Ultrasonic washing machine, method for injecting liquid into liquid storage part of ultrasonic washing machine, and automatic analysis device

Abstract

The present disclosure provides a technique that makes it possible to reduce a required amount of a washing liquid during washing and improving cleaning and maintenance performances. The present disclosure proposes an ultrasonic washing machine for ultrasonically washing a dispensing nozzle, and the ultrasonic washing machine comprises: an ultrasonic vibrator having a front mass; and a block member including a hole part that is provided in the longitudinal direction and that allows insertion therein of the front mass and including a washing tank installation recess that is for installing therein a washing tank in which a dispensing nozzle to be washed can be inserted and which has an elastic body wall in at least a portion thereof. The washing tank installation recess is provided in a direction different from the longitudinal direction where the hole part is provided in the block member. A liquid storage part for storing a liquid different from the washing liquid is configured by a gap formed from the front mass inserted in the hole part, the hole part, and the wall of the washing tank. The washing liquid held by the washing tank and the liquid stored in the liquid storage part are separated by the wall of the washing tank, and the leading end part of the front mass is disposed so as to emit ultrasonic waves from the lateral side of the washing tank.

Description

Ultrasonic cleaner, method for injecting liquid into liquid storage section of ultrasonic cleaner, and automatic analyzer

[0001] The present disclosure relates to an ultrasonic cleaner, a method for injecting a liquid into a liquid reservoir of an ultrasonic cleaner, and an automatic analyzer.

[0002] Automated analyzers perform component analysis by mixing a sample, such as serum or urine, with a reagent and measuring the transmittance of light irradiated onto the mixture. Because the same nozzle is repeatedly used to dispense samples, automated analyzers perform a nozzle cleaning process in which the nozzle tip is rinsed with a stream of water before aspirating another sample.

[0003] However, high-throughput automated analyzers perform dispensing at high speeds, which means there is not enough time to clean the nozzles. As a result, dirt from sample components can accumulate at the nozzle tip. When dirt accumulates at the nozzle tip, it can lead to variations in the amount of dispensing and carryover, where components from the previous sample are brought into the next sample, reducing measurement accuracy. For this reason, the dirt is removed during daily cleaning and maintenance.

[0004] For example, Patent Document 1 discloses an ultrasonic cleaner configured to address dirt on the nozzle tip by attaching a bolted Langevin transducer (hereinafter referred to as "BLT") to the side of a cleaning tank, and irradiating ultrasonic waves directly onto the nozzle from the front mass of the BLT located inside the cleaning tank via the liquid in the cleaning tank.

[0005] Furthermore, for example, Patent Document 2 discloses an example of an ultrasonic cleaner used for cleaning nozzles, in which a double tank is used to store liquid, an ultrasonic vibrator is attached to the outer tank for vibrating the liquid, and different types of liquid are placed in each of the inner and outer tanks for cleaning.

[0006] JP 2023-034566 A JP 2015-158426 A

[0007] For example, when adding a new unit for cleaning and maintaining the nozzle to an automated analyzer that has already been delivered and is in use, it is desirable to add a small cleaning unit in the narrow space remaining between the installed parts, or to add it temporarily during maintenance, as large-scale hardware changes have issues such as high modification costs and periods when analysis cannot be performed.

[0008] Meanwhile, according to Patent Document 1, the cleaning rack uses a BLT, whose front mass, which emits ultrasonic waves, located submerged in the liquid in the cleaning tank. Direct ultrasonic waves are applied to the nozzles, generating powerful cavitation (a phenomenon in which bubbles are generated and destroyed due to pressure differences in the liquid), enabling cleaning. To generate powerful ultrasonic waves with a BLT, the amplitude of the ultrasonic wave irradiated surface (front mass) must be amplified. Therefore, Patent Document 1 provides a seal (O-ring) at the flange, which serves as the vibration node, to prevent liquid leakage from the cleaning tank. Most of the front mass, located distal to the flange of the BLT, is submerged in the liquid. Furthermore, to achieve large amplitude vibration, BLTs are generally driven at their resonant frequency. In particular, they are designed with a long overall length to resonate at frequencies around 20 to 50 kHz, which are favorable for generating cavitation. Therefore, due to the elongated front mass, when placed submerged as described above, a large contact area with the liquid is required, resulting in a large volume of cleaning liquid. Furthermore, new cleaning liquid is added to the cleaning tank before nozzle cleaning and discarded after cleaning.

[0009] When disposing of the cleaning fluid, the areas that come into contact with the dirty fluid must be cleaned with water or other cleaning procedures. A configuration like the one described above, in which the entire long front mass is immersed in the cleaning fluid, requires a lot of effort to clean. Furthermore, because there is a gap between the long, narrow front mass and the cleaning tank, even if the same amount of liquid is poured into the cleaning tank, the liquid level can vary depending on whether or not the liquid seeps into the gap, affecting the cleaning area.

[0010] Furthermore, the example of ultrasonic cleaning described in Patent Document 2 employs a configuration similar to that of a general ultrasonic cleaner. When a piezoelectric element is installed in a general ultrasonic cleaner, a large area such as the bottom of the cleaning tank is used as a diaphragm to amplify the amplitude of the ultrasonic irradiation surface, and the resulting vibration generates a standing wave in the liquid. The standing wave has an area where the sound pressure is high (the antinode of the standing wave), and cavitation occurs in this area.

[0011] However, according to the cleaning principle described in Patent Document 2, when a rack is used that requires a smaller bottom (or side) (smaller area) than commercially available ultrasonic cleaners, sufficient amplitude is not generated, making it difficult to obtain a cleaning effect due to the generation of cavitation. In particular, cleaning efficiency is low when intensively cleaning the tip of a small nozzle with a diameter of 1 mm or less.

[0012] In addition, in the indirect tank method (double cleaning tank) where another tank is placed inside the cleaning tank in a general ultrasonic cleaner, a hard material (metal such as stainless steel or glass) is often chosen for the indirect tank (inner tank).The reason for this is that the principle is that the vibrations generated in the outer tank are propagated through the vibrating surface that comes into contact with the liquid and the indirect tank, generating ultrasonic waves inside the indirect tank, and the rigidity is required to propagate vibrations in the high-frequency ultrasonic band.

