Detection body and ultrasonic cleaning device

Abstract

Provided are a detection body and an ultrasonic cleaning device capable of determining whether the operation state of each component of the ultrasonic cleaning device is normal or abnormal when an abnormality such as a small output from a sound pressure sensor of the detection body occurs. To this end, the detection body, which detects the sound pressure of a cleaning liquid, comprises: a support body at least a portion of which is immersed in the cleaning liquid; and a plurality of sound pressure sensors that are disposed at equal intervals around the center axis of the support body in a non-liquid-contact part of the support body and have the same detection characteristics. Vibrations caused by ultrasonic waves propagated through the support body are detected as sound pressure values by each of the plurality of sound pressure sensors.

Description

Detector and ultrasonic cleaning device

[0001] The present invention relates to a sensing element used in an ultrasonic cleaning device, and to an ultrasonic cleaning device equipped with this sensing element.

[0002] In ultrasonic cleaning equipment, a configuration has been proposed in which a detector or sensor capable of detecting sound pressure is arranged to detect the sound pressure of liquid in a cleaning tank or treatment tank to which ultrasonic waves are applied. For example, the sound pressure detection device described in Patent Document 1 consists of a probe and a monitor. The probe includes a rod-shaped sensitive piece, a gripping portion for supporting the rear end of the sensitive piece, and a sound pressure sensor bonded to the rear end surface of the sensitive piece inside the gripping portion. A piezoelectric element is used as the sound pressure sensor. The adhesive portion of the sound pressure sensor and its surrounding area are fixed inside the tip of the gripping portion by screwing a holder onto the outer peripheral surface of the gripping portion so as to cover the rear end of the sensitive piece and the tip of the gripping portion from the outside.

[0003] Japanese Patent Application Laid-Open No. 2001-21412

[0004] However, the sound pressure detection device described in Patent Document 1 may experience problems over long-term use, such as the sound pressure sensor peeling off or floating from the sensitive piece, the holder loosening or breaking, or the sound pressure sensor itself deteriorating, and these problems may cause the amplitude of the detection signal to be smaller than it should be.On the other hand, when the amplitude of the detection signal becomes smaller, there may be a problem with the sound pressure sensor, as well as with the vibrator or oscillator that applies ultrasonic waves to the treatment tank, or there may be a case where the liquid in the treatment tank has decreased and the device is running dry, making it difficult to determine whether the operating status of each component is normal or abnormal.

[0005] Therefore, an object of the present invention is to provide a detecting element and an ultrasonic cleaning device that, when an abnormality occurs, such as a low output from a sound pressure sensor in a detecting element that detects the sound pressure of the liquid in the cleaning tank of the ultrasonic cleaning device, can determine whether the operating state of each component of the ultrasonic cleaning device is normal or abnormal, and can determine whether the operating state of the ultrasonic cleaning device is normal or abnormal based on whether the operating states of all components are normal or whether there is an abnormality in the operating state of at least one component. Another object of the present invention is to provide a detecting element and an ultrasonic cleaning device that can determine whether an abnormality has occurred in the sound pressure sensor. A further object of the present invention is to provide a detecting element and an ultrasonic cleaning device that, when an abnormality occurs in the output from the detecting element, can determine whether an abnormality has occurred in the sound pressure sensor, the cleaning tank, the vibrator that irradiates the cleaning tank with ultrasonic waves, or the oscillator.

[0006] In order to solve the above problem, the detection body of the present invention is a detection body that detects the sound pressure of the cleaning liquid in an ultrasonic cleaning device that includes a cleaning tank containing a cleaning liquid, a vibrator that irradiates ultrasonic waves into the cleaning tank, and an oscillator that provides a drive signal to the vibrator to generate the ultrasonic waves, and is characterized in that it includes a support at least a portion of which is immersed in the cleaning liquid, and a plurality of sound pressure sensors that are arranged at equal intervals around the central axis of the support in a non-liquid-contacting portion of the support and have the same detection characteristics, and each of the plurality of sound pressure sensors detects the vibrations caused by the ultrasonic waves propagated through the support as a sound pressure value.

[0007] The ultrasonic cleaning device of the present invention is an ultrasonic cleaning device comprising: a cleaning tank containing a cleaning liquid; a vibrator that irradiates ultrasonic waves into the cleaning tank; an oscillator that provides a drive signal to the vibrator to generate the ultrasonic waves; a support having at least its tip immersed in the cleaning liquid; a detecting element at the rear end of the support, which is arranged at equal intervals around the central axis of the support and has a plurality of sound pressure sensors having the same detection characteristics, and which detects vibrations caused by the ultrasonic waves propagated through the support as sound pressure values ​​by each of the plurality of sound pressure sensors; and a control means to which the detecting element is connected, wherein the control means determines whether the operating state of the ultrasonic cleaning device is normal or abnormal based on the detection result of the detecting element.

[0008] In the ultrasonic cleaning device of the present invention, the control means comprises a judgment unit that judges whether the operating state of the detection body is normal or abnormal based on the sound pressure values ​​detected by each of the plurality of sound pressure sensors, and a display unit that can display the detection results by the detection body, and the judgment unit sets the plurality of sound pressure sensors to one lower sound pressure sensor with the smallest sound pressure value and upper sound pressure sensors excluding the lower sound pressure sensor, and judges whether the operating state of the detection body is normal or abnormal based on the lower sound pressure value detected by the lower sound pressure sensor and a reference sound pressure value corresponding to the upper sound pressure value detected by the upper sound pressure sensor.

[0009] In the ultrasonic cleaning device of the present invention, the judgment unit is characterized in that it judges whether the operating state of the detection body is normal or abnormal based on the comparison result of the product of the reference sound pressure value and a predetermined threshold value with the lower sound pressure value.

[0010] In the ultrasonic cleaning device of the present invention, when the number of the plurality of sound pressure sensors is three or more, the reference sound pressure value is the average value of the upper sound pressure values ​​of the top two upper sound pressure sensors having larger sound pressure values ​​among the upper sound pressure sensors.

[0011] In the ultrasonic cleaning device of the present invention, the determination unit determines whether the operating state of the oscillator is normal or abnormal based on whether or not the drive signal is output from the oscillator.

[0012] In the ultrasonic cleaning device of the present invention, the judgment unit judges whether the operating state of the vibrator is normal or abnormal based on a comparison result between a predetermined initial sound pressure value and the reference sound pressure value.

[0013] In the ultrasonic cleaning device of the present invention, when the number of the plurality of sound pressure sensors is two, the reference sound pressure value is the upper sound pressure value detected by one of the upper sound pressure sensors.

[0014] The ultrasonic cleaning device of the present invention is characterized by including a control device that outputs a stop signal to stop operation of the ultrasonic cleaning device when the judgment unit judges that the operating state of the detection body is abnormal.

[0015] According to the present invention, when an abnormality occurs, such as a small output from the sound pressure sensor of the detecting body that detects the sound pressure of the liquid in the cleaning tank of the ultrasonic cleaning device, it is possible to determine whether the operating state of each component of the ultrasonic cleaning device is normal or abnormal, and it is also possible to determine whether an abnormality has occurred in the sound pressure sensor.Furthermore, when an abnormality occurs in the output from the detecting body, it is possible to determine whether an abnormality has occurred in the sound pressure sensor, the cleaning tank, the vibrator that irradiates the cleaning tank with ultrasonic waves, or the oscillator.

