JPS58216744A - Pipette for sucking and discharging liquid - Google Patents

Abstract

PURPOSE:To suck and discharge liquid automatically by providing a piston in a cylinder, providing acore fixedly to the piston, and driving the piston with the core. CONSTITUTION:A cylinderical frame 4 for mounting a coil is provided in one body to the other end part 12 of a cylinder 1, and a piston 3 to be moved airtightly in the cylinder 1 is provided. A core 5 serving also as a stopper is fixed and provided to the root end in a projection part 33 of the piston 3 projecting into the frame 4 so as to be coaxial with the piston 3. A cylindrical coil 6 is provided in the rear part in the frame 4 where the rear end 32 of the piston 3 extends and a suppressing member 7 which supporeses the piston 3 in the direction where the core 5 spaces from the coil 6 between the coil 6 and the core 5.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid suction and discharge pipette used for dispensing liquid from a liquid sample.

In general, there is often a need for chemical analysis of liquid samples, including body fluids from the human body.

Dry methods and wet methods are known as chemical analysis methods for liquid samples. Of these, the dry method is simpler than the wet method in that it does not require the preparation process of a diluent. It is. In Jin's dry method, a liquid sample to be analyzed is dripped into a liquid sample analysis element, which consists of a thin layer impregnated with a specific reagent sandwiched between a mount, and the reagent in the liquid sample analysis element is mixed with the liquid sample. The progress of the reaction and the results, for example, the color change due to the reaction, are investigated using an optical analysis device, and the presence or absence of a specific component in the liquid sample or its content t4! This is a way to know.

In such analyses, the liquid is dispensed from the liquid sample.
A pipette for sucking and discharging liquid is used for this purpose, and this pipette has a structure similar to a syringe, and consists of a cylinder with a liquid suction and discharge part at the end, and a piston installed inside the cylinder. and a driving means for moving the piston, and by moving the piston, liquid is sucked in and discharged.

Conventionally, known driving means for moving the piston include manual means, means using a suction pump, and mechanical means using a pinio and rack.

However, manual means have poor work efficiency, and means such as a suction pump tend to cause variations in the suction amount, especially when the amount of liquid sample to be dispensed is required to be an appropriate predetermined amount. Dispensing accuracy becomes low. Furthermore, mechanical reefs such as binio/and racks have the disadvantage of being made of multiple fibers and being large in size.

The present invention has been developed based on the above-mentioned circumstances, and is capable of automatically suctioning and discharging liquid, has a simple and compact structure, and can control the amount of suction and discharge with high precision. It is an object of the present invention to provide a pipette for inhaling and discharging liquid that can be used to inhale and discharge a constant amount of liquid.

The present invention is characterized by a cylinder having a liquid suction and discharge portion at its end, a piston provided within the cylinder, a core fixed to the piston, and a Drive the piston. and a coil fixed to the cylinder.

Other features of the present invention include a cylinder having a liquid suction and discharge portion at its end, a piston provided within this cylinder, and a shaft provided fixedly to this piston through a cono core. to drive the piston. and a plurality of coils fixed to the cylinder along the length direction of the cylinder.

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

FIG. 1 shows an embodiment of the invention, in which:
- For example, a cylindrical coil mounting frame 4 is integrally provided at the other end 12 of the cylinder 1, which has a liquid suction and discharge part 2 in the force ya part 11, and its tip 81 serves as the liquid suction and discharge part of the cylinder l. Located within part z.

A rod-shaped piston 8, for example, whose rear end 82 extends from the cylinder 1 and extends into the coil mounting frame 4 and moves airtight within the cylinder 1, is provided, and a protruding portion 88 of the piston 8 that projects into the coil mounting frame 4 is provided. A core, for example, a disk-shaped iron core 5, which also serves as a stopper, is fixed coaxially to the piston 8 at the base end of the coil mounting frame 4. For example, a cylindrical coil 6 is fixed to the coil mounting frame 4 so that the protrusion 88 of the piston B can be inserted thereinto. A restraining member that restrains the coil 6 in a direction away from it, such as a return spring 7
A drive power source (not shown) is connected to the coil 6.

