CN116116475A - Sealing structure with variable guide length and pipetting system - Google Patents

Abstract

The utility model discloses a sealing structure with variable guide length, which is characterized by comprising a screw motor, a bottom plate, a transmission block, a screw nut, a guide rail, a plunger, a body and a tip mounting structure; the screw rod motor is connected with the transmission block through a screw rod nut, and the transmission block is arranged on the guide rail and slides along the guide rail; the transmission block is also in floating connection with the plunger; the plunger keep away from drive piece one end and be provided with afterbody guide ring, body inner wall form the piston passageway, plunger slidable mounting in the body. The dual guide is structurally provided, the position of the tail guide ring is changed along with the movement of the plunger, and the coaxiality of the plunger and the inner cavity of the body can be maintained. According to the liquid-draining method, different motion parameters can be matched with liquids with different viscosities according to the viscosity difference detected during liquid-draining, so that the optimal liquid-draining effect is achieved, the tip liquid residue is avoided, and the advantage is obvious particularly when 2 mu l to 5 mu l of micro liquid-draining is carried out.

Description

Sealing structure with variable guide length and pipetting system

Technical Field

The utility model relates to the field of automatic sample and reagent pipetting, in particular to a sealing structure with variable guiding length and a pipetting system.

Background

The automatic instrument in the in vitro diagnosis industry mostly needs to automatically transfer additive reagent and sample (hereinafter referred to as automatic pipetting), but is very sensitive to liquid residue, especially the molecular diagnosis instrument is extremely sensitive to sample residue, even a very small amount of residue can also have serious influence on detection results, and the solution commonly used under the condition is to use a pipetting pump to be matched with a disposable tip, so that the trouble of a liquid pipeline is avoided, and meanwhile, the cross contamination of the liquid residue and the sample is avoided.

At present, in the field of automatic sample and reagent pipetting, the following four schemes are used for commonly used pipetting:

1) No guide structure and only a sealing structure; for example, chinese patent publication No. CN210114717U discloses a high seal syringe having only two seal structures with inclined angles.

2) The guiding structure and the sealing structure are arranged together, but only the side far away from the liquid outlet is provided with the guiding structure; such as the expanded examples of the patent issued to CN 1288426C.

3) The guiding and sealing are separated, but only the side far away from the liquid outlet is provided with a guiding structure; for example, the utility model of CN1288426C discloses a maintenance-free injector, in which a sealing member and a pressing ring are placed in an inner hole of a head of a body, the sealing member and the pressing ring are screwed and pressed by a cover of the injector, and a plunger is inserted into a central cavity of the body through the cover of the injector, the pressing ring and the central hole of the sealing member in sequence.

4) Structural style of conventional piston type transfer pump; the structure is suitable for manually pushing the piston, and because electromechanical power is used as power, when the transmission thrust is not coincident with the axis of the cavity, the sealing ring can be forced to deform to realize movement, and the sealing failure is easy to cause.

In the above schemes 1-3, since the piston and the sealing structure or the guiding structure can move relatively only when there is a gap, the existence of the gap can cause the axis of the plunger and the axis of the cavity to allow a different inclined included angle α, the calculated relationship between the distance t of the inclined offset of the axis and the included angle α and the distance L between the tail end of the piston and the guiding portion is t=tan α×l, when the piston is close to the guiding portion and far from the liquid outlet, the value of t is small, and the influence is small; however, when the plunger tail end is close to the liquid outlet side, the value of t is amplified many times similar to the lever principle, the plunger may scratch the inner wall of the cavity, abrasion, burrs and the like may be caused for a long time, and finally the sealing life is reduced.

In addition, the current pipetting system has no difference in liquid discharge parameters for liquids with different viscosities, namely, the automatic matching motion parameters are basically carried out by directly applying deionized water as a parameter for testing, but the pipetting system is required to pipette samples and reagents with different viscosities, so that the problem that liquid residues are easy to occur at tips of tips in pipetting, particularly, the pipetting accuracy is influenced for liquids with high viscosity, and particularly, when pipetting with 2 mu l to 5 mu l of trace amounts, the liquid residues often cause pipetting repeatability and accuracy to be far higher than a nominal value.

Disclosure of Invention

In order to overcome the problems in the prior art, the utility model provides a sealing structure with variable guide length and a pipetting system, wherein double guide is arranged on the structure, the position of a tail guide ring is changed along with the movement of a plunger, so that the coaxiality of the plunger and the inner cavity of a body can be well maintained, and the influence caused by different coaxiality is avoided. Pressure data are collected by using a pressure sensor, converted into liquid viscosity, and different motion parameters are matched with liquids with different viscosities, so that pipetting accuracy is ensured.

