JP3637677B2 - Dispensing device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a dispensing apparatus that dispenses a liquid sample using a disposable tip (disposable tip, hereinafter abbreviated as a tip).
[0002]
[Prior art]
For liquid samples used for biochemical analysis and immunochemical analysis, such as biological samples such as serum, blood, urine, etc., specify a million times or more between samples derived from healthy individuals and samples derived from diseased individuals Substance concentrations may vary. When measuring such substances, if a dispensing device that is in direct contact with the sample is contaminated with a sample containing a high concentration of a specific substance, other, particularly low-concentration samples that are dispensed later will be contaminated and accurate. Since it becomes impossible to measure, it is common to use a chip.
[0003]
That is, in the dispensing device, the portion that comes into contact with the liquid sample is made disposable, so that the carry-over of the high-concentration sample as described above is prevented and the propagation of contamination is prevented.
[0004]
The tip is usually used by being pressed against the lower end of a hollow nozzle shaft connected to a pump. The nozzle shaft can be moved in the horizontal and vertical directions by the XZ direction drive mechanism or by the XYZ direction drive mechanism. For example, after the tip is positioned on the nozzle axis line by the horizontal movement, the nozzle shaft can be moved by the vertical movement. Lower toward the tip and insert the tip.
[0005]
Here, even if the nozzle shaft is lowered to mount the chip, the chip position is shifted, and if the chip is not positioned on the axis of the nozzle, the chip mounting part can be mounted without being inserted into the chip. Otherwise, the tip may be detached during dispensing operation due to incomplete mounting. Even when the tip is not detached, when the tip is inclined and attached, a gap is opened between the nozzle shaft and the tip, and air may leak from the gap, resulting in poor dispensing accuracy.
[0006]
Usually, a nozzle shaft having a chip mounting portion processed into a tapered shape is correctly positioned with respect to a standardized chip and lowered to prevent chip detachment and air leakage due to mounting failure. Further, as disclosed in Japanese Patent Application No. 5-275305 by the present applicant, the nozzle shaft is lowered while being rotated, and the nozzle shaft is twisted into the chip opening at the time of chip mounting to improve the mountability. Techniques for preventing detachment of air and air leakage have also been proposed. Furthermore, there is also known a technique for improving the mountability by attaching an elastic body O-ring to the tip of the nozzle shaft and preventing chip detachment and air leakage.
[0007]
[Problems to be solved by the invention]
In order to improve tip mounting on the nozzle shaft and prevent tip detachment and air leakage, it is necessary to improve the relative positioning mechanism of the nozzle shaft and tip. It is also necessary to improve the drive mechanism for attaching the chip to the chip. That is, in order to improve the chip mounting property, it is necessary to insert the nozzle shaft into the chip with a large force, or insert it into the chip while rotating it.
[0008]
However, in order to insert the nozzle shaft into the chip with a large force, a motor that generates a large force, an XY drive mechanism that can withstand it, and the like are required. If this is realized, on the other hand, the manufacturing cost of the device may increase, and a new problem that the device becomes larger may occur. Also, mounting the nozzle shaft on the tip while rotating the nozzle shaft requires less force than simply inserting the nozzle shaft into the tip, but the mechanism for lowering the nozzle shaft is complicated, and there is a cost issue. Arise.
[0009]
If a large force is applied to the nozzle shaft, the reaction force will be applied to the mechanism such as the nozzle shaft holding part, resulting in distortion. If the rigidity of the nozzle shaft is not increased, the nozzle shaft will be distorted, resulting in poor chip mounting. Will lead to
[0010]
The chip is usually arranged with the opening mating with the nozzle axis facing upward, but it is difficult to match the axis of the nozzle with the axis of the nozzle. As a result, even if the nozzle shaft is simply inserted into the chip with a large force, it is difficult to improve the mounting property if the chip is oriented in a direction different from the nozzle axis.
[0011]
After dispensing one type of liquid sample, the tip is removed and replaced with another tip before dispensing another liquid sample, but when the tip is attached with great force, the force corresponding to this force The tip cannot be removed without adding. For this reason, when the drive mechanism is improved as described above, it is necessary to further improve the mechanism for removing the chip.
