Ultrasonic Emission Unit

Abstract

To provide an ultrasonic radiation unit at a low cost, which has a long life because of its excellent erosion resistance, and has less cleaning unevenness because of its excellent uniformity of vibration displacement distribution.SOLUTION: An ultrasonic radiation unit 21 includes a diaphragm 12 and a plurality of vibrating body units U1. The vibrating body unit U1 includes a plurality of ultrasonic vibrators 31, resonators 51, and a coupling plate 61 that transmits vibration of the ultrasonic vibrators 31 to the resonators 51. The coupling plate 61 has a mountain portion 62 and a valley portion 63 on both side edges to alternately form a wide width portion 64 and a narrow width portion 65, and a bolt insertion hole 67 is provided through a center portion of the wide width portion 64. The adjacent coupling plates 61 are alternately arranged in proximity to each other in a state where the mountain portion 62 are inserted into the valley portion 63. The plurality of ultrasonic vibrators 31 and the resonator 51 are fastened and fixed to a plurality of bolts 15 protruding through a plurality of bolt insertion holes 67 of the coupling plate 61.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an ultrasonic emitting unit that emits ultrasonic waves from an ultrasonic transducer. [Background technology]

[0002] Conventionally, ultrasonic cleaning devices equipped with an ultrasonic wave emission unit have been put into practical use to clean objects (ultrasonic cleaning) by irradiating ultrasonic waves into a cleaning solution. Ultrasonic cleaning can efficiently clean even the smallest details of objects with complex shapes by combining the physical action of ultrasonic waves with the chemical action of the cleaning solution. For this reason, it has become indispensable for the manufacture of precision machine parts, optical parts, liquid crystal displays, semiconductors, etc.

[0003] A conventional ultrasonic cleaning device 200 shown in FIG. 15 includes a vibration plate 201, also known as a radiation plate. Vibration plate 201 often doubles as the bottom of cleaning tank 202 and is made of a stainless steel plate several millimeters thick. Multiple bolt-tight Langevin-type ultrasonic vibrators 204 are attached to a non-radiating surface 203 of vibration plate 201, which constitutes an ultrasonic radiation unit. The surface of vibration plate 201 opposite non-radiating surface 203 serves as ultrasonic radiation surface 205. For example, when an ultrasonic radiation unit that generates ultrasonic waves of several tens of kilohertz is used, ultrasonic cleaning device 200 can be configured in which object 207 to be cleaned is cleaned by strong shock waves of cavitation caused by ultrasonic waves in cleaning solution 206. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-058883 A (Fig. 1, etc.) Summary of the Invention [Problem to be solved by the invention]

[0005] As the cleaning area of ​​the ultrasonic cleaning device 200 increases, the radiation surface of the diaphragm 201 also increases. Therefore, when constructing an ultrasonic radiation unit, it is desirable to install a large number of ultrasonic vibrators 204 on the diaphragm 201, which has a large radiation surface. However, using a large number of ultrasonic vibrators 204 to construct an ultrasonic radiation unit increases the manufacturing cost of the device. On the other hand, if the number of ultrasonic vibrators 204 does not match the size of the diaphragm 201, gaps (areas without vibrators) will occur between adjacent vibrators. As a result, there is a problem that erosion 208 occurs on the diaphragm 201 due to cavitation. Another problem is that uneven cleaning occurs due to non-uniform vibration displacement distribution (i.e., variations in sound pressure distribution) on the diaphragm 201.

[0006] Therefore, the inventors of the present application have already proposed an ultrasonic radiation unit with a structure in which a rod-shaped resonator is arranged between multiple ultrasonic transducers (see, for example, Patent Document 1). With this configuration, it is possible to reduce the area on the non-radiating surface where there are no transducers or resonators. However, even with this configuration, gaps still exist between the transducers or resonators, and it cannot necessarily be said that erosion reduction or uniformity of vibration displacement distribution has been sufficiently achieved.

[0007] Furthermore, the inventors of the present application have considered using a connecting plate in the ultrasonic radiation unit of the above structure in which a rod-shaped resonator is arranged between multiple ultrasonic vibrators. That is, they have considered using a connecting plate that mechanically connects the ultrasonic vibrators and the resonators, and installing the ultrasonic vibrators and the resonators on the non-radiating surface of the diaphragm via the connecting plate to transmit the vibration of the ultrasonic vibrators to the resonators. However, even with this configuration, it is expected that it will not be easy to arrange the ultrasonic vibrators and the resonators sufficiently closely.

