Telescopic sample adding device

Abstract

The utility model discloses a telescopic sample adding device, which belongs to the field of sample adding instruments, and comprises a steel needle seat and a needle installation detection structure arranged on the steel needle seat, a steel needle is arranged on the steel needle seat, a steel needle sleeve is arranged on the steel needle, the needle installation detection structure comprises a detection shaft arranged on the steel needle sleeve, and the detection shaft is connected with the steel needle sleeve. A sensor matched with the detection shaft is installed on the steel needle base, in the process of installing the suction head, the suction head can jack up the steel needle sleeve upwards so as to drive the detection shaft to move towards the sensor, when the suction head is installed in place, the sensor can detect the detection shaft, and the problem that in the prior art, when the end of a steel needle is sleeved with the suction head, the detection shaft cannot be detected is solved. And whether the suction head is installed in place cannot be determined, so that a gap is possibly formed between the suction head and the steel needle, and liquid suction cannot be realized.

Description

Technical Field

[0001] The utility model relates to a sample adding instrument, in particular to a telescopic sample adding device. Background Art

[0002] In current experimental instruments, fully automatic pipettes have long become the industry standard. The sample adding device is one of the core components of the fully automatic pipette. A steel needle is provided on the sample adding device. By installing a disposable pipette tip onto the steel needle, liquid suction and liquid dispensing for sample adding can be started. In the prior art, when the pipette tip is installed onto the steel needle, it is easy to be installed in place inaccurately, resulting in a gap between the pipette tip and the steel needle, and further resulting in the inability to achieve liquid suction.

[0003] For example, the "device for detecting the liquid level, sucking liquid and dispensing liquid of a disposable sample adding needle" disclosed in the Chinese patent document, with the publication number CN206671353U, includes a needle body, an operating device and a Z-axis stepping motor. The Z-axis stepping motor drives the needle body and the operating device to move up and down in the Z-axis guide rail. The needle body includes a steel needle and a disposable pipette tip. The disposable pipette tip is sleeved on the steel needle. A pressure sensor, a cylinder and a linear motor are provided in the operating device. The operating device is controlled by a control unit. A wiring harness is indirectly connected between the operating device and the control unit. The steel needle in the needle body is connected to the pressure sensor and the cylinder in the operating device through a three-way fixing seat. The disadvantage of this patent is that when the pipette tip is sleeved onto the end of the steel needle, it is impossible to determine whether it is installed in place, which may result in a gap between the pipette tip and the steel needle and the inability to achieve liquid suction. Content of the Utility Model

[0004] The utility model aims to overcome the problem in the prior art that when the pipette tip is sleeved onto the end of the steel needle, it is impossible to determine whether it is installed in place, which may result in a gap between the pipette tip and the steel needle and the inability to achieve liquid suction, and provides a telescopic sample adding device that can ensure the pipette tip is installed in place.

[0005] To achieve the above purpose, the utility model adopts the following technical solutions:

[0006] The utility model provides a telescopic sample adding device, which includes a steel needle seat and a needle loading detection structure installed on the steel needle seat. A steel needle is installed on the steel needle seat. A steel needle sleeve is provided on the steel needle. The needle loading detection structure includes a detection shaft installed on the steel needle sleeve. A sensor adapted to the detection shaft is installed on the steel needle seat.

[0007] The described needle-loading detection structure can detect whether the pipette tip is installed in place. Specifically, during the installation of the pipette tip, the pipette tip will push the steel needle sleeve upward, thereby driving the detection shaft to move towards the sensor. When the pipette tip is installed in place, the sensor can detect the detection shaft. If the pipette tip is automatically installed, the driving structure of the pipette tip can be stopped from further moving through signal transmission. If the pipette tip is manually installed, a signal lamp or other indicating structure can be used to prompt the operator that the pipette tip has been installed in place.

[0008] Preferably, a pressing plate is provided on the outer side wall of the steel needle sleeve, and the detection shaft is fixedly installed on the pressing plate. The detection shaft can be driven by the pressing plate.

