive base 29. As a result, the spring 30 contracts and the spring contraction sensor 31 operates to input a signal to the Z motor control interrupt input circuit 33 of the Z motor control circuit 32. Z motor control circuit 3
2 is instructed by the dispensing device control CPU 34 from the top dead center of the Z drive base 29 before the descent, and a pulse movement amount α longer than the sampling position of the nozzle tip 3 is instructed. After the constant pulse amount β is output, the pulse output to the Z motor drive circuit 35 is stopped, the Z drive motor 15 is stopped, and the lowering of the Z drive base 29 is stopped.
As a result, the dispensing nozzle 4 collects the nozzle tip 3 with a pressure contracted by the constant pulse amount β of the spring 30. Therefore, even if there is some error in the height direction of the housing 21, the nozzle tip rack rotating mechanism 1, and the nozzle tip rack 2, the nozzle tip 3 can always be sampled at the same stable pressure. The sampling pressure can be changed by changing the shape of the nozzle tip 3 or the like by changing the drive pulse amount β after the interrupt input. Furthermore, the Z motor control circuit 32 determines that there is no interrupt input from the spring contraction sensor 31 continuously during the period in which the drive pulse amount β is output, and judges that it is noise, thereby preventing malfunction due to noise without a filter.

After collecting the nozzle tip 3, the X drive base 5 is moved in the Y direction by the Y drive motor 7 and moved to the position of the suction source sample rack 17a. The dispensing nozzle 4 is connected to the syringe mechanism 6 by a piping tube 16 and the test tube 1
The liquid sample such as serum or urine that has entered 8 is sucked into the nozzle tip 3. Further, the X drive base 5 is the Y drive motor 7
To move in the Y direction by the discharge destination container A sample rack 17
b. Discharge destination container B The liquid sucked into the nozzle tip 3 at the position of the sample rack 17c is again discharged using the syringe mechanism 6 to the discharge destination container A sample cup 27a and the discharge destination container B.
Discharge to the sample cup 27b. The used nozzle tip 3 is scraped by the nozzle tip discarding port 12 by the nozzle tip remover 20 and discarded. After this series of dispensing operations, the X drive base 5 is moved again to the position of the nozzle tip rack 2 by the Y drive motor 7 and the next nozzle tip 3 is sampled. This is repeated to collect the nozzle chips 3 of the nozzle chip rack 2 for the position rack, and then the nozzle chip rack rotating mechanism 1 is rotated 90 degrees by the turntable drive motor 22 and the gears 23a and 23b to rotate the next nozzle chip rack 2.
The nozzle tip 3 of No. 3 can be collected.

When the nozzle tip 3 is not in the sampling position of the nozzle tip rack 2, the dispensing nozzle 4 does not touch the nozzle tip 3 and the spring 30 does not contract. Therefore, since the spring contraction sensor 31 does not input to the Z motor control interrupt input circuit 33 of the Z motor control circuit 32, the Z motor control circuit 32 causes the Z drive base 29 of the Z drive base 29 which is instructed by the dispensing device control CPU 34 before lowering. Even when the pulse movement amount α longer than the sampling position of the nozzle tip 3 is output from the top dead center, it is recognized that there is no interrupt input, and the nozzle tip 3 is recognized.
Is determined not to be at the sampling position, and the next nozzle tip 3 is picked up.

When the dispensing nozzle 4a and the dispensing nozzle 4b are mounted on the X drive base 5 having the same XY operating mechanism for improving the processing capacity, one nozzle tip 3 and two nozzle tips 3 are collected.
Since the sampling force is different from the sampling of the nozzle tip 3 of the book by half, the deflection amount of the X drive base 5 and the nozzle tip rack rotation mechanism 1 is different. Further, the X drive base 5 is one-pointed by the Y moving rail 14, and the flexure amount varies depending on the position in the X direction. Further, since the nozzle tip rack rotating mechanism 1 is also instructed by the center position, the amount of deflection differs depending on the distance from the center position. However, as described above, since the dispensing nozzle 4 is sampled by the constant contraction pressure of the spring 30 with respect to the nozzle tip 3, stable sampling is performed. Further, by controlling the lowering of the dispensing nozzle 4a and the dispensing nozzle 4b with a time lag, it is possible to eliminate the sampling pressure error caused by the transient interference of the deflection of the nozzles with each other.

