JP2019039701A - Chemical analysis device - Google Patents

Abstract

To provide a chemical analysis device capable of improving agitation performance by increasing the action of an agitation flow and agitating a sample of a small fluid volume and a reagent.SOLUTION: A chemical analysis device applies a waveform for changing a resonant frequency of a thickness vibration of a piezoelectric element to an agitation element 411 composed of an agitation element which outputs an ultrasonic wave using a waveform generator. A piezoelectric element constituting the agitation element 411 changes the resonant frequency by comprising a configuration in which the thickness in a horizontal direction (x direction) to a propagation direction of an ultrasonic wave 412 inclines and changes, thereby making it possible to change a distance 414 from the piezoelectric element which is a sound flow generation position in a reaction vessel 413. This allows the agitation performance to improve by increasing the action of an agitation flow in the reaction vessel 413.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a chemical analyzer, and more particularly to a stirring technique for mixing a sample and a reagent in a reaction vessel.

  In the field of chemical / medical analysis, the volume of liquids such as samples and reagents is increasing. As a technique for mixing and stirring small amounts of samples and reagents, Patent Document 1 uses samples and reagents without using a spatula or a screw. A method is described in which a sample and a reagent are agitated and mixed in a non-contact manner by irradiating ultrasonic waves from the bottom of the container into the opening of the container.

  In Patent Document 2, a sound source and a reflection plate are provided outside the reaction vessel, and the reaction vessel is disposed between the sound source and the reflection plate so that sound waves are intermittently irradiated from a plurality of directions toward the reaction vessel. A method for efficiently stirring and mixing the liquid in the reaction vessel is described.

  Further, Patent Document 3 describes a stirring device using a piezoelectric substrate having a vertical inclination in a reaction vessel as a thickness longitudinal vibrator.

JP-A-8-146007 JP 2006-234839 A JP 2007-108061 A

  The thing of patent document 1 is going to acquire strong stirring power regarding the structure provided with the structure which irradiates the sound wave from the side of a container further, or the structure which irradiates the sound wave from the bottom of a container. When strong sound waves are irradiated from the lower sound wave supply means, the liquid level of the sample rises, and there is a possibility that the sample liquid or the like may scatter. On the other hand, if too weak sound waves are irradiated, there is a possibility that the sample cannot sufficiently contribute to stirring.

  On the other hand, the one described in Patent Document 2 can obtain a strong stirring force, and uses an acoustic flow in which acoustic radiation pressure near the gas-liquid interface that is not affected by wall friction is dominant. A stirring flow that is a swirling flow in a direction perpendicular to the water surface is generated in the reaction vessel. However, in the stirring of a smaller amount of sample and reagent, a sufficient swirling flow was not obtained, and it was necessary to improve the performance of the stirring action.

  Patent Document 3 describes a stirrer using a piezoelectric substrate with a vertical inclination of a reaction vessel of an automatic analyzer as a thickness longitudinal vibrator, but depending on the amount of liquid held in the reaction vessel. The purpose is to change the frequency of the drive signal.

  An object of the present invention is to provide a chemical analyzer capable of solving the above-described problems and obtaining a sufficient swirling flow and improving the stirring action in stirring a small amount of sample and reagent. .

  In order to achieve the above object, in the present invention, a chemical analysis apparatus includes a reaction container into which a sample to be analyzed and a reagent are injected, and a piezoelectric element that irradiates ultrasonic waves to the side surface of the reaction container. An ultrasonic stirring mechanism having a waveform generator for driving the piezoelectric element, and a configuration for changing the acoustic flow generation distance from the piezoelectric element in the reaction vessel by changing the resonance frequency of the thickness vibration of the piezoelectric element A chemical analysis apparatus is provided.

  According to the present invention, by changing the acoustic flow generation position by changing the acoustic flow generation distance from the piezoelectric element, it is possible to agitate a smaller amount of liquid and the reagent.