[0016] 1A and 1B are side views showing the configuration of a support body of a sensing element according to a first embodiment, and 1C is a plan view of the support body. 1A and 1B are side views showing the configuration of a sensing element according to a first embodiment, 1C is a diagram showing a state in which wiring is fixed to the sensing element shown in 1A, and 1D is a plan view of the sensing element. 1A and 1B are diagrams showing the configuration of an ultrasonic cleaning device according to a first embodiment, including a block diagram. 1C is a flowchart showing the procedure of a normality / abnormality determination method according to a first embodiment. 1A is a side view showing the configuration of a support body in a first modification, 1B is a side view showing the configuration of a sensing element in a first modification, 1C is a plan view of the support body shown in 1A, and 1D is a plan view of the sensing element shown in 1B. 1A is a side view showing the configuration of a support body in a second modification, 1B is a side view showing the configuration of a sensing element in a second modification, 1C is a plan view of the support body shown in 1A, and 1D is a plan view of the sensing element shown in 1B. 1C is a side view showing the configuration of a sensing element in a second modification, 1C is a plan view of the support body shown in 1A, and 1D is a plan view of the sensing element shown in 1B. 1A is a plan view showing the arrangement of the support body and sound pressure sensors in Modification 3, (b) is a side view showing the configuration of the detection body according to Modification 3, (c) is a plan view showing the arrangement of the support body and sound pressure sensors in Modification 4, and (d) is a side view showing the configuration of the detection body according to Modification 4. 1A is a plan view showing the arrangement of the support body and sound pressure sensors in Modification 5, (b) is a side view showing the configuration of the detection body according to Modification 5, (c) is a plan view showing the arrangement of the support body and sound pressure sensors in Modification 6, and (d) is a side view showing the configuration of the detection body according to Modification 6. 1B is a diagram showing the state in which the detection body according to Modification 5 is fixed to a cleaning tank. 1C is a diagram including a block diagram of the configuration of an ultrasonic cleaning device according to a second embodiment. 1D is a flowchart showing the procedure of a normality / abnormality determination method according to a second embodiment.

[0017] <First Embodiment> A sensing element and an ultrasonic cleaning device according to a first embodiment of the present invention will be described in detail with reference to the drawings. Figures 1(a) and 1(b) are side views showing the configuration of a support body 110 of a sensing element 10 according to the first embodiment, and (c) is a plan view of the support body 110. Figures 1(a) and 1(b) are views seen from direction 1A in (c), and (b) are views seen from direction 1B in (c). Figures 2(a) and 2(b) are side views showing the configuration of the sensing element 10 according to the first embodiment, and (c) is a view showing the state in which wiring has been attached and fixed to the sensing element 10 shown in (a), and (d) is a plan view of the sensing element 10. Figures 2(a) and 2(b) are views seen from direction 2A in (c), and (b) are views seen from direction 2B in (c).

[0018] 3A and 3B are diagrams including a block diagram of the configuration of the ultrasonic cleaning device 100 according to the first embodiment.

[0019] As shown in Fig. 3(a), the ultrasonic cleaning device 100 has a configuration including a detection element 10 (Figs. 2(a), (b), and (c)), and as shown in Fig. 3(b), it is also possible to configure the device by adding an external device 60 having a control device 61 to the configuration shown in Fig. 3(a). The configuration of each part will be described below.

[0020] <Sensing element 10> The sensing element 10 has a configuration in which three piezoelectric elements serving as sound pressure sensors are arranged on a support 110 shown in FIGS. 1(a), 1(b), 1(c) and 1(d) as shown in FIGS. 2(a), 2(b), 2(c), 2(d)). The support 110 is a rod-shaped material capable of propagating vibrations based on the sound pressure of the cleaning liquid 23 when immersed in the cleaning tank 20 (FIGS. 3(a) and 3(b)). Examples of such rod-shaped materials include those molded from stainless steel or quartz, and the support 110 has a cylindrical shape with a central axis AX1. Changes in the sound pressure of the cleaning liquid 23 are caused by ultrasonic waves applied from a vibrator 30 (see FIGS. 3(a) and 3(b)) to the cleaning liquid 23 in the cleaning tank 20, and the vibrations propagated by the support 110 correspond to the sound pressure of the ultrasonic waves applied from the vibrator 30.

[0021] As shown in FIGS. 1A and 1B, the support 110 has a front end 110a and a rear end 110b in the Z1-Z2 direction along the central axis AX1. As shown in FIGS. 3A and 3B, the front end 110a of the support 110 is immersed in the cleaning liquid 23, and the rear end 110b is positioned above the liquid level 22 of the cleaning liquid 23. In other words, the front end 110a, which is a part of the support 110, is immersed in the cleaning liquid 23. The sound pressure sensors 121, 122, and 123 are positioned higher than the liquid level 22 of the cleaning liquid 23 when the liquid level is at its highest. Therefore, regardless of changes in the liquid level of the cleaning liquid 23, the sound pressure sensors 121, 122, and 123 are positioned so that they are not immersed in the cleaning liquid 23. In other words, the rear end 110b, which is a non-liquid-contacting portion, is always positioned above the liquid level 22 of the cleaning liquid 23. This makes it possible to prevent the sound pressure sensors 121 , 122 , 123 from changing in characteristics, deteriorating, peeling, etc., which may be caused by immersion in the cleaning liquid 23 in the cleaning tank 20 .

[0022] 1(a), (b), and (c), three inclined surfaces 111, 112, and 113 are formed on the rear end portion 110b of the support body 110, and are symmetrical with respect to one another with respect to the central axis AX1. In other words, these inclined surfaces 111, 112, and 113 are provided at equal angular intervals of 120° with respect to the central axis AX1. These inclined surfaces 111, 112, and 113 have the same or substantially the same planar shape, are provided in the same range in the Z1-Z2 direction, and are inclined so as to approach the central axis AX1 the further toward the rear end surface 110c, which is the rearmost side of the rear end portion 110b.

[0023] As shown in FIGS. 2( a), (b), (c), and (d), three sound pressure sensors 121, 122, and 123 are fixed to the three inclined surfaces 111, 112, and 113, respectively. The sensors are fixed using an adhesive, such as an epoxy adhesive. The sound pressure sensors 121, 122, and 123 are plate-shaped piezoelectric elements with the same shape, deformation mode, and detection characteristics. While the deformation mode is not limited, for example, if a piezoelectric element with a deformation mode that deforms in the thickness direction is used, its bottom surface is adhesively fixed to the corresponding inclined surface (inclined surface 111, 112, and 113). The three sound pressure sensors 121, 122, and 123 are positioned such that their Z2-side (rear end) corners are close to the adjacent sound pressure sensors in the Z1-Z2 direction. 2D, the sound pressure sensors 121, 122, and 123 are provided at equal angular intervals of 120° with respect to the central axis AX1. The sound pressure sensors 121, 122, and 123 are arranged in positions such that the corners on the Z2 side (rear end side) of the adjacent sound pressure sensors are close to each other in the Z1-Z2 direction, so that the rear end surface 110c side of the rear end portion 110b of the support body 110 among the inclined surfaces 111, 112, and 113 is exposed and not covered by the sound pressure sensors 121, 122, and 123.

