Ultrasonic cleaner, automatic analyzer using the same, and cleaning method for dispensing nozzle

Abstract

To provide an ultrasonic cleaning machine having a configuration suitable for being mounted in a narrow space such as a transport rack capable of irradiating the periphery of the nozzle with strong ultrasonic waves, with a small fluctuation of the liquid surface.SOLUTION: The ultrasonic cleaning machine includes: a washing tank having a concave portion capable of inserting a dispensing nozzle to be washed; and an ultrasonic transducer with a piezoelectric element and front mass. On the side of the cleaning tank, a through hole with an opening is provided on the outer wall surface of the cleaning tank and the inner wall surface of the concave portion, a front mass is inserted into the through hole, and the tip of the front mass is arranged for irradiation with ultrasonic waves from the side of the dispensing nozzle.SELECTED DRAWING: Figure 2B

Description

Technical Field

[0001] The present disclosure relates to an ultrasonic cleaner, an automatic analyzer using the same, and a method for cleaning a dispensing nozzle.

Background Art

[0002] An automatic analyzer mixes a sample such as serum or urine with a reagent and performs component analysis by measuring the transmittance of light irradiated on the mixed solution. In an automatic analyzer, since the same nozzle is repeatedly used to dispense samples, a nozzle cleaning process is performed to wash away the tip of the nozzle with a water stream before sucking another sample. However, in an automatic analyzer with high throughput performance, since the dispensing process is performed at high speed, sufficient time cannot be used for nozzle cleaning. Therefore, dirt derived from sample components may accumulate at the tip of the nozzle, and it is dealt with by removing it during daily cleaning and maintenance.

[0003] When dirt accumulates at the tip of the nozzle, variations in the dispensing volume and carry-over of the previous sample components into the next sample are likely to occur, and the measurement accuracy decreases.

[0004] Patent Document 1 discloses an ultrasonic cleaner having a diaphragm attached with a bolt-tight Langevin vibrator (BLT), which has an opening provided on the side surface of a cleaning tank for storing a cleaning liquid, and this opening is closed with a diaphragm, and generates cavitation by ultrasonic waves (a phenomenon in which bubbles are generated and disappear due to the pressure difference generated in the liquid) to clean the dispensing nozzle.

[0005] Further, Patent Document 2 discloses a cleaning rack for cleaning a nozzle used for sucking and discharging a sample or a reagent, which includes a cleaning tank, an ultrasonic generating element, and an electronic circuit for controlling the ultrasonic generating element, and is movable along a transport line.

Prior Art Documents

Patent Documents

[0006] [Patent Document 1] International Publication No. 2017 / 002740 [Patent Document 2] Japanese Unexamined Patent Application Publication No. 2014 - 89200 [Summary of the Invention] [Problems to be Solved by the Invention]

[0007] When adding a unit that can newly clean the nozzles to an automatic analyzer that has already been delivered and is actually in use, it is desirable to add a small cleaning unit to the narrow space remaining between the arranged components or to add it temporarily during maintenance. This is because major hardware changes have problems such as high modification costs and a period during which analysis cannot be performed.

[0008] The cleaning rack described in Patent Document 2 has a configuration in which an ultrasonic generating element (piezoelectric element) is directly installed on the bottom surface or side surface of the cleaning tank.

[0009] When installing a piezoelectric element in a general ultrasonic cleaner, the amplitude of the ultrasonic irradiation surface is amplified by using a wide - area portion such as the bottom surface of the cleaning tank as a diaphragm, and a standing wave is generated in the liquid by the vibration. In the standing wave, there is a region where the sound pressure becomes high (the antinode part of the standing wave), and cavitation occurs in this region. For cleaning based on such a principle, in a rack that requires miniaturization (small area) of the bottom surface (or side surface) compared to a commercially available ultrasonic cleaner, sufficient amplitude does not occur, and it is difficult to obtain a cleaning effect due to cavitation generation. In particular, for intensively cleaning the tip of a nozzle with a diameter of 1 mm or less, the cleaning efficiency is low.

[0010] Instead of manual cleaning and maintenance, to clean the outer periphery of the nozzle with ultrasonic waves, it is necessary to generate a high - sound - pressure region where ultrasonic cavitation stably occurs at the outer peripheral part of the nozzle tip.

[0011] In the ultrasonic cleaner described in Patent Document 1, a cleaning head provided at the tip of an ultrasonic vibrator is vibrated to intensively clean the tip of a nozzle, and an example of a configuration for generating ultrasonic cavitation in a hollow portion into which the nozzle is inserted is shown. In this configuration, the vibration amplified by the cleaning head is used to generate strong cavitation on the outer periphery of the nozzle tip. However, since the cleaning head is inserted from above the liquid level in the cleaning tank and the cleaning head vibrates in the liquid and in the air with the liquid level in between, there is a large swing of the liquid level, and there is a risk of liquid level fluctuations and liquid splashing. Therefore, it is not suitable for a conveyor-type cleaning method. For a cleaner with a large swing of the liquid like this configuration, a cleaning tank that can overflow the liquid to keep the liquid level constant is used, but it is difficult to use in a conveyor-type cleaning with limited size.

[0012] An object of the present disclosure is to provide an ultrasonic cleaner having a configuration suitable for mounting in a narrow space such as a conveyor rack, with little shaking of the liquid level and capable of irradiating strong ultrasonic waves to the outer peripheral portion of the nozzle.

Means for Solving the Problems

[0013] The ultrasonic cleaner of the present disclosure includes a cleaning tank having a recess into which a dispensing nozzle to be cleaned can be inserted, and an ultrasonic vibrator having a piezoelectric element and a front mass. On the side surface of the cleaning tank, a through hole having openings on the outer wall surface of the cleaning tank and the inner wall surface of the recess is provided. The front mass is inserted into the through hole, and the tip of the front mass is arranged to irradiate ultrasonic waves from the side of the dispensing nozzle.

Effects of the Invention

[0014] According to the present disclosure, it is possible to provide an ultrasonic cleaner having a configuration suitable for mounting in a narrow space such as a conveyor rack, with little shaking of the liquid level and capable of irradiating strong ultrasonic waves to the outer peripheral portion of the nozzle.