It is a perspective view which shows an example of the whole apparatus structure of the chemical analyzer which concerns on each Example. 1 is a longitudinal sectional view showing an example of an ultrasonic stirring mechanism according to Embodiment 1. FIG. 5 is a diagram illustrating an example of a sound source of an ultrasonic stirring mechanism according to Embodiment 1. FIG. 1 is a top view showing the principle of an ultrasonic stirring mechanism according to Embodiment 1. FIG. It is a figure explaining the characteristic of the stirring element of the sound source which concerns on Example 1. FIG. 6 is a top view illustrating an example of a sound source of an ultrasonic stirring mechanism according to Embodiment 2. FIG. It is a figure explaining the characteristic of the stirring element of the sound source which concerns on Example 2. FIG. 6 is a schematic diagram illustrating an outline of an ultrasonic stirring mechanism according to Example 3. FIG. It is a figure explaining the characteristic of the stirring element of the sound source which concerns on Example 3. FIG. FIG. 10 is a schematic diagram illustrating an outline of an ultrasonic stirring mechanism according to a fourth embodiment. It is a figure explaining the characteristic of the stirring element of the sound source which concerns on Example 4. FIG.

  Hereinafter, various embodiments of the chemical analysis apparatus of the present invention will be sequentially described with reference to the drawings. In addition, this invention is not limited to the structure of each Example demonstrated below, It can also be used for other embodiment.

  The chemical analysis apparatus according to each embodiment includes a sample to be analyzed, an automatic sample dispensing mechanism for supplying the reagent to the reaction container, an automatic reagent dispensing mechanism, and an automatic for stirring the sample / reagent in the reaction container. Stirring mechanism, measuring instrument for measuring physical properties of the sample during or after the reaction, automatic cleaning mechanism for aspirating and discharging the sample that has been measured by the measuring instrument, and washing the reaction vessel. It consists of a control mechanism for controlling.

  Example 1 will be described with reference to FIGS. The present embodiment is a chemical analyzer, a reaction container into which a sample to be analyzed and a reagent are injected, an ultrasonic stirring mechanism having a piezoelectric element that irradiates ultrasonic waves to the side surface of the reaction container, and a piezoelectric device. And a waveform generator for driving the element, and an embodiment of the chemical analyzer configured to change the acoustic flow generation distance from the piezoelectric element in the reaction vessel by changing the resonance frequency of the thickness vibration of the piezoelectric element. is there.

  FIG. 1 is a perspective view showing a configuration example of the chemical analyzer of the present embodiment, and FIG. 2 is a non-invasive method that performs non-contact stirring and mixing on an object to be stirred equipped in the chemical analyzer shown in FIG. It is a longitudinal cross-sectional view which shows one structural example of a non-contact stirring apparatus.

  As shown in FIG. 2, the chemical analyzer mainly stores a reaction disk 101 for storing the reaction container 102, a thermostatic chamber 114 for maintaining the constant temperature state of the reaction container 102 stored in the reaction disk 101, and a sample cup 104. Sample turntable 103, reagent turntable 106 for storing the reagent bottle 105, sampling dispensing mechanism 107 for dispensing the sample and reagent to the reaction container, reagent dispensing mechanism 108, and the dispensed sample and reagent From the stirring mechanism 109 for stirring in the reaction vessel, the reaction process of the mixed substance in the reaction vessel, and the photometric mechanism 110 for measuring the absorbance after the reaction, and the cleaning mechanism 111 for washing the reaction vessel after the photometry for the inspection is completed. Composed. Each of these components operates according to a program automatically created by the controller 112 based on information such as analysis items set in advance from the console 113 and information on the amount of liquid to be analyzed before starting the inspection.

  As shown in FIG. 2, the stirring mechanism 109 in the present embodiment corresponds to the thermostatic chamber 114, and generates sound waves provided on the side outside the reaction vessel 102 along the inner wall of the water bath 208 filled with the thermostatic water 204. It comprises means 201 (hereinafter simply referred to as a sound source). The sound source 201 has a structure in which segments 207 that can be driven independently are arranged in an array. The ultrasonic wave generated from the sound source 201 is irradiated to the reaction vessel 102 from the side.

  In the present embodiment, the array-like sound source 201 described above is configured by adopting a simple method of dividing one-side electrode with respect to one piezoelectric element as shown in FIG. The electrodes 301 thus divided are arranged in an array by selectively applying a voltage 305 to the electrode 301 corresponding to the desired irradiation region 302 using a switch 306 as shown in FIG. A sound source that is functionally equivalent to the sound source was realized. It should be noted that the connection of electric wires from the drive driver circuit can be concentrated on one surface by partially folding back the non-divided electrode 303 to the divided piezoelectric element surface as indicated by 304. By using a single piezoelectric element with such electrode processing, the cost of the stirring mechanism was reduced. Such a sound source is extremely advantageous at the time of mass production, and if the electrode pattern is formed by screen printing or the like, the production time can be shortened. Further, since the structure is extremely simple, high reliability as a stirring mechanism can be obtained. In addition, since the size is greatly reduced compared to a spatula equipped with a conventional robot arm, it contributes to the downsizing of the entire apparatus.