[0024] By providing the sound pressure sensors 121, 122, and 123 on the inclined surfaces 111, 112, and 113, respectively, a larger area can be secured for fixing the sound pressure sensors compared to a configuration without inclined surfaces. Furthermore, both vibrations along the central axis AX1 of the support 110 and vibrations at angles to the central axis AX1 can be detected with a certain degree of accuracy. This allows for greater freedom in selecting piezoelectric elements as sound pressure detection elements. The inclination angles of the inclined surfaces 111, 112, and 113 relative to the central axis AX1 can be set arbitrarily depending on the size of the sound pressure sensors 121, 122, and 123, etc.

[0025] As shown in Figures 2(c), 3(a), and 3(b), signal lines 131, 151, 152, and 153 are connected to the sensing element 10 at one end and electrically connected to the main body 50, which serves as a control means. These signal lines 131, 151, 152, and 153 are made of insulated electric wires. The first signal line 131 is soldered to the support 110, and three connection lines 141, 142, and 143 electrically connected to the first signal line 131 are connected to the negative electrodes of the sound pressure sensors 121, 122, and 123, respectively. Three second signal lines 151, 152, and 153 are connected to the positive electrodes of the sound pressure sensors 121, 122, and 123, respectively. This wiring converts the pressure applied to each of the sound pressure sensors 121, 122, and 123 by vibrations propagated through the support 110 into a voltage, which is detected by the main body 50 as the sound pressure value in the cleaning liquid 23 in the cleaning tank 20.

[0026] <Ultrasonic cleaning device 100> As shown in Fig. 3(a), the ultrasonic cleaning device 100 includes a detection element 10, a cleaning tank 20, a vibrator 30, an oscillator 40, and a main body 50. Also, as shown in Fig. 3(b), it is possible to configure the ultrasonic cleaning device 100 with an external device 60 added.

[0027] The cleaning tank 20 is filled with cleaning liquid 23 for cleaning, and the detection body 10 is fixed to the cleaning tank 20 or to a fixture (not shown) outside the cleaning tank 20 so that the central axis AX1 of the support 110 is aligned vertically, the front end 110a side is immersed in the cleaning liquid 23, and at least the sound pressure sensors 121, 122, 123 on the rear end 110b side are above the liquid surface 22. New cleaning liquid 23 is introduced into the cleaning tank 20 by a pump, electromagnetic valve, etc. (not shown) at a predetermined amount according to the expected progress of cleaning, and dirty cleaning liquid 23 is discharged to the outside by a pump, electromagnetic valve, etc. (not shown).

[0028] The inventors discovered that sound pressure sensors 121, 122, 123 are attached and fixed to the detection body 10, which is a single rod-shaped material, and that the same type of signal is generated from each of the sound pressure sensors 121, 122, 123, and that by comparing these same type of signals obtained, if an abnormality occurs in the output from the detection body 10, it is possible to determine in which operating state the abnormality has occurred: sound pressure sensors 121, 122, 123, cleaning tank 20, vibrator 30 that irradiates ultrasonic waves into the cleaning tank 20, or oscillator 40, and this discovery led to the completion of the present invention. In short, because the signals generated by the sound pressure sensors 121, 122, and 123 are the same type of signal, the sound pressure values ​​obtained from these signals are merely strength signals, and it is difficult to determine whether the operating status of each component of the cleaning device of the present invention is normal or abnormal by simply processing them. However, the inventors have completed the present invention by comparing signals of the same type, i.e., signals having the same detection characteristics, generated by the sound pressure sensors 121, 122, and 123. Details will be described later. Furthermore, by attaching and fixing the sound pressure sensors 121, 122, and 123 to the rear end 110b of the single rod-shaped sensing element 10, the sound pressure sensors 121, 122, and 123 are located near the rear end 110b of the single rod-shaped sensing element 10, thereby eliminating variations in the signals generated by the sound pressure sensors 121, 122, and 123 and improving the accuracy of the obtained signals.

[0029] A vibrator 30 is attached and fixed to the bottom surface 21 of the cleaning tank 20. Any type of vibrator 30 can be used depending on the cleaning specifications of the ultrasonic cleaning device 100. The vibrator 30 is ultrasonically vibrated by a drive signal provided by an oscillator 40. The ultrasonic waves are irradiated into the cleaning tank 20 and applied to the cleaning liquid 23 in the cleaning tank 20. The sound pressure in the cleaning liquid 23 fluctuates in accordance with the ultrasonic vibration.

[0030] The main body 50 includes a calculation unit 51, a storage unit 52, a determination unit 53, a display unit 54, an input unit 55, and a control device 61. The calculation unit 51 calculates the sound pressure values ​​detected by each of the sound pressure sensors 121, 122, and 123 based on the voltages between the first signal line 131 and each of the three second signal lines 151, 152, and 153. These sound pressure values ​​are calculated by displaying voltage values ​​stored in advance in the storage unit 52 as sound pressure intensities. The storage unit 52 stores conversion tables and conversion formulas based on the correlation between voltage values ​​and sound pressure values, and the calculation unit 51 calculates sound pressure values ​​from voltage values ​​based on these conversion tables and conversion formulas.

[0031] The calculation unit 51 associates the calculated sound pressure values ​​with the names of the corresponding sound pressure sensors (sound pressure sensors 121, 122, 123) and stores them in the storage unit 52. Furthermore, the calculation unit 51 calculates the average value Ave (reference sound pressure value) of the two highest sound pressure values ​​(i.e., the two largest sound pressure values) among the sound pressure values ​​detected by the three sound pressure sensors 121, 122, 123, and stores this average value Ave in the storage unit 52 in association with the names of the two sound pressure sensors (upper sound pressure sensors) that detected these sound pressure values. The calculation unit 51 also combines the lowest sound pressure value Min, i.e., the smallest sound pressure value (lower sound pressure value), with the name of the sound pressure sensor (lower sound pressure sensor) that detected this sound pressure value and stores this in the storage unit 52. Here, the upper sound pressure sensors are the two sound pressure sensors among the three sound pressure sensors 121, 122, 123 excluding the lower sound pressure sensor.

[0032] The sound pressure value calculated by the calculation unit 51 is output to the determination unit 53, which compares the product of the average value Ave and a predetermined threshold value X with the lowest sound pressure value Min. Based on the comparison result, the determination unit 53 determines whether the operating status of the sound pressure sensors 121, 122, and 123 is normal or abnormal, i.e., determines whether an abnormality has occurred in the operating status. The determination result is stored in the memory unit 52 and is displayed on the display unit 54 in a predetermined format in the process shown in FIG. 4. The threshold value X is input in advance by operating the input unit 55 and stored in the memory unit 52. The main body 50 (determination unit 53) as a control means determines that the operating status of the ultrasonic cleaning device 100 is normal when all of the sound pressure sensors 121, 122, and 123 are normal, and determines that the operating status of the ultrasonic cleaning device 100 is abnormal when any of the sound pressure sensors is abnormal.

