Ultrasonic cleaner and automated analyzer using same

Abstract

The ultrasonic cleaner includes: a cleaning tank having a liquid reservoir for storing a liquid; and an ultrasonic transducer having a piezoelectric element and a front mass, in which a through-hole having an opening in the outer wall surface of the cleaning tank and the inner wall surface of the liquid reservoir is provided in the side surface of the cleaning tank, the front mass is inserted into the through-hole, a cover is provided so as to cover the top of the front end surface of the front mass, and the cover is movable at least upward. As a result, it is possible to provide an ultrasonic cleaner which has a structure suitable for being mounted in a narrow space such as a transport rack, has little sloshing of the liquid surface, fluctuation of the liquid level, and generation of mist, and is capable of irradiating strong ultrasonic waves to the outer peripheral portion of the nozzle.

Description

Technical Field

[0001] The present invention relates to an ultrasonic cleaning machine and an automatic analyzing device using the ultrasonic cleaning machine. Background Art

[0002] The automatic analyzer mixes samples such as serum and urine with reagents, and measures the transmittance of light irradiated to the mixture to perform component analysis. In the automatic analyzer, the same nozzle is repeatedly used to dispense samples, so the nozzle cleaning process is performed by flushing the front end of the nozzle with water before attracting other samples. However, in the automatic analyzer with high productivity performance, since the dispensing process is performed at a high speed, it does not take enough time to clean the nozzle. Therefore, dirt from the sample components sometimes accumulates at the front end of the nozzle, which is dealt with by removing it through daily cleaning and maintenance.

[0003] If dirt accumulates at the tip of the nozzle, it is easy to cause deviations in the amount of dispensing, or carryover of components from the previous sample into the next sample, which reduces measurement accuracy.

[0004] Patent document 1 discloses an ultrasonic cleaner having a diaphragm installed with a bolt-fastened Langevin oscillator (BLT), which has a structure in which an opening is provided on the side of a cleaning tank for storing a cleaning liquid and the opening is blocked by the diaphragm, thereby generating cavitation (the phenomenon of the generation and disappearance of bubbles due to the pressure difference generated in the liquid) caused by ultrasonic waves to clean the dispensing nozzle.

[0005] In addition, Patent Document 2 discloses a cleaning rack that is equipped with a cleaning tank, an ultrasonic generating element, and an electronic circuit for controlling the ultrasonic generating element in order to automate maintenance operations, and utilizes the cleaning tank to clean nozzles used for suction and discharge of samples or reagents, wherein the cleaning rack is movable along a conveyor line.

[0006] Patent document 3 discloses an ultrasonic cleaner comprising: a vibrating head having a neck extending from an ultrasonic vibrator toward a cleaning tank and a front end portion having a cylindrical hole having a length direction in a vertical direction; and a cover having an opening corresponding to the neck and the cylindrical hole, the cover being arranged at a height in contact with the liquid surface of the cleaning liquid in a manner covering the cleaning tank.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: International Publication No. 2017 / 002740

[0010] Patent Document 2: Japanese Patent Application Publication No. 2014-89200

[0011] Patent Document 3: International Publication No. 2020 / 044998 Summary of the invention

[0012] Problems to be solved by the invention

[0013] When adding a unit that can clean and maintain the nozzle to an already delivered and actually used automatic analyzer, it is desirable to add a small cleaning unit in the narrow space remaining between the configured components, or to add it temporarily during maintenance. This is because large-scale hardware changes will increase the cost of modification and cause a period of time when analysis cannot be performed.

[0014] The cleaning rack described in Patent Document 2 has a structure in which an ultrasonic generating element (piezoelectric element) is directly provided on the bottom surface or the side surface of a cleaning tank.

[0015] In the case of a conventional ultrasonic cleaner with a piezoelectric element, the amplitude of the ultrasonic irradiation surface is amplified by using a large area such as the bottom surface of the cleaning tank as a diaphragm, and then a standing wave is generated in the liquid through the vibration. The standing wave has an area where the sound pressure becomes high (the part of the antinode of the standing wave), and cavitation occurs in this area. Since cleaning is performed according to such a principle, sufficient amplitude cannot be generated in a bracket that requires a smaller bottom surface (or side surface) (smaller area) than commercially available ultrasonic cleaners, and it is difficult to obtain a cleaning effect based on cavitation. In particular, the cleaning efficiency is low for concentrated cleaning of the front end of a small diameter nozzle of less than 1 mm.

[0016] In order to clean the periphery of the nozzle using ultrasonic waves instead of manual cleaning maintenance, it is necessary to generate a high sound pressure region at the periphery of the nozzle tip where ultrasonic cavitation is stably generated.

[0017] The ultrasonic cleaner described in patent document 1 shows the following structural example: in order to centrally clean the front end of the nozzle, the cleaning head equipped at the front end of the ultrasonic vibrator is vibrated to generate ultrasonic cavitation in the hollow part inserted into the nozzle. In this structure, strong cavitation is generated on the periphery of the front end of the nozzle by the vibration amplified by the cleaning head. 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 gas while sandwiching the liquid level, the liquid level shakes greatly, and there is a risk of liquid level change or liquid scattering, so it is not suitable for a transport-type cleaning method. Although a cleaning tank that can overflow the liquid is used to keep the liquid level constant for a cleaning device with a large liquid swing like this structure, it is difficult to use in a transport-type cleaning method with a limited size.

[0018] The ultrasonic cleaner described in Patent Document 3 has a cover covering the cleaning tank, but the front end of the vibration head has a special shape, and it is considered that there is room for improvement in terms of difficulty in making the size (height) compact and the difficulty in installing and removing the cover.