[0023]

According to the present invention, even if a plurality of nozzle chip racks are mounted, the moving range of one nozzle chip is provided by controlling the movement of the nozzle chip rack mounting the dispensing nozzle chips. If there is a nozzle moving mechanism, the mechanism can be made small and simple and low-cost device manufacturing becomes possible.

Further, the vertical operation mechanism of the nozzle is provided with a spring and a sensor for detecting contraction of the spring, and the output of the sensor is input to an interrupt input of a control circuit for controlling the vertical operation mechanism of the nozzle so that the nozzle touches the nozzle tip. Therefore, the nozzle tip mounting pressure can be made constant by contracting the spring for a certain distance, and the nozzle tip can be stably sampled even when the distance changes in the height direction due to error or deflection.

Further, a plurality of nozzles are provided in one horizontal moving mechanism and each of them has a vertical moving mechanism to improve the processing capacity, and a control circuit drives and controls the vertical moving mechanisms of the two nozzles with a time lag. Eliminates the interference of the detector output due to the flexure of the spring
It is possible to stably collect the nozzle tip.

[Brief description of drawings]

FIG. 1 is a plan view of a pipetting machine according to an embodiment of the present invention.

FIG. 2 is a side view of the pipetting machine.

FIG. 3 is a nozzle sampling block diagram.

[Explanation of symbols]

1 ... Nozzle tip rack rotating mechanism, 2 ... Nozzle tip rack, 3 ... Nozzle tip, 4a, 4b ... Dispensing nozzle, 5
... X drive base, 6a, 6b ... Syringe mechanism, 7 ... Y drive motor, 8 ... Y drive base, 9 ... Suction source sample line, 10 ... Discharge destination container A line, 11 ... Discharge destination container B line, 12 ... Nozzle Chip disposal port, 13 ... Y drive belt, 14 ... Y moving rail, 15 ... Z drive pulse motor,
16 ... Piping tube, 17a ... Suction source sample rack,
17b ... Discharge destination container A sample rack, 17c ... Discharge destination container B sample rack, 18 ... Test tube, 19 ... Sample rack guide, 20 ... Nozzle tip remover, 21 ... Casing, 22 ... Turntable drive motor, 23a, 23b
... Gear, 24 ... Pre-dispensing transport unit, 25 ... Post-dispensing transport unit, 26 ... Dispensing unit, 27a ... Discharge destination container A
Sample cup 27b ... Discharge destination container B sample cup,
28 ... Z drive belt, 29 ... Z drive base, 30 ... Spring, 31 ... Spring contraction sensor, 32 ... Z motor control circuit, 33 ... Z motor control interrupt input circuit, 34 ...
Dispensing device control CPU, 35 ... Z motor drive circuit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuaki Omiyama 882 Ichige, Katsuta City, Ibaraki Prefecture Hitachi Ltd., Measuring Instruments Division

Claims (3)

[Claims] 1. An automatic dispenser having a mechanism for sucking / discharging a liquid, a dispensing nozzle tip, a nozzle for mounting / demounting the nozzle tip, a mechanism for horizontally and vertically moving the nozzle, and a nozzle tip rack for setting the nozzle tip. An automatic pipetting device characterized in that the device has a mechanism for moving a plurality of nozzle tip racks and a control device for controlling the movement thereof to minimize the moving range of the mechanism for horizontally moving the nozzles. 2. The nozzle tip mounting pressure according to claim 1, further comprising a spring and a sensor for detecting contraction of the spring in the vertical operation mechanism of the nozzle, and a controller for controlling the vertical operation mechanism of the nozzle by the sensor. Automatic dispensing device characterized by the following. 3. The method according to claim 1, wherein a plurality of nozzles are provided in one horizontal movement mechanism, each of which has a vertical movement mechanism, and a control mechanism for shifting the timing of nozzle tip collection is provided to ensure nozzle tip collection. Characteristic automatic dispensing device.