[0033] The control device 61 receives the determination result from the determination unit 53, and generates a control signal for the oscillator 40 based on this determination result, and outputs it to the oscillator 40. An example of this control signal is a control signal that causes the oscillator 40 to stop sending a drive signal to the vibrator 30 when the determination result from the determination unit 53 determines that an abnormality has occurred in the operating state of any of the sound pressure sensors 121, 122, and 123.

[0034] As shown in Fig. 3(b), the external device 60 includes a control device 61 connected to the main body 50 and the oscillator 40 of the ultrasonic cleaning device 100. The control device 61 has the same functions as the control device 61 provided in the main body 50 in the configuration shown in Fig. 3(a).

[0035] 4 is a flowchart showing the procedure for determining whether the operating state of the ultrasonic cleaning device according to the first embodiment is normal or abnormal, i.e., determining whether the operating state of each component is normal or abnormal. Hereinafter, the normal / abnormal determination in the first embodiment will be described with reference to FIG.

[0036] Before starting to drive the vibrator 30, the input unit 55 is operated to set a threshold value X in advance and store it in the memory unit 52 (step S11 in FIG. 4). The threshold value X is set arbitrarily depending on the characteristics (such as frequency) of the ultrasonic waves generated by the vibrator 30, the temperature, liquid depth, and amount of the cleaning liquid 23, the placement height of the sound pressure sensors 121, 122, and 123 in the cleaning tank 20, the characteristics of the sound pressure sensors 121, 122, and 123, the vibration characteristics of the support 110, the placement of the detection body 10 in the cleaning tank 20, the shape and type of the object to be cleaned, etc. Since the sound pressure value of the cleaning tank 20 etc. constantly fluctuates depending on the environment, etc., the threshold value X is set to prevent erroneous detection due to these fluctuations.

[0037] Next, the oscillator 40 starts outputting a drive signal to the vibrator 30, and the vibrator 30 irradiates the cleaning tank 20 with ultrasonic waves. At this time, sound pressure corresponding to the irradiated ultrasonic waves is generated in the cleaning liquid 23 in the cleaning tank 20. In the support 110 of the detection body 10, vibrations corresponding to this sound pressure are generated in the portion immersed in the cleaning liquid 23, and these vibrations are propagated toward the rear end 110b. The vibrations are converted into voltages proportional to deformation by the sound pressure sensors 121, 122, and 123 provided on the inclined surfaces 111, 112, and 113 of the rear end 110b. The voltages are converted into sound pressure values ​​by the calculation unit 51, and the sound pressure values ​​of the sound pressure sensors 121, 122, and 123 are thereby detected (step S12). The detected sound pressure values ​​are stored in the memory unit 52 in association with the names of the sound pressure sensors 121, 122, and 123.

[0038] The calculation unit 51 compares the three sound pressure values ​​detected by the three sound pressure sensors 121, 122, and 123 at the same time and determines the ranking based on the magnitude of the sound pressure values. Furthermore, the calculation unit 51 calculates the average value Ave of the top two sound pressure values ​​and stores it in the storage unit 52 together with the name identifying the corresponding sound pressure sensor (step S13). The calculation unit 51 also stores the lowest sound pressure value Min in the storage unit 52 together with the name identifying the corresponding sound pressure sensor (step S14). The saving operations in steps S13 and S14 are also saved in association with the time at that time.

[0039] The lowest sound pressure value Min may be stored when determining the ranking. If the sound pressure values ​​of the three sound pressure sensors 121, 122, and 123 are the same, any two of them are set as the top two sound pressure values ​​to calculate the average Ave (step S13), and the remaining one is stored in the storage unit 52 as the lowest sound pressure value Min (step S14).

[0040] The average value Ave and the lowest sound pressure value Min are given to the determination unit 53, which reads the threshold value X from the storage unit 52, calculates the product of the average value Ave and the threshold value X, and compares it with the sound pressure value Min (step S15).

[0041] If the sound pressure value Min is greater than the product of the average value Ave and the threshold value X (YES in step S15), the determination unit 53 determines that the operating state of the sound pressure sensor corresponding to the sound pressure value Min is normal (step S16). At this time, the main body 50 as a control means determines that the operating state of the ultrasonic cleaning device 100 is normal.

[0042] On the other hand, if the sound pressure value Min is equal to or less than the product of the average value Ave and the threshold value X (NO in step S15), the operating state of the sound pressure sensor corresponding to the sound pressure value Min is determined to be abnormal. When determining that an abnormality exists, the determination unit 53 causes the display unit 54 to display a message indicating that an abnormality exists in the operating state of the sound pressure sensor (step S17). Subsequently, regardless of whether an abnormality exists, the determination unit 53 causes the display unit 54 to display the average value Ave as the sound pressure value following steps S16 and S17 (step S18). At this time, the main body 50 serving as a control unit determines that the operating state of the ultrasonic cleaning device 100 is abnormal.

[0043] When the threshold value X is used to determine whether the sound pressure value Min is greater than the product of the average value Ave and the threshold value X, as in step X15 above, it is preferable to set a value greater than 0 and less than 1. Here, if the threshold value X is made large (for example, 0.7 or more), an abnormality in the operating state of the sound pressure sensor can be determined early, thereby preventing the object to be cleaned from being affected by peeling or the like. If the threshold value X is made small (for example, 0.5 or less), it is possible to prevent a change in the sound pressure value due to the cleaning conditions or the like from being confused with an abnormality in the operating state of the sound pressure sensor and determining it as such.

[0044] As described above, when calculating the average of the top two sound pressure values ​​and judging whether the operating state is normal or abnormal based on this, the sound pressure value of the sound pressure sensor judged to be abnormal is significantly low, and it is considered extremely unlikely that two or more of the three sound pressure sensors 121, 122, and 123 will fail simultaneously, so the average of the top two is used as the criterion for judgment, thereby improving detection accuracy according to the present invention.

[0045] Regarding the determination of normal / abnormal operation of the sound pressure sensor based on the product of the average sound pressure value Ave of the upper sound pressure sensor and the threshold value X, rather than the sound pressure value itself, the detected sound pressure value fluctuates because the cleaning liquid 23 flows in and out of the cleaning tank 20 and the vibration propagation state constantly changes due to changes in the environment, such as the swaying of the liquid surface. Therefore, if the determination of normal / abnormal operation of the sound pressure sensor is based on the sound pressure value itself, there is a risk of false detection due to slight fluctuations in the sound pressure value. In contrast, using the product with the threshold value X makes it possible to prevent false detection due to minute fluctuations and also makes it easier to determine that the operation state of a sound pressure sensor with a significantly reduced sound pressure value is abnormal.

[0046] Modified examples are described below. The shape of the support used for the sensing element may be any shape as long as a certain area of ​​the support, i.e., a portion thereof, is immersed in the cleaning liquid 23 in the cleaning tank 20 and the support has a sound pressure sensor disposed in a non-liquid-contacting portion. For example, a cylindrical shape without an inclined surface as shown in Fig. 5(a), a prismatic shape as shown in Fig. 6(a), a cylindrical shape as shown in Fig. 7, or a cylindrical shape with a flange as shown in Fig. 8 may be used.