[0015] Also, according to the present disclosure, the nozzle can be inserted into a region close to the end face of the cylindrical portion where the maximum amplitude of the ultrasonic vibrator occurs, and the cleaning effect over the entire circumference of the nozzle can be improved by irradiation in two or more directions.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2A

Figure 2B

Figure 2C

Figure 2D

Figure 2E

Figure 2F

Figure 3

Figure 4A

Figure 4B

Figure 5A

Figure 5B

Figure 6A

Figure 6B

Figure 7

Figure 8A

Figure 8B

Figure 8C

Figure 8D

Figure 8E

Figure 9

Mode for Carrying Out the Invention

[0017] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

Example

[0018] FIG. 1 is a perspective view showing the automatic analyzer of Example 1.

[0019] As shown in this figure, the automatic analyzer 10 includes a reagent disk 12 for installing a plurality of reagent containers 11, a reaction disk 13 for mixing a reagent and a sample and measuring the reaction, a reagent dispensing mechanism 14 for sucking and discharging the reagent, and a sample dispensing mechanism 15 for sucking and discharging the sample.

[0020] The reagent dispensing mechanism 14 includes a reagent nozzle 21 for dispensing the reagent. The sample dispensing mechanism 15 includes a sample nozzle 22 for dispensing the sample. Here, nozzles such as the reagent nozzle 21 and the sample nozzle 22 are collectively referred to as "dispensing nozzles".

[0021] The sample introduced into the apparatus is placed in a sample container 23 (test tube) and installed in a rack 24, and is conveyed by a conveyance line 25. A plurality of sample containers 23 are installed in the rack 24. The sample is a blood-derived sample such as serum or whole blood or urine.

[0022] The sample dispensing mechanism 15 moves the sample nozzle 22 to a suction position for sucking the sample from the sample container 23, a discharge position for discharging the sample into the cell 26 (as shown enlarged in the figure, each of which is a small, separated container), and a cleaning position where there is a cleaning tank 27 for flushing the tip of the sample nozzle 22 with water. Further, the sample dispensing mechanism 15 lowers the sample nozzle 22 in accordance with the height of the sample container 23 at the suction position, the height of the cell 26 at the discharge position, and the height of the cleaning tank 27 at the cleaning position.

[0023] In summary, the sample dispensing mechanism 15 is configured to be able to move the sample nozzle 22 to each stop position by rotational movement and vertical movement.

[0024] Note that the control of the sample dispensing mechanism 15 and the control of devices such as the transport line 25 are performed by a control unit (not shown). Also, the automatic analyzer 10 has a measurement unit (not shown), and analyzes the concentration of a predetermined component contained in the sample by photometric measurement of the mixed solution of the sample and the reagent accommodated in the cell 26. The measurement unit has, for example, a light source and a photometer. The photometer is, for example, an absorption photometer or a scattering photometer.

[0025] The cleaning rack 30 equipped with an ultrasonic cleaner has a cleaning unit described later and is used to clean the tip of the sample nozzle 22 that has come into contact with the sample. The timing of use is the timing of the daily maintenance of the automatic analyzer 10, and it is mostly carried out before or after the analysis. When the number of samples handled per day is large, the cleaning rack 30 may be passed through the transport line 25 and used during the intervals between analyses. Thereby, the cleanliness of the sample nozzle 22 can be maintained.

[0026] The cleaning rack 30 can be used to clean not only samples but also reagent nozzles 21 or sample nozzles 22 that can access the transport line 25, without being limited to samples. Also, multiple sample nozzles 22 can be cleaned during one transport. However, since there is a possibility of reattachment of dirt due to the reuse of the cleaning liquid contaminated by cleaning, it is desirable to replace the cleaning liquid for each nozzle. In this case, there are methods such as flowing one cleaning rack 30 through the transport line 25 multiple times or flowing multiple cleaning racks 30. Also, the reagent nozzle 21 that cannot access the transport line 25 will be described in Example 2 below.

[0027] Note that as the transport method of the transport line 25, a belt that moves along the transport line 25, a method using push claws, a method using electromagnetic force, etc. can be applied.

[0028] FIG. 2A is a top view showing an example of the configuration of the cleaning unit of the ultrasonic cleaner of the present embodiment.

[0029] In this figure, the cleaning unit includes two ultrasonic vibrators 201A and 201B (vibrating units) and a cleaning tank 202. The cleaning tank 202 is provided with a liquid storage hole 210 (recess) having an opening on the upper surface.

[0030] FIG. 2B is a cross-sectional view taken along line A-A of FIG. 2A.

[0031] As shown in this figure, the cleaning tank 202 is provided with through holes 211 that penetrate the liquid storage hole 210 from the left and right sides in the figure. In other words, the through holes 211 have openings on the side surface of the cleaning tank 202, on the outer wall surface of the cleaning tank 202, and on the inner wall surface of the liquid storage hole 210 (recess). The ultrasonic vibrators 201A and 201B are inserted into the two through holes 211, respectively. The ultrasonic vibrators 201A and 201B are fixed to the side surface of the cleaning tank 202 by flanges 203 and seals 204 (O-rings). With this configuration, liquid leakage from the through holes 211 can be prevented.

[0032] The ultrasonic vibrators 201A and 201B have the same configuration.

[0033] The ultrasonic transducers 201A and 201B are composed of a front mass 205 (front metal block), a back mass 206 (rear metal block), a plurality of piezoelectric elements 207, a plurality of electrodes 208 (copper plates), and fastening bolts 209. The piezoelectric elements 207 and the electrodes 208 each have a configuration in which two sheets are alternately stacked. The stacked piezoelectric elements 207 and electrodes 208 are sandwiched between the front mass 205 and the back mass 206 and fixed by the fastening bolts 209.

[0034] Note that although the number of the piezoelectric elements 207 and the electrodes 208 shown in this figure is a configuration in which two sheets are alternately stacked, the ultrasonic transducers according to the present disclosure are not limited to this, and a configuration in which four sheets are alternately stacked or other numbers may be used.