[0009] Preferably, a limit screw is also fixedly installed on the pressing plate, and the axial direction of the limit screw is parallel to the axial direction of the detection shaft. The pressing plate can be limited by the limit screw to prevent the detection shaft from moving too far and colliding with the sensor, resulting in damage to components.

[0010] Preferably, a first spring is installed between the limit screw and the steel needle seat. The first spring can not only buffer the limit screw but also play a reset role. When the pipette tip is removed, the elastic force of the first spring can reset the steel needle sleeve.

[0011] Preferably, a needle-loading detection groove is installed in the steel needle seat, a needle-loading detection seat is installed in the needle-loading detection groove, the sensor is installed in the needle-loading detection seat, and a spring limit groove adapted to the first spring is also provided on the needle-loading detection seat. This structure enables the needle-loading detection seat to be disassembled on the steel needle seat, facilitating the replacement or setting of the sensor.

[0012] Preferably, the present application further includes a lead screw motor. A piston member is installed on the lead screw of the lead screw motor, and a cavity is provided between the piston member and the steel needle seat. The cavity is communicated with the inner channel of the steel needle. The lead screw motor can drive the piston member to move, thereby driving the volume change of the cavity to achieve liquid suction or liquid separation.

[0013] Preferably, the present application further includes a sleeve sleeved outside the lead screw. A sealing ring is installed between the piston and the sleeve. The sealing ring can ensure the sealing performance of the cavity and prevent liquid leakage.

[0014] Preferably, a washer coaxial with the piston is fixed inside the sleeve. The washer can limit the axial movement of the piston.

[0015] Preferably, the cavity is communicated with a pressure detection channel, and a pressure detection structure is installed at one end of the pressure detection channel. The pressure detection structure can detect the pressure in the cavity to judge the liquid suction situation.

[0016] Therefore, the utility model has the following beneficial effects: (1) It can detect whether the suction head is installed in place; (2) The liquid suction and liquid separation are driven by a motor, and the structure is simpler; (3) It has good sealing performance; (4) It can detect the pressure in the cavity. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is an exploded view of a structure of the utility model.

[0018] Figure 2 is a schematic cross-sectional view of the utility model.

[0019] In the figure: lead screw motor 1, sleeve 2, steel needle seat 3, steel needle 4, pressing plate 5, cavity 6, steel needle sleeve 7, limit screw 8, detection shaft 9, piston part 10, sealing ring 11, washer 12, pressure detection structure 13, needle loading detection seat 14. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] The following further describes the utility model in conjunction with the drawings and specific embodiments.

[0021] Example 1, as Figure 1-2 shown, a telescopic sample adding device successively includes a lead screw motor 1, a sleeve 2, a steel needle seat 3, and a steel needle 4 from top to bottom. A needle loading detection structure is installed on the steel needle seat 3 for detecting whether the position is in place when the suction head is installed on the steel needle 4. A sealing piston structure is installed in the sleeve 2. A cavity 6 is provided inside the steel needle seat 3. The sealing piston structure changes the volume of the cavity 6 through the movement of the piston, thereby realizing liquid suction or liquid separation. The cavity 6 is communicated with the liquid channel in the steel needle 4.

[0022] The existing sample adding devices generally use a cylinder as the core, and the movement of the cylinder piston is controlled by a motor. The pump seat connects the cylinder and the sample adding steel needle 4, and the suction and liquid separation of the suction head are realized through the movement of the cylinder piston. Although this design ensures the sample adding accuracy with the cylinder, it is also limited by the shape of the cylinder, which increases the number of parts required for the entire sample adding channel and most of them are assembled outside the cylinder, making the entire structure complex, the assembly difficulty increased, and the later maintenance difficult. In this application, the lead screw motor 1 is used instead of the cylinder, which can not only ensure the sample adding accuracy, but also occupy less space, is simple to assemble, and is convenient for maintenance.