[0019] The object of the present invention is to provide an ultrasonic cleaning machine having a structure suitable for being mounted in a narrow space such as a conveyor rack, with less swaying of the liquid surface, fluctuation of the liquid level and generation of mist, and capable of irradiating strong ultrasonic waves to the outer periphery of a nozzle.

[0020] Solutions to Solve Problems

[0021] The ultrasonic cleaning machine of the present invention includes: a cleaning tank, which has a liquid storage part for storing liquid; and an ultrasonic vibrator, which has a piezoelectric element and a front mass block, a through hole with an opening on the outer wall surface of the cleaning tank and the inner wall surface of the liquid storage part is provided on the side surface of the cleaning tank, the front mass block is inserted into the through hole, and a cover is provided in a manner covering the upper part of the front end surface of the front mass block, and the cover can at least move upward.

[0022] Effects of the Invention

[0023] According to the present invention, an ultrasonic cleaning machine can be provided which has a structure suitable for being mounted in a narrow space such as a conveyor rack, has less swaying of the liquid surface, fluctuation of the liquid level and generation of mist, and can irradiate strong ultrasonic waves to the outer periphery of the nozzle. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a perspective view showing the automatic analysis device of the embodiment.

[0025] Figure 2A It is a plan view showing an example of the structure of the cleaning unit of the ultrasonic cleaning machine according to the embodiment.

[0026] Figure 2B yes Figure 2A AA section view.

[0027] Figure 2C Yes Figure 2B The enlarged image within the dotted box.

[0028] Figure 2D Yes means Figure 2A Front view of the cleaning unit.

[0029] Figure 2E Yes means Figure 2A Side view of the cleaning section.

[0030] Figure 2F Yes means Figure 2A A three-dimensional diagram of the cleaning unit.

[0031] Figure 2G It means from Figure 2A The front view of the cleaning unit with the upper block removed.

[0032] Figure 2H It means from Figure 2A A three-dimensional view of the cleaning unit with the upper block removed.

[0033] Figure 3A It is a schematic diagram showing the sound pressure distribution and flow velocity generated at the front end of the front mass block of the ultrasonic cleaning machine when no cover is provided in the cleaning tank.

[0034] Figure 3B It is a schematic diagram showing the sound pressure distribution and flow velocity generated at the front end of the front mass block of the ultrasonic cleaning machine when a cover is installed in the cleaning tank.

[0035] Figure 4 It is a top view showing an example of arrangement of covers in a cleaning tank according to the embodiment.

[0036] Figure 5 It is a structural diagram showing an example of a cleaning frame of an ultrasonic cleaning machine according to an embodiment.

[0037] Figure 6 This is a flow chart showing a method for cleaning a dispensing nozzle using an ultrasonic cleaning machine.

[0038] Figure 7 This is a graph showing an example of a driving mode of an ultrasonic transducer.

[0039] Figure 8 This is a diagram showing the configuration of an automatic analyzer corresponding to the case of using an ultrasonic cleaner built in the transport rack of the embodiment. DETAILED DESCRIPTION

[0040] The ultrasonic cleaning machine of the present invention includes: a cleaning tank, which has a recessed portion (liquid storage portion) into which a dispensing nozzle to be cleaned can be inserted; and an ultrasonic vibrator, which has a piezoelectric element and a front mass block, a through hole having an opening on the outer wall surface of the cleaning tank and the inner wall surface of the recessed portion is provided on the side surface of the cleaning tank, the front mass block is inserted in the through hole, and the front end portion of the front mass block is configured to irradiate ultrasonic waves from the side of the dispensing nozzle.

[0041] In addition to the above structure, a detachable upper block is provided on the upper part of the cleaning tank, and a cover covering the front end of the front mass block is arranged between the upper block and the cleaning tank in an unfixed state (floating state due to the rise of the liquid level). In addition, an opening is preferably provided on the base side of the front mass block of the upper block.

[0042] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0043] Example

[0044] Figure 1 It is a perspective view showing the automatic analysis device of the embodiment.

[0045] As shown in this figure, the automatic analyzer 10 is composed of a reagent disk 12 with a plurality of reagent containers 11, a reaction disk 13 for mixing reagents and samples to measure reactions, a reagent dispensing mechanism 14 for sucking or discharging reagents, and a sample dispensing mechanism 15 for sucking or discharging samples.

[0046] 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 reagent nozzle 21, the sample nozzle 22, and other nozzles are collectively referred to as "dispensing nozzles."

[0047] The sample introduced into the device is placed in a sample container 23 (test tube) and placed on a rack 24, and transported by a transport line 25. A plurality of sample containers 23 are placed on the rack 24. The sample is a blood-derived sample such as serum or whole blood, or urine.

[0048] 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 cells 26 (containers divided into smaller portions one by one as shown in the enlarged view in the figure), and a cleaning position where the cleaning tank 27 at the front end of the sample nozzle 22 is cleaned with water. The sample dispensing mechanism 15 lowers the sample nozzle 22 according to the height of the sample container 23 at the suction position, lowers it according to the height of the cells 26 at the discharge position, and lowers it according to the height of the cleaning tank 27 at the cleaning position.

[0049] In short, 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.

[0050] In addition, the control of the sample dispensing mechanism 15 and the control of the conveying line 25 and other devices are performed by a control unit (not shown). In addition, the automatic analyzer 10 has a measuring unit (not shown) that analyzes the concentration of a predetermined component contained in the sample by measuring the photometry of the mixed solution of the sample and the reagent contained in the cell 26. The measuring unit has, for example, a light source and a photometer. The photometer is, for example, an absorbance photometer or a scattering photometer.