[0035] In summary, the ultrasonic transducers 201A and 201B have a configuration fixed by bolt tightening, similar to a general bolt-clamped Langevin type transducer (BLT). Since the configuration of the BLT is advantageous for amplitude amplification, it is used when using high-power ultrasonic waves and is also used in industrial ultrasonic cleaning machines that require strong cleaning performance.

[0036] By driving the ultrasonic transducer 201 at the resonance frequency, the amplitude of the tip surface 214 of the front mass 205 can be maximized.

[0037] The thin cylindrical portion, which is the portion inserted into the through hole 211 of the front mass 205, is positioned by the seal 204. For this reason, a substantially uniform gap is formed between the cylindrical portion and the wall surface of the through hole 211. Further, the seal 204 is disposed at the base of the cylindrical portion. Thereby, the cylindrical portion can transmit vibration to the liquid in the liquid storage hole 210 without contacting the wall surface of the through hole 211. Also, because of this gap, the deformation of the cylindrical portion 212 caused by the driving of the ultrasonic transducer 201 is not inhibited.

[0038] Note that the liquid in the liquid storage hole 210 can be injected up to near the upper end portion 215 of the liquid storage hole 210. As a result, the gap formed around the cylindrical portion of the front mass 205 inserted into the through hole 211 is filled with the liquid.

[0039] FIG. 2C is a front view showing the cleaning section of FIG. 2A.

[0040] As shown in FIG. 2C, the upper part of the cleaning tank 202 of the cleaning section 200 has a notch formed in the central part. This notch is formed to keep the liquid level position of the liquid storage hole 210 at the upper end portion 215 of the liquid storage hole 210.

[0041] FIG. 2D is a perspective view showing the ultrasonic vibrator used for the cleaning section of FIG. 2A.

[0042] As shown in FIG. 2D, a cylindrical portion 212 is formed on the front mass 205 of the ultrasonic vibrator 201. The base portion of the cylindrical portion 212 is a stepped portion 213. The front end surface 214 of the cylindrical portion 212 is the portion that irradiates ultrasonic waves to the contacting liquid.

[0043] A seal 204 is embedded in the side surface of the cleaning tank 202. The liquid stored in the liquid storage hole 210 is sealed by the seal 204 that contacts near the stepped portion 213 at the base of the cylindrical portion 212. In other words, the seal 204 is installed at the base of the cylindrical portion 212. Further in other words, the seal 204 is sandwiched between the base of the cylindrical portion 212 and the inner wall surface of the through hole 211.

[0044] Similar to a general BLT, the amplitude of the ultrasonic vibrator 201 is maximum at the front end surface 214, and the cylindrical portion 212 deforms.

[0045] If the cylindrical portion 212 is configured to be completely constrained by the through hole 211 of the cleaning tank, it will become a large load for driving the ultrasonic vibrator 201, inhibit its vibration, and a sufficient cleaning effect cannot be obtained.

[0046] In the ultrasonic vibrator 201 of this embodiment, a node of vibration (a region where the amplitude is always small) is provided near the step portion 213. Further, the seal 204 is made of an elastic material. Therefore, the influence due to the contact between the cylindrical portion 212 and the seal 204 is small. In summary, the front mass 205 has a step portion 213, and the seal 204 is installed on the step portion 213. With such a configuration, the vibration of the ultrasonic vibrator 201 is propagated to the liquid with almost no inhibition.

[0047] FIG. 2E is a perspective view showing the cleaning portion of FIG. 2A.

[0048] In FIG. 2E, the tip surface 214 of the cylindrical portion 212 of the ultrasonic vibrator 201 reaches the position of the inner wall surface of the liquid storage hole 210 through the through hole 211.

[0049] Even when the tip surface 214 does not reach the position of the inner wall surface of the liquid storage hole 210, in other words, even in a configuration where the tip surface 214 of the cylindrical portion 212 is in the through hole 211, if the condition of the distance between the two tip surfaces 214 described later is satisfied, a desired effect can be obtained.

[0050] FIG. 2F is a side view showing the cleaning portion of FIG. 2A.

[0051] In FIG. 2F, the arrangement of the fastening bolts 209 and the flange 203 of the ultrasonic vibrator 201 is shown.

[0052] When the liquid is injected into the liquid storage hole 210, the tip surface 214 of the front mass 205 is immersed in the liquid. In this state, the two ultrasonic vibrators 201 are driven to irradiate ultrasonic waves into the liquid from the tip surface 214. It is desirable that the upper end portion of the tip surface 214, which is the irradiation portion of the ultrasonic wave, is about 0.5 to 1 mm from the liquid surface (the upper end portion 215 of the liquid storage hole 210). By arranging in this way, only the portion of the sample nozzle 22 immersed in the liquid can be intensively cleaned.

[0053] If the front end surface 214 is placed deep from the liquid surface, since the cleaning area moves away from the liquid surface, in order to wash the tip of the sample nozzle 22, it is necessary to insert the sample nozzle 22 deeply into the liquid. With such an arrangement, the wetted range of the sample nozzle 22 increases. Since the sample nozzle 22 is designed to ensure dispensing accuracy by limiting the wetted range in the liquid, it is desirable not to wet a wide range. For this reason, it is desirable to provide a cleaning area near the liquid surface.

[0054] The cylindrical portions 212 of the two ultrasonic transducers 201 are arranged symmetrically with respect to the central axis of the liquid storage hole 210. Also, the central axes of the two cylindrical portions 212 are arranged to coincide. In other words, the central axes of the two cylindrical portions 212 are arranged coaxially. With this configuration, ultrasonic waves can be irradiated from two directions that are 180 degrees different with respect to the sample nozzle 22, and the entire circumference of the sample nozzle 22 can be cleaned.

[0055] Note that the dimensions of the cleaning unit 200 are preferably such that they fit within the rack 24. By having such dimensions, the cleaning unit 200 can be moved to the position of the sample nozzle 22 and cleaned.

[0056] The sample nozzle 22 is preferably inserted along the central axis in the vertical direction of the liquid storage hole 210. This is because ultrasonic waves can be evenly irradiated from the two ultrasonic transducers 201, and an appropriate and sufficient cleaning effect can be obtained. Note that even if the central axes of the two cylindrical portions 212 are not coaxial, a cleaning effect can still be obtained.