[0012]
[Means for Solving the Problems]
The present invention has been made in view of such a problem, and improves the mountability of the tip to the nozzle shaft without significant improvement in the relative positioning mechanism and nozzle drive mechanism of the nozzle shaft and the tip. .
[0013]
Such a dispensing apparatus of the present invention is communicated with a nozzle shaft having a hollow tip mounting portion for mounting a tip at one end so that gas can be discharged into the hollow portion and sucked from the hollow portion. Pump means, a nozzle shaft holding base for holding the nozzle shaft, a base for holding the nozzle shaft holding base so as to be movable in the vertical direction, a driving means for moving the nozzle shaft holding base in the vertical direction, and a nozzle shaft In a dispensing apparatus having a nozzle shaft holder and / or a means for moving the tip in a horizontal direction to position the tip to be held on the nozzle shaft on the axis of the tip, when the tip mounting portion comes into contact with the tip The dispensing is characterized in that the nozzle shaft is held by the nozzle shaft holding table so as to be horizontally movable with respect to the nozzle shaft holding table and / or swinging about an arbitrary point on the nozzle axis. apparatus A. The present invention is described in detail below.
[0014]
The present invention is a dispensing device using a disposable tip. The chip is, for example, a resin material such as polypropylene, polystyrene, polyethylene, or ABS, and is usually injection-molded in a cone shape (conical shape with a thin tip). A tip holding part of the nozzle shaft is inserted into the thicker opening, and the liquid sample is sucked and discharged from the other narrow opening.
[0015]
The tip is one-dimensional or two-dimensional so that the opening into which the nozzle mounting portion is inserted faces upward in a tip holding means called a rack, and more specifically, the tip axis and the nozzle axis are aligned. And is transferred on the axis of the nozzle shaft. This transfer can be realized by transferring the rack and / or transferring the nozzle shaft using a means comprising a driving device for transferring a nozzle shaft holding portion described later in the horizontal direction. As the means for this transfer, a driving device equipped with a motor such as a pulse motor or a DC servo motor that is usually used can be used. FIG. 1a shows a state in which nozzles are one-dimensionally arranged in a rack, and FIG. 2a shows a state in which nozzles are two-dimensionally arranged. These are examples, for example, arranged on a disk as a two-dimensional arrangement. You can also. The rack may be made of plastic, metal or the like, but a commercially available one can also be used.
[0016]
The nozzle shaft has a hollow tip mounting portion for mounting a tip at one end. The shape of this end is preferably the shape inside the opening of the chip to be mounted, but it is only necessary to maintain airtightness when the chip is mounted, and the shape is exactly the same as the shape inside the chip. There is no need. Further, the chip mounting portion does not need to have the same shape as a whole, and may have a tapered shape with a tapered tip so that it can be easily inserted into the chip, and a shape in which the root portion maintains airtightness with the chip.
[0017]
The chip holding part can be configured integrally with the other part of the nozzle shaft using a metal material, ABS resin, or the like. However, for example, it may be configured by a member different from other parts, and only the part may be exchangeable when worn due to friction generated during insertion into the chip. In this case, as a matter of course, a material different from other parts can be used. Further, for example, it may be configured integrally with the nozzle shaft, and a wear-resistant coating may be applied only to the tip mounting portion.
[0018]
Of the nozzle shaft, at least the tip holding part has a hollow structure. That is, the nozzle shaft may have a tip mounting portion having a hollow portion at one end of a simple rod-shaped member. Of course, the entire nozzle shaft may have a hollow portion. This hollow portion communicates with pump means described later. The nozzle shaft is not particularly limited in shape or the like except for the above-described tip mounting portion, but it is preferable in terms of handling and manufacturing cost to have a polygonal column shape such as a cylinder or a hexagonal column.