  The chemical analysis apparatus of the present embodiment configured as described above operates as follows. First, a sample is dispensed into the reaction vessel 102 by the sampling mechanism 107 from the sample cup 104 shown in FIG. Next, the turntable of the reaction disk 101 storing the reaction container 102 rotates to the reagent dispensing position, and the reagent is dispensed from the reagent bottle 106 into the reaction container 102 by the reagent dispensing mechanism 108. Further, the turntable rotates to a position where the stirring mechanism 109 is installed, and the sample and reagent in the reaction vessel 102 are stirred and mixed. The measurement is started from the time when the stirring is completed, and when the reaction is completed, the sample / reagent mixture in the reaction vessel 102 is sucked in the cleaning mechanism 111 and subjected to a cleaning process. Under the control of the controller 1112, such a series of processes is sequentially performed on a plurality of samples in a batch process.

  Next, an apparatus for stirring the object to be stirred in the reaction vessel 102 in a non-contact manner will be described using the longitudinal sectional view of the stirring apparatus of the present embodiment shown in FIG. The sound wave is irradiated from the side surface of the reaction vessel 102 toward the lower side, and the liquid such as the sample in the reaction vessel 102 is stirred. In FIG. 2, it has the sound wave reflection means 202 used as a sound wave generation part in the side surface of the water tank 208 which is a thermostat bath on the opposite side. Specifically, for example, the reaction container 102 can be arranged between the sound source 201 and the sound wave reflection means 202. FIG. 2 illustrates a configuration in which sound waves generated from the side surface 209 of the sound source 201 are reflected by the sound wave reflecting means 202 located on the opposite side of the thermostat and supplied to the reaction vessel 102.

  Next, the basic operation of the stirring device having the configuration of this embodiment will be described. The waveform generator, which is connected to the controller 112 of the entire apparatus and is a drive unit 205 having a drive driver circuit and a switch for the sound source 201, is the amount of liquid to be stirred in the reaction vessel 102, that is, the amount of sample and reagent dispensed. , Receives information 206 from the controller 112 regarding the timing of stirring it. Then, the drive driver circuit calculates the liquid level height of the liquid to be measured 203 filled in the reaction vessel 102 from the information regarding the liquid amount, and determines the optimum sound wave irradiation region including the liquid level. Then, the segment 207 of the sound source 201 corresponding to the irradiation area is selected to drive the sound source. Since the amplitude-modulated waveform voltage is applied from the driver circuit of the drive unit 205, which is a waveform generator, from the piezoelectric element, which is the sound source 201, the radiated sound wave is also emitted according to the change in the amplitude.

  The irradiated sound wave propagates through the constant temperature water 204 in the constant temperature chamber wall 208, is transmitted to the reaction vessel 102, and enters the reaction vessel 102. In general, when a sound wave propagating in a liquid reaches the free liquid level, a force (acoustic radiation pressure is a main factor) that the liquid jumps out to the gas side acts. At this time, in the present embodiment, the driver circuit inputs a voltage having an amplitude-modulated waveform to the sound source 201, so that the radiated sound wave also corresponds to the amplitude change. Note that the sound wave reflected by the acoustic reflecting means 202 and incident on the reaction vessel 102 is set in a direction where there is no liquid level in the traveling direction.

  Here, the principle of generating an acoustic flow in the reaction vessel 102 will be described. In this embodiment, the ultrasonic wave generated by utilizing the thickness vibration phenomenon propagates in the liquid and generates an acoustic stream 210 at the gas-liquid boundary surface in the reaction vessel 102, and the stirring flow as shown in FIG. 211 is generated. At that time, the acoustic flow 210 is generated by exciting a fundamental mode generated by the thickness vibration phenomenon with a large amplitude, and a higher order mode obtained by waveform distortion generated in the propagation process of the ultrasonic wave by a nonlinear phenomenon increases the energy ratio. It is necessary to do.