[0023] A steel needle 4 is installed on the steel needle seat 3. A steel needle sleeve 7 is provided on the steel needle 4. The needle loading detection structure includes a detection shaft 9 installed on the steel needle sleeve 7, and a sensor adapted to the detection shaft 9 is installed on the steel needle seat 3. The sensor can be a contact sensor, or a photoelectric sensor that can detect distance, or other structures that can effectively detect the detection shaft 9.

[0024] The described needle loading detection structure can detect whether the suction head is installed in place. Specifically, during the process of installing the suction head, the suction head will push the steel needle sleeve 7 upward, thereby driving the detection shaft 9 to move towards the sensor. When the suction head is installed in place, the sensor can detect the detection shaft 9. If the suction head is automatically installed, the driving structure of the suction head can be stopped from continuing to move through signal transmission. If the suction head is manually installed, a signal lamp or other indicating structure can be used to prompt the operator that the suction head has been installed in place.

[0025] A pressing plate 5 is provided on the outer side wall of the steel needle sleeve 7. The detection shaft 9 is fixedly installed on the pressing plate 5. The pressing plate 5 is perpendicular to the axial direction of the steel needle sleeve 7. By designing the length of the pressing plate 5, the distance between the detection shaft 9 and the steel needle sleeve 7 can be adjusted adaptively, so as to facilitate arranging the position of the sensor and avoid interference between the sensor and other structures. The pressing plate 5 can drive the detection shaft 9, and the detection shaft 9 can be adjusted axially on the pressing plate 5 to adapt to the distance required for the suction head to be inserted.

[0026] A limiting screw 8 is also fixedly installed on the pressing plate 5. The axial direction of the limiting screw 8 is parallel to the axial direction of the detection shaft 9. The limiting screw 8 can limit the pressing plate 5 to prevent the detection shaft 9 from moving too far and colliding with the sensor, resulting in damage to components. By screwing the limiting screw 8 on the pressing plate 5, the axial position of the limiting screw 8 relative to the pressing plate 5 can be adjusted, thereby adapting to the distance between the sensor and the detection shaft 9. The distance from the end of the limiting screw 8 to the steel needle seat 3 is not greater than the distance from the end of the detection shaft 9 to the sensor, so as to avoid collision between the sensor and the detection shaft 9.

[0027] A first spring is installed between the limiting screw 8 and the steel needle seat 3. The first spring can not only buffer the limiting screw 8 but also play a reset role. When the suction head is removed, the elastic force of the first spring can reset the steel needle sleeve 7.

[0028] The piston seal structure includes a piston member 10 and a sealing ring 11 installed outside the piston member 10. The sealing ring 11 is a nitrile rubber sealing ring 11. Through the sealing ring 11, the tightness of the cavity 6 can be ensured to avoid liquid leakage. A washer 12 coaxial with the piston is fixed inside the sleeve 2. The washer 12 can limit the axial movement of the piston.

[0029] The process of using the device is as follows: When it is necessary to load the pipette tip, the entire pipetting device moves downward to pierce into the pipette tip. The pipette tip pushes the steel needle sleeve 7 upward, and drives the detection shaft 9 upward through the pressure plate 5. When the sensor detects the detection shaft 9, it is considered that the pipette tip has been installed in place, thereby judging whether the needle installation detection is successful. When sucking liquid, the motor screw drives the sealing piston structure to move upward. At this time, the internal volume of the cavity 6 becomes larger, so that the liquid is pressed into the pipette tip by the external air; when dispensing liquid, the screw drives the optical axis to move downward, expelling the air in the cavity 6, thereby pushing out the liquid in the pipette tip.

[0030] Embodiment 2, as Figure 1-2 shown, a telescopic pipetting device includes a screw motor 1, a sleeve 2, a steel needle seat 3, and a steel needle 4 from top to bottom in sequence. A needle installation detection structure is installed on the steel needle seat 3 for detecting whether the position of the pipette tip is in place when it is installed on the steel needle 4. A sealing piston structure is installed in the pipetting sleeve 2. A cavity 6 is provided inside the steel needle seat 3. The sealing piston structure changes the volume of the cavity 6 through the movement of the piston, thereby realizing liquid suction or liquid dispensing. The cavity 6 is communicated with the liquid channel in the steel needle 4.