[0019]
The pump means communicated so as to discharge gas into the hollow part and suck gas from the hollow part is a means for sucking and discharging the liquid sample. Specifically, a normal pump such as a syringe pump or a plunger pump can be used. However, when an accurate amount of liquid sample is aspirated and discharged, a pulse motor-driven syringe pump or plan that is easy to control is used. It is particularly preferred to use a jar pump. The pump means may be directly connected to the hollow portion, but may be communicated with an appropriate pipe in order to simplify the configuration around the nozzle axis.
[0020]
The nozzle shaft holding table that holds the nozzle shaft holds the nozzle shaft so that the nozzle shaft can be moved horizontally and / or swung around an arbitrary point on the nozzle axis. By holding the nozzle shaft on the nozzle shaft holder in this way, the tip mounting portion can be moved horizontally and on a spherical surface while restricting movement in the vertical direction. In the present invention, the movement of the nozzle shaft in the vertical direction with respect to the nozzle shaft holding table is limited because the movement in the vertical direction releases the insertion force of the chip mounting portion to the chip due to the lowering of the nozzle shaft. This is to prevent the deterioration. However, it is also possible to allow vertical movement as long as a sufficient insertion force can be secured for chip mounting.
[0021]
The swiveling movement of the nozzle shaft is preferably a movement in which the axis of the nozzle shaft can be tilted around plus or minus 5 degrees with respect to the vertical direction. The swing movement is preferably a movement centered around the lower end of the nozzle shaft so that the axis of the nozzle shaft can be tilted in accordance with the axis of the tip. The center of the swing movement is located near the position where the elastic body, which will be described later, is attached to the nozzle shaft. However, the swing movement around the vicinity of the lower end of the nozzle shaft is centered on the position where the elastic body is attached to the nozzle shaft. It is obtained by the combined movement of the head movement and the horizontal movement of the nozzle shaft.
[0022]
The horizontal movement range of the nozzle shaft is preferably around plus or minus 10 mm. However, this value may be changed as appropriate in consideration of the range of the nozzle shaft swinging movement and the naturally occurring deflection of the nozzle shaft. If the nozzle shaft is made of a flexible material that can be bent easily, the mechanism for swinging the nozzle shaft can be omitted, but if it is a hard material, it can be equipped with a swing mechanism. Particularly preferred.
[0023]
In order to hold the nozzle shaft on the nozzle shaft holding base in this way, it is possible to exemplify using an elastic body having anisotropic rigidity. Here, the anisotropic rigidity means that it has elasticity in the horizontal direction in particular, but has rigidity in the vertical direction (centering around the nozzle shaft mounting position). A small elasticity is sufficient for swinging movement). The elastic body may be directly fixed to the nozzle shaft, but may be fixed to the member after the nozzle shaft is attached to another member.
[0024]
As an elastic body having anisotropic rigidity, for example, a leaf spring whose surface is oriented in the horizontal direction, a wire spring oriented in the vertical direction, rubber, sponge or soft plastics with metal, hard plastics, vegetable fiber, etc. The composite material which embedded the produced thin plate, a fiber, a thread | yarn, or a wire can be illustrated. For example, some rubbers have rigidity in the vertical direction and elasticity in the horizontal direction, which are used for earthquake-proof structures such as buildings. Even if it is a uniform elastic body, it can be used as the elastic body of the present invention that exhibits rigidity against a force in the vertical direction by sandwiching one or more fibers or thin plates having rigidity therebetween horizontally. In such an elastic body, if an extension force is applied in the vertical direction, it causes a joint to peel off. In other words, when the nozzle shaft is pushed into the tip and attached, and when the tip is removed, opposite forces act on each other, so pre-pressurize with multiple elastic bodies in advance and when the opposite force acts It can be exemplified that the tensile force does not work.
[0025]
The nozzle shaft holder is held by the base so as to be movable in the vertical direction. As described above, the nozzle shaft may be held on the base so as to be movable in the horizontal direction. In this case, it is possible to use a means for transferring the chip onto the axis of the nozzle shaft by moving in the horizontal direction. As the driving means for moving the nozzle shaft in the vertical direction, for example, a normal moving means such as a linear motion mechanism using an air cylinder or the like in addition to a motor such as a pulse motor, a DC servo motor or a normal DC motor may be used. it can.