The distance x _s from the ultrasonic radiation surface of the stirring element made of a piezoelectric element to the position where the acoustic flow is generated inside the reaction container is given by Equation (1).

（１）

(1)

Here, c ₀ is the sound velocity of the propagation medium, β is a nonlinear coefficient, ω is an angular frequency (where ω = 2πf: f is a frequency), and M is an acoustic Mach number.

The inventor has only to change the angular frequency ω, that is, the frequency f of the ultrasonic wave, in order to change the distance x _s generated by the acoustic flow in the reaction vessel 102 based on the equation (1). Pay attention.

  In FIG. 4, the top view for demonstrating the ultrasonic stirring principle based on the structure of a present Example is shown. The rectangles shown in each of FIGS. 4A and 4B indicate the liquid levels of the sample and the reagent in the reaction container 102. Until now, as shown in FIG. 4B, the stirring element 401 made of a piezoelectric element has a structure having a uniform thickness in the horizontal direction (x direction) with respect to the ultrasonic wave propagation direction. Therefore, the ultrasonic wave 402 oscillated from the stirring element 401 is irradiated to the reaction vessel 403 with the same phase and the same wavelength in the horizontal direction (x direction), and the distance 404 from the piezoelectric element where the acoustic flow is generated is Between the position x1 and the position x2, the position y0 in the y direction was constant.

  On the other hand, in the configuration of the present embodiment, as shown in FIG. 4A, the thickness of the stirring element 411 made of a piezoelectric element is inclined from the position x1 to the position x2 in the x direction. By adopting a configuration in which the thickness of the piezoelectric element changes in a horizontal direction with respect to the traveling direction of the ultrasonic wave, the resonance frequency at each position is changed. Then, the distance 414 from the piezoelectric element in which the acoustic flow is generated in the reaction vessel 413 is changed from the position x1 in the x direction to the position x2 from the position y1 in the y direction to y2. The sound wave 412 is applied to the reaction vessel 413 in a state where the phase is the same and the frequency (that is, the wavelength) is changed in the horizontal direction.

  In the configuration of the present embodiment, as shown in FIG. 5A, the thickness of the stirring element 411 made of a piezoelectric element is changed from the thickness d1 to the thickness d2 from the position x1 to the position x2 in the x direction. It changes so as to have an inclination, that is, the thickness of the piezoelectric element changes in a horizontal direction with respect to the traveling direction of the ultrasonic wave. Therefore, as shown in FIG. 5B, the resonance frequency f1 changes to the resonance frequency f2 at each position from the position x1 to the position x2 in the x direction. Then, the ultrasonic wave 412 emitted from the stirring element 411 is irradiated to the reaction vessel 413 in a state where the phase is the same in the horizontal direction and the frequency (that is, the wavelength) is changed to the resonance frequencies f1 to f2.

  As a result, the position where the acoustic flow is generated becomes closer to the piezoelectric element as the resonance frequency is higher according to the equation (1), so that the position x2 from the position x1 in the x direction as shown in FIG. 5C. From the generation distance y1 to the generation distance y2 of the acoustic flow, the piezoelectric element is close to the width, and a width can be generated in the ultrasonic wave propagation direction. For example, the generated distances y1 and y2 are about 12 mm and 7 mm, and a width of about 5 mm can be generated between y1 and y2.

  Preferably, the surface of the inclined piezoelectric element is a surface not facing the reaction vessel 413 as shown in FIG. 4A, and the surface facing the reaction vessel 413 is the surface of the reaction vessel 413. Parallel to That is, the thickness of the piezoelectric element is changed in the horizontal direction with respect to the traveling direction of the ultrasonic wave applied to the reaction vessel, and the ultrasonic wave irradiation surface of the piezoelectric element to the reaction vessel is arranged in parallel to the side surface of the reaction vessel. The other surface not facing the reaction vessel was inclined in the horizontal direction with respect to the traveling direction of the ultrasonic waves. When the thickness of the piezoelectric element 411 changes continuously as shown in FIG. 5A, the piezoelectric element can be finished by mechanical polishing or the like and is easy to process.

