A pipetting channel with dual liquid level detection function

Abstract

This invention relates to a pipetting channel with dual liquid level detection function, comprising a power source, a transmission mechanism, a guiding mechanism, an actuator, and a housing. The transmission mechanism includes bearings, a lead screw, and a plunger seat. The actuator includes a pump body, an optical coupler plate, a plunger, a processing plate, a pipette rod, a pipette tip retraction rod, a suction nozzle, and a stop rod. The pump body is mounted on the housing, and the optical coupler plate, processing plate, and pipette rod are all fixed to the pump body. One end of the plunger is connected to the plunger seat, and the other end is located in the cavity inside the pipette rod. The suction nozzle is fixed to the end of the pipette rod and is used to install external consumables. The pipette tip retraction rod is sleeved on the outside of the pipette rod and is movably connected to the pump body, possessing a spring force pointing outward from the pump body. Driven by the pipette tip retraction rod, the stop rod enters or exits the detection area of ​​the optical coupler plate. The processing plate, pipette rod, and suction nozzle are electrically connected in sequence. Compared with the prior art, this invention has the advantages of being compact, having comprehensive liquid level detection functions, high accuracy, and long service life.

Description

Technical Field

[0001] This invention relates to the field of pipetting channels, and in particular to a pipetting channel with dual liquid level detection function. Background Technology

[0002] Currently, most conventional pipetting channels are foreign products, while domestic products also exist, but they suffer from problems such as large size, poor accuracy, and lack of liquid level detection function.

[0003] The disadvantages of large size: it can basically only install a single channel, which is very inefficient and not as fast as manual operation. Single-channel products are basically not accepted by the market except in specific situations where speed is not a priority.

[0004] The disadvantage of poor accuracy is that it has limited application scenarios and can only meet the needs of low-end application scenarios where high accuracy is not required.

[0005] The disadvantages of lacking liquid level detection function: It is impossible to know the height of the liquid level, so you can only dab deeper in use, but there is still a risk of detaching from the liquid surface and drawing liquid; at the same time, some pipetting channels only have capacitance detection, such as the liquid level detection method and device based on capacitance detection disclosed in invention publication number CN113324619A, but the function is limited for non-conductive liquids; some pipetting channels only have pressure detection, which is much slower than capacitance detection. Summary of the Invention

[0006] The purpose of this invention is to overcome the defects of the prior art and provide a pipetting channel with dual liquid level detection function, which is compact in structure and has full liquid level detection function.

[0007] The objective of this invention can be achieved through the following technical solutions:

[0008] A pipetting channel with dual liquid level detection function includes a power source, a transmission mechanism, a guide mechanism, an actuator, and a housing. The power source and the transmission mechanism are both mounted on the housing. The guide mechanism is fixed inside the housing. The actuator is mounted inside the guide mechanism. The power source, the transmission mechanism, and the actuator are sequentially connected in a transmission manner.

[0009] The transmission mechanism includes a bearing, a lead screw, and a plunger seat. The lead screw is fixed to the housing via the bearing, and the nut of the lead screw is rotatably connected to the plunger seat. The plunger seat is limited by the guide mechanism.

[0010] The actuator includes a pump body, an optical coupler plate, a plunger, a processing plate, a gun rod, a gun retraction rod, a suction nozzle, and a stop bar. The pump body is mounted on the outer casing. The optical coupler plate, the processing plate, and the gun rod are all fixed to the pump body. One end of the plunger is connected to a plunger seat, and the other end is located in the cavity inside the gun rod. The suction nozzle is fixed to the end of the gun rod and is used to install external consumables. The gun retraction rod is sleeved on the outside of the gun rod and is movably connected to the pump body, and has a spring force pointing outward from the pump body. The stop bar is fixed to the gun retraction rod and, driven by the gun retraction rod, enters or exits the detection area of ​​the optical coupler plate. The processing plate, the gun rod, and the suction nozzle are electrically connected in sequence. The processing plate is also connected to the optical coupler plate.

