Automatic sample diluting device and method

Abstract

The invention discloses an automatic sample diluting device and method, the automatic sample diluting device comprises a sampling mechanism and a cleaning mechanism, the cleaning mechanism comprises a cleaning sleeve, and the side part of the cleaning sleeve is communicated with a cleaning introduction pipe and a cleaning discharge pipe; a sampling arm of the sampling mechanism is driven by a ball screw nut pair driven by a stepping motor I to ascend and descend along a left linear guide pair and a right linear guide pair, the overhanging end of the sampling arm is provided with a double-cavity needle tube sampling needle which downwards penetrates through a cleaning sleeve and is aligned to a sampling test tube, and at the top of the sampling needle, one cavity tube is connected with the sampling tube, and the other cavity tube is connected with a sampling test tube; at the descending limiting position of the sampling arm, the sampling needle extends into the sampling test tube and the needle tip at the lower end of the sampling needle does not touch the bottom of the sampling test tube, and at the ascending limiting position of the sampling arm, the sampling needle retreats from the sampling test tube and the needle tip of the sampling needle is located in the cleaning sleeve. According to the invention, the instrument detection efficiency is improved, sampling consumables are saved, and the defect of sample pollution caused by difficulty in complete manual cleaning is overcome.

Description

Technical Field

[0001] The invention relates to detection technology, in particular to an automatic sample dilution device and method. Background Art

[0002] Sample dilution is a common experimental operation method that can reduce the concentration of the test solution in the experiment so that its concentration range is controlled within the appropriate measurement range in order to obtain more accurate results.

[0003] At present, in analytical chemistry and medical testing applications, sample dilution is done by taking mother solution with a pipette or a pipette, and manually adding dilution solution to make the volume constant. In the continuous dilution process, manual operation errors are large and time is long; and the existing dilution methods cannot quickly and effectively clean the nozzle of the pipette or pipette during operation, causing sample contamination. Summary of the invention

[0004] The present invention provides an automatic sample dilution device and method, the technical problem to be solved is to overcome the problems of low efficiency of sample dilution means in the prior art and difficulty in complete cleaning during the sampling process, thereby causing sample contamination.

[0005] The automatic sample dilution device and method capable of solving the above technical problems include a sampling mechanism and a cleaning mechanism, the difference being that:

[0006] 1. The cleaning mechanism comprises a cleaning sleeve, and a cleaning inlet pipe and a cleaning outlet pipe are connected on the side of the cleaning sleeve.

[0007] 2. The sampling mechanism includes a sampling arm, which is driven by a ball screw nut pair driven by a stepper motor I to perform lifting and lowering movements along left and right linear guide pairs. The overhanging end of the sampling arm is provided with a sampling needle that penetrates downward through the cleaning sleeve and is aligned with the sampling test tube. The sampling needle is a double-lumen needle tube. At the top of the sampling needle, one lumen is connected to the sampling tube, and the other lumen is connected to the sampling test tube.

[0008] 3. At the limited position where the sampling arm descends, the sampling needle extends into the sampling test tube and the lower needle tip of the sampling needle does not touch the bottom of the sampling test tube.

[0009] 4. At the limited position where the sampling arm rises, the sampling needle exits the sampling tube and the needle tip of the sampling needle is in the cleaning sleeve.

[0010] Furthermore, a structure of the ball screw nut pair includes a screw and a ball screw nut that cooperate with each other, the ball screw nut is arranged in the sampling arm, the upper shaft end of the screw is connected to the rotating shaft of the stepper motor I, and the stepper motor I is installed on the top of the sampling rack.

[0011] Furthermore, a structure of each linear guide pair includes a guide rod and ball linear bearings that cooperate with each other. The left and right ball linear bearings are arranged in the sampling arm on both sides of the ball screw nut, and the left and right guide rods are installed between the top and bottom of the sampling frame.

[0012] Furthermore, an upper photoelectric sensor and a lower photoelectric sensor installed on the side of the sampling frame are respectively provided at the upper and lower limited positions, and a photoelectric sensor baffle I which can sense the upper and lower photoelectric sensors respectively is provided on the sampling arm.

[0013] Conventionally, the technical solution of the present invention also includes a turntable mechanism, and a plurality of sampling test tubes are evenly arranged on the turntable of the turntable mechanism. The turntable rotates under the drive of a synchronous belt wheel transmission pair driven by a stepper motor II to rotate each sampling test tube to a sampling position.

[0014] The automatic sample dilution device of the present invention operates in the following steps:

[0015] 1. After the starting position of the turntable is calibrated, place N sampling tubes containing samples on the turntable.

[0016] 2. Stepper motor II starts, the turntable rotates and transfers the first sampling tube to the sampling position.