[0057] FIG. 3 is a configuration diagram showing an example of a cleaning rack having the ultrasonic cleaner of the present embodiment.

[0058] As shown in this figure, the cleaning rack 30 includes a cleaning unit 200, an ultrasonic transducer control unit 301, a drive power source 302 (battery), and a transport base 303. The ultrasonic transducer control unit 301 controls the driving of the ultrasonic transducers 201A and 201B (FIG. 2A).

[0059] The ultrasonic oscillator control unit 301 generates sine waves of the resonance frequencies of the ultrasonic oscillators 201A and 201B to drive the ultrasonic oscillator 201. Further, the ultrasonic oscillator control unit 301 also has an impedance matching circuit for increasing the drive current of the ultrasonic oscillator 201 to amplify the amplitude and a circuit for automatically tracking the resonance frequency.

[0060] The drive power source 302 is a rechargeable battery and is charged each time the cleaning rack 30 is used. Since the cleaning time of the sample nozzle 22 is in the range of several minutes or less and there is no need for long-time driving, a small battery is sufficient. The charging of the drive power source 302 may be configured to be performed by installing a wireless power feeding unit at a predetermined position adjacent to the conveyance line 25.

[0061] The conveyance base 303 has the same shape as the bottom of the rack 24 used for the sample container 23. Therefore, there is no need to change the hardware of the conveyance line 25. Note that the cleaning rack 30 including the cleaning unit 200, the ultrasonic oscillator control unit 301, and the drive power source 302 has a size smaller than that of the rack 24 with the conventional sample container 23 installed.

[0062] The cleaning unit 200 is covered with a cover 304. The cover 304 prevents liquid from being applied to the piezoelectric element 207 and the electrode 208 when supplying and discharging liquid to and from the liquid storage hole 210 by a pipette or the like.

[0063] As described above, since the ultrasonic oscillator 201 is sealed at the node of vibration, the vibration amplification efficiency is high. Further, by arranging the tip surface 214 of the ultrasonic oscillator 201 close to the side surface portion of the sample nozzle 22, strong ultrasonic waves can be irradiated to the sample nozzle 22, and the cleaning effect can be enhanced. Furthermore, by irradiating ultrasonic waves from two directions, a configuration that enables cleaning even in a narrow space such as the small cleaning rack 30 is realized.

[0064] Incidentally, the amount of cleaning liquid required for cleaning varies depending on the size of the liquid storage hole 210, but is about several hundred μL to several mL. Also, water can be used as the cleaning liquid to obtain a cleaning effect, but a mixture containing a detergent or the detergent itself may also be used. When using a detergent, it is desirable to provide a cover on the upper surface of the liquid storage hole 210 to prevent the liquid from splashing.

[0065] As described above, the automatic analyzer according to the present disclosure has a configuration in which the ultrasonic cleaner of the present embodiment is used by being transported.

[0066] FIG. 4A is a schematic diagram showing a case where there is one ultrasonic vibrator in the ultrasonic cleaner.

[0067] In this figure, unlike FIG. 2A, it shows a case where the ultrasonic vibrator is arranged on only one side. In this case, since ultrasonic waves are irradiated from the tip surface 214 of one ultrasonic vibrator, only one side of the sample nozzle 22 inserted into the liquid storage hole 210 is cleaned. In this case, since ultrasonic waves are not directly irradiated on the outer surface of the sample nozzle 22 on the side opposite to the irradiation surface, dirt may remain. In this case, it is necessary to clean the sample nozzle 22 again using a cleaning rack having cleaning parts with different orientations of the tip surface 214.

[0068] FIG. 4B is a schematic diagram showing a case where there are two ultrasonic vibrators in the ultrasonic cleaner.

[0069] In this figure, it shows a case having the same configuration as the cleaning part 200 in FIG. 2C. That is, by irradiating ultrasonic waves from both sides (two directions) of the sample nozzle 22, the entire circumference can be cleaned if the sample nozzle 22 has a small diameter (about 1 mm).

[0070] The distance between the front end surfaces 214A and 214B is preferably about the same as the diameters of the cylindrical portions 212A and 212B. For example, if the cylindrical portion has a diameter of 3 mm, the distance between the front end surfaces 214A and 214B is set to 3 mm, and if the cylindrical portion has a diameter of 5 mm, the distance between the front end surfaces 214A and 214B is set to 5 mm. From the front end surface 214, a region where the sound pressure concentrates in a hemispherical shape is generated. At this time, the diameter of the hemisphere is about the same as the diameter of the front end surface 214. When ultrasonic waves are irradiated from two coaxial surfaces, the distance at which the two hemispheres do not interfere is twice the radius of the two hemispheres (the diameter of the hemisphere). Also, since the front end surfaces 214A and 214B on the same axis also act as reflection surfaces for the ultrasonic waves irradiated on each other, if the distance between the opposing front end surfaces 214A and 214B is too close, it will be a factor that reduces the cleaning efficiency.

[0071] In FIG. 4B, by approaching the distance between the sample nozzle 22 and the front end surface 214A and the distance between the sample nozzle 22 and the front end surface 214B, strong ultrasonic waves can be irradiated to the outer peripheral portion of the sample nozzle 22. However, as described above, the distance is set based on the diameter of the cylindrical portion 212. That is, the condition with high cleaning efficiency is when the distance between the front end surfaces 214A and 214B is about the same as the diameters of the cylindrical portions 212A and 212B.

[0072] However, as will be described later, when two ultrasonic vibrators are driven alternately, the distance between the front end surfaces 214A and 214B may be configured to be closer than the diameter of the cylindrical portion 212.

[0073] Also, in FIG. 4A, by making the distance from the front end surface 214A to the wall surface of the cleaning tank 210 about the same as the diameter of the cylindrical portion 212, the influence of the reflection of ultrasonic waves from the wall surface of the cleaning tank 210 can be suppressed.

[0074] FIG. 5A is a flowchart showing a method for cleaning a dispensing nozzle by the ultrasonic cleaner of the present embodiment.

