JP2945848B2 - Dispensing 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 dispensing apparatus for sucking and discharging a sample.

[0002]

2. Description of the Related Art A pipetting device is used for automatically pipetting a sample such as blood into a plurality of test tubes. In recent years, in order to avoid contamination between samples, a dispensing apparatus using a disposable tip (hereinafter, referred to as a tip) has been used.

In such a dispensing apparatus, a plastics chip is mounted on a metal nozzle provided in a movable pipetting section, and a sample is sucked and discharged through the chip. At the end of one dispensing, the tip is hooked and detached from the detachment fitting provided at a predetermined position of the apparatus, and then a new tip is mounted. Here, a large number of chips are held upright in the chip rack. The nozzle is positioned above any one of the chips, then lowered, and the tip of the nozzle is inserted into the upper opening of the chip, whereby the nozzle is positioned. Attach the chip to.

[0004]

However, when the chip is not mounted upright in the chip rack at the time of chip mounting, when there is a positioning error in the chip rack, or when there is a positioning error in the nozzle itself, the nozzle Jamming occurs in which the chip cannot be properly mounted on the portion. That is, if the tip of the nozzle collides with the upper surface of the chip, an error occurs and the automatic dispensing stops. On the other hand, if the air conditioner was mounted properly, but the mounting state is not perfect, and there is poor airtightness, the dispensing accuracy is reduced. Also, if dispensing is continued despite the tip falling from the nozzle part, it will have an adverse effect on the entire dispensing process,
Decreases device reliability.

In the conventional dispensing apparatus, a dispensing pump is installed in the main body of the apparatus, and the dispensing pump and the nozzle of the pipetting unit are connected by an air hose. Indeed, the responsiveness of suction / discharge was reduced. In addition, in the conventional dispensing device, the chip can be separated only at the point where the detachment fitting is provided.Therefore, the waste chips are heaped up in the chip disposal box immediately below the detachment fitting, and often. Artificial management was needed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned various problems relating to a chip, and has as its object to provide a dispensing apparatus capable of properly mounting a chip to a nozzle portion even with a slight positioning error. Is to provide.

An object of the present invention is to detect a drop of a chip.

An object of the present invention is to make a chip detachable at an arbitrary position.

[0009]

To achieve the above object, the present invention provides a dispensing apparatus for dispensing by a movable pipetting section, wherein the pipetting section comprises:
A disposable tip mounted at a lower end of the nozzle;
A swing mechanism for holding the upper end of the pole tip, and a restoring mechanism providing a restoring force in the direction perpendicular to the nozzle portion, vibration the neck
Provided above the nozzle mechanism and communicates with the nozzle section.
And a motor for driving a piston in the syringe
And the motor rotates in one direction and moves under the piston.
After the fall exceeds a predetermined value, the motor in one direction
A protruding rod to which the rotational force is transmitted and which moves downward,
A member slidably provided at the lower end of the chirping part.
The lower end of the rod is brought into contact with the
Horizontally extending protrusion receiver and its protrusion
When the catch is pushed down by the push rod
Of the nozzle tip attached to the tip of the nozzle portion
Push the upper surface downward to release the nozzle tip
And a slide member having a chip contact portion .

[0010] According to a second aspect of the present invention, the nozzle portion includes:
The upper first member and the lower first member sliding against it
Two members, and the second member downward with respect to the first member.
A first spring for biasing, said pipetting
The fitting portion provides an appropriate mounting force according to the upward movement of the second member.
Appropriate mounting force sensor to detect and upward movement of the lower member
To detect excessive mounting force that exceeds the
And a jamming sensor .

According to a third aspect of the present invention, there is provided the pipetting apparatus.
A sliding portion that moves the slide member downward with respect to the second member.
A second spring biasing the second member and the tip of the second member.
The nozzle tip is attached and the nozzle tip
Chip that detects when the guide member is pulled up
Presence / absence detection sensor, wherein the second spring is connected to the first spring.
It is a spring that is weaker than the above spring .