[0047] 5(a) is a side view showing the configuration of the support body 210 in Modification 1, (b) is a side view showing the configuration of the sensing element in Modification 1, (c) is a plan view of the support body 210 shown in (a), and (d) is a plan view of the sensing element shown in (b). Fig. 5(b) is a view seen from direction 5B in (d).

[0048] 5(a) includes a front end 210a and a rear end 210b in the Z1-Z2 direction along the central axis AX2. Sound pressure sensors 221, 222, and 223, each having the same configuration as the sound pressure sensors 121, 122, and 123 of the first embodiment, are adhesively fixed to the support 210 on an outer circumferential surface 211 of the rear end 210b at equal angular intervals with respect to the central axis AX2.

[0049] 6(a) is a side view showing the configuration of the support body 310 in Modification 2, (b) is a side view showing the configuration of the sensing element in Modification 2, (c) is a plan view of the support body 310 shown in (a), and (d) is a plan view of the sensing element shown in (b). Fig. 6(a) is a view seen from direction 6A in (c), and (b) is a view seen from direction 6B in (d).

[0050] 6(a) has a rectangular prism shape including a front end 310a and a rear end 310b in the Z1-Z2 direction along the central axis AX3, and four outer surfaces 311, 312, 313, and 314. Four sound pressure sensors 321, 322, 323, and 324 having the same configuration as the sound pressure sensors 121, 122, and 123 of the first embodiment are adhesively fixed to the support 310 on the four outer surfaces 311, 312, 313, and 314 of the rear end 310b, respectively. The sound pressure sensors 321, 322, 323, and 324 have a width smaller than that of the outer surfaces 311, 312, 313, and 314, and therefore can be fixed to the support 310 without coming into contact with each other.

[0051] (Variations 3 and 4) Fig. 7(a) is a plan view showing the arrangement of the support body 410 and sound pressure sensors 421, 422, and 423 in Variation 3, and Fig. 7(b) is a side view showing the configuration of the detection element according to Variation 3. Fig. 7(c) is a plan view showing the arrangement of the support body 410 and sound pressure sensors 451, 452, and 453 in Variation 4, and Fig. 7(d) is a side view showing the configuration of the detection element according to Variation 4. Figs. 7(a) and (c) show a state in which the support body 410 is closed with the lid portion 413, with the internal structure indicated by dashed lines. In Variations 3 and 4, common members will be described using the same reference numerals.

[0052] The support body 410 is a hollow, bottomed, cylindrical member made of the same material as in the first embodiment. In Modification 3 shown in Figures 7(a) and (b), three sound pressure sensors 421, 422, and 423 are adhesively fixed to a bottom surface 411 inside the support body 410. These sound pressure sensors 421, 422, and 423 are symmetrical to one another at equal angular intervals with respect to a central axis AX4 of the support body 410. In other words, they are arranged at equal intervals around the central axis AX4 and extend radially from the central axis AX4 side.

[0053] After the sound pressure sensors 421, 422, and 423 are placed inside the support 410, the top is sealed with a disk-shaped lid 413, which prevents liquid from entering the internal space in which the sound pressure sensors are placed.

[0054] A connector 430 is disposed on the lid 413 and is electrically connected to each of the sound pressure sensors 421, 422, and 423. A cable 440 connected to the main body 50 is connected to the connector 430, thereby connecting the sound pressure sensors 421, 422, and 423 to the main body 50.

[0055] 7(c) and (d), three sound pressure sensors 451, 452, and 453 are adhesively fixed to the inner peripheral surface 412 of the support body 410. These sound pressure sensors 451, 452, and 453 are symmetrical to one another at equal angular intervals with respect to the central axis AX4 of the support body 410; in other words, they are arranged at equal intervals around the central axis AX4 and extend along the central axis AX4. The configurations of the lid portion 413, the connector 430, and the cable 440 are the same as those of the third modification.

[0056] In the support 410, the bottom wall having the bottom surface 411 and the side wall having the inner peripheral surface 412 are preferably formed with thicknesses taking into consideration ultrasonic wave transmission and transparency, durability, and liquid-tightness.

[0057] With the configurations of Modifications 3 and 4, when the support 410 is immersed in the cleaning liquid 23, the internal space functions as a non-liquid-contact portion that does not allow the cleaning liquid 23 to enter. This makes it possible to realize a sensing element that is compact, has an easily manufacturable configuration, and has a form that reliably ensures liquid-tightness.

[0058] (Variations 5 and 6) FIG. 8(a) is a plan view showing the arrangement of the support 510 and sound pressure sensors 521, 522, and 523 in Variation 5, and FIG. 8(b) is a side view showing the configuration of the detection element according to Variation 5. FIG. 8(c) is a plan view showing the arrangement of the support 510 and sound pressure sensors 551, 552, and 553 in Variation 6, and FIG. 8(d) is a side view showing the configuration of the detection element according to Variation 6. FIG. 9 is a cross-sectional view of the cleaning tank 20 showing the state in which the detection element according to Variation 5 is fixed to the cleaning tank 20. FIGS. 8(a) and 8(c) show the state in which the support 510 is closed with the lid 513, with the internal structure indicated by dashed lines. In Variations 5 and 6, common components will be described using the same reference numerals.

[0059] The support body 510 is made of the same material as in the first embodiment and has a configuration in which a hollow, cylindrical main body portion 514 and a disk portion 515, which has a disk shape with a larger diameter than the main body portion 514 and closes the bottom of the main body portion 514, are integrally formed. The main body portion 514 and the disk portion 515 have a common central axis AX5. The outer periphery of the disk portion 515 extends radially outward beyond the outer periphery of the main body portion 514 in a flange-like shape.

[0060] 8(a) and 8(b), three sound pressure sensors 521, 522, and 523 are adhesively fixed to the bottom surface 511 inside the support body 510. These sound pressure sensors 521, 522, and 523 are arranged symmetrically with respect to the central axis AX5 of the support body 510 at equal angular intervals and extending radially from the central axis AX5 side.

[0061] After the sound pressure sensors 521, 522, and 523 are placed inside the support 510, the top is sealed with a disk-shaped lid 513, which prevents liquid from entering the internal space in which the sound pressure sensors are placed.

[0062] A connector 530 is disposed on the lid 513 and is electrically connected to each of the sound pressure sensors 521, 522, and 523. A cable 540 connected to the main body 50 is connected to the connector 530, thereby connecting the sound pressure sensors 521, 522, and 523 to the main body 50. The connector 530 and the cable 540 are disposed concentrically with the central axis AX5 and are provided in an area smaller in size than the support body 510 in the radial direction.

[0063] 8(c) and 8(d), three sound pressure sensors 551, 552, and 553 are adhesively fixed to the inner peripheral surface 512 of the support body 510. These sound pressure sensors 551, 552, and 553 are arranged to extend along the central axis AX5 at positions symmetrical to one another at equal angular intervals about the central axis AX5 of the support body 510. The configurations of the lid portion 513, the connector 530, and the cable 540 are the same as those of the fifth modification.