In order to achieve the above purpose, the present utility model provides the following technical solutions: a sealing structure with variable guide length comprises a screw motor, a bottom plate, a transmission block, a screw nut, a guide rail, a plunger, a body and a tip mounting structure;

the tip mounting structure comprises a tip unloading sleeve, a tip unloading column, a tip mounting column and a tip head;

the screw rod motor is connected with the transmission block through a screw rod nut, and the transmission block is arranged on the guide rail and slides along the guide rail; the transmission block is also in floating connection with the plunger; a tail guide ring is arranged at one end of the plunger, which is far away from the transmission block, and a sealing ring is arranged at the joint of the tail guide ring and the plunger; the inner wall of the body forms a piston channel, and the plunger is slidably arranged in the body.

The utility model is further provided with: a compression spring is also arranged between the transmission block and the plunger. The purpose is to eliminate the return stroke difference of the floating transmission.

The position of the tail guide ring changes along with the movement of the plunger, so that the effective guide length of the plunger is always large, the coaxiality of the plunger and the inner cavity of the body can be well maintained, and the influence caused by different axes can be avoided.

The utility model is further provided with: the base plate on still include motor installation piece and line ball board, lead screw motor install on the motor installation piece, the track sets up by the lead screw motor.

The utility model is further provided with: the sealing structure with the variable guide length further comprises a body fixing block, wherein a through hole is formed in the body fixing block, and the body penetrates through the through hole and is fixed in the body fixing block through a guide ring; the tip uninstallation cover sets up in body fixed block bottom to wrap up the body and pass the part of body fixed block.

The utility model is further provided with: the body fixing block is provided with a stop block at one end close to the transmission block, an optical coupler PCBA and a pressure sensor are arranged on the side face of the body fixing block, and a zero position optical coupler and a tip detection optical coupler are arranged on the optical coupler PCBA; and the transmission block is provided with an optocoupler baffle.

The utility model is further provided with: the side surface of the body is provided with a through hole which is communicated with the pressure sensor through a capillary tube and is used for collecting the change data of the pressure in the body; the body is also provided with an exhaust hole for keeping the pressure intensity of the gap between the guide ring and the sealing ring consistent with the outside, thereby avoiding the influence caused by pressure difference caused by trapped air and improving the precision of pipetting.

The utility model is further provided with: a tip unloading column is arranged in the body fixing block, a spring is sleeved outside the tip unloading column, and the tip unloading column is connected with the tip unloading sleeve. The spring is used for keeping the tip unloading column upwards, and avoiding interference from influencing the position of the tip unloading sleeve. One side of the tip unloading sleeve is provided with a convex baffle, the other side of the tip unloading sleeve is provided with a contact plate, and the tip unloading column is connected with the tip unloading sleeve through the contact plate.

The utility model is further provided with: one end of the tip unloading sleeve, which is close to the liquid transferring port, is connected with a tip mounting column, and the tip head is mounted on the tip mounting column.

The utility model also provides a pipetting system which is suitable for the sealing structure with variable guide length, realizes pressure acquisition and viscosity conversion of pipetting and performs optimal motion parameter matching of pipetting, and comprises the following steps:

s1: the pressure sensor acquires an atmospheric pressure AD value N1 before imbibition;

s2: the pressure sensor collects pressure AD value N2 during imbibition;

s3: transmitting the pressure AD values N1 and N2 to control software;

s4: the control software converts the difference delta N between N1 and N2 into liquid viscosity through an algorithm;

s5: when the liquid transferring pump executes liquid discharging action, the control software automatically matches motion parameters according to the calculation result and sends different pulse frequency signals to the motor;

s6: the motor discharges liquid at different speeds after receiving the pulse signals.

The utility model is further provided with: the motion parameters are liquid discharge speeds obtained by practical test verification of liquid under different viscosities.

For liquids with different viscosities, when the same motion parameters absorb liquid, the pressure change detected by the pressure sensor is related to the liquid viscosity, and the pressure is converted from the viscosity through an algorithm, so that the viscosity difference of the liquid is accurately judged; in the liquid draining process, according to the viscosity difference detected during liquid absorption, different motion parameters are matched with liquid with different viscosities, so that the optimal liquid-transferring effect is achieved, the tip liquid residue is avoided, and the advantages are very obvious particularly in 2-5 mu l micro-liquid-transferring.