[0075] As shown in this figure, cleaning liquid is injected into the liquid storage hole 210 of the cleaning unit 200 (step S501). Then, the signal output of the ultrasonic vibrator control unit 301 is turned on (step S502). The turning on of the signal output is performed by means of a switch on the cleaning rack 30 or communication with an external terminal. The cleaning rack 30 is installed on the transport line 25 (step S503). Thereafter, the automatic cleaning function is started from the terminal of the automatic analyzer 10 (step S504).

[0076] Here, steps S501 to S503 can be performed manually, but can also be performed automatically using a cleaning liquid dispensing unit or the like installed in the automatic analyzer 10. In this case, when a command signal for starting the automatic cleaning function is sent from the terminal of the automatic analyzer 10 as in step S504, the cleaning rack 30 is automatically installed on the transport line 25, and the cleaning liquid is automatically injected into the liquid storage hole 210 of the cleaning unit 200.

[0077] When the automatic cleaning starts, the cleaning rack 30 is transported to the position where the nozzle 22 for the target sample is located (step S505). When transporting the normal rack 24, the subsequent analysis and transport processes are branched by reading the barcode attached to the side of the rack 24. Therefore, by attaching a barcode to the cleaning rack 30 at the same position as the normal rack 24, it is possible to distinguish between the rack 24 used for inspection and the cleaning rack 30 used for cleaning within the automatic analyzer 10, and the cleaning operation can be executed.

[0078] After transporting the cleaning rack 30 close to the nozzle 22 for the target sample, the nozzle 22 for the sample is lowered toward the liquid storage hole 210, and the tip of the nozzle 22 for the sample is immersed in the cleaning liquid for a certain period of time to perform cleaning (step S506). After the cleaning is completed, the nozzle 22 for the sample is raised, and then the cleaning rack 30 is carried out (step S507). Then, the carried-out cleaning rack 30 is collected (step S508). Thereafter, the ultrasonic signal output is turned off (step S509).

[0079] After that, the cleaning liquid may be replaced as necessary, and the nozzle 22 for another sample may be cleaned. If not cleaned, the cleaning liquid in the liquid storage hole 210 is discharged to end. At the end, a new cleaning liquid is put into the liquid storage hole 210, and by driving the ultrasonic vibrator 201, it is possible to suppress the adhesion of dirt that has entered the gap. Therefore, as maintenance of the cleaning unit 200 itself, it may be driven other than during conveyance.

[0080] In the process shown in this figure, since the conveyance line 25 is moved while holding the cleaning liquid, it is desirable to provide control for detecting the sway of the cleaning rack 30 and stopping the output of the ultrasonic wave. If the ultrasonic wave is continuously irradiated while the cleaning rack 30 is swaying greatly, there is a concern that the cleaning liquid will scatter and wet the inside of the apparatus.

[0081] Figure 5B is a flowchart showing a method for dealing with the sway of the cleaning rack.

[0082] In this figure, while the ultrasonic vibrator 201 is being driven (step S511), if the detection of the sway of the cleaning rack 30 or the reception of a cleaning OFF signal (including the OFF of the switch) is detected (step S512), the driving of the ultrasonic vibrator 201 is stopped (step S513). If the sway of the cleaning rack 30 or the like is not detected in step S512, the driving of the ultrasonic vibrator 201 is continued (step S511).

[0083] As a method other than the detection of the sway of the cleaning rack 30 or the like, there is a method of controlling and communicating with the automatic analyzer 10 to limit the timing of driving the ultrasonic vibrator 201.

[0084] In addition, in order to prevent the dirt remaining in the liquid storage hole 210 after cleaning from adhering to the liquid storage hole 210, the front mass 205, etc., it is desirable to continue driving the ultrasonic vibrator 201 until immediately before discharging the cleaning liquid.

[0085] Figure 6A is a graph showing an example of the driving pattern of two ultrasonic vibrators included in the ultrasonic cleaner of this embodiment.

[0086] In this figure, two ultrasonic transducers A and B are driven alternately.

[0087] Figure 6B is a graph showing another example of the driving pattern of two ultrasonic transducers.

[0088] In this figure, two ultrasonic transducers A and B are driven simultaneously.

[0089] Any of the driving patterns is the timing for cleaning during the period from when the sample nozzle 22 descends into the liquid storage hole 210 until it ascends.

[0090] As described above, in the method of turning on the drive before conveyance, the driving of the ultrasonic transducers A and B is repeated from before the descent of the sample nozzle 22. When controlling and communicating with the automatic analyzer 10 to limit the driving timing of the ultrasonic transducers A and B, the period from when the sample nozzle 22 descends into the liquid storage hole 210 until it ascends is the timing for cleaning. In this case, it is acceptable for the ON-OFF timing to shift slightly back and forth.

[0091] In the driving pattern of alternately driving as shown in Figure 6A, control is performed so that the driving of the ultrasonic transducer A and the driving of the ultrasonic transducer B do not overlap. In the control circuit, there is a circuit for switching between the ultrasonic transducers A and B to which signals are output, and the output is switched at regular intervals. In this case, the ultrasonic transducer control unit 301 automatically tracks the resonance frequency of one of the driving ultrasonic transducers, and switches the ultrasonic transducer to be automatically tracked each time the driving is switched. As described above, since the ultrasonic transducers A and B can be maximized when driven at the resonance frequency, the cleaning effect by the ultrasonic waves irradiated from the respective ultrasonic transducers A and B is also enhanced.

[0092] The switching of driving between the ultrasonic vibrators A and B may be performed, for example, every several hundred milliseconds to several seconds during cleaning. In this case, the switching may be performed multiple times during one cleaning. To start driving either of the ultrasonic vibrators A and B in accordance with the descending timing of the sample nozzle 22, it can be achieved by controlling and communicating with the automatic analyzer 10 as described above.

[0093] In the pattern of driving simultaneously, it is desirable to drive the ultrasonic vibrators A and B with the same output. There is one driving signal of the vibrator output from the control circuit, and this signal is branched and output to the ultrasonic vibrators A and B. In this case, the ultrasonic vibrator control unit 301 automatically tracks the resonance frequency of either of the ultrasonic vibrators A and B, or drives at a frequency near (or intermediate) the resonance frequencies of the two ultrasonic vibrators A and B. To drive at a frequency near the resonance frequencies of the two ultrasonic vibrators A and B, there are a method of determining the driving frequency from the previously measured frequency and a method of adding a circuit for detecting the resonance frequency during driving and changing it as needed.