[0013] However, metal and glass have the property of easily reflecting ultrasonic waves, and ultrasonic waves from an outer tank are reflected by the indirect tank. The ultrasonic waves generated in the indirect tank are generated by the indirect tank itself being excited in the ultrasonic band, and the cavitation generation efficiency (cavitation-based cleaning efficiency) is lower than in methods that directly irradiate ultrasonic waves. Therefore, in the indirect tank method, which is the cleaning principle described above, in rack-type washer machines configured in narrow spaces, the distance between the BLT and the indirect tank must be set close, and ultrasonic waves reflected from the indirect tank become a load on the BLT drive, reducing drive efficiency. In consideration of these circumstances, the present disclosure provides a technology that reduces the amount of cleaning liquid required during cleaning and enables improved cleaning maintenance.

[0014] In order to solve the above problems, the present disclosure proposes an ultrasonic cleaner for ultrasonically cleaning dispensing nozzles, comprising: an ultrasonic vibrator having a front mass; and a block member including a longitudinally disposed hole for inserting the front mass; and a cleaning tank installation recess for installing a cleaning tank into which the dispensing nozzle to be cleaned can be inserted, the cleaning tank having at least a portion of an elastic wall; the cleaning tank installation recess is disposed in a direction different from the longitudinal direction in which the hole is disposed in the block member; a liquid storage section for storing a liquid other than the cleaning liquid is formed by a gap formed between the front mass inserted in the hole, the hole, and the wall of the cleaning tank; the cleaning liquid held in the cleaning tank and the liquid stored in the liquid storage section are separated by the wall of the cleaning tank; and the tip of the front mass is positioned so as to irradiate ultrasonic waves from the side of the cleaning tank.

[0015] Further features related to the present disclosure will become apparent from the description of this specification and the accompanying drawings. Also, aspects of the present disclosure are achieved and realized by the elements and combinations of various elements and the aspects of the following detailed description and the appended claims. The description of this specification is merely exemplary and does not limit the scope or application of the claims of the present disclosure in any way.

[0016] According to the present disclosure, it is possible to provide an ultrasonic cleaner that has a configuration suitable for installation in a small space such as a transport rack, requires a small amount of cleaning liquid during cleaning, is easy to clean and maintain, and can irradiate powerful ultrasonic waves to the outer periphery of the nozzle.

[0017] 2B is an enlarged view of the inside of the dotted line frame in FIG. 2B. FIG. 2C is a view showing an example of the front configuration of the cleaning unit 200 of FIG. 2A. FIG. 2D is a view showing an example of the side configuration of the cleaning unit 200 of FIG. 2A. FIG. 2E is a view showing an example of the overall external configuration of the cleaning unit 200 of FIG. 2A. FIG. 2F is a view showing an example of the cross-sectional configuration of the cleaning tank of FIG. 2A. FIG. 2G is a view showing an example of the external configuration of the cleaning tank of FIG. 2A. FIG. 2H is a schematic view showing an enlarged view of the periphery of the tip of the front mass 206 (206A and 206B in the figure) of the ultrasonic vibrators 201A and 201B (the black painted parts are the liquid in the liquid storage section 216). FIG. 2H is a schematic view (viewed from above) showing an example of a configuration in which the cleaning tank 210 is supported from the left and right to ensure a space (gap) between the cleaning tank 210 and the front mass 206. 1 is a schematic diagram (viewed from above) showing an example of a configuration in which the cleaning tank 210 is supported by a groove in the cleaning unit base 202, ensuring a space (gap) between the cleaning tank 210 and the front mass 206. FIG. 2 is a schematic diagram showing an example of a configuration in which the tip of the front mass 206 is inside a through-hole 214, ensuring a gap. FIG. 3 is a diagram showing an example of a configuration of a cleaning rack 30 having an ultrasonic cleaner according to the present embodiment. FIG. 4 is a flow chart for explaining the cleaning operation of a dispensing nozzle by the ultrasonic cleaner according to the present embodiment. FIG. 5 is a diagram showing an example of a functional configuration of an automatic analyzer 10 compatible with the case in which an ultrasonic cleaner built into a transport rack is used according to the present embodiment.

[0018] The ultrasonic cleaner according to the present embodiment is characterized by having a structure that prevents the cleaning liquid in the cleaning tank from entering the area that houses the front mass of the ultrasonic transducer. Hereinafter, the embodiment of the present disclosure will be described in detail with reference to the drawings.

[0019] 1 is a perspective view showing an example of the configuration of an automatic analyzer 10 according to this embodiment. As shown in Fig. 1, the automatic analyzer 10 includes a reagent disk 12 on which a plurality of reagent containers 11 are placed, a reaction disk 13 on which reagents and samples are mixed to measure a reaction, a reagent dispensing mechanism 14 that aspirates and dispenses the reagent, and a sample dispensing mechanism 15 that aspirates and dispenses the sample.

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

[0021] The samples introduced into the device are placed in sample containers (test tubes) 23, which are then placed in racks 24 and transported via transport lines 25. A plurality of sample containers 23 are placed in the racks 24. The samples may be blood-derived samples such as serum or whole blood, or urine.

[0022] The sample dispensing mechanism 15 moves the sample nozzle 22 to an aspiration position where it aspirates a sample from a sample container 23, a discharge position where it discharges a sample into a cell 26 (each of which is a small, partitioned container, as shown enlarged in the figure), and a washing position where a washing tank 27 is provided for rinsing the tip of the sample nozzle 22 with water. Furthermore, the sample dispensing mechanism 15 lowers the sample nozzle 22 to match the height of the sample container 23 at the aspiration position, the height of the cell 26 at the discharge position, and the height of the washing tank 27 at the washing position. In other words, the sample dispensing mechanism 15 is configured to move the sample nozzle 22 to each stop position by rotating and vertically moving it. The sample dispensing mechanism 15 and devices such as the conveying line 25 are controlled by a control unit (not shown).

[0023] The automated analyzer 10 further includes a measurement unit (not shown) that measures the photometry of the mixture of the sample and the reagent contained in the cell 26 to analyze the concentration of a predetermined component contained in the sample. The measurement unit (not shown) includes, for example, a light source and a photometer. Here, the photometer may be, for example, an absorption photometer or a scattering photometer.