[0026]
The means for transferring the tip onto the axis of the nozzle shaft can change the relative position of the tip and the nozzle shaft so that when the nozzle shaft is lowered, the tip mounting part can generally reach the tip opening. If it is good. Therefore, the nozzle shaft may be configured to move in the horizontal direction, or the chip disposed in the rack may be moved in the horizontal direction.
[0027]
In addition to the configuration described above, the present invention also provides a dispensing device in which, for example, a nozzle shaft is attached to an arm that is rotatably attached to a nozzle shaft holding base in the horizontal direction. In this case, it is easy to control the apparatus and the like by positioning the arm at a predetermined neutral position except when the chip is mounted.
[0028]
【The invention's effect】
In the present invention, the horizontal movement of the nozzle axis is effective when the axis of the nozzle axis and the axis of the tip are parallel but shifted. Therefore, even if the positioning of the nozzle shaft and the tip is not perfect, the tip mountability can be improved.
[0029]
On the other hand, the swivel movement of the nozzle shaft, particularly the swivel movement around the vicinity of the lower end of the nozzle shaft by combining with the horizontal movement, causes the nozzle shaft and the tip axis to be inconsistent, that is, the tip is tilted to the rack. This is particularly effective for the case where they are arranged. In addition, when inserting the nozzle shaft into the chip, it is also effective for absorbing distortion generated in the mechanism that holds the nozzle shaft.
[0030]
As described above, according to the present invention, even if the position and the orientation of the tip and the nozzle shaft are shifted, as long as the tip of the nozzle shaft, that is, the tip mounting portion enters the opening of the tip, the nozzle shaft is aligned with the tip. It is possible to improve the wearability by moving. As a result, according to the present invention, it is possible to improve the mounting rate without inserting the nozzle shaft into the chip with a large force, so that the nozzle shaft driving mechanism such as the XZ mechanism or the XYZ mechanism has excessive strength. There is no need to let Further, since the variation in the strength of chip mounting is reduced, the force required for removing the chip is almost the same, and the chip removing mechanism can be simplified.
[0031]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail based on examples described in the drawings, but the present invention is not limited to these examples.
[0032]
FIG. 2 shows a dispensing apparatus of the present invention using a leaf spring whose surface is oriented in the horizontal direction as an elastic body having anisotropic rigidity. In the figure, 21 is a nozzle shaft, 22 is a nozzle shaft holder, and 23 is a leaf spring which is an elastic body. In order to allow the nozzle shaft to move in the horizontal direction, the leaf spring is not flat as shown in this figure, but it is bent at least at one place, or two or more leaf springs are attached at an angle. Use it in such a way that it can be bent. The thickness, length, and shape of the leaf spring can be selected as appropriate. In this example, a phosphor bronze plate having a thickness of 0.5 mm was bent twice into a 180 ° arc. In this example, the nozzle shaft is not directly coupled to the leaf spring, but is attached via the nozzle shaft holder 24.
[0033]
In the dispensing apparatus of this example, the nozzle shaft can be moved in the horizontal direction when the leaf spring is deflected in the horizontal direction, and further, can be swung around the holder. On the other hand, in the vertical direction, the leaf spring does not exhibit elasticity but exhibits rigidity.
[0034]
FIG. 3 shows a dispensing apparatus of the present invention using a wire spring oriented in the vertical direction as an elastic body having anisotropic rigidity. In the figure, reference numerals 31, 32, and 34 are the same as those in FIG. 1, and 33 is a wire spring that is an elastic body. In this example as well, the nozzle shaft can be moved in the horizontal direction by bending the wire spring in the horizontal direction, and further, the head can swing around the holder. On the other hand, in the vertical direction, the wire spring does not exhibit elasticity but exhibits rigidity.