[0094] Since the ultrasonic vibrators A and B of this embodiment have a simple shape, the variation in resonance frequency due to the manufacture and assembly of the vibrators is small. Therefore, if the driving frequency is near the resonance frequencies of the two ultrasonic vibrators A and B, the two ultrasonic vibrators A and B can be driven with a large amplitude.

[0095] The piezoelectric elements 207 of the ultrasonic vibrators A and B may have their characteristics changed due to heat generation, and the resonance frequency may shift when driven for a long time. In this embodiment, from the time of installation on the conveyance line until the sample nozzle 22 descends, it is a short time of about several tens of seconds, and the cleaning time, including the conveyance time, is also within several minutes or less. In the cleaning process, the resonance frequency does not shift significantly. Therefore, even if the driving frequency is a fixed value, there are few practical problems. However, assuming an environment with a change in room temperature throughout the year, it is desirable to have a resonance frequency detection function.

[0096] Incidentally, although impedance variations due to the manufacturing and assembly of the ultrasonic vibrator 201 can be suppressed within a certain range during shipping inspections and the like, if the difference between the two impedances is known, the cleaning power balance of the two ultrasonic vibrators 201 can be adjusted by adjusting the drive voltage and cleaning time for each. However, as described above, the variations due to manufacturing and assembly are small, so by providing a sufficient cleaning time (for example, several tens of seconds or more), the entire circumference of the sample nozzle 22 can be cleaned.

[0097] Incidentally, there may be three or more ultrasonic vibrators 201. In this case as well, ultrasonic waves may be irradiated simultaneously from the ultrasonic vibrators 201, or ultrasonic waves may be irradiated from any two or fewer of the three or more ultrasonic vibrators 201. In other words, one or more of the ultrasonic vibrators 201 may be alternately paused, and ultrasonic waves may be alternately irradiated from some of the ultrasonic vibrators 201.

[0098] FIG. 7 is a configuration diagram showing an automatic analyzer corresponding to the case of using the ultrasonic cleaner built in the transport rack of the present embodiment.

[0099] In this figure, the automatic analyzer is controlled by an automatic analyzer control unit 701. The user of the automatic analyzer can give instructions for analysis processing and cleaning processing from a graphical user interface 702 (GUI). The switching between the normal analysis processing and the cleaning maintenance mode according to the present embodiment is performed by a normal mode / automatic cleaning maintenance mode switching means 703 (normal mode / automatic cleaning maintenance mode switching unit), and the sample dispensing mechanism 15 and the transport line 25 are controlled according to each mode.

[0100] The sample dispensing mechanism 15 controls the position of the sample nozzle 22 via the dispensing arm horizontal movement means 705 (dispensing arm horizontal movement unit) and the dispensing arm vertical movement means 706 (dispensing arm vertical movement unit) from the dispensing arm control means 704 (dispensing arm control unit). In the cleaning maintenance mode, the horizontal position and vertical position of the sample nozzle 22 are controlled so that the cleaning range at the tip of the sample nozzle 22 is immersed in the liquid in the liquid storage hole 210. The horizontal position of the sample nozzle 22 is preferably the intermediate position between the two tip surfaces 214, but it is also possible to perform control such as moving horizontally while immersing and approaching the tip surface 214A or the tip surface 214B.

[0101] The transport line 25 is driven from the rack transport control means 707 (rack transport control unit) via the rack transport means 708 (rack transport unit). The barcode reader 709 (barcode reader) installed on the transport line 25 reads the barcode provided on the transported rack 24 or the cleaning rack 30, discriminates the type of the rack by the rack type detection means 710 (rack type detection unit), and sends the rack type information to the normal mode / auto cleaning maintenance mode switching means 703. Based on this information, the switching to the cleaning maintenance mode is performed. It is also possible to perform the switching to the cleaning maintenance mode from the GUI in advance. Also, instead of the barcode, a QR code (registered trademark), an IC chip, etc. may be used. Also, discrimination by image recognition using a camera may be used. Note that the rack information acquisition means 709 is also referred to as the "rack information acquisition unit".

[0102] The cleaning rack 30 has a shake detection means 721 (shake detection unit) that stops the drive of the ultrasonic vibrator 201 when the above-mentioned shake is detected, a vibrator drive means 722 (vibrator drive unit) that detects and drives the resonance frequency of the ultrasonic vibrator 201, and a drive control means 723 (drive control unit) that switches the drive of the two ultrasonic vibrators 201, independently of the automatic analyzer control unit 701. The shake detection means 721 is preferably an acceleration sensor or the like.

[0103] With the above configuration, the cleaning rack 30 is conveyed to a position on the conveyance line 25 where the sample nozzle 22 can access, and by immersing the sample nozzle 22 in the liquid storage hole 210, the cleaning area of the sample nozzle 22 can be cleaned.

[0104] Regarding the reagent nozzle 21 as well, if it can access the conveyance line 25, it can be implemented with a similar configuration.

[0105] In addition, in this embodiment, the case where the reagent nozzle 21 and the sample nozzle 22 are provided separately is described. However, depending on the analyzer, there may be a case where dispensing of the reagent and the sample is performed by one shared nozzle. Even in such a device, cleaning with water flow is performed every time the reagent or the sample is dispensed, but daily maintenance is necessary. By performing the ultrasonic cleaning of the present invention, the dispensing accuracy can be maintained.

Example

[0106] FIG. 8A is a partial cross-sectional view showing one of two types of ultrasonic cleaners according to Example 2.

[0107] In the cleaning rack 801A shown in this figure, one ultrasonic vibrator 201 is installed in the cleaning unit 802A, and the ultrasonic vibrator 201 is arranged on the advancing direction side of the conveyance base 303.

[0108] FIG. 8B is a partial cross-sectional view showing the other of two types of ultrasonic cleaners according to this example.

[0109] In the cleaning rack 801B shown in this figure, one ultrasonic vibrator 201 is installed in the cleaning unit 802B, and the ultrasonic vibrator 201 is arranged on the side opposite to the advancing direction of the conveyance base 303.