[0064] In the support body 510, the disk portion 515 having the bottom surface 511 and the side wall having the inner peripheral surface 512 are preferably formed with thicknesses that take into consideration ultrasonic wave transmission and transparency, durability, and liquid-tightness.

[0065] A spiral groove is formed on the outer peripheral surface 514a of the main body 514 of the support 510. A ring-shaped nut 516 having a spiral groove on its inner peripheral surface is threadedly engaged with this outer peripheral surface 514a. This nut 516 is movable in a direction along the central axis AX5 of the support 510 as the spiral groove on its inner peripheral surface engages with the spiral groove on the outer peripheral surface 514a of the main body 514.

[0066] As shown in FIG. 9 , a circular fixing hole 25 having the same diameter as the main body 514 of the support 510 is formed through the side wall 24 of the cleaning tank 20. The detection element according to Variation 5 is inserted into the fixing hole 25 from inside the cleaning tank 20, so that the cable 540, connector 530, and the lid 513 side of the main body 514 are exposed to the outside of the cleaning tank 20. In this state, a nut 516 is threaded onto the main body 514 on the outside of the cleaning tank 20, and the side wall 24 of the cleaning tank 20 is sandwiched between the nut 516 and the disc 515, and the sandwiched portions are fixed with adhesive. This allows the disc 515 to be sealed inside the cleaning tank 20 to prevent the cleaning liquid 23 from entering or exiting the fixing hole 25. Note that this type of arrangement of the detection element can also be performed on the detection element according to Variation 6.

[0067] The configurations of Modifications 5 and 6 enable the disk portion 515 of the support 510 to be immersed in the cleaning liquid 23 in the cleaning tank 20 with a compact configuration, and to be reliably fixed to the cleaning tank 20. Furthermore, when the disk portion 515 is immersed in the cleaning liquid 23, the internal space of the support 510 functions as a non-liquid-contact portion into which the cleaning liquid 23 does not penetrate. This allows the detection element to be realized in a compact, easily manufactured configuration that reliably ensures liquid-tightness.

[0068] In the first embodiment and modified examples 1, 3, 4, 5, and 6, a configuration including three sound pressure sensors has been described, and in modified example 2, a configuration including four sound pressure sensors has been described. However, the number of sound pressure sensors is not limited to these, and two or five or more may be arranged at equal angular intervals. When two sound pressure sensors are used, the sound pressure value of one upper sound pressure sensor is used as the reference sound pressure value, instead of the average value Ave of the sound pressure values ​​of the two upper sound pressure sensors in the first embodiment. When four or more sound pressure sensors are used, it is preferable to use the average value Ave of the sound pressure values ​​of the two upper sound pressure sensors as in the first embodiment. However, all sound pressure sensors except for one lower sound pressure sensor, or three or more sound pressure sensors, may be set as upper sound pressure sensors, and the average value of their sound pressure values ​​may be used as the reference sound pressure value.

[0069] In the first embodiment described above, in order to determine whether the operating state of the sound pressure sensor is normal or abnormal, the product of the average sound pressure value Ave of the upper sound pressure sensor and the threshold value X is compared with the lowest sound pressure value Min. However, the object to be compared with the sound pressure value Min is not limited to this, and for example, a value obtained by adding or subtracting a threshold value instead of the threshold value X to or from the average sound pressure value Ave may be used.

[0070] In the first embodiment, a piezoelectric element is used as the sound pressure sensor, but the invention is not limited to this as long as it can detect the sound pressure of the cleaning liquid 23 in the cleaning tank 20, and for example, a diaphragm (vibration plate) may also be used.

[0071] In the first embodiment, adjacent sound pressure sensors are arranged close to each other. This proximity distance is determined by the size of the piezoelectric element serving as the sound pressure sensor and the radial size of the support 110. By arranging the sensors close to each other in this manner, it is possible to suppress the variation in the sound pressure values ​​detected by each sound pressure sensor to a certain value or less. In terms of the effect of suppressing such variation, it is preferable that the minimum distance between adjacent sound pressure sensors is greater than 0 and equal to or less than 50% of the width of the sound pressure sensor.

[0072] In the first embodiment described above, the detection body 10 was positioned so that the sound pressure sensors 121, 122, and 123 were exposed from the cleaning liquid 23. However, if a cover or the like is provided to cover the rear end portion 110b of the support body 110 in a watertight manner so as not to hinder deformation of the sound pressure sensors 121, 122, and 123, the sound pressure sensors 121, 122, and 123 may also be positioned below the water surface of the cleaning liquid 23.

[0073] Examples 1 and 2 Tables 1 and 2 show numerical examples 1 and 2 of the detection results in the ultrasonic cleaning device 100 according to the first embodiment, respectively.

[0074]

[0075]

[0076] In Example 1 shown in Table 1, the sound pressure value A detected by sound pressure sensor 121 is 51 (unit: mV), the sound pressure value B detected by sound pressure sensor 122 is 48 (unit: mV), and the sound pressure value C detected by sound pressure sensor 123 is 53 (unit: mV). From these sound pressure values, the average value Ave of the sound pressure values ​​of the two sound pressure sensors 121 and 123, which are the upper sound pressure sensors, is 52 (unit: mV). On the other hand, the sound pressure value 48 of sound pressure sensor 122, which is the lower sound pressure sensor, becomes the lowest sound pressure value Min. When the threshold value X is set to 0.5, the average value Ave x X becomes 26. Therefore, this sound pressure value 26 is compared with the sound pressure value Min of 48. Since 48 is larger, it is determined that the operating state of sound pressure sensor 122, which is the lower sound pressure sensor, is normal.

[0077] In Example 2 shown in Table 2, the sound pressure value A detected by sound pressure sensor 121 is 51 (unit: mV), the sound pressure value B detected by sound pressure sensor 122 is 15 (unit: mV), and the sound pressure value C detected by sound pressure sensor 123 is 53 (unit: mV). From these sound pressure values, the average value Ave of the sound pressure values ​​of the two sound pressure sensors 121 and 123, which are the upper sound pressure sensors, is 52 (unit: mV). On the other hand, the sound pressure value 15 of sound pressure sensor 122, which is the lower sound pressure sensor, becomes the lowest sound pressure value Min. When threshold value X is set to 0.5, the average value Ave × X becomes 26. Therefore, this sound pressure value 26 is compared with the sound pressure value Min of 15. Since 15 is smaller, it is determined that the operating state of sound pressure sensor 122, which is the lower sound pressure sensor, is abnormal, and a message to that effect is displayed on display unit 54.

[0078] According to the first embodiment described above, when an abnormality occurs in the operating state, such as a small output from the sound pressure sensors 121, 122, and 123 that detect the sound pressure of the cleaning liquid 23 in the cleaning tank 20 of the ultrasonic cleaning device 100, it is possible to quickly and simply determine which of the sound pressure sensors 121, 122, and 123 has experienced an abnormality.