The working process of the pipetting system is divided into four parts of a loading tip, a liquid sucking, a liquid discharging and an unloading tip.

The loading tip procedure is as follows: under the drive of a motion mechanism, a tip mounting column on the pipetting system can load a tip, in the loading process, the tip is pushed upwards by the tip unloading sleeve, and a raised baffle plate on the tip unloading sleeve is used as an optical coupler baffle plate to shield a tip detection optical coupler on the optical coupler PCBA, so that control software obtains signal feedback; if the loading is not successful, for example, the position is inaccurate, or a tip head is not placed, no signal feedback is obtained; if the control software does not obtain signal feedback in the set time, the control software reports and prompts loading error information, so that the condition that the tip head is installed but not known and repeatedly installed can be avoided.

The imbibition process is as follows: the screw motor drives the transmission block, further drives the plunger to move away from the liquid outlet direction, causes the internal cavity pressure of body to diminish, further because there is pressure difference with the atmospheric pressure to inhale the tip with liquid in, can be through control software, the displacement volume of the motion of the plunger of liquid volume adjustment that absorbs as required. Meanwhile, in the process, the pressure sensor collects pressure change and converts the pressure change into the viscosity of the liquid.

The liquid discharge process is as follows: before the liquid discharge starts, the control software collects the liquid viscosity information obtained by pressure change calculation according to the liquid suction process and matches the optimal motion parameters with the screw motor. The screw motor drives the transmission block, further drives the plunger to move towards the direction close to the liquid outlet, causes the pressure intensity of the cavity in the body to become large, and further causes the pressure difference between the pressure intensity of the cavity and the atmospheric pressure, so that liquid is discharged out of the tip head, the displacement of the plunger can be adjusted according to the liquid amount required to be sucked through control software, the liquid can be sucked once and discharged, and the liquid can be sucked once and discharged for a plurality of times.

The unload tip procedure is as follows: the pipetting system of the utility model is moved by the movement mechanism to a position for unloading the tip head, which is typically above the tip head collection box. The screw rod motor drives the transmission block to further drive the plunger to move towards the direction close to the liquid outlet, the small section displacement at the tail end of the lower part is the stroke of the tip unloading head, the unloading stroke is usually set to be 1-5mm, in the unloading stroke, the transmission block can move downwards from the position close to the tip unloading column, the tip unloading column pushes the tip unloading sleeve to move downwards, the tip head is pushed out of the installation position to finish tip unloading, meanwhile, the optical coupler baffle above the tip unloading sleeve is separated from the shielding area of the tip detection optical coupler above the optical coupler PCBA, and a feedback signal is triggered to the control software. In the process, the tip unloading column presses the spring, and after the unloading is completed, the spring helps the tip unloading column to reset.

In summary, the technical scheme of the utility model has the following beneficial effects:

1. the pipetting system has double guidance on the structure, and the position of the tail guide ring changes along with the movement of the plunger, so that the effective guide length of the plunger is always large, the coaxiality of the plunger and the inner cavity of the body can be well maintained, and the influence caused by different axes can be avoided.

2. For liquids with different viscosities, when the same motion parameters absorb liquid, the pressure change detected by the pressure sensor is related to the liquid viscosity, and the pressure is converted from the viscosity through an algorithm, so that the viscosity difference of the liquid is accurately judged; in the liquid draining process, according to the viscosity difference detected during liquid absorption, different motion parameters are matched with liquid with different viscosities, so that the optimal liquid-transferring effect is achieved, the tip liquid residue is avoided, and the advantages are very obvious particularly in 2-5 mu l micro-liquid-transferring.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings that are needed for the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present utility model, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of the overall structure of the present utility model;

FIG. 2 is a partial cross-sectional view of the present utility model;

FIG. 3 is an exploded view of the present utility model;

FIG. 4 is a flow chart of the automatic matching motion parameters of the pipetting system of the utility model;

FIG. 5 is a plot of viscosity versus pulse frequency for automatic matching.

In the drawings, the list of components represented by the various numbers is as follows:

the device comprises a 1-screw motor, a 2-motor mounting block, a 3-bottom plate, a 4-transmission block, a 5-screw nut, a 6-optical coupler baffle, a 7-baffle, an 8-optical coupler PCBA, a 9-pressure sensor, a 10-tip unloading sleeve, an 11-plunger, a 12-sealing ring, a 13-tail guide ring, a 14-wire pressing plate, a 15-guide rail, a 16-compression spring, a 17-tip unloading column, a 18-guide ring, a 19-spring, a 20-body fixing block, a 21-body, a 22-tip mounting column and a 23-tip head.