[0011] The processing board is used to collect changes in capacitance on the nozzle in real time to determine whether external consumables mounted on the nozzle are in contact with the liquid surface.

[0012] Furthermore, the processing plate is connected to a sensor that senses the pressure in the gun barrel cavity, and the pump body is provided with an air hole that connects the sensor and the cavity inside the gun barrel.

[0013] The processing board is used to determine whether the external consumables mounted on the nozzle are in contact with the liquid surface based on the changes in the pressure of the gun barrel cavity detected by the sensor.

[0014] Furthermore, the actuator also includes a thrust rod and a thrust spring. The thrust rod is movably connected to the pump body, one end of the thrust rod is connected to the pump body through the thrust spring, and the other end is fixedly connected to the ejector head rod.

[0015] Furthermore, both the gun barrel and the suction nozzle are made of conductive materials, while the gun retraction rod is made of insulating material.

[0016] Furthermore, the actuator is also provided with a conductive spring and a conductive screw. The gun rod is fixed to the pump body by the conductive screw and the conductive spring. The processing plate, the conductive screw, the conductive spring, the gun rod and the suction nozzle are electrically connected in sequence.

[0017] Furthermore, the power source includes a motor, a motor mount, and a coupling. The motor and the coupling are both mounted on the motor mount, which is fixed to the outer casing. The motor, coupling, and lead screw are sequentially connected for transmission.

[0018] Furthermore, a first seal is provided at the connection between the plunger and the pump body.

[0019] Furthermore, the outer surface of the gun barrel is provided with a groove, and a second seal is provided at the connection between the pump body and the gun barrel, the second seal being located within the groove.

[0020] Furthermore, the external consumable is a conductive material.

[0021] Furthermore, when external consumables are installed on the nozzle, the ejector rod drives the stop rod to enter the detection area of ​​the optical coupler plate.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] (1) Compact: The structure is compact and the width is small enough to not occupy too much internal space of the device that integrates the pipetting channel; the thickness is thin enough (less than 18mm) so that multiple channels can be installed on one device to add liquid to the misaligned wells of the ELISA plate, which greatly improves the efficiency of the device.

[0024] (2) Full liquid level detection function: It has both pressure detection and capacitance detection modes, which fully meet the liquid level detection needs of the market.

[0025] (3) High precision: The extremely small cavity and high-quality plunger surface ensure accurate liquid addition.

[0026] (4) Long life: The seal is elastic and made of wear-resistant material. Even if it wears a little after a long period of use, it will still be tightly bound to the plunger due to its elasticity, thus ensuring airtightness. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the first structure of a pipetting channel with dual liquid level detection function provided in an embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of the second structure of a pipetting channel with dual liquid level detection function provided in an embodiment of the present invention;

[0029] Figure 3 This is a schematic diagram of the third structure of a pipetting channel with dual liquid level detection function provided in an embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram of the fourth structure of a pipetting channel with dual liquid level detection function provided in an embodiment of the present invention;

[0031] In the diagram, 1. Pump body, 2. Optical coupler plate, 3. Front plate, 4. Bearing, 5. Guide module, 6. Lead screw, 7. Bearing, 8. Upper plate, 9. Coupling, 10. Motor base, 11. Motor, 12. Rear plate, 13. Plunger seat, 14. Plunger, 15. Processing plate, 16. Seal, 17. Seal, 18. Seal, 19. Conductive spring, 20. Conductive screw, 21. Gun rod, 22. Gun head retraction rod, 23. Seal, 24. Suction nozzle, 25. Retaining ring, 26. Thrust rod, 27. Stop rod, 28. Spring, 29. Pressure plate, 30. Nut;