[0008] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to realize an ultrasonic emission unit at low cost that has excellent erosion resistance, resulting in a long life, and excellent uniformity in vibration displacement distribution, resulting in little uneven cleaning. [Means for solving the problem]

[0009] In order to solve the above problem, the invention described in claim 1 provides an ultrasonic radiation unit comprising: a vibration plate having a radiation surface that emits ultrasonic waves and a non-radiating surface located opposite the radiation surface, with a plurality of bolts protruding from the non-radiating surface; a plurality of ultrasonic vibrators; a resonator arranged between the plurality of ultrasonic vibrators; and a connecting plate that mechanically couples the plurality of ultrasonic vibrators and the resonators to transmit vibrations of the plurality of ultrasonic vibrators to the resonators, wherein the connecting plate has peaks and valleys on both side edges to form a plurality of alternate wide portions and narrow portions, and a plurality of bolt insertion holes through which the plurality of bolts can be inserted are formed in the centers of the plurality of wide portions, and adjacent connecting plates are arranged close to each other in a staggered manner so that the peaks are inserted into the valleys, and the plurality of ultrasonic vibrators and the resonators are fastened and fixed to the plurality of bolts protruding through the plurality of bolt insertion holes of the connecting plate, thereby providing a plurality of the vibration body units on the non-radiating surface side.

[0010] Therefore, according to the invention described in claim 1, multiple vibrator units are used, each consisting of multiple ultrasonic vibrators and resonators mechanically coupled via a connecting plate, and the resonators are excited by the resonance phenomenon associated with the vibration of the ultrasonic vibrators. At this time, the connecting plate functions as a radiation plate for the vibrator consisting of multiple ultrasonic vibrators and resonators, allowing for uniform longitudinal vibration over a relatively wide radiation surface. Furthermore, adjacent connecting plates are arranged close to each other in a staggered manner, with the peaks nested within the valleys, allowing for a sufficiently dense arrangement of ultrasonic vibrators and resonators. As a result, bending vibrations occurring in the gaps between the vibrator units are suppressed, reducing erosion in the vibration plate and facilitating a uniform vibration displacement distribution.

[0011] Furthermore, since resonators have a simpler structure than ultrasonic vibrators, which are made up of multiple types of parts, they can be manufactured relatively inexpensively. Since the connecting plate also has a relatively simple structure, it can be manufactured relatively inexpensively using sheet metal processing such as punching and laser processing. Therefore, even in an ultrasonic emission unit equipped with a vibration plate that requires a large cleaning area, for example, by using inexpensive resonators and connecting plates instead of arranging multiple ultrasonic vibrators, a device with excellent erosion resistance and uniform vibration displacement distribution can be realized at low cost.

[0012] The invention as set forth in claim 2 is characterized in that in claim 1, the plurality of ultrasonic vibrators and the plurality of resonators are both arranged in a staggered pattern along the width direction of the vibrating body unit.

[0013] The invention described in claim 3 is characterized in that, in claim 2, when a specific vibrating body unit is defined as a reference unit and the vibrating body unit adjacent to the specific vibrating body unit is defined as an adjacent unit, when a line segment circumscribing the multiple ultrasonic vibrators belonging to the reference unit is imagined, the outer peripheries of the ultrasonic vibrators and resonators belonging to the adjacent units intersect with the line segment.

[0014] The invention as set forth in claim 4 is characterized in that, in claim 3, the peaks and valleys are regularly formed at equal pitches.

[0015] The invention described in claim 5 is characterized in that in any one of claims 1 to 4, the connecting plate has a structure in which a plurality of regular hexagonal plates are arranged in a planar direction and connected together.

[0016] The invention described in claim 6 is characterized in that, in any one of claims 1 to 4, adjacent connecting plates are arranged closely spaced apart with a gap of 0.1 mm or more and 1 / 8 or less of the longitudinal vibration wavelength.