[0012]

[0013]

[0014]

According to the structure of the first aspect, when the nozzle portion is lowered from above and the chip is mounted on the nozzle portion, even if there is a positioning error between the two, the pipetting portion has a swing mechanism and a swinging mechanism. Since the restoring mechanism is provided, it is possible to give a degree of freedom to the tip of the nozzle portion and smoothly slide it into the upper opening of the chip, and as a result, it is possible to surely mount the chip. That is, according to the present invention, there is an advantage in that the allowable range of the positional deviation can be expanded as compared with the related art, so that the occurrence of jamming can be suppressed. Here, since the restoring mechanism always applies a restoring force in the vertical direction to the nozzle portion, swinging of the lower end of the nozzle portion is allowed during chip mounting, and in other states, the nozzle portion is always turned. It will be oriented vertically. That is, the tip is always kept vertical when aspirating and discharging the sample. Ma
Further, according to the present invention, the descending amount of the piston exceeds the predetermined value.
The nozzle tip can be removed under the conditions
The nozzle tip smoothly from the state after discharging the sample.
Can withdraw. Also protrudes only when the nozzle tip is detached
The tip of the rod comes into contact with the protrusion
In this case, swinging of the nozzle portion can be allowed.

[0015]

[0016]

[0017]

[0018]

As described above, the present invention is intended to comprehensively solve the problems relating to chips, thereby improving dispensing accuracy and reliability of the apparatus.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the principle of the centering mechanism 10. The centering mechanism 10 swingably supports a nozzle portion 14 on which a disposable tip (hereinafter, referred to as a chip) 12 is mounted, and applies a constant returning force to the nozzle portion 14 in the vertical direction.

That is, the centering mechanism 10 includes a swing mechanism 16 and a restoring spring 18. Specifically, the swing mechanism 16 includes a hanger plate 20 on a disk formed above the nozzle portion 14 and the hanger plate 2.
0, and a horizontal support plate 24 in which a circular opening 24A through which the positioning portion 22 is inserted is formed.

As shown in FIG. 1, the diameter of the opening 24A is formed to be slightly larger than the diameter of the positioning portion 22, and allows the lower end of the nozzle portion 14 to swing. The lower surface of the hanger plate 20 is supported by a pedestal 24B, which is the upper surface of the horizontal support plate 24. When the nozzle 14 is swung, the lower end of the hanger plate 20 has a direction opposite to the direction in which the tip of the nozzle 14 moves. The hanger plate edge will be supported by the pedestal 24B.

A restoration spring 18 having a strong spring pressure is provided between the hanger plate 20 and the ceiling surface 28A of the spring storage chamber 28.
The restoring spring 18 constantly applies a constant restoring force to the nozzle portion 14. That is, as shown in FIG. 1, when one side (the right side in the figure) of the hanger plate 20 is lifted, a downward pressing force is applied to the raised portion of the hanger plate 20 by the action of the restoring spring 18. It acts to restore the raised state. As a result, in a normal state, the tip of the nozzle portion 14 always faces in the vertical direction.

One end of the tube 30 inserted along the central axis of the nozzle portion 14 and the restoring spring 18 is
The other end is connected to a dispensing pump (not shown). That is,
By increasing or decreasing the air pressure in the tube 30, the tip 1 attached to the tip 14B of the nozzle 14
2. The suction / discharge of the sample is executed by increasing / decreasing the internal pressure.

Next, the operation of the centering mechanism 10 will be described. In FIG. 1, the central axis of the nozzle portion 14 in the vertical state is indicated by A, and the central axis of the chip 12 is indicated by A '. That is, the positioning error AA 'has occurred.

When mounting the chip 12 on the nozzle section 14, first, the robot (not shown) positions the nozzle section 14 above the chip 12, and then lowers the nozzle section 14 from that state. In this state,
The nozzle section 14 maintains a vertical state. Then, when the nozzle portion 14 is further lowered, the tip becomes the tip 12.
Into the upper opening 12A. Of course, the allowable positioning error depends on the extent of the upper opening 12A, the degree of taper at the tip of the nozzle, and the like. However, in this embodiment, since the swing mechanism 16 is provided, the tip of the nozzle 14 is If even a little bit enters the upper opening 12A, the tip portion 14B
Can be smoothly entered.

That is, conventionally, even if the tip 1
Even if the 4A is desired in the upper opening 12A, the above-described jamming has occurred because the swing is not allowed. According to the present embodiment, such jamming can be effectively suppressed. is there.

FIG. 1 shows a state in which both the axial centers are shifted from each other. However, for example, even when the chip 12 is inclined, the same effect as described above can be obtained.

Next, a dispensing apparatus according to the present embodiment to which the principle shown in FIG. 1 is applied will be described.