[0051] The cleaning rack 30 equipped with an ultrasonic cleaner is provided with a cleaning unit described below, which is used to clean the front end of the sample nozzle 22 after contacting the sample. The use time is the time of daily maintenance of the automatic analyzer 10, which is mostly performed before or after the analysis. When the number of samples processed in one day is large, the cleaning rack 30 can also be used on the conveying line 25 during the intervals of analysis. In this way, the cleanliness of the sample nozzle 22 can be maintained.

[0052] The cleaning rack 30 can clean any sample nozzle 22 or reagent nozzle 21 that can access the transport line 25, and is not limited to the sample. In addition, multiple sample nozzles 22 can be cleaned in one transport, but there is a possibility that dirt will re-attach due to reuse of the cleaning liquid that has been contaminated during cleaning, so it is preferable to replace the cleaning liquid for each nozzle. In this case, there is a method of flowing one cleaning rack 30 multiple times on the transport line 25, or flowing multiple cleaning racks 30.

[0053] As a conveying method of the conveying line 25 , a method using a belt moving along the conveying line 25 , a pressing claw, or the like, a method using an electromagnetic force, or the like can be applied.

[0054] Figure 2A It is a plan view showing an example of the structure of the cleaning unit of the ultrasonic cleaning machine according to the present embodiment.

[0055] In this figure, the cleaning section includes two ultrasonic vibrators 201A and 201B (excitation section), a cleaning tank 202, and an upper block 203 mounted on the upper part of the cleaning tank 202. The upper block 203 is provided with a through hole 211 and an opening 212. The through hole 211 is provided for cleaning the sample nozzle. The through hole 211 is provided at a position where a cleaning hole 210 provided in a cover described later is exposed. The sample nozzle is inserted from the cleaning hole 210 into the liquid below it. Therefore, the through hole 211 is also called a "cleaning opening".

[0056] The opening 212 is provided for supplying liquid to the liquid storage portion in the cleaning tank 202. The opening 212 also has a function of alleviating the fluctuation of the liquid level described later. Therefore, the opening 212 is also referred to as a "liquid injection opening".

[0057] Figure 2B yes Figure 2A AA section view.

[0058] like Figure 2BAs shown in the figure, a through hole 214 is provided in the liquid storage part 213, which is a recessed part provided in the central part of the cleaning tank 202, and penetrates the liquid storage part 213 from the left and right sides in the figure. In other words, the through hole 214 has an opening on the outer wall surface of the cleaning tank 202 and the inner wall surface of the liquid storage part 213 (recessed part) at the side part of the cleaning tank 202. Ultrasonic vibrators 201A and 201B are respectively inserted into the two through holes 214. The ultrasonic vibrators 201A and 201B are fixed to the side of the cleaning tank 202 by the flange 204 and the seal 205 (O-ring).

[0059] The flange 204 may be a component different from the ultrasonic vibrators 201A and 202B. In practice, the ultrasonic vibrators 201A and 201B are fixed by pressing the flange 204 (or other fixing components for pressing the ultrasonic vibrators 201A and 201B) against the cleaning tank 202 with screws including the fastening bolts 209. This structure can prevent liquid from leaking from the through hole 211.

[0060] The ultrasonic vibrators 201A and 201B have the same structure.

[0061] The ultrasonic vibrators 201A and 201B are composed of a front mass block 225 (a metal block on the front surface), a rear mass block 226 (a metal block on the back surface), 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 structure in which two sheets are alternately stacked. The stacked piezoelectric elements 207 and electrodes 208 are sandwiched between the front mass block 225 and the rear mass block 226 and fixed by the fastening bolts 209.

[0062] In addition, regarding the number of piezoelectric elements 207 and electrodes 208, the figure shows a structure in which two piezoelectric elements 207 and electrodes 208 are alternately stacked, but the ultrasonic vibrator of the present invention is not limited to this and may be a structure in which four piezoelectric elements 207 and electrodes 208 are alternately stacked or a number other than this.

[0063] The ultrasonic transducers 201A and 201B are characterized in that they have an elongated cylindrical metal portion at the front end. In other words, the front end portion of the front mass 225 is made of an elongated cylindrical metal.

[0064] In short, the ultrasonic transducers 201A and 201B have a structure that is fixed by bolting, similar to a conventional bolt-clamped Langevin Type Transducer (BLT). The BLT structure is advantageous for amplifying the amplitude, and is therefore used in situations where strong ultrasonic waves are used, and is also used in industrial ultrasonic cleaning machines that require strong cleaning performance.

[0065] Figure 2C Yes Figure 2B The enlarged view within the dotted frame shows the details of the main parts of the cleaning unit.

[0066] like Figure 2C As shown, a recess 235 is provided on the lower surface of the upper block 203 .

[0067] The recessed portion 235 is located above the liquid storage portion 213 and the front end surface 215 of the front mass block 225 .

[0068] A cover 216 is provided between the cleaning tank 202 and the upper block 203. The width dimension of the cover 216 is smaller than the width dimension of the recess 235. A cleaning hole 210 is provided in the central portion of the cover 216. Since the width dimension of the recess 235 is larger than the width dimension of the cover 216, when the cover 216 floats on the liquid surface below, it becomes a space that allows the cover 216 to move.

[0069] In order to prevent the liquid from overflowing above the upper surface of the cover 216, it is preferred that the cover 216 be made of a resin or the like that floats on the liquid. On the contrary, if the liquid is located above the upper surface of the cover 216, it is preferred that the cover 216 be made of a metal that does not float on the liquid and can block ultrasonic waves. In addition, even if the cover 216 is made of metal, in the case of an aluminum alloy foil, it will float on the liquid surface.