[0017] The invention described in claim 7 is characterized in that in any one of claims 1 to 4, the thickness of the connecting plate is 1 / 200 or more and 1 / 10 or less of the longitudinal vibration wavelength. [Effects of the Invention]

[0018] As described above in detail, according to the inventions described in claims 1 to 7, an ultrasonic emission unit can be realized at low cost, which has excellent erosion resistance, a long life, and excellent uniformity in vibration displacement distribution, resulting in little uneven cleaning. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a schematic configuration diagram showing an ultrasonic cleaning device according to a first embodiment. [Figure 2] FIG. 2 is a partially exploded perspective view showing a diaphragm-type ultrasonic radiating unit according to the first embodiment. [Figure 3] FIG. 2 is a plan view showing a diaphragm-type ultrasonic radiating unit according to the first embodiment. [Figure 4] FIG. 2 is a perspective view showing a connecting plate used in the ultrasound radiating unit of the first embodiment. [Figure 5] FIG. 2 is a side view showing the ultrasonic radiating unit of the first embodiment in a state before assembly. [Figure 6] FIG. 2 is a side view showing the ultrasonic radiating unit of the first embodiment in an assembled state. [Figure 7] 1 is a table showing the vibration displacement analysis results of Comparative Example 1, Comparative Example 2, and an example. [Figure 8] 10A and 10B are plan views illustrating a state in which adjacent connecting plates are disposed close to each other in the vibrating body unit of the embodiment. [Figure 9] 10A and 10B are plan views illustrating a state in which adjacent connecting plates are disposed close to each other in the vibrating body unit of Comparative Example 3. FIG. [Figure 10] FIG. 10 is a perspective view showing a diaphragm-type ultrasonic radiation unit according to a second embodiment. [Figure 11] FIG. 10 is a plan view showing a diaphragm-type ultrasonic radiating unit according to another embodiment. [Figure 12] FIG. 10 is a side view showing an assembled state of an ultrasound radiating unit according to another embodiment. [Figure 13] 10A and 10B are plan views illustrating a state in which adjacent connecting plates are disposed close to each other in a vibrating body unit according to another embodiment. [Figure 14] 10A and 10B are plan views illustrating a state in which adjacent connecting plates are disposed close to each other in a vibrating body unit according to another embodiment. [Figure 15] FIG. 1 is a schematic diagram showing the configuration of a conventional ultrasonic cleaning device. DETAILED DESCRIPTION OF THE INVENTION

[0020] [First embodiment] A first embodiment of the present invention, which is an ultrasonic cleaning device, will be described in detail below with reference to FIGS.

[0021] As shown in FIGS. 1 to 3, an ultrasonic cleaning device 10 includes a metal cleaning tank 11 that stores cleaning liquid W1 and an ultrasonic radiation unit 21. The cleaning tank 11 has a plurality of bolt holes 11a at its lower end. The vibration plate 12 in the ultrasonic radiation unit 21 constitutes the bottom of the cleaning tank 11 and is a substantially rectangular metal plate (a stainless steel plate in this embodiment) measuring 390 mm long, 240 mm wide, and 2.5 mm thick. That is, the ultrasonic radiation unit 21 in this embodiment is a vibration plate-type ultrasonic radiation unit in which the vibration plate 12 is disposed at the lower end of the cleaning tank 11 via a packing 1 and secured with bolts 2 and nuts 3. The vibration plate 12 has a radiation surface 13 that radiates ultrasonic waves and a non-radiation surface 14 located opposite the radiation surface 13. Stud bolts 15 (see FIGS. 2 and 5) are protruding from multiple locations on the non-radiation surface 14 of the vibration plate 12. A plurality of fixing holes 16 are formed at equal intervals around the outer periphery of the diaphragm 12 .

[0022] As shown in FIGS. 2 and 3 , the ultrasonic wave emission unit 21 includes the above-mentioned vibration plate 12 and a plurality of vibration body units U1. The number of vibration body units U1 is not particularly limited, but is seven in this embodiment. Each vibration body unit U1 includes a plurality of ultrasonic vibrators 31, resonator rods 51 (resonators) arranged between the plurality of ultrasonic vibrators 31, and a connecting plate 61 serving as a vibration transmitter. Specifically, in this embodiment, each vibration body unit U1 has a structure in which one resonator rod 51 is arranged between two ultrasonic vibrators 31. The connecting plate 61 mechanically couples the two ultrasonic vibrators 31 and the one resonator rod 51 and serves to transmit ultrasonic vibrations generated by both ultrasonic vibrators 31 to the resonator rod 51. The ultrasonic cleaning device 10 of this embodiment, which uses the above-mentioned vibration body unit U1, is configured to clean the surface of an object 17 (see FIG. 1 ) contained in the cleaning tank 11 by irradiating ultrasonic waves from each ultrasonic vibrator 31 to the cleaning liquid W1 in the cleaning tank 11.