FIG. 2 shows the entire configuration of the dispensing apparatus of this embodiment. The pipetting unit 32 is for attaching a chip to the nozzle unit to suck and discharge a sample, and can be freely moved in the XYZ directions by a transfer robot.

FIG. 3 shows a main configuration of the pipetting unit 32. The same components as those shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

The nozzle portion 14 shown in FIG. 3 is roughly composed of a first member 34 and a second member 36. As shown, the hanger plate 20 and the positioning part 22 shown in FIG. 1 are formed on the upper part of the first member 34. On the other hand, the lower end of the first member 34 is slid and stored in the upper part of the second member 36. A spring 38 is interposed between the two members, and the second member 36
Is biased downward.

A slide member 40 is slidably provided with respect to the second member 36, and a distal end portion 36B of the second member 36 projects from a lower opening 40A. The spring 4 is provided between the second member 36 and the slide member 40.
2 are arranged. Here, the restoration spring 18 and the spring 3
8. Among the springs 42, the spring 42 is the weakest spring, and the spring 38 is the next weakest spring.

When the tip 12 is mounted on the tip 36B of the nozzle 14, the slide member 40 is pushed upward, and the bar 40B is also moved upward. The chip presence / absence detection sensor 44 optically detects the upward movement of the bar, and sends a signal indicating that the chip is mounted to the main body as a signal.

As will be described later, the slide member 42 is formed with a rib-shaped protrusion receiver 40C, and is pushed downward by the lower ends of the two protrusion rods 46. This will be described later.

The second member 36 is provided with a bar 36C that moves integrally, and the position of the bar 36C is detected by the mounting force sensor 50. The mounting force sensor 50 is
The first sensor 52 and the second sensor 54 detect the pressure applied to the nozzle portion 14 at the time of mounting in two stages. If excessive mounting force is applied,
The bar 36C is excessively pulled up and the first sensor 52
Detects this and performs jamming determination.

As shown in FIG. 1, the restoring spring 18 is accommodated in the spring accommodating chamber 28 and exerts a tension between the ceiling 28A and the upper surface of the hanger plate 20. The base 56 forming the upper part of the spring storage chamber 28 includes
A syringe 58 is fixedly arranged. In particular,
The protrusion 58A of the syringe 58 is inserted into a through hole 56A formed in the base 56. And the insertion hole 58
A tube 30 for transmitting pressure is inserted into B, and the inside of the syringe 58 and the inside of the tip 12 are communicated. Here, since the tube 30 is made of a bendable material, it does not hinder the swing of the nozzle portion 14. Further, the insertion hole 58B of the projecting portion 58A and the tube 30
An O-ring 60 is disposed between the O-ring 60 and the O-ring 60, and the air-tight state is maintained while allowing the tube to move up and down. That is, as described above, the second member 36 is slidable with respect to the first member 34, thereby changing the path length.
Is slidable. Although one O-ring 60 is shown in FIG. 3, a plurality of O-rings may be provided in order to enhance the airtight effect.

A feed screw 64 is connected to a piston 62 constituting a dispensing pump together with the syringe 58, and the driving force of a motor 66 is transmitted as described below.

That is, the rotation of the motor 66 disposed on the plate 68 is transmitted to the feed screw 64 via the gear 70, the shaft 72 and the gear 74. That is, when the shaft 66A of the motor 66 rotates, it rotates the feed screw 64, and as a result, the piston 62 moves up and down. The rotation of the shaft 66A of the motor 66 is detected by the encoder 80, and the signal is output to the apparatus main body. Note that the feed screw 64 may be driven using a belt.

The pipetting section 32 of this embodiment is provided with a detachment mechanism 100 for detaching the tip 12 at an arbitrary position. This detachment mechanism 100
Specifically, the drive mechanism includes a drive mechanism including a slide member 40, two push rods 46, and a motor 66. That is, in the pipetting section 32 of the present embodiment, the dispensing motor 66 is also used as a motor for driving the detachment mechanism 100, and the disengagement mechanism is operated in a state where the position of the piston 62 is lower than the predetermined height. 100 can be operated.