[0032] Hole 1-2 for mounting bearing 4; hole 1-1 for mounting seal 16; hole 1-3 for passing the plunger; cavity 1-4 for mounting optocoupler plate 2; hole 1-5 for tight fit with gun rod 21 and seal 18; hole 1-6 for passing the stop rod 27; hole 1-7 for passing the thrust rod 26; hole and end face 1-9 for mounting conductive screw 20; hole 1-10 for passing the conductive spring; vent hole 1-11 for ventilation; hole 1-12 for tight fit with seal 17; optocoupler 2-1; hole 4-1; face 5-1; shaft ends 6-1, 6-3, 6-4; face 6-2 for mating with plunger seat; holes 9-1, 9-3; screw hole 9-2; motor shaft 11- 1; Cavity 13-1, surface 13-2, surface 13-3, surface 13-4, and protruding end 13-4 that are precisely fitted with the plunger 14; Precision boss 14-1 and precision surface 14-2; Optical coupler 15-1 for initializing the plunger position; Sensor 15-2 for sensing the pressure of the gun barrel cavity; Conductive surface 15-3; Inner surface 16-1 and outer surface 16-2; Cavity 21-1, groove 21-2, precision outer surface 21-3, and precision inner surface 21-4; Holes 22-1 and 22-2; Hole 24-1, precision outer surface 24-2, and groove 24-3; Groove 26-1, shaft end 26-2, groove 26-3, and end face 26-4. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0034] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0035] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0036] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed during use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0037] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0038] Furthermore, terms such as "horizontal" and "vertical" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0039] Example 1

[0040] like Figure 1-4 As shown, this embodiment provides a pipetting channel with dual liquid level detection function, including a power source, a transmission mechanism, a guide mechanism, an actuator, and a housing. The power source and the transmission mechanism are both mounted on the housing, the guide mechanism is fixed inside the housing, and the actuator is mounted inside the guide mechanism. The power source, the transmission mechanism, and the actuator are sequentially connected in a transmission manner.

[0041] The transmission mechanism includes a bearing, a lead screw 6, and a plunger seat 13. The lead screw 6 is fixed to the housing by the bearing, and the nut of the lead screw 6 is rotatably connected to the plunger seat 13. The plunger seat 13 is limited by the guide mechanism.

[0042] The actuator includes a pump body 1, an optical coupler plate 2, a plunger 14, a processing plate 15, a gun rod 21, a gun retraction rod 22, a suction nozzle 24, and a stop rod 27. The pump body 1 is mounted on the outer casing. The optical coupler plate 2, the processing plate 15, and the gun rod 21 are all fixed to the pump body 1. One end of the plunger 14 is connected to the plunger seat 13, and the other end is located in the cavity inside the gun rod 21. The suction nozzle 24 is fixed to the end of the gun rod 21 and is used to install external consumables. The gun retraction rod 22 is sleeved on the outside of the gun rod 21. The gun retraction rod 22 is movably connected to the pump body 1 and has a spring force pointing outward from the pump body 1. The stop rod 27 is fixed to the gun retraction rod 22 and, driven by the gun retraction rod 22, enters or exits the detection area of ​​the optical coupler plate 2. The processing plate 15, the gun rod 21, and the suction nozzle 24 are electrically connected in sequence. The processing plate 15 is also connected to the optical coupler plate 2.

[0043] When external consumables are inserted into the nozzle 24, they push the ejector rod 22, causing the stop lever 27 to enter the optocoupler's recognition area, indicating to the system that external consumables have been inserted. The processing board can collect changes in capacitance on the nozzle 24 in real time to determine whether the external consumables on the nozzle 24 are in contact with the liquid surface. After detecting the liquid surface, the motor 11 moves down a certain distance, driving the plunger 14 to move and draw liquid through the rod 21 and nozzle 24. The motor 11 then reverses to discharge the liquid. When it is time to remove the external consumables, the motor continues to reverse, and the external consumables are pushed off the nozzle 24 by the ejector rod 22. At the same time, the stop lever 27 also moves down, leaving the optocoupler's recognition area, indicating to the system that the external consumables have been removed.

[0044] Optionally, the processing plate 15 is connected to a sensor that senses the pressure in the gun barrel cavity, and the pump body 1 is provided with an air hole that connects the sensor and the cavity inside the gun barrel 21.

[0045] The processing board 15 is used to determine whether the external consumables mounted on the nozzle 24 are in contact with the liquid surface based on the change in pressure in the gun barrel cavity detected by the sensor.