[0070] The ultrasonic transducers 201A and 201B can maximize the amplitude of the front end surface 215 of the front mass 225 by being driven at the resonance frequency.

[0071] The ultrasonic vibrators 201A and 201B are preferably configured to generate a node of vibration (a region where the amplitude is always small) within the range from the flange 204 to the step portion (the connection portion between the small diameter portion and the large diameter portion) of the front mass block 225. In addition, the seal 205 is made of an elastic material. Therefore, the influence caused by the contact between the front mass block 225 and the seal 205 is small.

[0072] The through hole 214 for passing the front mass block 225 is formed into a cylindrical shape by combining the cleaning tank 202 and the upper block 203. Depending on the shape of the ultrasonic vibrators 201A and 201B used, an inclined portion or a step may also be provided at the root of the through hole 214. In addition, approximately the same gap is formed between the wall surface of the through hole 211 and the ultrasonic vibrators 201A and 201B. The seal 205 is arranged near the root of the cylindrical portion to prevent liquid from leaking from the through hole 211. As a result, the deformation of the front end portion of the front mass block 225, which is greatly deformed when the ultrasonic vibrators 201A and 201B are driven, will not be hindered, and the vibration can be transmitted to the liquid in the liquid storage portion 213 without contacting the wall surface of the through hole 211.

[0073] In addition, in the liquid storage part 213, the liquid injected from the opening 212 can be placed on the bottom surface of the cover 216. As a result, the gap formed around the cylindrical part of the front mass block 225 inserted into the through hole 211 is filled with liquid. For the reasons described later, even if the liquid level is higher than the cover 216, the effect of the ultrasonic cleaning machine disclosed in the present invention can be obtained.

[0074] When liquid is injected into the liquid storage part 213, the front end face 215 of the front mass block 225 is immersed in the liquid. In this state, the two ultrasonic vibrators 201 are driven to irradiate the liquid with ultrasonic waves from the front end face 215. The front end face 215, which is the irradiation part of the ultrasonic wave, is preferably arranged so that its upper end is about 0.5 to 1 mm away from the liquid surface. By configuring in this way, only the part of the sample nozzle immersed in the liquid can be cleaned intensively. That is, the distance between the lower surface of the cover 216 and the upper end of the front end face 215 is preferably about 0.5 to 1 mm.

[0075] If the front end face 215 is arranged to be deeper from the liquid surface, the cleaning area is far from the liquid surface, so in order to clean the front end of the sample nozzle, the sample nozzle needs to be inserted deeper into the liquid. If such a configuration is adopted, the range of wetting of the sample nozzle increases. The sample nozzle is designed to ensure the accuracy of dispensing by limiting the range wetted by the liquid, so it is preferred not to wet a larger range. Therefore, it is preferred to set the cleaning area near the liquid surface.

[0076] Figure 2D Yes means Figure 2A Front view of the cleaning unit.

[0077] exist Figure 2D In the cleaning section 200 shown, an upper block 203 is connected to the upper part of the cleaning tank 202. The upper block 203 may also be two or more components. By adopting a structure in which the two or more components clamp the cover 216, it can be integrated with the cover 216, making it easier to disassemble and install the cleaning tank 202 when cleaning.

[0078] Figure 2E Yes means Figure 2A Side view of the cleaning section.

[0079] exist Figure 2E In the embodiment, the flange 204 is formed into a circular shape, but in order to set the size not exceeding the size of the cleaning tank 202, it can also be cut partially to set the shape other than the circular shape.

[0080] Figure 2F It is shown Figure 2A A three-dimensional diagram of the cleaning unit.

[0081] The upper block 203 has a through hole 211 and an opening 212 for supplying liquid on its upper surface, each of which is accessible from above. That is, the cleaning liquid can be supplied from the opening 212 and the sample nozzle can be inserted into the through hole 211 .

[0082] Figure 2G It shows the state after removing the upper block 203 Figure 2A Side view of the cleaning section.

[0083] Figure 2H It shows the state after removing the upper block 203 Figure 2A A three-dimensional diagram of the cleaning unit.

[0084] like Figure 2H As shown in FIG. 1 , by removing the upper block 203, the front mass block 225 of the ultrasonic vibrator 201 is exposed, and the inside can be cleaned. During cleaning, if the cover 216 is fixed to the upper block 203 as described above, the cover 216 is also removed at the same time, thereby improving the operability during cleaning. In addition, the cleaning inside the cleaning tank 202 can be directly sprayed with running water such as tap water to remove dirt.

[0085] In addition, if Figure 2F As shown, two openings 212 and a through hole 211 are provided in the upper block 203. Thus, for example, even when tap water flows directly into one opening 212, water can be discharged from the other opening 212 or the through hole 211, so that the interior can be easily cleaned. That is, the following application can be realized: in daily cleaning, the upper block 203 is not disassembled but cleaned in the state where the upper block 203 is assembled, and the upper block 203 is removed only for regular cleaning once every few weeks to clean the interior.

[0086] Although not shown, since the cleaning unit 200 is in direct contact with running water, electrical components such as the ultrasonic vibrator 201 need to be protected by a cover or the like for waterproofing. Figure 1 In the embodiment of the cleaning rack 30 shown, the cleaning unit 200 is inside the housing, so the ultrasonic vibrator 201 is covered and is not directly wetted by water or the like.

[0087] In addition, the size of the cleaning unit 200 is preferably a size that can be accommodated in the holder 24. By setting it to such a size, the cleaning unit 200 can be moved to the position of the sample nozzle 22 to perform cleaning.