[0110] FIG. 8C is a schematic diagram showing the cleaning mode corresponding to FIG. 8A.

[0111] In Fig. 8C, ultrasonic waves are irradiated from the tip surface 214C (left side in the figure) of the cylindrical portion 212C to the sample nozzle 22 immersed in the liquid in the liquid storage hole 210C.

[0112] Fig. 8D is a schematic diagram showing the cleaning mode corresponding to Fig. 8B.

[0113] In Fig. 8D, ultrasonic waves are irradiated from the tip surface 214D (right side in the figure) of the cylindrical portion 212D to the sample nozzle 22 immersed in the liquid in the liquid storage hole 210D.

[0114] Fig. 8E is a schematic diagram showing a modified example of the ultrasonic cleaner of Fig. 8A.

[0115] When the ultrasonic vibrator control unit 301 and the drive power source 302 are integrated with the cleaning unit 200 as in the cleaning rack 30 shown in Fig. 3, the size becomes large and may not fit into one reagent container.

[0116] The ultrasonic cleaner of Fig. 8E has components separated and placed in two containers. That is, the cleaning unit is placed in one container 811, and the ultrasonic vibrator control unit and the drive power source are placed in another container 812. In other words, the ultrasonic cleaner has a configuration in which the cleaning tank and the ultrasonic vibrator, and the ultrasonic vibrator control unit and the drive power source can be installed separately.

[0117] By separating them into two in this way, two containers 811 and 812 can be installed on the reagent disk 12 instead of the two reagent containers 11 installed on the reagent disk 12 (Fig. 1).

[0118] Since the reagent containers 11 can be installed adjacent to each other as shown in Fig. 1, it is possible to adopt a configuration in which the container 811 and the container 812 are connected by wiring.

[0119] Therefore, the example of Fig. 8E can be called a reagent container type cleaner 810 by combining the two containers 811 and 812.

[0120] The ultrasonic cleaner of this embodiment is configured such that one ultrasonic vibrator is provided in one cleaning unit. In this case, cleaning is performed using two cleaning racks 801A and 801B.

[0121] In the cleaning racks 801A and 801B, the traveling directions are the same, but the directions in which ultrasonic waves are irradiated are different. The transport line 25 of the automatic analyzer 10 has a structure that can only transport in one direction. For this reason, the transport base 303 has notches or the like, and has a structure in which the rack 24 cannot be installed in the wrong direction. Therefore, between the cleaning rack 801A and the cleaning rack 801B, only the shape of the transport base 303 is different.

[0122] The insertion position of the sample nozzle 22 of the liquid storage hole 210 is a position shorter than the distance half of the diameter of the cylindrical portion 212 from the tip surface 214. As described above, since a region with strong sound pressure is generated in a hemispherical shape from the tip surface 214, if the sample nozzle 22 is inserted at a distant position, the cleaning efficiency will decrease.

[0123] Also, by setting the insertion position of the sample nozzle 22 as the center of the cleaning rack, it is possible to control without changing the horizontal position when the sample nozzle 22 descends two times (or multiple times).

[0124] The cleaning effect according to this embodiment can clean the entire circumference of the sample nozzle 22 by cleaning in two separate directions, similar to when the ultrasonic vibrators 201 of Embodiment 1 are driven alternately. Although not shown in FIG. 1, since the transport line 25 also has a return transport line that returns to the position where the rack 24 was inserted, it is also possible to perform cleaning alternately multiple times by circulating the cleaning racks 801A and 801B.

[0125] If the transport base 303 or the cleaning unit can be rotated 180 degrees, it is possible to change the traveling direction even with a single cleaning rack. In that case, a shaft may be provided at the center of the cleaning rack, and only the transport base 303 (or the cleaning unit 802) may be structured to rotate. In this case, the cleaning rack is arranged so that the center line of the cleaning rack overlaps with the descending position of the sample nozzle 22. That is, as described above, the tip surface 214 is at a position shorter than half the diameter of the cylindrical portion 212 from the center line.

[0126] The cleaning unit of this embodiment has a smaller width compared to Embodiment 1 and can be installed on the reagent disk 12 in the same manner as the reagent container 11. Even in this case, by installing a reagent container type cleaning machine having two different irradiation directions, it is possible to perform cleaning from two directions in the same manner as in FIGS. 8A and 8B.

[0127] In addition, since the reagent container type cleaning machine can be installed on the reagent disk 12, it is suitable for cleaning the reagent nozzle 21.

[0128] According to the configuration of this embodiment, in the cleaning of the sample nozzle 22 and the reagent nozzle 21, by irradiating ultrasonic waves from different directions in two or more times, it is possible to clean the entire circumference of the tip portions of the reagent nozzle 21 and the sample nozzle 22.

Example

[0129] FIG. 9 is a cross-sectional view showing the cleaning unit of Embodiment 3.

[0130] In this figure, the cleaning unit 900 has a configuration in which two ultrasonic transducers 201 are installed in the cleaning tank 901. The two ultrasonic transducers 201 have a waterproof configuration. The ultrasonic transducer 201 has a configuration in which a piezoelectric element 207, a back mass 206, and a part of a front mass 205 are covered by a cover 902. Waterproofing is achieved by providing a seal portion 903 between the large-diameter portion of the front mass 205 and the pressing portion 904. The cylindrical portion, which is the small-diameter portion of the front mass 205, is in contact with the liquid 910 in the cleaning tank 901. With such a configuration, the liquid 910 does not come into contact with the electrical components such as the piezoelectric element 207 and the electrode 208. A gap is provided between the pressing portion 904 and the cylindrical portion 212 so that they do not come into contact with each other.

[0131] Regarding the arrangement, cleaning method, and control method of the two ultrasonic transducers 201, they are the same as those in the foregoing embodiments.

[0132] By adding means for automatically supplying and discharging the cleaning liquid, the cleaning units of the above three embodiments can also be fixedly used in the automatic analyzer 10. In the embodiments, two directions are described as an example, but ultrasonic waves may be irradiated from two or more directions, and the entire circumference of the nozzle can be more reliably cleaned. If it is three directions, the cleaning efficiency can be improved by installing the irradiation surfaces at 120-degree intervals. That is, three or more ultrasonic transducers may be installed in one cleaning unit.