[0031] The pipetting devices in the prior art generally use a cylinder as the core, and use a motor to control the movement of the cylinder piston. The pump seat connects the cylinder and the pipetting steel needle 4, and realizes the liquid suction and dispensing of the pipette tip through the movement of the cylinder piston. Although this design ensures the pipetting accuracy with the cylinder, it is also limited by the shape of the cylinder, which increases the number of parts required for the entire pipetting channel and most of them are assembled outside the cylinder, making the entire structure complex, the assembly difficulty increased, and the later maintenance difficult. And in this application, the screw motor 1 is used instead of the cylinder, which can not only ensure the pipetting accuracy, but also occupy less space, is simple to assemble, and is convenient for maintenance.

[0032] A steel needle 4 is installed on the steel needle seat 3. A steel needle sleeve 7 is provided on the steel needle 4. The needle installation detection structure includes a detection shaft 9 installed on the steel needle sleeve 7. A sensor adapted to the detection shaft 9 is installed on the steel needle seat 3. The sensor can be a contact sensor, or a photoelectric sensor that can detect distance, or other structures that can effectively detect the detection shaft 9.

[0033] The needle installation detection structure can detect whether the pipette tip is installed in place. Specifically, during the process of installing the pipette tip, the pipette tip will push the steel needle sleeve 7 upward, thereby driving the detection shaft 9 to move toward the sensor. When the pipette tip is installed in place, the sensor can detect the detection shaft 9. If the pipette tip is automatically installed, the driving structure of the pipette tip can be stopped from continuing to move through signal transmission. If the pipette tip is manually installed, the operator can be prompted that the pipette tip has been installed in place through a signal lamp or other indication structures.

[0034] A pressing plate 5 is provided on the outer side wall of the steel needle sleeve 7, and the detection shaft 9 is fixedly installed on the pressing plate 5. The pressing plate 5 is perpendicular to the axial direction of the steel needle sleeve 7. By designing the length of the pressing plate 5, the distance between the detection shaft 9 and the steel needle sleeve 7 can be adjusted adaptively, so as to facilitate arranging the position of the sensor and avoid interference between the sensor and other structures. The pressing plate 5 can drive the detection shaft 9, and the detection shaft 9 can be adjusted axially on the pressing plate 5 to adapt to the distance required for the suction head to be inserted.

[0035] A limit screw 8 is also fixedly installed on the pressing plate 5. The axial direction of the limit screw 8 is parallel to the axial direction of the detection shaft 9. The pressing plate 5 can be limited by the limit screw 8 to avoid the situation that the detection shaft 9 moves too far and collides with the sensor, resulting in damage to parts. By screwing the limit screw 8 on the pressing plate 5, the axial position of the limit screw 8 relative to the pressing plate 5 can be adjusted, so as to adapt to the distance between the sensor and the detection shaft 9. The distance from the end of the limit screw 8 to the steel needle seat 3 is not greater than the distance from the end of the detection shaft 9 to the sensor, so as to avoid collision between the sensor and the detection shaft 9.

[0036] A first spring is installed between the limit screw 8 and the steel needle seat 3. The first spring can not only buffer the limit screw 8, but also play a reset role. When the suction head is removed, the elastic force of the first spring can make the steel needle sleeve 7 reset.

[0037] The piston sealing structure includes a piston member 10 and a sealing ring 11 installed on the outside of the piston member 10. The sealing ring 11 is a nitrile sealing ring 11. The sealing of the cavity 6 can be ensured through the sealing ring 11 to avoid liquid leakage. A washer 12 coaxial with the piston is fixed inside the sleeve 2. The axial movement of the piston can be limited through the washer 12.

[0038] The difference between this embodiment and the first embodiment is that the internal pressure of the cavity 6 can also be detected: the cavity 6 is connected to a pressure detection channel, and a pressure detection structure 13 is installed at one end of the pressure detection channel. The pressure detection structure 13 includes a second spring and a pressure sensor. The pressure inside the cavity 6 can be detected through the pressure detection structure 13, so as to judge the sample addition situation, such as the viscosity of the liquid, the height of the liquid during liquid separation, etc.