A pipette tip 8 is removably fitted into the liquid suction and discharge portion 2 in an airtight manner.

According to such a configuration, a liquid sample is dispensed as follows. That is, when the coil 6 is demagnetized, the elastic force of the return spring 70 keeps the iron core 5 in contact with the front wall of the coil mounting frame 4, and in this state, the tip of the pipette tip 8 touches the liquid sample. be put inside. Next, when the coil 6 is excited, the magnetic force generated in the coil 6 causes the iron core 5 to be attracted to the coil 6 against the elastic force of the return spring 70). Simultaneously with the movement, the piston 8 is moved, thereby creating a negative pressure within the liquid suction/discharge section 2 and sucking the liquid sample into the pipette tip 8 . Next, while maintaining this state, for example, an analytical element is placed directly below the pipette tip 8 by an appropriate means and the coil 6 is demagnetized, the attraction force by the coil 6 disappears and the iron core 5 Only the elastic force of the return spring 7 acts, and the iron core 5 is moved until it comes into contact with the front wall of the coil mounting frame 4, that is, to its original position. Simultaneously with the movement of the wick 5, the piston 8 is moved, whereby the liquid sample that has been sucked into the liquid suction and discharge section 2 is discharged to the outside and drip-supplied to the analysis element.

According to the above embodiment, by energizing and demagnetizing the coil 6, the liquid sample can be sucked and discharged automatically, and moreover, when a suction ponder is used as in the conventional case, or when a pinion and rack are used, etc. It has a simpler configuration and can be made smaller. Since the moving distance of the iron core 5 is reliably constant by setting the iron core 5,
The moving distance of the piston 8, which moves integrally with the piston 8, is always a constant value, so that the suction and discharge amounts of the liquid sample can always be constant. In addition, when sucking a liquid sample, the iron core 5 resists the elastic force of the return spring 70 and the coil 7
Since the piston 8 moves smoothly and suction is performed without difficulty, the accuracy of the suction amount is further improved from this point of view as well.

The fsz diagram shows another embodiment of the present invention, in which a cylinder l having a liquid suction and discharge part 2 at one end 11 has a cylindrical coil mounting frame, for example, at the other end 12. 4 is integrally provided, its tip 31 is located within the liquid suction and discharge portion 2 of the cylinder 1, and its rear end 32 extends from the cylinder 1 to protrude into the coil mounting frame 4, and is moved airtight within the cylinder 1. For example, a rod-shaped piston 3 is provided, and a protruding portion 330 that protrudes into the coil mounting frame 4 of this piston 3 is provided.
Cores, for example disc-shaped iron cores 51 and 52, are provided at the base end and the other end 32, respectively, and are fixed coaxially to the cough piston/3, and within the coil mounting frame 4, the iron cores 51 and 52, respectively, are provided. A first coil group 6A and a second coil group 6B consisting of a plurality of cylindrical coils are fixed to the coil mounting frame 4 so as to be inserted into the coil mounting frame 4. A control mechanism for operating the second coil group 6B is connected to the second coil group 6B.

The first coil group 6A is composed of electrically independent coils 61A, 62A, 63A, and 64A, which are arranged adjacent to each other in the length direction of the piston/3. , the second coil group 6B
are arranged adjacent to each other in order along the length direction of the piston 8. Coil 61B, coil laB, coil 68B, coil 64B and coil 6 are respectively independent.
5B. The relative positional relationship between the six members of the first coil group and the second coil group 6B and the iron core 51 and the iron core 52 is 1, for example, as shown in FIG. When doing so, the iron core 51 is shifted to the right side of the coil 61.

When the iron core 51 is moved from this state and positioned inside the coil 61A, the iron core 52 is shifted to the right side of the coil 62B, and when the iron core 52 is further moved and positioned inside the coil 61, the iron core 52 is moved to the right side of the coil 62B. When the piston 8 is moved in one direction such that the iron core 51 is shifted to the right side of the person 6z.