Detailed Description

In order to make the technical solution of the present utility model better understood by those skilled in the art, the technical solution of the present utility model will be clearly and completely described below with reference to the accompanying drawings, and based on the embodiments in the present application, other similar embodiments obtained by those skilled in the art without making creative efforts should fall within the scope of protection of the present application. In addition, directional words such as "upper", "lower", "left" and "right" in the following embodiments are merely directions with reference to the drawings, and thus, the directional words used are intended to illustrate rather than limit the utility model.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

The utility model will be further described with reference to the drawings and preferred embodiments.

Example 1:

1-3, a sealing structure with variable guide length according to the preferred embodiment of the present utility model comprises a screw motor 1, a bottom plate 3, a transmission block 4, a screw nut 5, a guide rail 15, a plunger 11, a body 21 and a tip mounting structure;

the tip mounting structure comprises a tip unloading sleeve 10, a tip unloading column 17, a tip mounting column 22 and a tip head 23;

as shown in fig. 3, the screw motor 1 is connected with a transmission block 4 through a screw nut 5, and the transmission block 4 is arranged on the guide rail 15 and slides along the guide rail 15; the transmission block 4 is also in floating connection with the plunger 11; a tail guide ring 13 is arranged at one end of the plunger 11 far away from the transmission block 4, and a sealing ring 12 is arranged at the joint of the tail guide ring 13 and the plunger 11; the inner wall of the body 21 forms a piston channel, and the plunger 11 is slidably mounted in the body 21.

A compression spring 19 is also provided between the transmission block 4 and the plunger 11. The purpose is to eliminate the return stroke difference of the floating transmission.

The position of the tail guide ring 13 changes along with the movement of the plunger 11, so that the effective guide length of the plunger 11 is always large, the coaxiality of the plunger 11 and the inner cavity of the body 21 can be well maintained, and the influence caused by different coaxiality can be avoided.

The base plate 3 on still include motor installation piece 2 and line ball board 14, lead screw motor 1 install on motor installation piece 2, track 15 sets up by lead screw motor 1.

As shown in fig. 2, the sealing structure with variable guiding length further comprises a body fixing block 20, wherein a through hole is formed in the body fixing block 20, and a body 21 penetrates through the through hole and is fixed in the body fixing block 20 through a guiding ring 18; the tip unloading sleeve 10 is disposed at the bottom of the body fixing block 20 and wraps the portion of the body 21 passing through the body fixing block 20.

The body fixing block 20 is provided with a stop block 7 at one end close to the transmission block 4, an optocoupler PCBA8 and a pressure sensor 9 are arranged on the side face, and a zero-position optocoupler and a tip detection optocoupler are arranged on the optocoupler PCBA 8; the transmission block 4 is provided with an optocoupler baffle 6.

The side surface of the body 21 is provided with a through hole which is communicated with the pressure sensor 9 through a capillary tube and is used for collecting the change data of the pressure in the body; the body 21 is also provided with an exhaust hole for keeping the pressure of the gap between the guide ring 18 and the sealing ring consistent with the outside, thereby avoiding the influence caused by pressure difference caused by trapped air and improving the precision of pipetting.

A tip unloading column 17 is arranged in the body fixing block 20, a spring 19 is sleeved outside the tip unloading column, and the tip unloading column 17 is connected with the tip unloading sleeve 10. The spring 19 is used to hold the tip unloading post 17 upward to avoid interference from affecting the position of the tip unloading sleeve 10. One side of the tip unloading sleeve is provided with a convex baffle, the other side of the tip unloading sleeve is provided with a contact plate, and the tip unloading column is connected with the tip unloading sleeve through the contact plate.

The tip uninstallation cover 10 be close to liquid transfer port one end and connect tip erection column 22, tip 23 install on tip erection column 22.

Example 2:

as shown in fig. 4, in the embodiment, the pipetting system is suitable for the sealing structure with a variable guiding length, and the specific steps of implementing pressure collection and viscosity conversion of pipetting and performing optimal motion parameter matching of pipetting include:

s1: the pressure sensor 9 acquires an atmospheric pressure AD value N1 before imbibition;

s2: the pressure sensor 9 collects the pressure AD value N2 during liquid suction;

s3: transmitting the pressure AD values N1 and N2 to control software;

s4: the control software converts the difference delta N between N1 and N2 into liquid viscosity through an algorithm;

s5: when the liquid transferring pump executes liquid discharging action, the control software automatically matches motion parameters according to the calculation result and sends different pulse frequency signals to the screw motor 1; the relationship between viscosity and pulse frequency of automatic matching is shown in fig. 5;

s6: the screw motor 1 discharges liquid at different speeds after receiving the pulse signal.