[0088] In this embodiment, although the upper block 203 is shown as one, the ultrasonic cleaning machine of the present invention is not limited to this. For example, the upper block 203 is divided into two, each upper block is provided with an opening 212, and a gap is provided between the two upper blocks. Thus, if the gap is provided as a structure replacing the through hole 211, it is not necessary to provide the through hole 211. In this case, it is sufficient to configure the cover 216 to be sandwiched between any one of the two upper blocks and the cleaning tank 202.

[0089] Next, a description will be given of a state in which ultrasonic waves are irradiated into liquid from the front end portion of the front mass 225 of the ultrasonic transducer 201 .

[0090] Figure 3A It is a schematic diagram showing the sound pressure distribution and flow velocity generated at the front end of the front mass block of the ultrasonic cleaning machine when no cover is provided in the cleaning tank.

[0091] Figure 3B It is a schematic diagram showing the sound pressure distribution and flow velocity generated at the front end of the front mass block of the ultrasonic cleaning machine when a cover is installed in the cleaning tank.

[0092] In these figures, arrows are vectors indicating the flow of liquid, and thick arrows indicate the portion with the fastest flow velocity. In addition, the semicircle indicated by the dotted line indicates an area with high sound pressure.

[0093] According to the acoustic wave analysis, by driving the ultrasonic transducer 201 at the resonance frequency, a flow of liquid is generated from the front end surfaces 215A and 215B of the front mass blocks 225A and 225B in the direction of the arrow. Figure 3A In the structure shown, the thick arrow extending toward the liquid surface was confirmed based on the experimental observation results and the condition that the liquid overflowed to the outside of the cleaning tank 202 (the phenomenon of generating a liquid column). This phenomenon is the same even when only one ultrasonic vibrator 201 is driven, and the effect of the cover 216 described later is the same even when there is only one ultrasonic vibrator 201.

[0094] When the liquid surface swings greatly due to the driving of the ultrasonic vibrator 201, the wetting range of the sample nozzle 22 increases, and the cleaning water is brought into other samples, etc., or it becomes a cause of failure of the liquid surface detection sensor built into the sample nozzle 22. In addition, there is a problem that the liquid overflows from the cleaning tank 202 and wets the conveying line 25 or its surroundings. In addition, if the cleaning liquid overflows, the liquid level drops, and the front end of the ultrasonic vibrator 201 is exposed to the air, mist is generated. If the surroundings or the sample nozzle 22 are wetted by the mist, the above-mentioned problems will occur.

[0095] exist Figure 3BIn the figure, the portion with a fast flow rate indicated by a thick arrow collides with the cover 216 set on the liquid surface, so overflow can be prevented. It is preferred to cover the point where the central axis of the front mass block 225A, 225B intersects with the front end surface 215A, 215B of the front mass block 225A, 225B, that is, the center of the front end surface, as the origin, and cover a range of approximately 60 degrees to 90 degrees relative to the central axis direction of the front mass block 225A, 225B, and more preferably cover a range of approximately 50 degrees to 90 degrees. In this way, overflow caused by the generation of a liquid column can be prevented. In particular, after the ultrasonic vibrator 201 is just started to be driven, a strong water flow is generated, and the liquid level around the cleaning hole 210 temporarily rises. When the liquid level exceeds the cover 216, the liquid remains on the upper surface of the cover 216, the amount of liquid in the cleaning tank 202 is reduced, and sometimes fog is generated.

[0096] In this embodiment, the cover 216 is not fixed but is movable according to the up and down movement of the liquid. Therefore, the temporary rise of the liquid can be absorbed and the liquid can be prevented from overflowing after the ultrasonic vibrator 201 is driven.

[0097] In addition, in addition to the cover 216, Figure 2F The opening 212 shown is located in a region where the amplitude of the ultrasonic vibrator 201 is smaller than that of the tip, and is located in a region where the change in liquid level due to the driving of the ultrasonic vibrator 201 is small.

[0098] On the contrary, by providing the opening 212, there is also an effect of absorbing the flow velocity fluctuation between the front end surfaces 215A and 215B. For example, in the absence of the opening 212, if the pressure in the cleaning tank 202 rises, there is only an area where the pressure is released from the cleaning hole 210, so the fluctuation of the liquid level around the cleaning hole 210 is concentrated. However, by providing the opening 212, there are multiple areas where the pressure escapes, and the effect of dispersing the fluctuation of the liquid level at the cleaning hole 210 is obtained.

[0099] As described above, the high flow velocity portion generated from the front end surfaces 215A and 215B of the front masses 225A and 225B is suppressed, so that the liquid does not overflow from the cleaning tank 202, and cleaning can be performed without wetting the outside of the cleaning range of the sample nozzle 22 or the transport line 25.

[0100] In this embodiment, the effect of the cover 216 of the structure floating on the liquid surface is described, but even if it is a cover of the type opened and closed by an actuator, as long as it covers the above range, the same effect can be obtained. For example, it can also be an opening and closing mechanism that opens the cover before the sample nozzle 22 passes through and closes the cover after insertion. As a structure, there is a lens cover mechanism of a digital camera, etc.

[0101] Figure 4It is a top view showing an example of arrangement of a cover of a cleaning tank according to the embodiment.

[0102] In this figure, an example of the relationship between the cover 216 and the wall surface of the cleaning tank 202 is shown.

[0103] As described above, cover 216 is not fixed to cleaning tank 202. In order to suppress the restriction by the surface tension of the liquid, it is preferable to provide convex portion 410 on the inner wall surface of cleaning tank 202 as shown in this figure to reduce the contact portion with cover 216.