[0024] The washing rack 30 equipped with an ultrasonic cleaner includes a washing unit 200 (including a vibration unit, washing unit base, and washing tank) described below, and is used to wash the tip of the sample nozzle 22 that has come into contact with the sample. The washing rack 30 is used during daily maintenance of the automated analyzer 10, often before or after an analysis. When a large number of samples are handled per day, the washing rack 30 may be transported on the transport line 25 between analyses. This allows the cleanliness of the sample nozzle 22 to be maintained.

[0025] The washing rack 30 can be washed for any sample nozzle 22 or reagent nozzle 21 that can access the transport line 25, regardless of the sample. It is also possible to wash multiple sample nozzles 22 during a single transport. However, since reusing a cleaning solution contaminated by cleaning can result in reattachment of contaminants, it is desirable to replace the cleaning solution for each nozzle. In this case, methods include running one washing rack 30 through the transport line 25 multiple times (after replacing the cleaning solution) or running multiple washing racks 30. The transport method for the transport line 25 can be a belt that moves along the transport line 25, a push pawl, or an electromagnetic force.

[0026] 2A is a top view showing an example of the configuration of the cleaning unit 200 of the ultrasonic cleaner according to this embodiment. In Fig. 2A, the cleaning unit 200 includes two ultrasonic vibrators 201A and 201B (vibration units), a cleaning unit base 202, and a cleaning tank 210. The cleaning tank 210 also includes a cleaning liquid storage area 211.

[0027] FIG. 2B is a diagram showing an example of the cross-sectional configuration taken along the line A-A in FIG. 2A. FIG. 2C is an enlarged view of the area enclosed by the dotted line in FIG. 2B. As shown in FIG. 2B, an upper block 203 having an opening for inserting a cleaning tank 210 is provided on top of the cleaning unit base 202. The upper end of the cleaning tank 210 is preferably at a height equal to or greater than that of the upper block. The cleaning tank 210 is disposed in a recessed portion located in the center of the cleaning unit base 202 and the upper block 203. The cleaning unit base 202 has a through-hole 214 on its side for inserting the ultrasonic vibrator 201. The upper surface of the cleaning unit base 202 also has a hole (cleaning tank insertion hole 215) for inserting the cleaning tank 210. The through-hole 214 is formed in the outer wall of the cleaning tank 210, extending from the left and right sides in FIG. 2B to the recessed portion (cleaning tank insertion hole 215).

[0028] Ultrasonic vibrators 201A and 201B are inserted into the two through-holes 214, respectively. Ultrasonic vibrators 201A and 201B are fixed to the side of cleaning unit base 202 by flange 204 and seal 205 (O-ring). Flange 204 may be a separate part from ultrasonic vibrators 201A and 201B. In practice, ultrasonic vibrators 201A and 201B can be fixed by pressing flange 204 (or another fixing part for holding ultrasonic vibrator 201) toward cleaning tank 210 with a screw or the like (however, the tip of front mass 206 does not contact cleaning tank 210). This configuration prevents liquid from leaking from through-hole 214. In other words, liquid can be stored without leakage from the O-ring pressed by ultrasonic vibrators 201A and 201B to the central cleaning tank insertion hole 215 (hereinafter, this part that stores liquid will be referred to as the "liquid storage section 216" to distinguish it from cleaning tank 210).

[0029] The ultrasonic transducers 201A and 201B have a configuration similar to that of a typical bolt-clamped Langevin type transducer (BLT). That is, the ultrasonic transducers 201A and 201B are configured by fastening multiple piezoelectric elements 208 and multiple copper plates (not shown) for electrodes between a front mass 206 (a metal block on the front side) and a back mass 207 (a metal block on the back side) with bolts 209. The ultrasonic transducers 201A and 201B also include a thin, cylindrical metal portion (front mass 206) at their tips. By removing the upper block 203 (including the cleaning tank 210) from the cleaning unit base 202, the cylindrical portion of the front mass 206 of the ultrasonic transducer 201 is exposed. In this way, the ultrasonic transducers 201A and 201B are configured to be fixed by bolting, similar to a typical BLT. The BLT configuration is advantageous for amplitude amplification and is therefore used when using powerful ultrasonic waves, including in industrial ultrasonic cleaners that require powerful cleaning performance. Furthermore, by driving the ultrasonic transducers 201A and 201B at their resonant frequency, the amplitude at the tip of the front mass 206 can be maximized.

[0030] The ultrasonic vibrators 201A and 201B have vibration nodes (areas where the amplitude is always small) near the flange 204. The seal 205 is made of an elastic material, so the impact of contact between the front mass 206 and the seal 205 is small.

[0031] The through-hole 214 for passing the front mass 206 is formed into a cylindrical shape by combining the cleaning unit base 202 and the upper block 203 (the base of the through-hole 214 may be sloped or stepped depending on the shape of the ultrasonic vibrators 201A and 201B used). A substantially uniform gap is formed between the wall of the through-hole 214 and the ultrasonic vibrator 201. A seal 205 is disposed near the base of the cylindrical portion (front mass 206) to prevent liquid leakage from the through-hole 214. By filling a gap between the front mass 206 and the cleaning tank 210 with a liquid (such as silicone oil) that does not easily evaporate, the ultrasonic vibrator 201 can vibrate without its function being hindered by deformation of the tip of the front mass 206 or without contacting the wall of the through-hole 214.

[0032] The liquid in the liquid storage section 216 can be added by removing the upper block 203 or by removing only the cleaning tank 210, which exposes the cylindrical portion of the front mass 206 as described above. This allows the gap formed around the cylindrical portion of the front mass 206 inserted into the through-hole 214 to be filled with liquid. Since the liquid filling the liquid storage section 216 does not come into contact with the sample nozzle 22, which is the object to be cleaned, it is only necessary to periodically replenish the liquid, and there is no need to pour or drain the liquid daily. Furthermore, it is desirable to use a liquid that does not evaporate easily, such as silicone oil, as the liquid to fill the liquid storage section 216.

[0033] The cleaning liquid is poured into a cleaning liquid storage area 211 (the solid area in FIG. 2C ) in the cleaning tank 210 so that the liquid level is positioned at a height equal to or higher than the upper end of the tip of the front mass 206. For example, the cleaning liquid can be stored in the cleaning tank 210 by forming a step or marking (the step or marking can be referred to as a "liquid level mark") on the inside of the cleaning tank 210 and pouring a fixed amount of cleaning liquid using a pipette or the like, or by pouring using a dedicated dispenser.