That is, when the motor 66 is further operated from the state shown in FIG. 3 to move the piston 62 downward, the arm 8 connected to the feed screw 64 is simultaneously
2 moves downward, which pushes down the upper ends of the two push rods 46, so that the positive ends of the push rods 46 push the push receivers 40C down. Then, the chip contact portion 40 </ b> D formed at the lower end of the slide member 40 pushes the upper surface of the chip 12, whereby the chip 12 can be detached from the nozzle part 14.

In a state other than the detaching operation as described above, an upward urging force is applied to the protruding rod 46 by the spring 84.

In FIG. 3, reference numeral 86 denotes a pressure sensor for detecting the pressure in the syringe 58, which is connected to the syringe 58 by a pressure detection tube 88.

Next, the operation of the pipetting unit 32 will be described.

First, the pipetting portion 32 is positioned above the chip erected on the chip rack. Specifically, the pipetting unit 32 is positioned such that the axis center of the nozzle unit 14 and the axis center of the tip 12 match.
Of course, even if there is a positioning error between the two in this state, it is possible to obtain a reliable chip fitting without causing jamming by the centering mechanism 10 up to a certain range as described above.

After the positioning of the pipetting section 32 is completed, the pipetting section 32 is lowered. In this state, the slide member 40 is in a state of being dropped by the action of the spring 42. Note that the stopper for determining the height of the downward drop is not shown in FIG.

When the tip (tip opening) 36A of the nozzle portion 14 enters the upper opening 12A of the chip 12, the centering mechanism 10 works and the tip of the nozzle portion 14 swings so as to absorb the above positioning error. Gives freedom of movement. That is, the entire nozzle portion 14 swings by a small angle against the restoring spring 18 with the hanger plate 20 as a fulcrum.

Accordingly, it is possible to securely mount the tip 12 on the distal end portion 36B.

In the mounted state, the slide member 40 is pulled upward, and accordingly, the bar 40B is also pulled upward. This state is detected by the chip presence / absence detection sensor 44, and chip mounting is determined in the apparatus main body. In addition,
The spring 38 contracts due to the load at the time of mounting the chip, whereby the second member 36 is slightly pushed upward. Then, the bar 36C also moves upward in conjunction therewith, and this is detected by the second sensor 54. Thus, the apparatus main body determines that the tip has been mounted with an appropriate load.

On the other hand, when the positioning error between the nozzle portion 14 and the chip 12 is large and the tip 36A of the nozzle portion 14 completely collides with the upper surface of the chip 12, the lowering of the nozzle portion 14 is completely prevented. Therefore, the second member 3
The load is transmitted to the spring 38 via 6 and the spring 38 is greatly contracted. Then, the bar 36C is also largely lifted upward, and the first sensor 52 detects it. When the signal from the first sensor 52 is output, the apparatus body issues an alarm indicating that jamming has occurred. Incidentally, in this embodiment, since the spring 38 is provided, even when a collision occurs, the collision is absorbed and the adverse effect on the entire pipetting portion 32 is reduced.

Here, supplementing the description of each spring, for example, assuming that the tip mounting force is about 2 kgF, for example, the strength of the spring 42 is set to about 50 gF,
The spring 38 is set to, for example, 2 kgF or more. And
The restoration spring 18 is set to, for example, about 5 kgF.

After the tip 12 is mounted on the nozzle section 14, the pipetting section 32 is pulled up. At this time, the nozzle portion 14 is always maintained in the vertical direction by the restoring spring 18, and as a result, the tip 12
Are also maintained vertically. Then, the pipetting unit 32 is moved, the motor 66 is driven, and the tip 12 is moved.
The sample is sucked. Then, the sample is dispensed to a plurality of test tubes to be dispensed. The air pressure at the time of suction and discharge of the sample is monitored by the pressure sensor 86.

After the dispensing of one sample is completed, the tip 12 is replaced. At this time, the motor 66 is driven and the feed screw 64 is moved downward. Then, the arm 82 is also lowered, and the upper end of the protruding rod 46 is pushed down to the two waiting rods. Then, the lower end of the protruding rod 46 pushes down the brim-shaped protrusion receiver 40C, and the chip contact portion 40D pushes down the upper part of the chip 12 to detach the chip.

Therefore, according to the detaching mechanism 100, the chip 12 can be detached at an arbitrary position. For example, by detaching the chip from various positions above the chip disposal box, It is possible to solve the problem that a chip pile is formed as in the conventional case. Of course, according to the detachment mechanism 100 of the present embodiment, it is possible to provide a plurality of chip disposal boxes according to the type of the sample, and to discard the chips by selecting the disposal box according to the sample. Become.