[0104] If the gap between the wall surface of the cleaning tank 202 and the cover 216 is too large, the position of the cleaning hole 210 will be greatly displaced due to the shaking and fluctuation of the liquid surface, and the risk of the sample nozzle 22 contacting the cover 216 will increase when inserting the sample nozzle 22. Therefore, it is preferable to design the size of the gap between the wall surface of the cleaning tank 202 and the cover 216 in consideration of the outer diameter and stop accuracy of the sample nozzle 22 and the shape and size of the cleaning hole 210.

[0105] Figure 5 It is a structural diagram showing an example of a cleaning rack of the ultrasonic cleaning machine according to the present embodiment.

[0106] As shown in this figure, the cleaning rack 30 includes a cleaning unit 200, an ultrasonic vibrator control unit 301, a driving power source 302 (battery), and a transport base 303. The ultrasonic vibrator control unit 301 controls the ultrasonic vibrators 201A and 201B ( Figure 2A ) driver.

[0107] The ultrasonic vibrator control unit 301 generates a sine wave of the resonance frequency of the ultrasonic vibrators 201A and 201B to drive the ultrasonic vibrators 201. The ultrasonic vibrator control unit 301 also includes an impedance matching circuit for increasing the drive current of the ultrasonic vibrators 201 and amplifying the amplitude, and a circuit for automatically tracking the resonance frequency.

[0108] The driving power source 302 is a rechargeable battery, and is charged every time the cleaning rack 30 is used. The cleaning time of the sample nozzle 22 is within a few minutes, and it does not need to be driven for a long time, so a small battery is sufficient. It can also be configured so that a wireless power supply unit is set at a predetermined position adjacent to the conveying line 25 to charge the driving power source 302.

[0109] The transport base 303 has the same shape as the bottom of the holder 24 used for the sample container 23. Therefore, there is no need to change the hardware of the transport line 25. In addition, the cleaning rack 30 including the cleaning unit 200, the ultrasonic vibrator control unit 301 and the driving power supply 302 has a size smaller than the holder 24 in a state where the existing sample container 23 is set.

[0110] The cleaning unit 200 is covered with a cover 304. The cover 304 prevents the liquid from splashing onto the piezoelectric element 207, the electrode 208, and other electrical components when the liquid is supplied or discharged to the opening 212 by a pipette or the like.

[0111] As described above, the ultrasonic vibrator 201 is sealed at the node of vibration, so the vibration amplification efficiency becomes high. In addition, by adopting a configuration in which the front end surface 215 of the ultrasonic vibrator 201 is close to the side surface of the sample nozzle 22, it is possible to irradiate the sample nozzle 22 with strong ultrasonic waves, which can improve the cleaning effect. In addition, by irradiating ultrasonic waves from two directions, a structure that can clean even in a small space such as a small cleaning rack 30 can be realized.

[0112] The amount of cleaning liquid required for cleaning varies depending on the size of the liquid storage unit 213, but is about several hundred μL to several mL. The cleaning liquid can achieve a cleaning effect even if it is water, but a liquid mixed with a detergent or the detergent itself may also be used.

[0113] As described above, the automatic analyzer of the present invention has a structure in which the ultrasonic cleaning machine of the present embodiment is used by conveyance.

[0114] Figure 6 This is a flow chart showing a method for cleaning a dispensing nozzle using the ultrasonic cleaning machine of this embodiment.

[0115] As shown in this figure, the cleaning liquid is injected from the opening 212 of the cleaning unit 200 (step S601). As a result, the cleaning liquid fills the liquid storage unit 213. At this time, by using a container of a dedicated size that does not allow liquid to enter an amount exceeding the capacity of the liquid storage unit 213, the liquid can be injected without exceeding the cover 216. In addition, the discharge amount of the pipette can be set to the same amount as the capacity of the liquid storage unit 213 for injection.

[0116] As described above, it is not recommended to inject liquid beyond the cover 216 in order to prevent wetting outside the cleaning range of the sample nozzle 22. Therefore, it is preferable to use a method that can inject the same amount of liquid as the capacity of the liquid storage part 213.

[0117] After the liquid is injected, the cleaning rack 30 is placed on the transport line 25 (step S602 ). Then, the cleaning rack 30 is transported to the cleaning position under the control of the automatic analyzer 10 (step S603 ), and the automatic cleaning operation is started.

[0118] The cleaning rack 30 has a built-in communication function described later, and can start driving in response to an instruction from the control unit of the automatic analyzer 10 , and can start ultrasonic driving after stopping at the cleaning position (step S604 ).

[0119] Here, steps S601 to S603 can be performed manually, but can also be performed automatically using a cleaning solution dispensing unit or the like provided 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 S604, the cleaning rack 30 is automatically installed on the conveying line 25, and the cleaning solution is automatically injected into the liquid storage section 213 of the cleaning section 200.

[0120] When the normal rack 24 is transported, the subsequent analysis / transportation process is branched by reading the barcode attached to the side of the rack 24. Therefore, by attaching the barcode to the cleaning rack 30 at the same position as the normal rack 24, the rack 24 for inspection and the cleaning rack 30 for cleaning can be distinguished in the automatic analyzer 10, and the maintenance operation for cleaning can be performed.

[0121] After the cleaning rack 30 is transported to the vicinity of the target sample nozzle 22, the sample nozzle 22 is lowered toward the liquid storage portion 213 (step S605), and the front end of the sample nozzle 22 is immersed in the cleaning liquid for a certain period of time to clean (step S606). After the cleaning is completed, the sample nozzle 22 is raised and then the cleaning rack 30 is moved out (step S607). Regarding the stop of ultrasonic drive (step S608), the above-mentioned communication function is used to stop by an instruction from the control unit of the automatic analyzer 10. By using the built-in timer function, it can also be stopped after a certain period of time.