[0034] The ultrasonic cleaner according to this embodiment is used with a predetermined liquid poured into the liquid storage section 216 and the cleaning tank 210. The arrangement of the cleaning tank 210 will be described in detail below with reference to Figures 4A to 4C. There is a gap between the front mass 206 and the cleaning tank 210, and this gap is also filled with the poured liquid. In other words, the cleaning tank 210 and the front mass 206 face each other with the filled liquid between them. In this state, the two ultrasonic vibrators 201 are driven to irradiate ultrasonic waves into the liquid from their tip surfaces. Although the transmittance varies depending on the material of the cleaning tank 210 (described in detail below), a certain amount of ultrasonic waves penetrates the wall surface of the cleaning tank 210 and propagates to the cleaning liquid in the cleaning tank 210.

[0035] As described above, the cleaning liquid for cleaning the sample nozzle 22 and the liquid around the front mass 206 can store different types of liquid at different times.

[0036] 2D is a diagram showing an example of the front configuration of the cleaning unit 200 in FIG. 2A. As shown in FIG. 2D, an upper block 203 is connected to the upper part of the cleaning unit base 202 of the cleaning unit 200. The upper block 203 may be made up of two or more parts, and may be integrated with the cleaning tank 210 by welding, adhesive, or the like, without any problems. Integration makes removal and installation easier.

[0037] Fig. 2E is a diagram showing an example of a side configuration of the cleaning unit 200 in Fig. 2A. As shown in Fig. 2E, in this embodiment, the flange 204 has a circular shape, but it may be partially cut away to have a shape other than a circle so that it fits within the size of the cleaning tank 210.

[0038] 2F is a diagram showing an example of the overall external configuration of the cleaning unit 200 in FIG. 2A. As described above, the cleaning tank 210 may be configured to be fixed integrally with the upper block 203, or may be configured as a replaceable container. The cleaning tank 210 may also be replaced after each use. Furthermore, the cleaning tank 210 may be provided in a form that allows replacement with the cleaning liquid already filled in it. Regarding the cleaning tank 210, other than the form of a container, the liquid storage unit 216 and the cleaning tank 210 may be separated by a wall, and the liquid storage unit 216 may be configured as a partition wall on the wall surface of the cleaning unit base 202.

[0039] 2G and 2H are a cross-sectional view and a perspective view of the cleaning tank 210. As shown in FIG. 2G, the cleaning tank 210 may be thinned at the portion closest to the front mass 206. This increases the ultrasonic transmission efficiency. The cleaning tank 210 may also be made of an elastic material. In FIG. 2G, the distance between the walls of the cleaning tank 210 in the X direction is, for example, about 3 mm, and the thinner portion is, for example, about 0.5 mm. By making the thickness of the other portions about 2 to 3 mm, the rigidity required to maintain the shape of the container can be obtained even when an elastic material is used.

[0040] The dimensions of the washing unit 200 are preferably such that it can be accommodated in the rack 24. By making it have such dimensions, the washing unit 200 can be moved to the position of the sample nozzle 22 and washed there.

[0041] <Effect of Ultrasound> Figure 3 is an enlarged schematic diagram of the periphery (black areas represent the liquid in the liquid storage section 216) of the tip of the front mass 206 (206A and 206B in the figure) of the ultrasonic transducers 201A and 201B, the same as in Figure 2C. In Figure 3, the dotted line area indicates the area where sound pressure increases due to ultrasonic irradiation (how the ultrasonic waves pass through). In particular, when the left and right ultrasonic transducers 201A and 201B are driven in phase, the sound pressure increases in the area where the ultrasonic waves overlap. The sample nozzle 22 can be effectively cleaned by inserting it into the area where the sound pressure increases near the center of the cleaning tank 210.

[0042] Ultrasonic waves have the property of being easily reflected when the difference in acoustic impedance is large, and easily transmitted when the difference in acoustic impedance is small. In this embodiment, under the condition that the difference in acoustic impedance between the liquid around the front mass 206 and the cleaning tank 210 is small, ultrasonic waves generated by the ultrasonic vibrator 201 are efficiently propagated to the liquid in the cleaning tank 210, thereby achieving a high cleaning effect.

[0043] Acoustic impedance is determined by the density and sound velocity of a material, and for water (liquid), it is 1.5 x 10 ６ Ns / m ３ For elastic materials such as silicone rubber, the resistance is 1.2 to 1.5 x 10 ６ Ns / m３ Since the difference in acoustic impedance between them is small, the acoustic impedance of metal is approximately 10 to 40 times that of rubber, and metal has a higher reflectivity, making it difficult for light to pass through. In other words, by constructing the wall separating the cleaning liquid from the liquid (e.g., silicone oil) around the front mass 206 using an elastic material such as silicone rubber, it is possible to prevent the cleaning liquid in the cleaning layer 210 from penetrating into the liquid storage section 216, thereby enabling ultrasonic waves to be generated in the cleaning liquid into which the sample nozzle 22 is inserted without contaminating the liquid around the front mass 206.

[0044] The material of the wall separating the cleaning liquid from the liquid around the front mass 206 of the cleaning tank 210 is a material having an acoustic impedance of 1.5×10 ６ Ns / m ３ The difference is small, for example, 1.2 to 1.9 × 10 ６ Ns / m ３ It is desirable to have the following characteristics.

[0045] <Positional Relationship Between Cleaning Tank 210 and Front Mass 206> FIGS. 4A to 4C are diagrams schematically showing the positional relationship between the cleaning tank 210 and the front mass 206. FIG.

[0046] If the cleaning tank 210 and the front mass 206 come into contact with each other, the thin cleaning tank 210 may be damaged or a driving load may be imposed on the ultrasonic vibrator 201. Therefore, in this embodiment, a gap is provided between the cleaning tank 210 and the front mass 206, and the gap is filled with liquid to propagate ultrasonic waves.