In the configuration of this embodiment, the waveform of the voltage 304 applied from the drive unit 205, which is a waveform generator, to the stirring element 411 made of a piezoelectric element is greater than the resonance frequency f1 described above, rather than using a single frequency waveform. It is desirable to perform frequency modulation between f2 and the bands before and after it. That is, the waveform generator has a function of frequency modulating the vibration waveform of the fundamental frequency of the thickness vibration of the piezoelectric element,
Preferably, the drive unit 205, which is a waveform generator, uses a chirp wave that changes the wavelength with time, thereby giving electric energy of each resonance frequency, so that the stirring element 411 made of a piezoelectric element can be efficiently A mechanical energy having a resonance frequency can be obtained, and an ultrasonic wave having the same phase in the horizontal direction and the wavelength changing from f1 to f2 can be oscillated. In other words, the waveform generator that frequency modulates the vibration waveform of the fundamental frequency of the thickness vibration of the piezoelectric element can change the modulation band in accordance with the change of the resonance frequency.

  As described above, with the configuration in which the thickness of the piezoelectric element of the present embodiment is changed in the horizontal direction (x direction) with respect to the ultrasonic wave propagation direction, the resonance frequency is related to the generation of acoustic flow at the gas-liquid interface in the reaction vessel 413. The acoustic flow generation position can be changed from the distance y1 to y2 by the change from f1 to f2. Furthermore, since the ultrasonic energy used for stirring can be increased, the stirring force is improved. In addition, the ultrasonic stirring performance can be improved by controlling the distance at which the acoustic flow is generated by changing the resonance frequency in accordance with the change of the gas-liquid interface.

  Thus, according to the present embodiment, by changing the thickness of the piezoelectric element in the horizontal direction with respect to the traveling direction of the ultrasonic wave, the acoustic flow generation position is changed by changing the resonance frequency, and a smaller amount of liquid is obtained. It is possible to provide a chemical analyzer that can stir the reagent.

  Next, the structure and characteristics of a stirring element composed of a piezoelectric element of the chemical analysis apparatus of Example 2 will be described with reference to FIGS. The present embodiment also has a configuration with a single sound source and a reaction vessel as in the first embodiment, but the shape of the stirring element made of a piezoelectric element serving as the sound source is different from the configuration of the first embodiment. FIG. 6 is a top view for explaining the positional relationship between the sound source and the reaction vessel and the stirring action in the configuration of the chemical analyzer of Example 2. The rectangles in the figure also indicate the reaction vessel sample and reagent liquid levels. FIG. 7 is a diagram for explaining the characteristics of the stirring element shown in FIG.

  In the structure of the first embodiment shown in FIG. 4, the thickness of the stirring element 411 is continuously changed in the horizontal direction. However, in the stirring element 611 of the second embodiment shown in FIG. The thickness is changed. Then, the distance 614 from the piezoelectric element in which the acoustic flow is generated changes in the reaction vessel 613 corresponding to the discrete thickness.

  As shown in FIG. 7A, the stirring element 611 of the present embodiment changes so as to have a discrete thickness from a position d1 to a position x2 in the x direction, such as a thickness d1 to a thickness d2. To do. Therefore, as shown in FIG. 7B, the resonance frequency also changes discretely as f1... F2, and the frequency of the applied voltage waveform is the resonance frequency of the piezoelectric elements having these discrete thicknesses. Therefore, in the first embodiment, the configuration of the drive circuit in the drive unit 205, which is a waveform generator having a function of modulating the fundamental frequency, is one. Can be simplified.

  Regarding the generation distance of the acoustic flow, as shown by y1 and y2 in FIG. 7 (c), the distance can be changed although it is discrete. The liquid sample and reagent can be stirred.

  In Examples 1 and 2 above, by changing the thickness of the piezoelectric element in the horizontal direction with respect to the traveling direction of the ultrasonic wave, the resonance frequency is changed, and the acoustic flow generation position in the reaction vessel is changed. Although a chemical analysis apparatus capable of stirring a small amount of liquid and a reagent has been provided, Examples 3 and 4 described below bring about a change in resonance frequency by changing the hardness of the piezoelectric material of the stirring element. The acoustic flow generation position in the reaction vessel is changed.

  The structure of the stirring element of the chemical analyzer of Example 3 will be described with reference to FIGS. FIG. 8 is a schematic diagram for explaining a sound source and a drive circuit portion in the configuration of the chemical analysis apparatus of the present embodiment. The configurations of other portions are the same as those of the first and second embodiments. FIG. 9 is a diagram for explaining the characteristics of the stirring element of this embodiment shown in FIG.