[0039] The process of using the device is as follows: When it is necessary to load the pipette tip, the entire pipetting device moves downward to pierce into the pipette tip. The pipette tip pushes the steel needle sleeve 7 upward, and drives the detection shaft 9 upward through the pressure plate 5. When the sensor detects the detection shaft 9, it is considered that the pipette tip has been installed in place, thereby judging whether the needle loading is successful. When sucking liquid, the motor screw drives the sealing piston structure to move upward. At this time, the internal volume of the cavity 6 becomes larger, so that the liquid is pressed into the pipette tip by the external air; when dispensing liquid, the screw drives the optical axis to move downward, expelling the air in the cavity 6, thereby pushing the liquid in the pipette tip out.

[0040] Embodiment 3, as Figure 1-2 shown, a telescopic pipetting device successively includes a screw motor 1, a sleeve 2, a steel needle seat 3, and a steel needle 4 from top to bottom. A needle loading detection structure is installed on the steel needle seat 3 to detect whether the position is in place when the pipette tip is installed on the steel needle 4. A sealing piston structure is installed in the pipetting sleeve 2. A cavity 6 is provided inside the steel needle seat 3. The sealing piston structure changes the volume of the cavity 6 through the movement of the piston, thereby realizing liquid suction or liquid dispensing. The cavity 6 is communicated with the liquid channel in the steel needle 4.

[0041] The pipetting devices in the prior art generally use a cylinder as the core, and the movement of the cylinder piston is controlled by a motor. The pump seat connects the cylinder and the pipetting steel needle 4, and the liquid suction and dispensing of the pipette tip are realized through the movement of the cylinder piston. Although this design has the cylinder to ensure the pipetting accuracy, it is also limited by the shape of the cylinder, which increases the number of parts required for the entire pipetting channel and most of them are assembled outside the cylinder, making the entire structure complex, the assembly difficulty increased, and the later maintenance difficult. And in this application, the screw motor 1 is used instead of the cylinder, which can not only ensure the pipetting accuracy, but also occupy less space, is simple to assemble, and is convenient for maintenance.

[0042] A steel needle 4 is installed on the steel needle seat 3. A steel needle sleeve 7 is provided on the steel needle 4. The needle loading detection structure includes a detection shaft 9 installed on the steel needle sleeve 7. A sensor adapted to the detection shaft 9 is installed on the steel needle seat 3. The sensor can be a contact sensor, or a photoelectric sensor that can detect distance, or other structures that can effectively detect the detection shaft 9.

[0043] The difference between this embodiment and Embodiment 1 is that a needle loading detection groove is installed inside the steel needle seat 3. A needle loading detection seat 14 is installed in the needle loading detection groove. The sensor is installed in the needle loading detection seat 14. A spring limiting groove adapted to the first spring is also provided on the needle loading detection seat 14. Through this structure, the needle loading detection seat 14 can be disassembled on the steel needle seat 3, so as to facilitate the replacement or setting of the sensor.

[0044] The described needle loading detection structure can detect whether the suction head is properly installed. Specifically, during the process of installing the suction head, the suction head will push the steel needle sleeve 7 upward, thereby driving the detection shaft 9 to move towards the sensor. When the suction head is properly installed, the sensor can detect the detection shaft 9. If the suction head is automatically installed, the driving structure of the suction head can be stopped from further moving through signal transmission. If the suction head is manually installed, the operator can be prompted that the suction head has been properly installed through a signal lamp or other indicating structures.

[0045] A pressing plate 5 is provided on the outer side wall of the steel needle sleeve 7. The detection shaft 9 is fixedly installed on the pressing plate 5. The pressing plate 5 is perpendicular to the axial direction of the steel needle sleeve 7. By designing the length of the pressing plate 5, the distance between the detection shaft 9 and the steel needle sleeve 7 can be adaptively adjusted, so as to facilitate arranging the position of the sensor and avoid interference between the sensor and other structures. The pressing plate 5 can drive the detection shaft 9, and the detection shaft 9 can be adjusted axially on the pressing plate 5 to adapt to the distance required for the suction head to be inserted.