A state in which one iron core 51 is sequentially located in each coil of the six members of the first coil group, and a state in which the other iron core 52 is sequentially located in each coil of the second coil group 6B are alternated. Set it to appear in . Reference numeral 18 denotes a partition section that partitions the six people in the first coil group and the second coil group 6B, and also serves as a stopper for the iron cores 51 and 52.

The control mechanism 1 is as shown in FIG. 8, for example.

Drivers (amplifiers) 111-114 and 121-125 connected to each of coils 61A-64A and coils 618-65B, and a selected one of P drivers ill-114 and 121-125 depending on the combination of input signals. a decoder 20 that supplies a drive signal to the decoder 2;
a counter 21 that supplies an input signal to 0;

A clock pulse is supplied to this counter 21.

Pulse generator 22. It is composed of a fritzoflozzo circuit 28, an AND circuit 24, and a fritzoflozzo circuit 25 that supplies up/down signals to the counter 21.
is an AND circuit, and 27.28 is a switch.

According to such a configuration, a liquid sample is dispensed as follows. That is, in the control mechanism.

First, when the switch 27 is turned on, a reset signal is sent to the counter 21, and the counter 21 is moved to a predetermined position (hereinafter referred to as "reset position j"), for example, the iron core 52.
A drive signal is supplied from the decoder 20 to the driver 121 to excite the coil 61B so that the iron core 52 is moved to a position inside the coil 61B.
1B and placed in the reset position. At this time, the other iron core 51 is shifted to the right side of the coil 61A. In this state, when the tip of the pipette tip 8, which is airtightly fitted and attached to the tip of the liquid suction and discharge part 2, is put into the liquid sample, the switch 28 is turned on and the counter 21 is placed as shown in FIG. A clock pulse is supplied to

According to this number of clock pulses, the coil 61A.

Coil 62B, Coil 62A, Coil 63B, Coil 6
3A, coil 64B, coil 64A, and coil 65B are energized in this order for a certain period of time determined by the period of the clock pulse, thereby attracting the iron cores 51 and 52 to be alternately positioned in each coil. moved to the left side. To explain in detail, the coil 61A is excited at the same time as the coil 61B is demagnetized, and as a result, the magnetic force acting on the υ iron core 52 is released and the coil 61
The magnetic force generated at A attracts the iron core 51 into the coil 61A and moves the iron core 51 to the left side. Subsequently, the coil 61A is demagnetized and at the same time the coil 62B is excited.
As a result, the magnetic force acting on the iron core 51 is released, and the iron core 52 is attracted into the coil 62B by the magnetic force generated in the coil 62B, and the iron core 52 is further moved to the left side. Ru. Thereafter, each coil is similarly demagnetized and excited in the above-mentioned order and moved until the suction completion position, that is, the iron core 52 is located within the coil 65B. In this way, the iron core 51
and the iron core 52 is alternately moved to the left side,
Since the piston/3 is moved at the same time, the liquid suction and discharge part 2
A negative pressure is created within the pipette tip 8, which draws the liquid sample into the pipette tip 8. However, the coil 65B is not demagnetized immediately, but is kept in an excited state until preparations are made to discharge the sucked liquid sample.

Next, when an analytical element, for example, is placed directly under the pipette tip 8 by an appropriate means and preparation for dispensing is completed, the coil 65B, coil 64
A, coil 64B1 coil 63A1 coil 63B1 coil 62A, coil 62B, coil 61A and coil 61
Demagnetization and excitation are repeatedly performed in the order of B, whereby the iron core 51 and the iron core 52 are alternately moved in the opposite direction to that described above, that is, to the right side, and this causes the sivist/3 to move at the same time. Since the pipette tip 8 is moved to the right side, the liquid sample in the pipette tip 8 is discharged, and the liquid sample is dripped and supplied to the analysis element.