[0046] Optionally, the actuator also includes a thrust rod 26 and a thrust spring 28. The thrust rod 26 is movably connected inside the pump body 1. One end of the thrust rod 26 is connected to the pump body 1 through the thrust spring 28, and the other end is fixedly connected to the gun head rod 22.

[0047] Optionally, the gun barrel 21 and the suction nozzle 24 are both made of conductive materials, while the gun head retractor 22 is made of insulating material.

[0048] Optionally, the actuator is also provided with a conductive spring 19 and a conductive screw 20. The gun rod 21 is fixed to the pump body 1 by the conductive screw 20 and the conductive spring 19. The processing plate 15, the conductive screw 20, the conductive spring 19, the gun rod 21 and the suction nozzle 24 are electrically connected in sequence.

[0049] Optionally, the power source includes a motor 11, a motor base 10, and a coupling 9. The motor 11 and the coupling 9 are both mounted on the motor base 10, which is fixed to the housing. The motor 11, the coupling 9, and the lead screw 6 are connected in sequence for transmission.

[0050] Optionally, a first seal is provided at the connection between the plunger 14 and the pump body 1; a groove is provided on the outer surface of the gun rod 21, and a second seal is provided at the connection between the pump body 1 and the gun rod 21. The second seal is located in the groove, and the first seal and the second seal achieve a sealed connection between the components.

[0051] The following section combines all the available implementation schemes to obtain an optimal implementation scheme, and provides a detailed description thereof.

[0052] A high-precision pipetting channel with dual liquid level detection function is disclosed. The channel includes a power source, a transmission mechanism, a guiding mechanism, an actuator, and a housing. The power source includes a motor 11, a motor mount 10, and a coupling 9. The transmission mechanism includes a bearing 7, a lead screw 6, a plunger seat 13, and a bearing 4. The guiding mechanism includes a guide module 5. The actuator includes a pump body 1, an optical coupler plate 2, a plunger 14, a processing plate 15, seals 16, 17, and 18, a conductive spring 19, a conductive screw 20, a pipette rod 21, a pipette tip retraction rod 22, a seal 23, a suction nozzle 24, a retaining ring 25, a thrust rod 26, and a stop rod 27. Spring 28, pressure plate 29 and nut 30; the outer casing includes front plate 3, upper plate 8 and rear plate 12; the pump body 1 has a hole 1-2 for mounting bearing 4, a hole 1-1 for mounting seal 16, a hole 1-3 for passing plunger, a cavity 1-4 for mounting optical coupler plate 2, a hole 1-5 for tightly fitting with gun rod 21 and seal 18, a hole 1-6 for passing with stop rod 27, a hole 1-7 for passing with thrust rod 26, a hole and end face 1-9 for mounting conductive screw 20, a hole 1-10 for passing with conductive spring, an air hole 1-11 for ventilation, and a hole 1-12 for tightly fitting with seal 17; Optical coupler plate 2 has an optical coupler 2-1 for sensing whether a sensing tip head is installed; bearing 4 has a hole 4-1; guide module has a surface 5-1; lead screw 6 has shaft ends 6-1, 6-3, and 6-4, and a surface 6-2 for engaging with the plunger seat; bearing 7 has a hole 7-1; coupling 9 has holes 9-1 and 9-3, and a screw hole 9-2; motor 11 has a motor shaft 11-1; plunger seat 13 has a cavity 13-1 for precise fitting with plunger 14, a surface 13-2, a surface 13-3 for engaging with guide module 5, a surface 13-4 for engaging with lead screw 6, and a protruding end 13-4; plunger 14 has a precision boss 14-1. It has a precision surface 14-2; the processing plate 15 has an optocoupler 15-1 for initializing the plunger position and a sensor 15-2 for sensing the pressure of the gun barrel cavity; it has a conductive surface 15-3; the seal 16 has an inner surface 16-1 and an outer surface 16-2; the gun barrel 21 has a cavity 21-1, a groove 21-2, a precision outer surface 21-3, and a precision inner surface 21-4; the gun head retraction rod has holes 22-1 and 22-2; the suction nozzle 24 has a hole 24-1, a precision outer surface 24-2, and a groove 24-3; the thrust rod 26 has a groove 26-1, a shaft end 26-2, a groove 26-3, and an end face 26-4.