[0133] It is desirable that the diameter of the common circle with which the front end surfaces of the front masses of three or more (a plurality of) ultrasonic transducers are in contact is substantially equal to the diameter of the front end surface of the front mass. Here, the common circle refers to the circle with which the front end surfaces of a plurality of front masses arranged around the liquid storage hole 210 (recess) of the cleaning tank 202 are all in contact. The center of this circle coincides with the central axis of the recess when the recess is circular when viewed from above.

[0134] When there are two ultrasonic transducers and the front end surfaces of the front masses are facing each other, the distance between the two front end surfaces corresponds to the diameter of the common circle.

Explanation of Reference Numerals

[0135] 10: Automatic analyzer, 11: Reagent container, 12: Reagent disk, 13: Reaction disk, 14: Reagent dispensing mechanism, 15: Sample dispensing mechanism, 21: Reagent nozzle, 22: Sample nozzle, 23: Sample container, 24: Rack, 25: Conveyor line, 26: Cell, 27: Cleaning tank, 201: Ultrasonic vibrator, 202: Cleaning tank, 203: Flange, 204: Seal, 205: Front mass, 206: Back mass, 207: Piezoelectric element, 208: Electrode, 209: Fastening bolt, 210: Liquid storage hole, 211: Through hole, 212: Cylindrical portion, 213: Step portion, 214: Tip surface, 301: Ultrasonic vibrator control unit, 302: Drive power supply, 303: Conveyor base, 304: Cover, 701: Automatic analyzer control unit, 702: Graphical user interface, 703: Normal mode / automatic cleaning maintenance mode switching means, 704: Dispensing arm control means, 705: Dispensing arm horizontal movement means, 706: Dispensing arm vertical movement means, 707: Rack conveyance control means, 708: Rack conveyance means, 709: Rack information acquisition means, 710: Rack type detection means, 721: Vibration detection means, 722: Vibrator drive means, 723: Drive control means, 801A, 801B: Cleaning rack, 802A, 802B: Cleaning section, 810: Reagent container type washer, 811, 812: Container, 900: Cleaning section, 901: Cleaning tank, 902: Cover, 903: Seal section, 904: Pressing section.

Claims

1. A cleaning tank having a recess into which a dispensing nozzle to be cleaned can be inserted, and an ultrasonic vibrator having a piezoelectric element and a front mass, wherein a through-hole having openings in the outer wall surface of the cleaning tank and the inner wall surface of the recess is provided on a side surface of the cleaning tank, the front mass is inserted into the through-hole, and a tip of the front mass is arranged to irradiate ultrasonic waves from a side of the dispensing nozzle. An ultrasonic cleaning machine.

2. The ultrasonic cleaning machine according to claim 1, wherein a plurality of the ultrasonic vibrators are installed on the side surface of the cleaning tank.

3. The ultrasonic cleaning machine according to claim 2, wherein a diameter of a common circle with which tip surfaces of the front masses of the plurality of ultrasonic vibrators are in contact is substantially equal to a diameter of the tip surface of the front mass.

4. The ultrasonic cleaning machine according to claim 3, wherein two of the ultrasonic vibrators are arranged coaxially.

5. The front mass has a stepped portion, and a seal is installed in the stepped portion. The ultrasonic cleaning machine according to claim 1.

6. The ultrasonic cleaning machine according to claim 3, wherein an upper end portion of the recess is 0.5 to 1 mm from an upper end portion of the tip surface of the front mass.

7. Further including a shake detection unit, and when the shake detection unit detects a shake, the ultrasonic vibrator is configured to stop driving. The ultrasonic cleaning machine according to claim 1.

8. The ultrasonic cleaning machine according to claim 1, further including an ultrasonic vibrator control unit and a drive power source.

9. The ultrasonic cleaning machine according to claim 8, further including a transport base.

10. The ultrasonic cleaning machine according to claim 8, having a configuration in which the cleaning tank and the ultrasonic vibrator, the ultrasonic vibrator control unit and the drive power source can be installed separately.

11. The ultrasonic cleaning machine according to claim 1, further including a barcode, a QR code (registered trademark) or an IC chip capable of discriminating a type.

12. An automatic analyzer having the ultrasonic cleaning machine according to any one of claims 1 to 11.

13. An automatic analyzer having a configuration in which the ultrasonic cleaning machine according to any one of claims 1 to 11 is used by conveyance.

14. A method of cleaning the dispensing nozzle using the ultrasonic cleaning machine according to claim 1 by a signal from an automatic analyzer control unit, the method including: a step of immersing the dispensing nozzle in a cleaning liquid injected into the recess, A method for cleaning a dispensing nozzle, comprising: irradiating the ultrasonic wave from the tip of the front mass.

15. The method for cleaning a dispensing nozzle according to claim 14, further comprising a step of transporting the ultrasonic cleaner to a position where the dispensing nozzle can be inserted into the recess before the step of immersing the dispensing nozzle.

16. The ultrasonic cleaner has a plurality of ultrasonic vibrators. The method for cleaning a dispensing nozzle according to claim 14, wherein the ultrasonic waves are irradiated simultaneously from the plurality of ultrasonic vibrators.

17. The ultrasonic cleaner has a plurality of ultrasonic vibrators. The method for cleaning a dispensing nozzle according to claim 14, wherein the ultrasonic waves are irradiated alternately from a part of the plurality of ultrasonic vibrators.

18. The method for cleaning a dispensing nozzle according to claim 14, wherein two or more ultrasonic cleaners with different directions of the tip of the front mass are used to irradiate the ultrasonic waves toward the dispensing nozzle from different directions.

19. A cleaning tank having a recess into which a dispensing nozzle to be cleaned can be inserted, An ultrasonic vibrator having a piezoelectric element and a front mass, The ultrasonic vibrator is installed in the recess of the cleaning tank. An ultrasonic cleaner, wherein the tip of the front mass is arranged to irradiate ultrasonic waves from the side of the dispensing nozzle.

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