[0035]
FIG. 4 shows the dispensing apparatus of the present invention in which the nozzle shaft is attached to an arm that is attached to the nozzle shaft holder so as to be rotatable in the horizontal direction. In this figure, the nozzle shaft 41 is attached to an arm 46 attached to the nozzle shaft holder 42 so as to be rotatable in the horizontal direction so as to be rotatable in the horizontal direction around the attachment point to the arm. The nozzle shaft is directly attached to the nozzle shaft holder 44. In the apparatus of this figure, the arm 46 is connected to the nozzle shaft holding base 42 at one point by a rotating shaft 47 and can be rotated in the horizontal direction. The nozzle shaft holder 44 is also connected to the arm 46 at one point by a rotation shaft 48 and can be rotated in the horizontal direction around the rotation shaft 48. A ball bearing 49 is embedded at a connection point between the rotation shafts 47 and 48 for the purpose of smooth rotation of the arm 46 and the nozzle shaft holder 44 in the horizontal direction. Further, the arm 46 and the nozzle shaft holder 44 are applied with a force in the vertical direction by the ball plunger ball 45 fitting in the hole formed in the nozzle shaft holder so that the nozzle shaft holder 44 does not rotate carelessly. When not, it is configured to be located at a predetermined reference position.
[0036]
FIG. 5 shows a dispensing apparatus of the present invention using an elastic body with a thin metal plate sandwiched between rubbers. FIG. 5a shows its appearance and FIG. 5b shows its cross section. A plurality of thin metal plates 511 are sandwiched between the rubbers 510, and this makes the nozzles 51 particularly rigid with respect to a vertical force generated when the nozzle shaft 51 is inserted into the chip. The shaft is movable in the horizontal direction. Reference numeral 52 denotes a nozzle shaft holder, 54 denotes a nozzle shaft holder, and 512 denotes a hollow portion of the tip mounting portion of the nozzle shaft. In this example, the hollow portion extends to the other end 513 of the nozzle shaft, and the like. The end communicates with a pump (not shown) through a pipe 514.
[0037]
FIG. 6 shows another example of the dispensing apparatus of the present invention using an elastic body with a thin metal plate sandwiched between rubbers. The nozzle shaft holder 62 is clamped by an elastic body from above and below so as to show resistance to upward force and downward force acting on the nozzle shaft (force acting when removing the tip). Therefore, even if an excessive force is applied when removing the chip, the bonded rubber is not peeled off.
[0038]
FIG. 7 shows a dispensing apparatus of the present invention using rubber as an elastic body. In order to increase the resistance to the vertical force of the rubber itself in this example, a plurality of wires 715 are embedded in the vertical direction. A member having rigidity in the vertical direction may be used instead of the wire.
[0039]
FIG. 8 is a diagram showing another configuration of the present invention. 8a shows the appearance, FIG. 8b shows a cross section, and FIG. 8c shows the top surface. In the example shown in the figure, the nozzle shaft 81 is held by sandwiching the nozzle shaft holding base 82 between the flange 820 and the flat plate 817. The first spring 816 is engaged between a flange 820 of the tip mounting portion of the nozzle shaft and a flat plate 817 attached to the nozzle shaft so as to be movable in the vertical direction, thereby applying an upward force to the nozzle shaft. Is kept at a certain position.
[0040]
As shown in FIG. 8b, there is a gap between the nozzle shaft 81 and the nozzle shaft holder 82, and the nozzle shaft can move in the horizontal direction. In the dispensing apparatus having such a configuration, when the nozzle shaft moves in the horizontal direction, a frictional force is generated between the nozzle shaft holding base and the flat plate, so that they are processed flat so that they can easily slide with each other. It is preferable to use a member, and at least one is lined with Teflon or polyacetal, or a Teflon or polyacetal thin plate is sandwiched between them. In the figure, the portion indicated by 818 is a Teflon plate. Similarly, a Teflon plate 818 is preferably inserted into the lower portion of the nozzle shaft holding base 82 and the flange portion 820 of the nozzle shaft for the same reason. The flange portion of the nozzle shaft is a latch for the nozzle shaft holder, and receives the upward force applied by the first spring to the nozzle shaft and the upward force when the tip is mounted. In the example of this figure, in order to facilitate the swing movement of the nozzle shaft around the lower end of the nozzle shaft, the contact surface between the flange 820 and the nozzle shaft holding table 82 and the contact between the flat plate 817 and the nozzle shaft holding table 82 are used. The surface is a spherical surface centered on the lower end of the nozzle shaft.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an example of a rack that holds chips.