  In this embodiment, the ultrasonic wave 804 is generated using one sound source as in the first and second embodiments. However, the thickness of the piezoelectric element, that is, the stirring element 801 is constant, and is connected to the stirring element 801. The configuration of the drive circuit in the drive unit 205 is different. In addition to the AC power source 802 for applying a voltage to the stirring element 801 to generate ultrasonic waves, a variable DC power source 803 for changing the hardness of the piezoelectric material of the stirring element is connected in parallel.

  As shown in FIG. 9A, the hardness of the piezoelectric material of the stirrer 801 is changed from s1 to s2 by controlling to change the value of the DC voltage generated by the DC power supply 803 of the waveform generator such as the drive unit 205. Can be controlled. Thus, when the hardness of the piezoelectric material of the stirring element 801 changes, the sound velocity of the thickness vibration changes, and the resonance frequency changes as shown in FIG. 9B. Then, as shown in Expression (1), the acoustic flow generation distance has a characteristic that changes from the distance y1 to y2 as shown in FIG.

  In the conventional agitation method using ultrasonic waves, an acoustic flow in which the acoustic radiation pressure near the gas-liquid interface that is not affected by wall friction is dominant is used. Although the ultrasonic wave was irradiated when the interface was settled, in the configuration of this example, the resonance frequency was changed by changing the hardness of the piezoelectric material with time in accordance with the flow of the gas-liquid interface. Therefore, it becomes possible to irradiate more ultrasonic energy than before, and the stirring performance is improved.

  The flow characteristics at the gas-liquid interface are determined by the size and shape of the reaction vessel, the sound velocity and viscosity of the liquid, the amount of reagent, etc., and the ultrasonic frequency and irradiation timing are determined in advance according to these specifications. Such a stirring specification may be input to the apparatus and read out appropriately before stirring to perform stirring.

  Also, a mechanism for detecting the liquid level of the reaction vessel with a high-speed camera or the like may be provided, and the information read by this detection mechanism may be processed and fed back to the above-described ultrasonic stirring specifications of this embodiment. Good.

  Next, the structure of the stirring element of the chemical analyzer of Example 4 will be described with reference to FIGS. FIG. 10 is a schematic diagram for explaining a sound source and a drive circuit portion in the configuration of the chemical analysis apparatus of the present embodiment. The configurations of other portions are the same as those of the first, second, and third embodiments. FIG. 11 is a diagram for explaining the characteristics of the stirring element of this embodiment shown in FIG.

  In the present embodiment, similarly to the above-described third embodiment, the ultrasonic wave 1004 is generated while changing the hardness of the piezoelectric element that is one sound source, that is, the piezoelectric material of the stirring element 1001, but the hardness of the piezoelectric material is reduced. In order to change, the driving unit 205 that is a waveform generator is different from the DC power source in that a pressurizing jig 1002 that pressurizes a stirring element 1001 that is a piezoelectric element is attached. In addition, a controller 1005 for driving the pressurizing jig 1002 and a controller 1005 for controlling the driver 1006 and the stirring element 1001 in synchronization with an AC power source 1003 for generating an ultrasonic wave by applying an AC voltage to the driver 1006 The difference is that the drive unit 205 which is a waveform generator is provided.

  The stirring element 1001 of this embodiment can control the hardness of the piezoelectric material by the amount of pressure applied by the pressing jig 1002, as shown in FIG. When the hardness of the piezoelectric material changes, the sound velocity of the thickness vibration changes, and the resonance frequency of the stirring element 1001 changes as shown in FIG. Then, as shown in the equation (1), the generation distance of the acoustic flow changes due to the change of the resonance frequency, and thus the characteristic as shown in (c) of FIG. 11 can be shown.

  In the conventional agitation method using ultrasonic waves, an acoustic flow in which the acoustic radiation pressure near the gas-liquid interface that is not affected by wall friction is dominant is used. Ultrasonic waves were applied when the interface settled, but in this example as well as in Example 3, the resonance frequency was changed by changing the hardness of the piezoelectric material with time in accordance with the flow of the gas-liquid interface. Since it can change, it becomes possible to irradiate more ultrasonic energy than before, and agitation performance improves.