[0047] On the other hand, in typical ultrasonic cleaning, the ultrasonic vibrator is tightly fixed to the wall, such as the bottom, of the cleaning tank (in this case, the outer tank, not the indirect tank) with adhesive (or welding). However, when an ultrasonic vibrator driven at a large amplitude is fixed to the cleaning tank, there is a high possibility that the adhesive will peel off or crack (including damage to the cleaning tank itself) (or the cleaning tank will become a load and reduce the amplitude of the ultrasonic vibrator 201). Furthermore, if the vibrator is fixed to a cleaning tank made of a high-rigidity material (e.g., stainless steel), the vibrations of the two ultrasonic vibrators will be transmitted simultaneously to the metal cleaning tank and transmitted through the cleaning tank in the same way as if ultrasonic waves were reflected toward each ultrasonic vibrator, resulting in a drive load. Therefore, there is a great advantage to providing a gap between the cleaning tank 210 and the front mass 206 (so that they do not come into contact), as in this embodiment.

[0048] 4A is a schematic diagram (viewed from above) showing an example of a configuration in which the cleaning tank 210 is supported from the left and right to ensure a space (gap) between the cleaning tank 210 and the front mass 206. The cleaning tank 210 has container support parts 401 at the top and bottom of the drawing (the sides of the cleaning tank 210 in the Y-axis direction), and the position of the cleaning tank 210 is fixed by contact with the wall surface of the cleaning tank insertion hole 215 in the cleaning unit base 202. This provides a gap with the front mass 206.

[0049] 4B is a schematic diagram (viewed from above) showing an example of a configuration in which the cleaning tank 210 is supported by a groove in the cleaning unit base 202, ensuring a space (gap) between the cleaning tank 210 and the front mass 206. The position of the cleaning tank 210 is fixed by inserting the cleaning tank 210 into the groove provided in the cleaning tank insertion hole 215 in the cleaning unit base 202. FIG. 4B shows a fixing method for the cleaning tank 210 that is different from the fixing method shown in FIG. 4A.

[0050] 4C is a schematic diagram showing an example of a configuration in which the tip of front mass 206 is located within through-hole 214 to ensure a gap. When cleaning tank 210 is inserted into cleaning tank insertion hole 215 of cleaning unit base 202, the tip of front mass 206 is located within through-hole 214 and is a certain distance from cleaning tank 210, thereby providing a gap.

[0051] In the above configuration, the closer the distance between the front mass 206 and the cleaning tank 210 is (1.0 mm or less), the higher the sound pressure inside the cleaning tank 210. For example, it is desirable to set the distance between the tip surface of the front mass 206 and the wall surface of the cleaning tank 210 to about 0.1 to 0.3 mm.

[0052] As explained above, to increase the sound pressure of the ultrasonic waves generated between the two front masses 206A and 206B, it is necessary to reduce the distance between the front masses 206A and 206B as much as possible, reduce the width (length in the X direction) of the cleaning tank 210, and further reduce the thickness (wall thickness). Also, reducing the distance between the front masses 206A and 206B and the cleaning tank 210 increases the sound pressure inside the cleaning tank 210. While the above conditions do not depend on the material of the cleaning tank 210, using an elastic material for the cleaning tank 210 to increase its transmittance can further increase the sound pressure and improve cleaning efficiency.

[0053] <Configuration example of cleaning rack> Fig. 5 is a diagram showing a configuration example of a cleaning rack 30 having an ultrasonic cleaner according to this embodiment. As shown in Fig. 5, the cleaning rack 30 includes a cleaning unit 200, an ultrasonic transducer control unit 301, a driving power supply 302 (battery), and a transport base 303.

[0054] The ultrasonic transducer control unit 301 controls the driving of the ultrasonic transducers 201A and 201B (see FIG. 2A). The ultrasonic transducer control unit 301 also generates a sine wave at the resonant frequency of the ultrasonic transducers 201A and 201B to drive the ultrasonic transducers 201A and 201B. Furthermore, the ultrasonic transducer control unit 301 has an impedance matching circuit for increasing the driving current of the ultrasonic transducers 201A and 201B and amplifying the amplitude, as well as a circuit for automatically tracking the resonant frequency. The driving power supply 302 is a rechargeable battery that is charged each time the cleaning rack 30 is used.

[0055] The transport base 303 has the same shape as the bottom of the rack 24 used for the sample containers 23. Therefore, there is no need to change the hardware of the transport line 25. The cleaning rack 30, which includes the cleaning unit 200, ultrasonic vibrator control unit 301, and drive power supply 302, is smaller than the rack 24 when a conventional sample container 23 is installed.

[0056] The cleaning unit 200 may be covered with a cover 304. The cover 304 prevents liquid from splashing on electrical components such as the piezoelectric element 208 and electrodes when injecting or discharging liquid into the cleaning tank 210 using a pipette or the like. The volume of cleaning liquid required for cleaning depends on the shape of the cleaning tank 210, but is approximately several hundred μL (assumed to be 150 μL or less in this embodiment). While water can provide a cleaning effect, a mixture of water and detergent or the detergent itself may also be used. A certain amount of cleaning liquid is injected into the cleaning tank 210 before the cleaning rack 30 is placed in the device. The start and stop of the ultrasonic cleaning operation can be controlled, for example, by providing a sensor on the top of the cleaning unit 200 that detects the passage of the sample nozzle 22. As described above, the automated analyzer 10 according to this embodiment is configured to clean the dispensing nozzle by transporting the ultrasonic cleaner.

[0057] <Example of Dispensing Nozzle Cleaning Operation> Figure 6 is a flowchart for explaining the dispensing nozzle cleaning operation using the ultrasonic cleaner of this embodiment. Note that, in the dispensing nozzle cleaning operation, the cleaning liquid in the cleaning tank 210 may be replaced daily. Furthermore, the liquid (silicone oil) in the liquid storage section 216 may be filled at the time of shipment and then replenished when the ultrasonic cleaner is maintained (several months or more later).

[0058] (i) Step S601 The operator (user) injects a fixed amount of cleaning liquid into the cleaning tank 210 of the cleaning unit 200. This causes the cleaning liquid to fill the cleaning liquid storage area 211 of the cleaning tank 210. At this time, by using a dedicated size container that does not hold more liquid than fills the capacity of the cleaning liquid storage area 211 or a pipette with an adjusted discharge amount, the liquid level can be kept constant for each cleaning. Alternatively, a dedicated dispenser may be prepared to inject the cleaning liquid. In the method of use in which the cleaning tank 210 is replaced as described above, the cleaning tank 210 may be filled with cleaning liquid in advance and then set in the cleaning unit 200.