[0122] Then, the cleaning rack 30 is transported to the recovery position (step S609), and the cleaning rack is recovered and cleaned (step S610). Regarding cleaning, as mentioned above, there is a method of cleaning by flowing water into the opening 212 of the upper block 203 and a method of removing the upper block 203 for cleaning.

[0123] In addition, the cleaning liquid may be replaced as needed, and the cleaning of other sample nozzles 22 may be continuously performed. When no cleaning is performed, the cleaning liquid is discharged and the process is finished.

[0124] Figure 7 This is a graph showing an example of the driving mode of two ultrasonic vibrators.

[0125] This figure shows the period from when the sample nozzle 22 starts to descend toward the liquid storage section 213 to when it finishes to ascend.

[0126] The ultrasonic vibrators A and B started to be driven in the above-mentioned manner are repeatedly driven before or at the same time as the sample nozzle 22 descends. In this case, a certain time difference between the driving of the ultrasonic vibrators A and B and the descending of the sample nozzle 22 is acceptable.

[0127] In this driving mode, it is preferable to drive the ultrasonic vibrators A and B with the same output. The driving signal of the vibrator output from the control circuit is one, and the 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 any one of the ultrasonic vibrators A and B, or drives at a frequency near (or in the middle of) the resonance frequency of the two ultrasonic vibrators A and B. In order to drive at a frequency near the resonance frequency of the two ultrasonic vibrators A and B, there are a method of determining the driving frequency based on a frequency measured in advance and a method of adding a circuit to detect the resonance frequency during driving and changing it at any time.

[0128] The ultrasonic vibrators A and B have simple shapes, so the resonance frequency deviation caused by the manufacture or assembly of the vibrators is small. Therefore, the two ultrasonic vibrators A and B can be driven with a large amplitude as long as the driving frequency is close to the resonance frequency of the two ultrasonic vibrators A and B.

[0129] As described above, the effect of the cover 216 suppresses the high flow rate portion generated after the start of driving of the ultrasonic vibrators A and B and generated from the front end surface 215, and the liquid does not overflow from the cleaning tank 202. Therefore, the stabilization time of the liquid level is shortened, and the time from the start of driving of the ultrasonic vibrators A and B to the completion of the nozzle descent can be shortened. That is, even if the driving of the ultrasonic vibrators A and B is started just before the nozzle 22 for the sample is inserted, stable cleaning can be performed.

[0130] Figure 8 This is a diagram showing the configuration of an automatic analyzer corresponding to the case of using an ultrasonic cleaner built in the transport rack of this embodiment.

[0131] In this figure, the automatic analyzer is controlled by an automatic analyzer control unit 801. The user of the automatic analyzer can instruct the analysis process and the cleaning process from a graphical user interface 802 (GUI). The normal analysis process and the cleaning maintenance mode of this embodiment are performed by a maintenance control member 803, and the sample dispensing mechanism 15 and the conveying line 25 are controlled.

[0132] The sample dispensing mechanism 15 controls the position of the sample nozzle 22 from the dispensing arm control member 804 (dispensing arm control unit) via the dispensing arm horizontal moving member 805 (dispensing arm horizontal moving unit) and the dispensing arm vertical moving member 806 (dispensing arm vertical moving unit). In the maintenance mode, the horizontal position and vertical position of the sample nozzle 22 are controlled so that the cleaning range of the front end of the sample nozzle 22 is immersed in the liquid in the liquid storage part 213.

[0133] The horizontal position of the sample nozzle 22 is preferably the middle position of the two front end surfaces 215, but it can also be controlled to move horizontally while immersed and approach the front end surface 215A or the front end surface 215B.

[0134] The transport line 25 is driven by the rack transport control means 807 (rack transport control unit) via the rack transport means 808 (rack transport unit).

[0135] The cleaning rack 30 and the automatic analyzer control unit 801 independently include a communication unit 821 for communicating with the automatic analyzer, a vibrator driving unit 822 (vibrator driving unit) for detecting and driving the resonance frequency of the ultrasonic vibrator 201 , and a power management unit 823 for managing the state of the driving power source 302 .

[0136] As described above, the communication means 821 controls the start / end of driving the ultrasonic vibrator 201 by the vibrator driving means 822 according to the instruction from the automatic analyzer 10 .

[0137] The power management component 823 manages the charging state of the driving power source 302 and transmits the state to the outside by displaying the state by changing the color of the LED provided on the washing rack 30 or by the communication component 821 .

[0138] With the above configuration, the cleaning rack 30 is transported to a position on the transport line 25 accessible to the sample nozzle 22 , and the driving of the ultrasonic vibrator 201 mounted on the cleaning rack 30 is started to immerse the sample nozzle 22 in the liquid storage portion 213 , thereby cleaning the cleaning area of ​​the sample nozzle 22 .

[0139] Furthermore, the reagent nozzle 21 can be implemented with the same configuration as long as it can access the transport line 25 .

[0140] In this embodiment, the case where the reagent nozzle 21 and the sample nozzle 22 are separately provided is described, but depending on the different analysis devices, there is also a case where the reagent and the sample are dispensed using a common nozzle. In such a device, water flow cleaning is performed every time the reagent and the sample are dispensed, but daily maintenance is required. By performing ultrasonic cleaning of the present invention, the dispensing accuracy can be maintained.

[0141] Furthermore, according to the present invention, the cover can be easily attached and detached in a state where the ultrasonic transducer is mounted.

[0142] In the above-mentioned embodiment, the front end surfaces 215A and 215B of the two ultrasonic vibrators 201A and 201B are arranged to face each other. However, the ultrasonic cleaning machine of the present invention is not limited to this, and may include a case where one ultrasonic vibrator is horizontally arranged.