[0017] 3. Stepper motor I starts, and the sampling arm drives the sampling needle down and extends into the sampling test tube until the photoelectric sensor baffle I senses the lower photoelectric sensor and stops. At this time, the needle tip of the sampling needle does not touch the bottom of the sampling test tube.

[0018] 4. Perform sampling and dilution operations through sampling tubes, and perform sampling and testing operations through sampling test tubes.

[0019] 5. After the dilution and sampling test are completed, the stepper motor I starts, and the sampling arm drives the sampling needle to rise and move out of the sampling tube until the photoelectric sensor baffle I senses the upper photoelectric sensor and stops. At this time, the needle tip of the sampling needle is inside the cleaning sleeve.

[0020] 6. Inject cleaning liquid into the cleaning sleeve through the cleaning introduction tube to clean the needle tip surface and the needle hole of the sampling needle, and draw the cleaning liquid out of the cleaning sleeve through the cleaning discharge tube to complete the cleaning process.

[0021] 7. Stepper motor II starts, and the turntable rotates the next sampling tube to the sampling position, and the first sampling tube that has completed dilution is rotated out of the sampling position.

[0022] 8. Repeat steps 3 to 7 continuously to automatically complete the dilution operation of the samples in all sampling test tubes.

[0023] Beneficial effects of the present invention:

[0024] 1. The present invention can cooperate with the detection instrument to perform sample dilution processing, such as automatic test tube sampling, automatic liquid dilution, automatic detection, and cleaning of the sampling needle and liquid path after completion. Especially when the number of samples is large, it can effectively reduce manual steps and improve the detection efficiency of the instrument.

[0025] 2. In the structure of the present invention, the sampling mechanism, the cleaning mechanism and the turntable mechanism cooperate with each other to realize cyclical, precise and automatic sampling, dilution and cleaning operations.

[0026] 3. The present invention eliminates the need for disposable sampling nozzle consumables, effectively saving costs and being energy-efficient and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is an axonometric view of an embodiment of the present invention.

[0028] Figure 2 for Figure 1 Exploded view of an embodiment.

[0029] Figure 3 for Figure 1 Axonometric view of the sampling mechanism from a first perspective in an embodiment.

[0030] Figure 4 for Figure 1 Axonometric view of the sampling mechanism from a second perspective in an embodiment.

[0031] Figure number identification: 1. Sampling arm; 2. Stepper motor I; 3. Sampling needle; 4. Sampling tube; 5. Sampling test tube; 6. Cleaning sleeve; 7. Cleaning inlet tube; 8. Cleaning outlet tube; 9. Sampling test tube; 10. Screw; 11. Ball screw nut; 12. Guide rod; 13. Ball linear bearing; 14. Sampling rack; 15. Upper photoelectric sensor; 16. Lower photoelectric sensor; 17. Photoelectric sensor baffle I; 18. Turntable; 19. Stepper motor II; 20. Synchronous belt pulley transmission pair; 21. Base; 22. Cleaning rack; 23. Motor base; 24. Photoelectric sensor baffle II; 25. Zero position photoelectric sensor. DETAILED DESCRIPTION

[0032] The technical solution of the present invention is further described below in conjunction with the embodiments shown in the accompanying drawings.

[0033] The automatic sample dilution device of the present invention comprises a sampling mechanism, a cleaning mechanism and a turntable mechanism arranged on a base 21, such as Figure 1 , Figure 2 shown.

[0034] The sampling mechanism is arranged on the rear left side of the base 21, including a sampling frame 14 fixedly mounted on the base 21, the sampling frame 14 includes a top plate and a bottom plate and a side plate connected to the rear side of the top plate and the bottom plate, a stepper motor Ⅰ2 is installed on the top plate, a sampling arm 1 is arranged between the top plate and the bottom plate, and a ball screw nut pair is arranged between the top plate and the bottom plate in correspondence with the stepper motor Ⅰ2, the ball screw nut pair includes a screw 10 and a ball screw nut 11 screwed together, the upper and lower ends of the screw 10 are respectively installed on the top plate and the bottom plate through bearings, and the screw 1 The upper end of 0 passes through the top plate and is connected to the downward rotating shaft of the stepper motor Ⅰ2. The ball screw nut 11 is arranged inside the sampling arm 1. The stepper motor Ⅰ2 drives the sampling arm 1 to rise and fall between the top plate and the bottom plate along the left and right linear guide pairs through the ball screw nut pair; each linear guide pair includes a sliding guide rod 12 and a ball linear bearing 13. The left and right guide rods 12 are vertically arranged between the top plate and the bottom plate on both sides of the screw rod 10, and the left and right ball linear bearings 13 are arranged inside the sampling arm 1 on both sides of the ball screw nut 11. Figure 1 , Figure 2 , Figure 3 , Figure 4 shown.