[0059] (ii) Step S602: The operator pours the washing solution into the washing tank 210, and then places the washing rack 30 on the transport line 25. After placing the washing rack 30, in which the washing tank 210 filled with the washing solution has been set, on the transport line 25, the operator may use the GUI 702 (see FIG. 7 ) to notify the automated analyzer 10 that the setting of the washing rack 30 has been completed (by clicking the setting complete button (UI)).

[0060] (iii) Step S603 The automatic analyzer control unit 701 (see FIG. 7 : composed of, for example, a processor) of the automatic analyzer 10 transports the washing rack 30 to the cleaning position (the position where the target nozzle (sample nozzle 22) is located) and starts the automatic washing operation. The bottom of the washing rack 30 has the same shape as the transport portion of the rack 24. Therefore, the washing rack 30 can be installed on the transport line 25 in the same way as the rack 24 that transports the sample containers (blood collection tubes) 23. Furthermore, because the amount of liquid placed in the washing tank 210 is small, on the order of several hundred μL, there is little risk of the washing liquid splashing out due to shaking when the washing rack 30 is transported.

[0061] (iv) Step S604: When the automatic analyzer control unit 701 has completed transporting the washing rack 30 to the cleaning position (the washing rack 30 has stopped), the ultrasonic vibrator control unit 301 (see FIG. 5 : for example, composed of a processor) lowers the sample nozzle 22 in response to a transport completion notification received from the automatic analyzer control unit 701.

[0062] (v) Step S605: When the passage of the descending sample nozzle 22 is detected by a sensor (nozzle detection means 721: see FIG. 7) provided in the washing rack 30, the ultrasonic vibrator control unit 301 controls the vibrator drive means 722 to start ultrasonic drive. The ultrasonic vibrator control unit 301 also instructs the timer control means 723 (see FIG. 7) to operate a timer (not shown) and start measuring time.

[0063] When transporting a normal rack 24, the subsequent analysis and transport process can be branched by reading the barcode attached to the side of the rack 24. Therefore, by attaching a barcode to the washing rack 30 in the same position as the normal rack 24, it is possible to distinguish between the rack 24 used for testing and the washing rack 30 used for cleaning within the automated analyzer 10. Therefore, the cleaning maintenance operation from step S603 onwards can be executed separately from the normal testing operation.

[0064] (vi) Step S606 After starting the cleaning operation, the ultrasonic transducer control unit 301 immerses the tip of the sample nozzle 22 in a cleaning liquid to perform cleaning.

[0065] (vii) Step S607: Upon receiving notification of the time measurement result from the timer control means 723 and recognizing that the sample nozzle 22 has been washed for a certain period of time, the ultrasonic transducer control means 301 notifies the automatic analyzer control means 701 of the completion of the washing operation. In response to this notification, the automatic analyzer control means 701 instructs the dispensing arm control means 704 to raise the sample nozzle 22.

[0066] (viii) Step S608: The ultrasonic vibrator control unit 301 controls the vibrator driving means to stop ultrasonic driving after a predetermined time has elapsed since the start of driving the ultrasonic vibrator (based on time measurement information from the timer). Note that, although there is a method in which the nozzle detection means 721 detects nozzle lift and stops driving the ultrasonic vibrator based on that, by using the timer function, it is possible to avoid malfunctions such as repeated stops and starts during cleaning due to the nozzle detection means 721 erroneously detecting nozzle lift.

[0067] (ix) Step S609 In response to an instruction from the automatic analyzer control unit 701, the rack transport control means 707 (see FIG. 7) controls the rack transport means 708 (see FIG. 7) to transport the washing rack 30 to a recovery position.

[0068] (x) Step S610 The operator retrieves the washing rack 30 and discharges the washing liquid.

[0069] The above is the cleaning operation of the dispensing nozzle using the ultrasonic cleaner, but if necessary, the cleaning solution may be replaced and cleaning may be performed continuously on another sample nozzle 22. If cleaning is not required, the cleaning solution is discharged and the process ends.

[0070] <Example of Functional Configuration of Automated Analyzer 10> FIG. 7 is a diagram showing an example of the functional configuration of the automated analyzer 10 according to this embodiment, which is compatible with the case where an ultrasonic cleaner built into a transport rack is used.

[0071] The automatic analyzer 10 is controlled by an automatic analyzer control unit 701. A user (operator) of the automatic analyzer 10 can issue instructions for analysis processing and cleaning processing from a graphical user interface (GUI) 702. Normal analysis processing and the cleaning maintenance mode according to this embodiment are performed by a maintenance control means 703 under the control of the automatic analyzer control unit 701, which controls the sample dispensing mechanism 15 and the transport line 25.

[0072] The sample dispensing mechanism 15 controls the position of the sample nozzle 22 from a dispensing arm control means 704 (dispensing arm control unit) via a dispensing arm horizontal movement means 705 (dispensing arm horizontal movement unit) and a dispensing arm up / down movement means 706 (dispensing arm up / down movement unit). In maintenance mode, the horizontal and up / down positions of the sample nozzle 22 are controlled so that the cleaning range of the tip of the sample nozzle 22 is immersed in the liquid in the cleaning liquid storage area 211 in the cleaning tank 210 (positioning the sample nozzle 22 to a depth at which the object to be cleaned is immersed in the cleaning liquid). The horizontal position of the sample nozzle 22 is preferably the center of the cleaning liquid storage area 211, but it is also possible to move the sample nozzle 22 horizontally while it is immersed. The transport line 25 is driven by a rack transport control means 707 (rack transport control unit) via a rack transport means 708 (rack transport unit).

[0073] The cleaning rack 30 is independent of the automatic analyzer control unit 701 and includes a nozzle detection means 721, a vibrator drive means 722 (vibrator drive unit) that detects the resonance frequency of the ultrasonic vibrator 201 and drives it, and a timer control means 723 that manages the ultrasonic drive time. The nozzle detection means (sensor) 721 detects the sample nozzle 22, and the timer control means 723 starts counting, stopping ultrasonic cleaning when a certain counter has elapsed. As described above, the vibrator drive means 722 controls the start and end of driving the ultrasonic vibrator 201.