[0053] Specifically,

[0054] 1. The suction nozzle 24, the conductive consumable for the tip user mounted on the suction nozzle 24, and the gun barrel 21 are all made of conductive materials. The gun barrel 21 has holes for mounting the conductive screw 20 and end faces 1-9, and holes 1-10 for passing the conductive spring. When the conductive screw 20 and the conductive spring 19 are installed, the conductive spring 19 can conduct electricity with the suction nozzle 24. The processing plate 15 has a conductive surface 15-3, which contacts the conductive spring 19, enabling the processing plate 15 to collect changes in capacitance on the suction nozzle 24 in real time. At the same time, the gun retraction rod 22 is made of non-conductive material, thereby avoiding interference from the gun retraction rod 22 on changes in capacitance on the suction nozzle 24. This allows the processing plate 15 to determine whether the conductive consumable for the tip user mounted on the suction nozzle 24 is in contact with the liquid surface by observing changes in capacitance.

[0055] 2. The pump body 1 has a hole 1-1 for installing the seal 16 and a hole 1-3 for passing the plunger. The seal 16 has an inner surface 16-1 and an outer surface 16-2, and the plunger 14 has a precision surface 14-2. When the three are installed, the inner surface 16-1 of the seal 16 is in close contact with the precision surface 14-2 of the plunger 14, and the outer surface 16-2 of the seal 16 is in close contact with the inner wall of the hole 1-1 of the seal 16. This ensures that the fit of the parts is sealed and airtight.

[0056] 3. The gun rod 21 has a groove 21-2 and a precision outer surface 21-3. The pump body 1 has a hole 1-5 for tight fitting with the gun rod 21 and the seal 18. When the seal 18 is fitted into the groove 21-2 of the gun rod 21 and the gun rod 21 is fixed to the pump body 1 with a conductive screw 20, the connection between the pump body 1 and the gun rod 21 is also in a sealed and airtight state.

[0057] 4. The suction nozzle 24 has a precision outer surface 24-2 that matches the precision inner surface 21-4 of the gun barrel 21, and a groove 24-3 for installing the sealing element 23. When the three are fixed, the connection between the three is also in a sealed and airtight state.

[0058] 5. The processing board 15 has a sensor 15-2 that senses the pressure in the cavity of the gun barrel 21, the pump body 1 has an air vent 1-11, and the nozzle 24 has a hole 24-1. Since other parts are sealed and airtight, only the sensor 15-2 and the user's consumables mounted on the tip of the nozzle 24 are connected. Whether they are conductive or not is irrelevant. This ensures that when the tip of the nozzle 24 comes into contact with the liquid and causes a slight change in the pressure in the cavity of the gun barrel 21, it can be detected by the sensor 15-2. This allows the sensor to know whether the tip of the nozzle 24 has touched the liquid surface.

[0059] 6. The seal 16 is elastic. As the inner surface 16-1 wears with use, the elasticity will keep the inner surface in close contact with the precision surface 14-2 of the plunger 14, thereby ensuring the airtightness of this area.

[0060] 7. The ejector rod 22 has a hole 22-1 and the rod 21 has a cylindrical outer surface 21-5, so that the ejector rod 22 can slide easily on the rod 21;

[0061] 8. The ejector rod 22 has a hole 22-2, and the thrust rod 26 has a shaft end 26-2 and a groove 26-1. When the shaft end 26-2 is inserted into the hole 22-2, the retaining ring 25 is inserted into the groove 26-1, and the thrust rod and the ejector rod are fixed together.

[0062] 9. The thrust rod 26 has a groove 26-3 and a shaft surface 26-4. When the retaining ring 25 is inserted into the groove 26-1 and the spring 28 is fitted into the shaft surface 26-4, the spring force of the spring 28 will move the ejector rod 22 to the bottom.