[0143] Hereinafter, preferred embodiments of the present invention will be summarized and described.

[0144] A plurality of ultrasonic vibrators are provided on the side surface of the cleaning tank.

[0145] The liquid storage portion is capable of inserting a dispensing nozzle to be cleaned, and the cover is provided with a cleaning hole having an inner diameter larger than an outer diameter of the dispensing nozzle.

[0146] The movable range of the cover in the horizontal direction is limited so as to maintain a state of being separated from the dispensing nozzle inserted into the cleaning hole.

[0147] The cleaning tank is provided with an upper block covering the front mass block, and the upper block is provided with a liquid injection opening for injecting liquid into the liquid storage part.

[0148] The upper block is provided with a cleaning opening into which the dispensing nozzle is inserted.

[0149] The cover covers a range of 60 to 90 degrees relative to the central axis of the front mass block, with the point where the central axis of the front mass block intersects with the front end surface of the front mass block, that is, the center of the front end surface as the origin.

[0150] The liquid injection opening of the upper block is provided between the front end surface of the front mass block and the through hole into which the front mass block is inserted.

[0151] The upper block is configured to be detachable from the cleaning tank so that the front mass block is exposed.

[0152] The cover is formed of resin or metal.

[0153] The cleaning tank is provided with an upper block covering the front mass block. The upper block is provided with two liquid injection openings for injecting liquid into the liquid storage part and a cleaning opening for inserting the dispensing nozzle. The cleaning opening is provided between the two liquid injection openings.

[0154] The inner wall surface of the cleaning tank is provided with a convex portion that contacts the cover.

[0155] The automatic analysis device has a mechanism for transporting the ultrasonic cleaning machine using a transport line to clean the dispensing nozzle.

[0156] Explanation of symbols

[0157] 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—conveying line, 26—cell, 27—cleaning tank, 30—cleaning rack, 201, 201A, 201B—ultrasonic vibrator, 202—cleaning tank, 203—upper block, 204—flange, 205—seal, 207—piezoelectric element, 208—electrode, 209—fastening bolt, 210—cleaning hole, 211—through hole, 212—opening, 213— 3—liquid storage part, 215, 215A, 215B—front end face, 216—cover, 225—front mass block, 226—rear mass block, 301—ultrasonic vibrator control part, 302—driving power supply, 303—conveying base, 304—cover, 801—automatic analysis device control part, 802—graphical user interface, 803—maintenance control component, 804—dispensing arm control component, 805—dispensing arm horizontal moving component, 806—dispensing arm up and down moving component, 807—bracket conveying control component, 808—bracket conveying component, 821—communication component, 822—vibrator driving component, 823—power management component.

Claims

1. An ultrasonic cleaning machine, It is characterized in that include: A cleaning tank having a liquid storage portion for storing liquid; as well as The ultrasonic vibrator comprises a piezoelectric element and a front mass block. A through hole having an opening on the outer wall surface of the cleaning tank and the inner wall surface of the liquid storage portion is provided on the side surface of the cleaning tank. The front mass block is inserted into the through hole, A cover is provided above the front end surface of the front mass block in a manner covering the front end surface of the front mass block. The cover is movable at least upward.

2. The ultrasonic cleaning machine according to claim 1, It is characterized in that A plurality of the ultrasonic vibrators are provided on the side surface of the cleaning tank.

3. The ultrasonic cleaning machine according to claim 1, It is characterized in that The liquid storage part can be inserted into the dispensing nozzle to be cleaned. The cover is provided with a cleaning hole having an inner diameter larger than an outer diameter of the dispensing nozzle.

4. The ultrasonic cleaning machine according to claim 3, It is characterized in that The movable range of the cover in the horizontal direction is limited so as to maintain a state of being separated from the dispensing nozzle inserted into the cleaning hole.

5. The ultrasonic cleaning machine according to claim 3, It is characterized in that An upper block covering the front mass block is arranged in the cleaning tank, The upper block is provided with a liquid injection opening for injecting liquid into the liquid storage portion.

6. The ultrasonic cleaning machine according to claim 5, It is characterized in that The upper block is provided with a cleaning opening into which the dispensing nozzle is inserted.

7. The ultrasonic cleaning machine according to claim 4, It is characterized in that The cover covers a range of 60 to 90 degrees relative to the central axis of the front mass block, with the point where the central axis of the front mass block intersects with the front end surface of the front mass block, namely, the center of the front end surface as the origin.

8. The ultrasonic cleaning machine according to claim 5, It is characterized in that The liquid injection opening of the upper block is provided between the front end surface of the front mass block and the through hole into which the front mass block is inserted.

9. The ultrasonic cleaning machine according to claim 5, It is characterized in that The upper block is configured to be detachable from the cleaning tank so that the front mass block is exposed.

10. The ultrasonic cleaning machine according to claim 1, It is characterized in that The cover is formed of resin or metal.

11. The ultrasonic cleaning machine according to claim 3, It is characterized in that An upper block covering the front mass block is arranged in the cleaning tank, The upper block is provided with two openings for injecting liquid into the liquid storage part and an opening for cleaning through which the dispensing nozzle is inserted. The cleaning opening is disposed between the two liquid injection openings.

12. The ultrasonic cleaning machine according to claim 1, It is characterized in that A convex portion that contacts the cover is provided on the inner wall surface of the cleaning tank.

13. An automatic analysis device, Features ， An ultrasonic cleaning machine according to claim 1, The ultrasonic cleaning machine is transported by a transport line to clean the dispensing nozzle.

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