[0079] Second Embodiment Next, a second embodiment of the present invention will be described. Figures 10(a) and 10(b) are diagrams showing the configuration of an ultrasonic cleaning device 600 according to the second embodiment, including a block diagram. As shown in Figure 10(a), the ultrasonic cleaning device 600 of the second embodiment has the same configuration as the ultrasonic cleaning device 100 of the first embodiment, and in addition, a drive signal that is the same as the drive signal applied from the oscillator 40 to the vibrator 30 is also simultaneously output to the main body 50. Furthermore, as shown in Figure 10(b), the ultrasonic cleaning device 600 can also be configured to include an external device 60 having a control device 61 similar to that of the first embodiment.

[0080] In the ultrasonic cleaning device 600, the oscillator 40 is configured to simultaneously send the same drive signal to the vibrator 30 and the main body 50. In the main body 50, the determination unit 53 identifies whether or not a drive signal has been received from the oscillator 40, and determines, based on the result of this identification, whether or not the oscillator 40 is correctly outputting the drive signal. The main body 50 (determination unit 53) as control means determines that the operating state of the ultrasonic cleaning device 600 is normal when the operating states of all of the sound pressure sensors 121, 122, and 123, the vibrator 30, and the oscillator 40 are all normal, and determines that the operating state of the ultrasonic cleaning device 600 is abnormal when there is an abnormality in the operating state of any of the components.

[0081] 11 is a flowchart showing the procedure for determining whether the device is normal or abnormal according to the second embodiment. The flow of determining whether the device is normal or abnormal according to the second embodiment will be described below with reference to FIG.

[0082] Before starting to drive the vibrator 30, the input unit 55 is operated to set the thresholds X and Y and the initial sound pressure value I in advance and store them in the storage unit 52 (step S21 in FIG. 11 ). The thresholds X and Y are set in the same manner as the threshold X in the first embodiment, and may be set to the same value. The initial sound pressure value I is a sound pressure value estimated to be detected when the sound pressure sensors 121, 122, and 123 normally detect ultrasonic waves generated by a drive signal provided from an oscillator 40 in a normal operating state to a vibrator 30 in a normal operating state. Alternatively, it may be a sound pressure value actually detected by a sound pressure sensor known to be in a normal operating state.

[0083] Next, the oscillator 40 starts to output a drive signal to the vibrator 30 and the main body 50, and the determination unit 53 determines whether or not a predetermined drive signal has arrived from the oscillator 40 (step S22).

[0084] In determining whether a predetermined drive signal has been received from oscillator 40 (step S22), if the drive signal has been received (YES in step S22), the determination unit 53 determines that oscillator 40 is operating normally (step S23), and if the drive signal has not been received (NO in step S22), the determination unit 53 determines that there is an abnormality in the operating state of oscillator 40 (step S34).

[0085] If a predetermined drive signal is received from the oscillator 40 and reaches the main body 50 (YES in step S22), the drive signal is also input to the transducer 30, and ultrasonic waves generated by the transducer 30 are irradiated into the cleaning tank 20. At this time, sound pressure corresponding to the irradiated ultrasonic waves is generated in the cleaning liquid 23 in the cleaning tank 20. Vibrations corresponding to this sound pressure are generated in the support 110 of the detection body 10 at the portion immersed in the cleaning liquid 23, and these vibrations propagate toward the rear end 110b. The vibrations are converted into voltages proportional to deformation by the sound pressure sensors 121, 122, and 123 provided on the inclined surfaces 111, 112, and 113 of the rear end 110b. The voltages are converted into sound pressure values ​​by the calculation unit 51, thereby detecting the sound pressure values ​​at each of the sound pressure sensors 121, 122, and 123 (step S24). The detected sound pressure values ​​are stored in the memory unit 52 in association with the sound pressure sensors 121, 122, and 123.

[0086] The calculation unit 51 compares the three sound pressure values ​​detected by the three sound pressure sensors 121, 122, and 123 at the same time and determines the order based on the magnitude of the sound pressure values. Furthermore, the calculation unit 51 calculates the average value Ave (reference sound pressure value) of the top two sound pressure values ​​(top sound pressure values) and stores this in the storage unit 52 together with the names of the corresponding sound pressure sensors (step S25). The calculation unit 51 also stores the lowest sound pressure value Min (bottom sound pressure value) in the storage unit 52 together with the names of the corresponding sound pressure sensors (step S26). The saving operations in steps S25 and S26 are also saved in association with the time at which they were saved.

[0087] Next, the average value Ave and the lowest sound pressure value Min are provided to the determination unit 53, which reads the threshold value X from the memory unit 52, calculates the product of the average value Ave and the threshold value X, and compares it with the sound pressure value Min (step S27).

[0088] If the sound pressure value Min is greater than the product of the average value Ave and the threshold value X (YES in step S27), the determination unit 53 determines that the sound pressure sensor corresponding to the sound pressure value Min is in a normal operating state (step S28). On the other hand, if the sound pressure value Min is smaller than or equal to the product of the average value Ave and the threshold value X (NO in step S27), the determination unit 53 determines that the operating state of the sound pressure sensor corresponding to the sound pressure value Min is abnormal. If the determination unit 53 determines that the operating state of the sound pressure sensor is abnormal, the determination unit 53 causes the display unit 54 to display a message indicating that the operating state of the sound pressure sensor is abnormal (step S29).

[0089] Regardless of whether or not there is an abnormality in the operating state of the sound pressure sensor, following steps S28 and S29, the judgment unit 53 reads out the threshold value Y and the initial sound pressure value I from the memory unit 52 and compares their product with the average value Ave (step S30).

[0090] If the average value Ave is greater than the product of the threshold value Y and the initial sound pressure value I (YES in step S30), the determination unit 53 determines that the operating state of the vibrator 30 is normal (step S31) and causes the display unit 54 to display the average value Ave as a sound pressure value (step S32). At this time, the main body 50 (determination unit 53) as a control means determines that the operating state of the ultrasonic cleaning device 600 is normal, since the operating states of all of the components are normal.

[0091] On the other hand, if the average value Ave is smaller than or equal to the product of the threshold value Y and the initial sound pressure value I (NO in step S30), the judgment unit 53 judges that the operating state of the vibrator 30 is abnormal or that it is running dry (step S33).

[0092] After determining in step S33 that the operating state of the vibrator 30 is abnormal, and after determining in step S34 that the operating state of the oscillator 40 is abnormal, the determination unit 53 sends an error signal to the control device 61 (step S35). The control device 61, having received the error signal, sends a stop signal to the oscillator 40 to stop sending the drive signal to the vibrator 30 (step S36). Here, the main body 50 serving as a control means determines that the operating state of the ultrasonic cleaning device 600 is abnormal when the operating state of any of the components is abnormal.

[0093] The threshold value Y is set based on fluctuations in sound pressure values ​​due to factors such as the environment and the allowable range of performance degradation of the sound pressure sensor. When used to determine whether the average value Ave is greater than the product of the initial sound pressure value I and the threshold value Y, as in step S30 above, it is preferable to set a value greater than or equal to 0.5 and less than 1. By setting the threshold value Y to 0.5 or greater, the operating state of the vibrator 30 will not be determined to be abnormal due to slight changes in the average value Ave, which changes depending on the actual cleaning situation, and cleaning can be continued stably. However, since the threshold value changes depending on the usage situation, it is desirable to set it according to the usage environment.