FIG. 2 shows the dispensing device of the present invention using a leaf spring whose surface is oriented in the horizontal direction as an elastic body having anisotropic rigidity.
FIG. 3 shows a dispensing device of the present invention using a wire spring oriented in the vertical direction as an elastic body having anisotropic rigidity.
FIG. 4 shows a dispensing apparatus according to the present invention in which a nozzle shaft is attached to an arm that is attached to a nozzle shaft holder so as to be rotatable in the horizontal direction.
FIG. 5 shows a dispensing device of the present invention using an elastic body with a thin metal plate sandwiched between rubbers.
FIG. 6 shows a dispensing apparatus of the present invention using an elastic body in which a thin metal plate is sandwiched between rubbers.
FIG. 7 shows a dispensing apparatus of the present invention using rubber as an elastic body.
FIG. 8 is a view showing a dispensing device of the present invention in which a spring and a sliding surface are combined.
[Explanation of symbols]
21, 31, 41, 51, 61, 71, 81 Nozzle shaft 22, 32, 42, 52, 62, 72, 82 Nozzle shaft holder 23, 33 Elastic bodies 24, 34, 44, 54 Nozzle shaft holder 45 Ball Plunger ball 46 Arm 47, 48 Rotating shaft 49 Ball bearing 510, 610 Elastic body 511, 611 Metal plate 512 Nozzle shaft hollow portion 513 One end of nozzle shaft 514 Pipe 715 Wire 816 Spring 817 Flat plate 818 Teflon plate 819 Spring 820 Flange

Claims (5)

  A nozzle shaft having a hollow tip mounting portion for mounting a disposable tip at one end, pump means communicated so as to discharge gas into the hollow portion and suck gas from the hollow portion, and a nozzle shaft A nozzle shaft holding table for holding, a base for holding the nozzle shaft holding table so as to be movable in the vertical direction, driving means for moving the nozzle shaft holding table in the vertical direction, and the nozzle axis on the axis of the nozzle axis In a dispensing apparatus having a nozzle shaft holding base and / or means for transferring the disposable tip in a horizontal direction to position the disposable tip to be held, when the tip mounting portion comes into contact with the disposable tip, the nozzle shaft is a nozzle Anisotropic so that it can move horizontally with respect to the axis holder and / or swing around an arbitrary point on the nozzle axis. An elastic body having a rigid (but showing the elasticity with respect to the horizontal direction, the elastic member having a rigidity against vertical direction) dispensing apparatus characterized by being held by the nozzle shaft holder via.   2. The dispensing apparatus according to claim 1, wherein the elastic body having anisotropic rigidity is a leaf spring whose surface is oriented in the horizontal direction.   2. The dispensing apparatus according to claim 1, wherein the elastic body having anisotropic rigidity is a wire spring oriented in the vertical direction.   2. The apparatus according to claim 1, wherein the elastic body having anisotropic rigidity is a rubber member.     A nozzle shaft having a hollow tip mounting portion for mounting a disposable tip at one end, pump means communicated so as to discharge gas into the hollow portion and suck gas from the hollow portion, and a nozzle shaft A nozzle shaft holding table for holding, a base for holding the nozzle shaft holding table so as to be movable in the vertical direction, driving means for moving the nozzle shaft holding table in the vertical direction, and the nozzle axis on the axis of the nozzle axis In a dispensing apparatus having a nozzle shaft holding base and / or means for transferring the disposable tip in a horizontal direction to position the disposable tip to be held, when the tip mounting portion comes into contact with the disposable tip, the nozzle shaft is a nozzle Nozzle shaft so that it can move horizontally with respect to the shaft holder and / or swivel around an arbitrary point on the nozzle axis. Dispensing device, characterized in that fixedly or swing movably attached to an arm which is rotatably mounted horizontally lifting stand.

Images