  The flow characteristics of the gas-liquid interface are determined by the size and shape of the reaction vessel, the sound velocity and viscosity of the liquid, the amount of reagent, etc., and in this embodiment, the frequency of the ultrasonic wave is previously determined according to these specifications. Stirring specifications such as irradiation timing and the like may be input to the apparatus, read out before stirring, and stirred.

  Note that the pressing jig 1002 has, for example, a structure in which the stirring element 1001 is bolted. By obtaining electric power from the driver 1006, the torque can be automatically adjusted. The drive timing is controlled by the controller 1005.

  According to the present invention described in detail above, it is possible to agitate a sample with a smaller amount of liquid and a reagent by changing the acoustic flow generation position by changing the resonance frequency of the piezoelectric element constituting the agitation element. A chemical analyzer can be provided.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. The above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

101 Reaction disk 102, 403, 413, 613 Reaction vessel 103 Sample turntable 104 Sample cup 105 Reagent bottle 106 Reagent turntable 107 Sampling mechanism 108 Reagent dispensing mechanism 109 Stirring mechanism 110 Photometric mechanism 111 Washing mechanism 112 Controller 113 Console 114 Constant temperature bath 201 Sound wave generation means (sound source)
202 Sound wave reflection means 203 Liquid to be measured 204 Constant temperature water 205 Drive unit 206 Information 207 Segment 208 Temperature chamber wall 209 Side surface 210 Acoustic flow 211 Stir flow 301 Divided electrode 302 Irradiation region 303 Non-divided electrode 304 Voltage 305 Non-divided side Electrode 306 Switching device 401, 411, 611, 801, 1001 Stirring element 402, 412, 612, 804, 1004 Ultrasonic wave 404, 414, 614 Distance 802, 1003 AC power source 803 DC power source 1002 Pressing jig 1005 Controller 1006 Driver

Claims (11)

A chemical analyzer,
A reaction vessel into which a sample to be analyzed and a reagent are injected;
An ultrasonic stirring mechanism having a piezoelectric element for irradiating ultrasonic waves to the side surface of the reaction vessel;
A waveform generator for driving the piezoelectric element,
By changing the resonance frequency of the thickness vibration of the piezoelectric element, the acoustic flow generation distance from the piezoelectric element in the reaction container is changed,
A chemical analyzer characterized by that. The chemical analyzer according to claim 1,
The thickness of the piezoelectric element was changed in the horizontal direction with respect to the traveling direction of the ultrasonic wave irradiated to the reaction vessel,
A chemical analyzer characterized by that. The chemical analyzer according to claim 2,
The ultrasonic irradiation surface of the piezoelectric element with respect to the reaction vessel is arranged in parallel with the side surface of the reaction vessel, and the other surface not facing the reaction vessel is inclined in a horizontal direction with respect to the traveling direction of the ultrasonic wave. Let
A chemical analyzer characterized by that. The chemical analyzer according to claim 2,
The thickness of the piezoelectric element is continuously changing,
A chemical analyzer characterized by that. The chemical analyzer according to claim 2,
The thickness of the piezoelectric element changes discretely,
A chemical analyzer characterized by that. The chemical analyzer according to claim 1,
The waveform generator frequency-modulates a vibration waveform of a fundamental frequency of thickness vibration of the piezoelectric element;
A chemical analyzer characterized by that. The chemical analyzer according to claim 6,
The waveform generator changes the modulation band according to the change in the resonance frequency.
A chemical analyzer characterized by that. The chemical analyzer according to claim 1,
The waveform generator changes the resonance frequency of the piezoelectric element by changing the hardness of the piezoelectric material of the piezoelectric element.
A chemical analyzer characterized by that. The chemical analysis apparatus according to claim 8,
The waveform generator has a DC voltage source that applies a DC voltage to the piezoelectric element, changes the DC voltage applied to the piezoelectric element, and changes a resonance frequency of the piezoelectric element.
A chemical analyzer characterized by that. The chemical analysis apparatus according to claim 8,
The waveform generator includes a pressurizing jig that applies pressure to the piezoelectric element, and a driver that drives the pressurizing jig,
Changing the pressure applied to the piezoelectric element to change the resonance frequency of the piezoelectric element;
A chemical analyzer characterized by that. The chemical analyzer according to claim 10,
The waveform generator has a controller that controls the driver and an AC power source for generating ultrasonic waves in the piezoelectric element in synchronization with each other.
A chemical analyzer characterized by that.

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