[0063] 10. The gun retraction rod 22 has a hole 22-1, the stop rod 27 has a cylindrical surface 27-1, and the optical coupler plate 2 has an optical coupler 2-1. After the stop rod 27 is inserted into the hole 22-1, it can enter or leave the recognition area of ​​the optical coupler 2-1 under the action of the gun retraction rod 22.

[0064] 11. When the Tip user's consumables are loaded onto the nozzle 24, the Tip will push the ejector rod 22 to the top, thereby causing the stop rod 27 to enter the recognition area of ​​the optocoupler 2-1, so that the system knows that the Tip user's consumables have been loaded.

[0065] 12. The motor 11 has a motor shaft 11-1, the coupling 9 has holes 9-1 and 9-3, a screw hole 9-2, and the lead screw 6 has a shaft end 6-1. When the three are assembled together, when the motor shaft 11-1 rotates, the lead screw 6 will also rotate.

[0066] 13. The lead screw 6 has shaft ends 6-1 and 6-3 and threaded end 6-5. The bearing 4 has hole 4-1 and the bearing 7 has hole 7-1. The nut 30 has threaded hole 30-1. When these parts are assembled with the upper plate 8, it can be ensured that the lead screw 6 can only rotate.

[0067] 14. The plunger seat 13 has a surface 13-3 that engages with the guide module 5 and a surface 13-4 that engages with the lead screw 6. The guide module 5 has a surface 5-1 and the lead screw 6 has a surface 6-2. When the three are assembled, the plunger seat 13 can reciprocate linearly along the direction guided by the guide module 5 under the rotation of the lead screw 6.

[0068] 15. The plunger seat 13 has a cavity 13-1 that fits precisely with the plunger 14. The plunger 14 has a precision boss 14-1. After the precision boss 14-1 is inserted into the cavity 13-1, the plunger 14 will be carried by the plunger seat 13 to make a linear reciprocating motion. Finally, the rest of the cavity 21-1 is sealed. Therefore, when the plunger 14 makes a reciprocating motion, due to the pressure change, the open end can realize the suction and discharge of liquid.

[0069] 16. The plunger seat 13 has a surface 13-2, and the push rod 26 has a surface 26-5. When the plunger seat 13 moves downward, and surface 13-2 contacts surface 26-5, the plunger seat 13 will push the push rod 26 downward, thereby realizing the downward movement of the nozzle retraction rod 22. When the nozzle retraction rod 22 moves downward to a certain extent, the consumable of the tip user will be pushed away from the nozzle 24 by the nozzle retraction rod 22. At the same time, the stop rod 27 also moves downward and moves away from the recognition area of ​​the optocoupler 2-1, so that the system knows that the consumable of the tip user has been removed. At the same time, because of the presence of the spring 28, even if the plunger seat 13 moves upward, the nozzle rod 22 and the stop rod 27 will not move upward until the user re-inserts the consumable of the tip user.

[0070] 17. The plunger seat 13 has a protruding end 13-4, and the processing plate 15 has an optocoupler 15-1. When the surface 13-2 contacts the surface 26-5, the protruding end 13-4 just enters the recognition area of ​​the optocoupler 15-1, and the system will recognize the position where the gun head begins to retract.

[0071] Working principle:

[0072] After the channel is powered on, it initializes and identifies the position where the tip retraction begins. When the user's consumable is loaded onto the nozzle 24, the tip pushes the tip retraction lever 22 to the top, causing the stop lever 27 to enter the recognition area of ​​the optocoupler 2-1, thus informing the system that the user's consumable has been loaded. Depending on the user's needs, pressure or capacitive liquid level detection is used to locate the liquid level to be drawn. After detecting the liquid level, the lever moves down a certain distance, and the motor 11 drives the plunger 14 to draw in the liquid. Reversing the motor 11 discharges the liquid. When the tip needs to be retracted, the motor continues to reverse, thus retracting the tip and notifying the system.