[0046] A limiting screw 8 is also fixedly installed on the pressing plate 5. The axial direction of the limiting screw 8 is parallel to the axial direction of the detection shaft 9. The limiting screw 8 can limit the pressing plate 5 to prevent the detection shaft 9 from moving too far and colliding with the sensor, resulting in damage to components. By screwing the limiting screw 8 on the pressing plate 5, the axial position of the limiting screw 8 relative to the pressing plate 5 can be adjusted, thereby adapting to the distance between the sensor and the detection shaft 9. The distance from the end of the limiting screw 8 to the steel needle seat 3 is not greater than the distance from the end of the detection shaft 9 to the sensor, so as to avoid collision between the sensor and the detection shaft 9.

[0047] A first spring is installed between the limiting screw 8 and the steel needle seat 3. The first spring can not only buffer the limiting screw 8 but also play a reset role. When the suction head is removed, the elastic force of the first spring can reset the steel needle sleeve 7.

[0048] The piston sealing structure includes a piston member 10 and a sealing ring 11 installed outside the piston member 10. The sealing ring 11 is a nitrile rubber sealing ring 11. Through the sealing ring 11, the sealing performance of the cavity 6 can be ensured to avoid liquid leakage. A washer 12 coaxial with the piston is fixed inside the sleeve 2. The washer 12 can limit the axial movement of the piston.

[0049] The process of using the device is as follows: When it is necessary to load the pipette tip, the entire pipetting device moves downward to pierce into the pipette tip. The pipette tip pushes the steel needle sleeve 7 upward, and drives the detection shaft 9 upward through the pressure plate 5. When the sensor detects the detection shaft 9, it is considered that the pipette tip has been installed in place, so as to judge whether the needle loading is successful. When sucking liquid, the motor screw drives the sealing piston structure to move upward. At this time, the internal volume of the cavity 6 becomes larger, so that the liquid is pressed into the pipette tip by the external air; when dispensing liquid, the screw drives the optical axis to move downward, expelling the air in the cavity 6, so as to push out the liquid in the pipette tip.

Claims

1. A telescopic sampling device, characterized in that, It includes a steel needle seat and a needle loading detection structure installed on the steel needle seat. A steel needle is installed on the steel needle seat, and a steel needle sleeve is provided on the steel needle. The needle loading detection structure includes a detection shaft installed on the steel needle sleeve. A sensor adapted to the detection shaft is installed on the steel needle seat. A pressing plate is provided on the outer side wall of the steel needle sleeve, and the detection shaft is fixedly installed on the pressing plate. A limit screw is also fixedly installed on the pressing plate, and the axial direction of the limit screw is parallel to the axial direction of the detection shaft.

2. The telescopic sampling device according to claim 1, wherein A first spring is installed between the limit screw and the steel needle seat.

3. The telescopic sampling device according to claim 2, characterized in that, A needle loading detection groove is installed in the steel needle seat, and a needle loading detection seat is installed in the needle loading detection groove. The sensor is installed in the needle loading detection seat, and a spring limit groove adapted to the first spring is also provided on the needle loading detection seat.

4. A telescopic sampling device according to any one of claims 1-3, characterized in that, It further includes a lead screw motor. A piston part is installed on the lead screw of the lead screw motor. A cavity is provided between the piston part and the steel needle seat, and the cavity is communicated with the inner channel of the steel needle.

5. The telescopic sampling device according to claim 4, wherein, It further includes a sleeve sleeved outside the lead screw, and a sealing ring is installed between the piston and the sleeve.

6. A telescopic sampling device according to claim 4, characterized in that, A washer coaxial with the piston is fixed on the inner side of the sleeve.

7. The telescopic sampling device according to claim 4, characterized in that, The cavity is communicated with a pressure detection channel, and a pressure detection structure is installed at one end of the pressure detection channel.

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