According to this embodiment, the movement of the piston/3 is controlled by the coil 61A.
Since this is done by the magnetic force generated in ~64A and coils 61B~65B, there is no need for suction bobbins, racks, binions, electric motors, etc. that are used to move the piston in conventional equipment. Then,
Therefore, the configuration is simple, and the coil and iron core 51,
52 can be designed to be small, so the overall cost is low.
It is possible to achieve compactization. Since multiple coils are installed, the magnetic force of the coils moves the piston 3 in the direction of discharging the liquid sample by excitation and demagnetization of the coils in the reverse order of excitation and demagnetization of the coils when sucking in the liquid sample. You can force it. and iron core 5
1 or the iron core 52 is reliably positioned within the energized coil.
is a constant value up to the suction completion position in the coil 65B. Therefore, it is possible to always keep the suction and discharge amount of the liquid sample determined according to the moving distance of the piston/3 constant with high accuracy. In the above-described embodiment, all of the coils 61A to 64A and 61B to 65B are energized to move the piston 3 to the maximum extent, but the suction completion position can be determined by appropriately selecting the coils to be energized. The moving distance of the piston/3 can be changed by changing the movement distance of the piston/3, thereby making it possible to change the suction and discharge amount of the liquid sample as required. Further, two coil groups, a first coil group 6A and a second coil group 6B, are provided, and an iron core 51 and an iron core 52 are provided corresponding to each of these coil groups 6A and 6B.
The distance between the iron core 51 and the iron core 52 is such that when one of the iron core 51 and the iron core 52 is located in the coil, the other is shifted to the other coil. Because it is set like this.

Since the movement of the piston 8 is gradually carried out by small distances, the movement of the piston 8 is smooth, and the suction and discharge of the liquid sample can be performed smoothly, thereby further increasing the accuracy of the amount of suction and discharge.

In the above, the number of coils may be determined as necessary.2 For example, if a large number of coils are provided and the coils to be energized and demagnetized can be appropriately selected depending on the type of dispensing process, the amount of suction and discharge This has the advantage that it can be appropriately selected over a wide range. Further, by providing a large number of coils having a small width, the movement of the piston 8 can be made even smoother.

Although the present invention has been described in detail above, the present invention is not limited to these embodiments and various modifications can be made.

For example, the coil may be provided on the outer periphery of the coil mounting frame, and in this case, the coil mounting frame may be made of a non-magnetic material with a small outer diameter. As the material of the core, any material other than iron can be used as long as it has magnetism. Further, the width of each coil may be the same or different.

There may be eight or more sets of coil groups and cores, or there may be one set.

As described above, according to the present invention, liquid can be sucked and discharged automatically, and the structure is simple and small.
Furthermore, it is possible to provide a pipette for sucking and discharging liquid that can maintain a constant amount of suction and discharge with high precision.

[Brief explanation of drawings]

FIG. 1 is an explanatory sectional view showing one embodiment of the present invention. FIG. 2 is an explanatory sectional view showing another embodiment of the present invention. Figure 8 is! FIG. 2 is an explanatory block diagram showing an example of a control mechanism in another embodiment shown in FIG. 2, and FIG. 4 is an explanatory diagram showing the operation of the control mechanism shown in FIG. 8. l...Cylinder 2...Liquid suction and discharge part 8...Piston 4...Coil mounting frame 5.
...Iron core 6...Coil 7...Return spring 8...6 pipette tips...First coil group 6B...Second coil group 61A, 62A, 8
"8A, 64A...Coil 61B, 62B, 68B
, 64B, 65B-: 51.62-...iron core for x4
18...Division section 111.112, 118, 114
, 121. IJ? a, 128, 124゜125...driver

Claims (1)

[Scope of Claims] 1) A cylinder having a liquid suction and discharge part at the end, a nine piston installed in the cylinder, a core fixed to the piston, and a three-dimensional core. A pipette for sucking and discharging liquid, comprising: a coil fixed to the cylinder, which drives the piston through the cylinder. 2) A patent characterized in that a suppressing member is provided that is fixed to the cylinder and suppresses the piston in a direction in which the core moves away from the coil, and the coil company attracts the core against the suppressing member. A liquid suction and discharge pipette according to claim 1. 3) a cylinder having a liquid suction and discharge portion at its end; nine pistons installed in the cylinder; a core fixed to the piston; and driving the piston via the core. A liquid suction/discharge pipette comprising: a plurality of coils fixed to the cylinder along the length of the cylinder.