Since the dispensing pump and the motor 66 as its driving source are arranged in the pipetting section 32 itself of the present embodiment, the piping route to the tip 12 can be made as short as possible.
As a result, responsiveness and dispensing accuracy can be improved. further,
According to the present embodiment, there is no need to separately provide a drive source for the detachment mechanism 100, and the motor 66 can be used as well, so that the pipetting unit 32 can be reduced in size and weight.

Each of the mechanisms shown in FIG. 3 is housed in the frame of the pipetting section 32. In FIG. 3, for example, members for restricting the rotation of the arm 32 are not shown.

FIG. 4 shows a seal 110 having the same function as the O-ring 60 described above. That is,
The seal 110 is provided at a lower portion of the cylinder 58, and slidably and air-tightly holds a tube that communicates the opening of the nozzle portion with the inside of the cylinder 58. Here, the seal 110 is made of, for example, a rubber material, and allows the tube 30 to slide and keeps the inside of the cylinder 58 airtight.

[0059]

As described above, according to the present invention,
It is possible to increase the allowable range of the positional deviation generated between the nozzle portion and the chip. Then, even if there is such a displacement, the chip can be reliably mounted on the nozzle portion. Also, while providing a nozzle tip release mechanism,
Swing of the nozzle portion can be allowed when the nozzle tip is mounted.

Further, according to the present invention, it is possible to detect a drop of a chip or the like. Further, by mounting the syringe and the motor on the pipetting section, it is possible to reduce the size and weight of the pipetting section.

Further, according to the present invention, the chip can be freely detached at an arbitrary position by the detachment mechanism. Therefore, according to the present invention, the dispensing accuracy can be improved, and the reliability of the device can be improved.

[Brief description of the drawings]

FIG. 1 is a principle explanatory view showing the principle of a centering mechanism according to the present invention.

FIG. 2 is an external view showing the entire dispensing apparatus.

FIG. 3 is a main part configuration diagram showing a specific configuration of a pipetting unit.

FIG. 4 is a cross-sectional view of the seal 110.

[Explanation of symbols]

10 alignment mechanism, 12 disposable tip, 14
Nozzle part, 16 swing mechanism, 18 restoration spring.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-188538 (JP, A) JP-A-6-3364 (JP, A) JP-A-5-281241 (JP, A) JP-A-2- 243962 (JP, A) Japanese Utility Model Hei 5-31599 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) G01N 35/10

Claims (3)

(57) [Claims] 1. A dispensing apparatus which performs dispensing by movable pipetting unit, the pipetting unit includes a nozzle portion which the disposable tip is attached to the lower end, the lower end of the nozzle portion is pivotable While the nozzle portion
A swing mechanism that holds the upper end of the nozzle, a restoring mechanism that applies a restoring force in a vertical direction to the nozzle portion, and a swing mechanism that is provided above the swing mechanism and communicates with the nozzle portion.
A syringe, a motor for driving a piston in the syringe, and a lowering amount of the piston when the motor rotates in one direction.
After the motor exceeds a predetermined value, the motor rotates in one direction.
A protruding rod to which the force is transmitted and descends, and a member slidably provided at the lower end of the nozzle portion
The lower end of the push rod is pressed by the downward movement of the push rod.
Horizontally protruding catch that comes in contact with the
The catch is pushed down by the push rod
The nozzle tip attached to the tip of the nozzle
Push the upper surface of the nozzle downward to release the nozzle tip.
A dispensing device , comprising: a slide member having a tip abutting portion to be made. 2. The apparatus according to claim 1, wherein the nozzle portion includes an upper first member and a first member on the upper portion.
A second member at a lower portion to be guided, and the first member
A first spring for urging the second member downward, wherein the pipetting portion follows the upward movement of the second member.
A proper mounting force sensor for detecting a proper mounting force
Excessive mounting exceeding the proper mounting force in accordance with the two members
A dispensing device comprising: a jamming sensor for detecting an applied force . 3. The apparatus according to claim 2 , wherein the pipetting portion urges the slide member downward with respect to the second member.
A second spring, and the nozzle tip is mounted on the tip of the second member.
The slide member is pulled up by the nozzle tip
A tip presence / absence detection sensor for detecting that the second spring is used , wherein the second spring is a spring that is weaker than the first spring .