[0094] Example 3 Table 3 shows an example of numerical values ​​of the detection results in the ultrasonic cleaning device 600 according to the second embodiment.

[0095]

[0096] In Example 3 shown in Table 3, the initial sound pressure value I is 55 (unit: mV), the sound pressure value A detected by sound pressure sensor 121 is 21 (unit: mV), the sound pressure value B detected by sound pressure sensor 122 is 21 (unit: mV), and the sound pressure value C detected by sound pressure sensor 123 is 19 (unit: mV). From these sound pressure values, the average value Ave of the sound pressure values ​​of the two sound pressure sensors 121 and 122, which are the upper sound pressure sensors, is 21 (unit: mV). On the other hand, the sound pressure value 19 of sound pressure sensor 123, which is the lower sound pressure sensor, is the lowest sound pressure value Min. If the threshold value X is 0.5 and the threshold value Y is 0.6, the average value Ave × X is 10.5, and the initial sound pressure value I × threshold value Y is 33.

[0097] In such a situation, provided that there is a signal from oscillator 40 (Yes in step S22 of FIG. 11, oscillator 40 is operating normally), the results of the determinations in steps S27 and S30 are as follows: (1) In step S27, "Is Min > Ave x X?", since sound pressure value Min is 19 and Ave x X is 10.5, it is determined that sound pressure value Min is larger and therefore the operating state of the sound pressure sensor is normal. (2) In step S30, "Is Ave > I x Y?", since average value Ave is 21 and I x Y is 33, it is determined that average value Ave is smaller and therefore there is an abnormality in the operating state of vibrator 30.

[0098] According to the second embodiment, in addition to the effects of the first embodiment, when an abnormality occurs in the output from the detection object 10, it becomes possible to determine which of the sound pressure sensors 121, 122, 123, the vibrator 30, and the oscillator 40 has experienced the abnormality. Note that other effects, advantages, and modifications are the same as those of the first embodiment. Although the present invention has been described with reference to the above embodiment, the present invention is not limited to the above embodiment, and improvements or modifications are possible within the scope of the purpose of improvement or the concept of the present invention.

[0099] REFERENCE SIGNS LIST 10 detection body 20 cleaning tank 21 bottom surface 22 liquid surface 23 cleaning liquid 25 fixing hole portion 30 vibrator 40 oscillator 50 main body portion (control means) 51 calculation portion 52 memory portion 53 determination portion 54 display portion 55 input portion 60 external device 61 control device 100, 600 ultrasonic cleaning device 110, 210, 310, 410, 510 support 110a, 210a, 310a tip portion 110b, 210b, 310b rear end portion 110c rear end surface 111, 112, 113 inclined surface 121, 122, 123 sound pressure sensor 131 first signal line 141, 142, 143 connection line 151, 152, 153 Second signal line 211 Outer peripheral surface 221, 222, 223 Sound pressure sensor 311, 312, 313, 314 Outer surface 321, 322, 323, 324 Sound pressure sensor 411, 511 Bottom surface 412, 512 Inner peripheral surface 413, 513 Lid portion 421, 422, 423 Sound pressure sensor 430, 530 Connector 440, 540 Cable 451, 452, 453 Sound pressure sensor 514 Main body portion 514a Outer peripheral surface 515 Disk portion 516 Nut 521, 522, 523 Sound pressure sensor 551, 552, 553 Sound pressure sensor Ave Average value of sound pressure values ​​of upper sound pressure sensors AX1, AX2, AX3, AX4, AX5 Central axis I Initial sound pressure value Min Sound pressure value Min of lowest sound pressure sensor X, Y Threshold

Claims

1. An ultrasonic cleaning device comprising: a cleaning tank containing a cleaning liquid; a vibrator which irradiates ultrasonic waves into the cleaning tank; and an oscillator which applies a drive signal to the vibrator to generate the ultrasonic waves. The detector detects the sound pressure of the cleaning liquid, comprising: a support at least a portion of which is immersed in the cleaning liquid; and a plurality of sound pressure sensors which are disposed at equal intervals around the central axis of the support in a non-liquid-contacting portion of the support and have the same detection characteristics, wherein each of the plurality of sound pressure sensors detects the vibrations caused by the ultrasonic waves propagated through the support as a sound pressure value.

2. An ultrasonic cleaning device comprising: a cleaning tank containing a cleaning liquid; a vibrator which irradiates ultrasonic waves into the cleaning tank; an oscillator which gives a drive signal to the vibrator to generate the ultrasonic waves; a support having at least a tip immersed in the cleaning liquid; and a detector which is disposed at an equal interval around the central axis of the support at the rear end of the support and which has a plurality of sound pressure sensors having the same detection characteristics, each of which detects vibrations caused by the ultrasonic waves propagated through the support as a sound pressure value by each of the plurality of sound pressure sensors; and a control means to which the detector is connected, wherein the control means determines whether the operating status of the ultrasonic cleaning device is normal or abnormal based on the detection result of the detector.

3. The ultrasonic cleaning device of claim 2, wherein the control means comprises: a judgment unit which judges whether the operating state of the detection object is normal or abnormal based on the sound pressure values ​​detected by each of the plurality of sound pressure sensors; and a display unit which is capable of displaying the detection results by the detection object, and the judgment unit sets the plurality of sound pressure sensors to one lower sound pressure sensor having the smallest sound pressure value and upper sound pressure sensors excluding the lower sound pressure sensor, and judges whether the operating state of the detection object is normal or abnormal based on the lower sound pressure value detected by the lower sound pressure sensor and a reference sound pressure value corresponding to the upper sound pressure value detected by the upper sound pressure sensor.

4. The ultrasonic cleaning device according to claim 3, wherein the judgment unit judges whether the operating condition of the detection body is normal or abnormal based on the result of comparing the product of the reference sound pressure value and a predetermined threshold value with the lower sound pressure value.

5. The ultrasonic cleaning device according to claim 4, characterized in that when the number of said plurality of sound pressure sensors is three or more, said reference sound pressure value is the average value of the upper sound pressure values ​​of the top two upper sound pressure sensors having larger sound pressure values ​​among said upper sound pressure sensors.

6. The ultrasonic cleaning device according to claim 5, wherein the judgment unit judges whether the operating condition of the oscillator is normal or abnormal based on the presence or absence of the output of the drive signal from the oscillator.

7. The ultrasonic cleaning device according to claim 6, wherein the judgment unit judges whether the operating condition of the vibrator is normal or abnormal based on the result of comparison between a predetermined initial sound pressure value and the reference sound pressure value.

8. The ultrasonic cleaning device according to claim 4, characterized in that when the number of said plurality of sound pressure sensors is two, said reference sound pressure value is said upper sound pressure value detected by one of said upper sound pressure sensors.

9. An ultrasonic cleaning device as described in claim 3, further comprising a control device which outputs a stop signal to stop the operation of the ultrasonic cleaning device when the judgment unit judges that the operating condition of the detection body is abnormal.

Images