[0074] With the above configuration, the cleaning rack 30 is transported to a position on the transport line 25 that is accessible to the sample nozzle 22, and the ultrasonic vibrator 201 mounted on the cleaning rack 30 is started to be driven, and the sample nozzle 22 is immersed in the liquid in the cleaning tank 210, thereby cleaning the cleaning area of ​​the sample nozzle 22.

[0075] The reagent nozzle 21 can also be configured in a similar manner as long as it has access to the transport line 25. Although the present embodiment describes a case in which the reagent nozzle 21 and the sample nozzle 22 are provided separately, some analyzers use a single shared nozzle for dispensing both reagent and sample. Even in such analyzers, water flow cleaning is performed each time a reagent or sample is dispensed, but daily maintenance is necessary, and ultrasonic cleaning according to the present invention can maintain dispensing accuracy.

[0076] Summary of the Embodiment (i) The ultrasonic cleaner according to this embodiment includes a block member (cleaning unit base 202 + upper block 203) including a hole (through-hole 214) for inserting a front mass 206 and a cleaning tank installation recess (cleaning tank insertion hole 215) for installing a cleaning tank (having at least a portion of an elastic wall) into which a dispensing nozzle (sample nozzle 22) to be cleaned can be inserted. The through-hole 214 is provided in the longitudinal direction (horizontal direction) of the block member, and the cleaning tank insertion hole 215 is provided in the vertical direction. In this ultrasonic cleaner, a liquid storage section 216 for storing a liquid (e.g., silicone oil) other than the cleaning liquid is formed by a gap formed between the front mass 206, the through-hole 214, and the wall of the cleaning tank 210. The cleaning liquid held in the cleaning tank 210 and the liquid (silicone oil) stored in the liquid storage section 216 are separated by the wall of the cleaning tank 210 (see FIG. 2C ). The ultrasonic cleaner is configured as shown in FIGS. 2B and 2C , and ultrasonic waves are applied to the tip of the front mass 206 from the side of the cleaning tank 210. Because the front mass 206 is not immersed in the cleaning liquid, cleaning work can be reduced and a smaller amount of cleaning liquid can be used. In the above-described embodiment, as shown in FIGS. 2A to 2F , the block member is configured by combining the cleaning unit base 202 and the upper block 203, making the ultrasonic cleaner easier to assemble and disassemble. However, a monolithic block member with a through hole 214 may also be used. Furthermore, when combining two components to form a block member, two upper and lower block members (the cleaning unit base 202 and the upper block 203) may be combined (superimposed one on top of the other), or two left and right block members (not shown) may be combined to form a single block member.

[0077] (ii) As shown in Figure 2B, the front mass 206 is inserted from both sides of the through-hole 214. In this case, the cleaning tank 210 is placed in a position sandwiched between the two front masses 206. Since ultrasonic waves are irradiated from both sides of the cleaning tank 210, it is possible to efficiently clean the dispensing nozzle.

[0078] (iii) The tip of the front mass 206 is installed at a position within 1 mm of the wall of the cleaning tank 210 so as not to come into contact with the wall of the cleaning tank 210. The space between the tip of the front mass 206 and the wall of the cleaning tank 210 is filled with liquid (silicone oil). In other words, ultrasonic waves emitted from the tip of the front mass 206 propagate to the cleaning liquid in the cleaning tank 210 via the liquid (silicone oil) in the liquid storage section 216. Because the front mass 206 does not come into direct contact with the cleaning tank 210, the possibility of damaging the cleaning tank 210 can be reduced. In addition, the wall of the cleaning tank 210 facing (directly facing) the tip of the front mass 206 has an acoustic impedance of 1.2×10 ６ ~1.9 x 10 ６ Ns / m ３ The acoustic impedance of the cleaning liquid is 1.5×10. ６ Ns / m ３ By using a material for the wall that has a small difference in thickness between the front mass 206 and the cleaning liquid, ultrasonic waves can be efficiently propagated to the cleaning liquid. In order to further efficiently propagate ultrasonic waves to the cleaning liquid, the wall of the cleaning tank 210 that faces (directly confronts) the tip of the front mass 206 is made thinner than the other walls that do not face the tip of the front mass 206.

[0079] (iv) The cleaning tank 210 may be provided with a mark indicating that the level of the cleaning liquid to be poured should be above the upper end of the front mass 206 (see FIG. 2C ). This allows the user (operator) to use this as a guide when pouring the cleaning liquid into the cleaning tank 210.

[0080] (v) As shown in Figures 2G and 2H, the cleaning tank 210 has a lower section and an upper section whose longitudinal outer walls are spaced apart from each other by a greater distance than the lower section. The cleaning section base (first block section) 202 has a cleaning tank lower section fixing hole (which allows a certain gap to be provided between the front end of the front mass 206) that fixes the position of the lower section of the cleaning tank 210. The upper block (second block) 203 also has a through hole that regulates the position of the upper section of the cleaning tank 210. The through hole and the cleaning tank lower section fixing hole form the cleaning tank installation recess (cleaning tank insertion hole 215).

[0081] (vi) A method for injecting liquid (e.g., silicone oil) into the liquid storage section 216 will be described. First, the user places the front mass 206 on the cleaning section base (first block) 202 and covers it with the upper block (second block) 203. This inserts the front mass 206 into the through-hole 214. Before inserting the cleaning tank 210 into the cleaning tank insertion hole (cleaning tank installation recess) 215 formed by joining the first block and the second block, the user injects liquid (silicone oil) into the liquid storage section 216 from the cleaning tank installation recess. Then, after injecting the liquid (silicone oil) into the liquid storage section 216, the user inserts the cleaning tank 210 into the cleaning tank installation recess.

[0082] Alternatively, the following procedure may be adopted: The user aligns the cleaning unit base (first block) 202 and the upper block (second block) 203, and inserts the front mass 206 of the ultrasonic cleaner into the through-hole 214 formed thereby. Furthermore, before inserting the cleaning tank 210 into the cleaning tank insertion hole (cleaning tank installation recess) 215 formed by joining the first block and the second block, the user injects liquid (silicone oil) from the cleaning tank installation recess into the liquid storage section 216. Then, after injecting the liquid (silicone oil) into the liquid storage section 216, the user inserts the cleaning tank 210 into the cleaning tank installation recess.