[0035] The right end of the sampling arm 1 is a cantilever, and a sampling needle 3 is installed vertically downward in the right end hole of the cantilever. The sampling needle 3 is a double-lumen needle tube, and the position corresponding to the sampling needle 3 downward is the sampling position. At the top of the sampling needle 3, one lumen is connected to a sampling tube 4 located above the sampling arm 1, and the other lumen is connected to a sampling test tube 5 located above the sampling arm 1; a photoelectric sensor baffle Ⅰ17 extending backward is installed on the cantilever, and an upper photoelectric sensor 15 and a lower photoelectric sensor 16 are provided on the side plate of the sampling frame 14 corresponding to the photoelectric sensor baffle Ⅰ17. When the sampling arm 1 rises and falls, the photoelectric sensor baffle Ⅰ17 respectively senses the upper and lower photoelectric sensors 15 and 16 to limit the height position of the sampling arm 1 rising and falling, as shown in FIG. Figure 1 , Figure 2 , Figure 3 , Figure 4 shown.

[0036] The cleaning mechanism includes a cleaning sleeve 6, and the upper and lower interfaces on the side of the cleaning sleeve 6 are respectively connected with a cleaning introduction pipe 7 and a cleaning discharge pipe 8. The sampling needle 3 passes through the cleaning sleeve 6, and the cleaning sleeve 6 is installed on the side plate of the sampling frame 14 through the cleaning frame 22. The installation height of the cleaning sleeve 6 corresponds to the upper photoelectric sensor 15, that is, when the sampling arm 1 stops at the limited rising position, the lower end needle tip of the sampling needle 3 is inside the cleaning sleeve 6, as shown in FIG. Figure 1 , Figure 2 , Figure 3 , Figure 4 shown.

[0037] The turntable mechanism is arranged on the right side of the sampling mechanism. The I-shaped turntable 18 of the turntable mechanism is installed on the base 21 through a rotating shaft. The front side of the turntable 18 is provided with a stepper motor II 19 installed on the base 21 through a motor seat 23. The stepper motor II 19 is connected to the rotating shaft through a synchronous belt pulley transmission pair 20. The synchronous belt pulley transmission pair 20 includes a driving pulley and a driven pulley connected by a synchronous belt. The driving pulley is installed on the downward rotating shaft of the stepper motor II 19, and the driven pulley is installed on the rotating shaft between the turntable 18 and the base 21. The circumference of the turntable 18 is evenly distributed with upper and lower pairs of The base 21 is provided with a zero-position photoelectric sensor 25, and a photoelectric sensor baffle II 24 is provided on the lower part of the turntable 18 corresponding to the zero-position photoelectric sensor 25. The photoelectric sensor baffle II 24 triggers the zero-position photoelectric sensor 25 once for each rotation of the turntable 18, so as to calibrate the origin position of each rotation of the turntable 18, thereby ensuring that each sampling tube 9 reaches the sampling position accurately. Figure 1 , Figure 2 shown.

[0038] The automatic sample dilution device of the present invention is used, and the operation scheme steps are as follows:

[0039] 1. First, calibrate the starting position of the turntable 18 , and then place N sampling tubes 9 containing samples in the corresponding insertion holes on the turntable 18 .

[0040] 2. The stepper motor II 19 is started, and the rotating turntable 18 rotates the first sampling tube 9 to the sampling position.

[0041] 3. The stepper motor Ⅰ2 is started, and the sampling arm 1 drives the sampling needle 3 to descend (extend out of the cleaning sleeve 6) and extend into the sampling test tube 9 until the photoelectric sensor baffle Ⅰ17 and the lower photoelectric sensor 16 are inductively sensed and stop. At this time, the needle tip of the sampling needle 3 does not touch the bottom of the sampling test tube 9.

[0042] 4. Perform sampling and dilution work through the sampling tube 4, and perform sampling and testing work through the sampling test tube 5.

[0043] 5. After the dilution and sampling test are completed, the stepper motor Ⅰ2 is started, and the sampling arm 1 drives the sampling needle 3 to rise and move out of the sampling tube 9 until the photoelectric sensor baffle Ⅰ17 and the upper photoelectric sensor 15 are sensed and stop. At this time, the needle tip of the sampling needle 3 returns to the inside of the cleaning sleeve 6.

[0044] 6. Inject cleaning liquid into the cleaning sleeve 6 through the cleaning introduction tube 7 to clean the needle tip surface and the needle hole of the sampling needle 3, and quickly draw the cleaning liquid out of the cleaning sleeve 6 through the cleaning discharge tube 8 to complete the cleaning process.

[0045] 7. The stepper motor II 19 is started, and the rotating turntable 18 rotates the next sampling tube 9 to the sampling position, and the first sampling tube 9 that has completed dilution is rotated out of the sampling position.