[0073] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A pipetting channel with dual liquid level detection function, characterized in that, It includes a power source, a transmission mechanism, a guide mechanism, an actuator, and a housing. The power source and the transmission mechanism are both mounted on the housing. The guide mechanism is fixed inside the housing. The actuator is mounted inside the guide mechanism. The power source, the transmission mechanism, and the actuator are sequentially connected in a transmission manner. The transmission mechanism includes a bearing, a lead screw (6) and a plunger seat (13). The lead screw (6) is fixed to the housing by the bearing. The nut of the lead screw (6) is rotatably connected to the plunger seat (13). The plunger seat (13) is limited by the guide mechanism. The actuator includes a pump body (1), an optical coupler plate (2), a plunger (14), a processing plate (15), a gun rod (21), a gun head retraction rod (22), a suction nozzle (24), and a stop rod (27). The pump body (1) is mounted on the outer casing. The optical coupler plate (2), the processing plate (15), and the gun rod (21) are all fixed to the pump body (1). One end of the plunger (14) is connected to the plunger seat (13), and the other end is located in the cavity inside the gun rod (21). The suction nozzle (24) is fixed to the end of the gun rod (21). The suction nozzle (24) is used to install external consumables. The gun retraction rod (22) is sleeved on the outside of the gun rod (21). The gun retraction rod (22) is movably connected to the pump body (1) and has a spring force pointing outward from the pump body (1). The stop rod (27) is fixed to the gun retraction rod (22) and enters or exits the detection area of ​​the optical coupler plate (2) under the drive of the gun retraction rod (22). The processing plate (15), the gun rod (21) and the suction nozzle (24) are electrically connected in sequence. The processing plate (15) is also connected to the optical coupler plate (2). The processing plate (15) is used to collect the changes in capacitance on the suction nozzle (24) in real time to determine whether the external consumables mounted on the suction nozzle (24) are in contact with the liquid surface; The processing plate (15) is connected to a sensor that senses the pressure of the gun barrel cavity. The pump body (1) is provided with an air hole that connects the sensor and the cavity inside the gun barrel (21). The processing plate (15) is used to determine whether the external consumables mounted on the suction nozzle (24) are in contact with the liquid surface based on the change in pressure of the gun barrel cavity detected by the sensor. The actuator also includes a thrust rod (26) and a thrust spring (28). The thrust rod (26) is movably connected inside the pump body (1). One end of the thrust rod (26) is connected to the pump body (1) through the thrust spring (28), and the other end is fixedly connected to the gun retraction rod (22).

2. The pipetting channel with dual liquid level detection function according to claim 1, characterized in that, The gun barrel (21) and the suction nozzle (24) are both made of conductive materials, while the gun head retractor (22) is made of insulating material.

3. A pipetting channel with dual liquid level detection function according to claim 2, characterized in that, The actuator is also provided with a conductive spring (19) and a conductive screw (20). The gun rod (21) is fixed to the pump body (1) by the conductive screw (20) and the conductive spring (19). The processing plate (15), the conductive screw (20), the conductive spring (19), the gun rod (21) and the suction nozzle (24) are electrically connected in sequence.

4. A pipetting channel with dual liquid level detection function according to claim 1, characterized in that, The power source includes a motor (11), a motor base (10), and a coupling (9). The motor (11) and the coupling (9) are both mounted on the motor base (10), which is fixed to the outer casing. The motor (11), the coupling (9), and the lead screw (6) are connected in sequence for transmission.

5. A pipetting channel with dual liquid level detection function according to claim 1, characterized in that, The connection between the plunger (14) and the pump body (1) is provided with a first seal.

6. A pipetting channel with dual liquid level detection function according to claim 1, characterized in that, The outer surface of the gun rod (21) is provided with a groove, and a second seal is provided at the connection between the pump body (1) and the gun rod (21), the second seal being located in the groove.

7. A pipetting channel with dual liquid level detection function according to claim 1, characterized in that, The external consumable is a conductive material.

8. A pipetting channel with dual liquid level detection function according to claim 1, characterized in that, When external consumables are installed on the nozzle (24), the gun retraction rod (22) drives the stop rod (27) to enter the detection area of ​​the optical coupler plate (2).

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