[0083] (vii) This embodiment also discloses an automated analyzer equipped with the ultrasonic cleaner. The automated analyzer includes a washing rack 30 on which the ultrasonic cleaner is mounted, a transport line 25 that transports the washing rack 30 to a predetermined cleaning position, and a control unit (e.g., automated analyzer control unit 701) that controls the transport operation by the transport line 25 and the cleaning operation of the sample nozzle (dispensing nozzle) 22. The automated analyzer control unit 701, etc., performs the following operations for the washing rack 30 at the cleaning position: lowering the sample nozzle 22 and inserting it into the cleaning tank 210; starting ultrasonic cleaning of the sample nozzle 22 inserted into the cleaning tank 210 using the ultrasonic cleaner; and stopping ultrasonic cleaning.

[0084] The washing rack 30 also has a sensor (nozzle detection means 721) that detects the insertion of the sample nozzle 22. The automatic analyzer control unit 701 receives a signal from the sensor notifying that the sample nozzle 22 has been inserted into the washing tank 210, and starts ultrasonic cleaning in response to the signal. The washing rack 30 also has a timer that measures the time from the detection of the insertion of the sample nozzle 22. The automatic analyzer control unit 701 then stops the ultrasonic cleaning when the timer has measured a predetermined time (the measured value is obtained from the timer control means 723).

[0085] REFERENCE SIGNS LIST 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 Transport line 26 Cell 27, 210 Washing tank 30 Washing rack 201 Ultrasonic vibrator 202 Washing unit base 203 Upper block 204 Flange 205 Seal 206 Front mass 207 Back mass 208 Piezoelectric element 209 Bolt 211 Washing solution storage area 214 Through hole 215 Washing tank insertion hole 401 Container support section 701 Automatic analyzer control section 702 Graphical user interface 703 Maintenance control means 704 Dispensing arm control means 705 Dispensing arm horizontal movement means 706 Dispensing arm vertical movement means 707 Rack transport control means 708 Rack transport means 721 Nozzle detection means 722 Vibrator drive means 723 Timer control means

Claims

1. An ultrasonic cleaner for ultrasonically cleaning dispensing nozzles, comprising: an ultrasonic vibrator having a front mass; and a block member including: a hole provided in the longitudinal direction for inserting the front mass; and a cleaning tank installation recess for installing a cleaning tank into which a dispensing nozzle to be cleaned can be inserted, the cleaning tank having at least a portion of an elastic wall; the cleaning tank installation recess is provided in a direction different from the longitudinal direction in which the hole is provided in the block member; a liquid storage section for storing a liquid other than a cleaning liquid is formed by a gap formed between the front mass inserted in the hole, the hole, and the wall of the cleaning tank; the cleaning liquid held by the cleaning tank and the liquid stored in the liquid storage section are separated by the wall of the cleaning tank; and the tip of the front mass is positioned so as to irradiate ultrasonic waves from the side of the cleaning tank.

2. An ultrasonic cleaner according to claim 1, wherein the front masses of the two ultrasonic transducers are inserted into the holes of the block member at corresponding positions in the longitudinal direction, and the cleaning tank is placed in a position sandwiched between the front masses of the two ultrasonic transducers.

3. An ultrasonic cleaner as claimed in claim 1, wherein the tip of the front mass of the ultrasonic transducer is not in contact with the wall of the cleaning tank and is positioned within 1 mm away from the wall, and the space between the tip of the front mass and the wall of the cleaning tank is filled with the liquid.

4. In the case of claim 1, the material of the wall of the cleaning tank facing the tip of the front mass has an acoustic impedance of 1.2×10 ６ ~1.9 x 10 ６ Ns / m ３ An ultrasonic cleaner that has the following characteristics.

5. The ultrasonic cleaner according to claim 1, wherein the wall of the cleaning tank facing the tip of the front mass is thinner than other walls not facing the tip of the front mass.

6. An ultrasonic cleaner according to claim 1, wherein the block member has a first block portion for fixing the ultrasonic vibrator and a second block portion for covering the front mass, and is constructed by combining the first block portion with the second block portion, and when the first block portion and the second block portion are combined, a recess for installing the cleaning tank is formed.

7. An ultrasonic cleaner according to claim 6, wherein the cleaning tank has a mark to indicate that the level of the cleaning liquid to be poured is to be equal to or higher than the upper end of the front mass.

8. An ultrasonic cleaner as claimed in claim 6, wherein the cleaning tank has a lower portion and an upper portion in which the distance between the outer walls in the longitudinal direction is greater than that of the lower portion, the first block portion has a cleaning tank lower portion fixing hole that fixes the position of the lower portion of the cleaning tank and enables a certain gap to be provided between the tip of the front mass, and the second block portion has a through hole that regulates the position of the upper portion of the cleaning tank.

9. A method for injecting the liquid into the liquid storage section of the ultrasonic cleaner described in claim 6, comprising: placing the front mass on the first block section and covering the front mass with the second block section; inserting the front mass of the ultrasonic cleaner into the hole formed by joining the first block section and the second block section; injecting the liquid into the liquid storage section from the cleaning tank installation recess before inserting the cleaning tank into the cleaning tank installation recess formed by joining the first block section and the second block section; and inserting the cleaning tank into the cleaning tank installation recess after injecting the liquid into the liquid storage section.

10. An automatic analyzer comprising: a cleaning rack equipped with the ultrasonic cleaner according to claim 1 that holds the cleaning solution in the cleaning tank; a transport line that transports the cleaning rack to a predetermined cleaning position; and a control unit that controls the transport operation by the transport line and the cleaning operation of the dispensing nozzle, wherein the control unit performs the following processes: a process of lowering the dispensing nozzle and inserting it into the cleaning tank with respect to the cleaning rack at the predetermined cleaning position; a process of starting ultrasonic cleaning of the dispensing nozzle inserted into the cleaning tank using the ultrasonic cleaner; and a process of stopping the ultrasonic cleaning.

11. An automatic analyzer according to claim 10, wherein the cleaning rack has a sensor that detects the insertion of the dispensing nozzle, and the control unit receives a signal from the sensor notifying that the dispensing nozzle has been inserted into the cleaning tank, and initiates the ultrasonic cleaning in response to the signal.

12. An automatic analyzer according to claim 11, wherein the cleaning rack further has a timer which measures the time from when the insertion of the dispensing nozzle is detected, and the control unit stops the ultrasonic cleaning when a predetermined time has been measured by the timer.

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