[0046] 8. Repeat steps 3 to 7 continuously to automatically complete the dilution operation of the samples in all the sampling test tubes 9.

Claims

1. A sample automatic dilution device, comprising a sampling mechanism and a cleaning mechanism, characterized in that: The cleaning mechanism comprises a cleaning sleeve (6), and a cleaning inlet pipe (7) and a cleaning outlet pipe (8) are connected on the side of the cleaning sleeve (6); The sampling mechanism comprises a sampling arm (1), and the sampling arm (1) is driven by a ball screw nut pair driven by a stepping motor I (2) to perform an ascending and descending motion along left and right linear guide pairs. A sampling needle (3) is provided at the cantilevered end of the sampling arm (1), which penetrates downward through a cleaning sleeve (6) and is aligned with a sampling test tube (9). The sampling needle (3) is a double-lumen needle tube, and at the top of the sampling needle (3), one lumen is connected to the sampling tube (4), and the other lumen is connected to the sampling test tube (5); At a limited position where the sampling arm (1) is lowered, the sampling needle (3) extends into the sampling test tube (9) and the lower needle tip of the sampling needle (3) does not touch the bottom of the sampling test tube (9); At the limited position where the sampling arm (1) rises, the sampling needle (3) exits the sampling test tube (9) and the needle tip of the sampling needle (3) is located in the cleaning sleeve (6).

2. The automatic sample dilution device according to claim 1, characterized in that: The ball screw nut pair comprises a screw (10) and a ball screw nut (11) which cooperate with each other. The ball screw nut (11) is arranged in the sampling arm (1). The upper shaft end of the screw (10) is connected to the rotating shaft of the stepper motor I (2). The stepper motor I (2) is installed on the top of the sampling frame (14).

3. The automatic sample dilution device according to claim 2, characterized in that: Each linear guide pair comprises a guide rod (12) and a ball linear bearing (13) that cooperate with each other. The left and right ball linear bearings (13) are arranged in the sampling arm (1) on both sides of the ball screw nut (11). The left and right guide rods (12) are installed between the top and the bottom of the sampling frame (14).

4. The automatic sample dilution device according to claim 2, characterized in that: An upper photoelectric sensor (15) and a lower photoelectric sensor (16) mounted on the side of the sampling frame (14) are respectively provided at the upper and lower limited positions, and a photoelectric sensor baffle I (17) capable of induction with the upper and lower photoelectric sensors (15, 16) is provided on the sampling arm (1).

5. The automatic sample dilution device according to any one of claims 1 to 4, characterized in that: The invention also comprises a turntable mechanism, wherein a plurality of sampling test tubes (9) are evenly arranged on a turntable (18) of the turntable mechanism. The turntable (18) is driven by a synchronous belt wheel transmission pair (20) driven by a stepping motor II (19) to perform a rotary motion to rotate each sampling test tube (9) to a sampling position.

6. The automatic sample dilution method is characterized by The automatic sample dilution device as claimed in claim 5 is used, and the steps of its operation scheme are as follows: ① After the starting position of the turntable (18) is calibrated, N sampling tubes (9) containing samples are placed in place on the turntable (18); ②, the stepping motor II (19) is started, the turntable (18) rotates and the first sampling tube (9) is transferred to the sampling position; ③. The stepper motor I (2) is started, and the sampling arm (1) drives the sampling needle (3) to descend and extend into the sampling test tube (9) until the photoelectric sensor baffle I (17) and the lower photoelectric sensor (16) are inductively coupled and stop. At this time, the needle tip of the sampling needle (3) does not touch the bottom of the sampling test tube (9); ④, performing sampling and dilution operations through the sampling tube (4), and performing sampling and testing operations through the sampling test tube (5); ⑤. After the dilution and sampling test are completed, the stepper motor I (2) is started, and the sampling arm (1) drives the sampling needle (3) to rise and move out of the sampling tube (9) until the photoelectric sensor baffle I (17) and the upper photoelectric sensor (15) are inductively sensed and stop, at which time the needle tip of the sampling needle (3) is inside the cleaning sleeve (6); ⑥, injecting cleaning liquid into the cleaning sleeve (6) through the cleaning introduction tube (7) to clean the needle tip surface and the needle hole of the sampling needle (3), and drawing the cleaning liquid out of the cleaning sleeve (6) through the cleaning discharge tube (8) to complete the cleaning process; ⑦. The stepping motor II (19) is started, and the turntable (18) rotates the next sampling tube (9) to the sampling position, and the first sampling tube (9) that has been diluted is rotated out of the sampling position. ⑧. Repeating steps ③ to ⑦ continuously will automatically complete the dilution operation of the samples in all the sampling test tubes (9).

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