It should be noted that, according to the reference, the liquid viscosity and the suction pressure change are in positive correlation, that is, the larger the liquid viscosity is, the larger the suction pressure is, and the specific conversion relationship is the prior art, which is not explained in detail herein. The motion parameters are liquid discharge speeds obtained by practical test verification of liquid under different viscosities.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above description is only a preferred embodiment of the present utility model, and the protection scope of the present utility model is not limited to the above examples, and all technical solutions belonging to the concept of the present utility model belong to the protection scope of the present utility model. It should be noted that modifications and adaptations to the present utility model may occur to one skilled in the art without departing from the principles of the present utility model and are intended to be within the scope of the present utility model.

Claims (10)

1. The sealing structure with the variable guide length is characterized by comprising a screw motor, a bottom plate, a transmission block, a screw nut, a guide rail, a plunger, a body and a tip mounting structure;

the tip mounting structure comprises a tip unloading sleeve, a tip unloading column, a tip mounting column and a tip head;

the screw rod motor is connected with the transmission block through a screw rod nut, and the transmission block is arranged on the guide rail and slides along the guide rail; the transmission block is in floating connection with the plunger; a tail guide ring is arranged at one end of the plunger, which is far away from the transmission block, and a sealing ring is arranged at the joint of the tail guide ring and the plunger; the inner wall of the body forms a piston channel, and the plunger is slidably arranged in the body.

2. A variable guide length seal according to claim 1, wherein a compression spring is also provided between the drive block and the plunger.

3. The variable guide length seal of claim 2, further comprising a motor mounting block and a wire pressing plate, the motor mounting block and the wire pressing plate being mounted on the base plate, the lead screw motor being mounted on the motor mounting block, the track being disposed beside the lead screw motor.

4. A variable guide length seal structure according to claim 3, further comprising a body fixing block, wherein the body fixing block is provided with a through hole, and the body is fixed in the body fixing block through the through hole by a guide ring; the tip uninstallation cover sets up in body fixed block bottom to wrap up the body and pass the part of body fixed block.

5. The sealing structure with variable guide length according to claim 4, wherein a stop block is arranged at one end of the body fixing block, which is close to the transmission block, and an optical coupler PCBA and a pressure sensor are arranged on the side surface of the body fixing block, and a zero position optical coupler and a tip detection optical coupler are arranged on the optical coupler PCBA; and the transmission block is provided with an optocoupler baffle.

6. The variable guide length seal of claim 5, wherein a through hole is formed in a side of the body, and is in communication with the pressure sensor via a capillary tube; the body is also provided with an exhaust hole.

7. The sealing structure with variable guide length according to claim 6, wherein a tip unloading column is arranged in the body fixing block, a spring is sleeved outside the tip unloading column, and the tip unloading column is connected with the tip unloading sleeve; one side of the tip unloading sleeve is provided with a convex baffle, the other side of the tip unloading sleeve is provided with a contact plate, and the tip unloading column is connected with the tip unloading sleeve through the contact plate.

8. The variable guide length seal of claim 7 wherein said tip relief boot is connected to said tip mounting post adjacent said port and said tip head is mounted to said tip mounting post.

9. A pipetting system adapted for use in a variable guide length seal as recited in any one of claims 1-8 for achieving pressure acquisition and viscosity conversion of pipetting and optimal kinetic parameter matching of pipetting, comprising the steps of:

s1: the pressure sensor acquires an atmospheric pressure AD value N1 before imbibition;

s2: the pressure sensor collects pressure AD value N2 during imbibition;

s3: transmitting the pressure AD values N1 and N2 to control software;

s4: the control software converts the difference delta N between N1 and N2 into liquid viscosity through an algorithm;

s5: when the liquid transferring pump executes liquid discharging action, the control software automatically matches motion parameters according to the calculation result and sends different pulse frequency signals to the motor;

s6: the motor discharges liquid at different speeds after receiving the pulse signals.

10. The sealing structure with variable guide length according to claim 9, wherein the motion parameter is a liquid discharge speed obtained by actual test verification of liquid under different viscosities.

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