[0023] As shown in FIGS. 2, 5, and 6, each ultrasonic transducer 31 is a device for emitting ultrasonic waves and is composed of a transducer front panel 32, a transducer backing plate 33, a driving unit 41, and transducer assembly bolts 34. That is, each ultrasonic transducer 31 of this embodiment is a bolt-clamped Langevin transducer (BLT). The transducer front panel 32 is disposed on the front end side of the ultrasonic transducer 31. The transducer front panel 32 has a circular and substantially cylindrical shape in a plan view. The circular radiation surface of the transducer front panel 32 is bonded to the upper surface of the connecting plate 61 via an adhesive such as an epoxy resin. The lower surface of the connecting plate 61 is bonded to the non-radiating surface 14 of the diaphragm 12 via an adhesive such as an epoxy resin. The transducer front panel 32 is formed using a metal material such as aluminum, an aluminum alloy, stainless steel, or a titanium alloy.

[0024] The transducer backing plate 33 is disposed on the rear end side of the ultrasonic transducer 31. The transducer backing plate 33 has a circular and substantially cylindrical shape in a plan view, and in this embodiment, has a diameter slightly smaller than that of the transducer front plate 32. The driving unit 41 is formed by alternately stacking two piezoelectric elements 42 and two electrode plates 43, and is sandwiched between the transducer front plate 32 and the transducer backing plate 33. The transducer backing plate 33 is formed using a metal material such as aluminum, an aluminum alloy, stainless steel, or a titanium alloy.

[0025] The piezoelectric element 42 is annular, and the electrode plate 43 is generally annular with a tab portion on one side, so that the driving unit 41 has a bolt insertion hole 44 passing through the center of the driving unit 41. Each piezoelectric element 42 is polarized in the thickness direction.

[0026] The piezoelectric element 42 of this embodiment is formed using a ceramic piezoelectric material containing Pb (lead), such as lead zirconate titanate (PZT), although it is not particularly limited thereto. Alternatively, the piezoelectric element 42 may be formed using a lead-free ceramic piezoelectric material, specifically, an alkali niobate-based ceramic piezoelectric material.

[0027] 5 and 6, a female threaded hole 35 extending along the height direction of the vibrator front plate 32 (vertical direction in FIGS. 5 and 6) is formed in the center of the rear end side of the vibrator front plate 32. This female threaded hole 35 does not pass through the vibrator front plate 32. In other words, this female threaded hole 35 is open only on the rear surface of the vibrator front plate 32. Meanwhile, a bolt insertion hole 56 through which a stud bolt 15 is inserted is provided in the center of the front end side of the vibrator front plate 32 so as to extend along the height direction.

[0028] The female threaded hole 35 in the vibrator front plate 32 communicates with the bolt insertion hole 44 in the drive unit 41. Meanwhile, a through hole 36 is formed in the center of the vibrator back plate 33, extending along the height direction of the vibrator back plate 33 (the up-and-down direction in FIG. 3 ). The through hole 36 opens at the front surface and communicates with the bolt insertion hole 44, and also opens at the rear surface. Note that a vibrator assembly bolt 34, which has a male thread formed on its outer periphery, is inserted from the vibrator back plate 33 side, and its tip reaches the female threaded hole 35 on the vibrator front plate 32 side via the through hole 36 and the bolt insertion hole 44. In other words, the tip of this vibrator assembly bolt 34 stops halfway through the vibrator front plate 32 and does not reach the diaphragm 12. This vibrator assembly bolt 34 is threaded into the female threaded hole 35. Then, the vibrator front panel 32, drive unit 41, and vibrator backing plate 33 are fastened together and integrated by screwing nuts 38 onto the protruding portions of the vibrator assembly bolts 34 that have passed through the vibrator backing plate 33. The vibrator assembly bolts 34 and nuts 38 may be made of any metal material, but stainless steel is used here.

[0029] The connecting plate 61 has a plurality of bolt insertion holes 67 formed therethrough, and a plurality of stud bolts 15 protruding through these bolt insertion holes 67 are screwed into the bolt insertion holes 56 of the transducer front plate 32. By this screwing, the two ultrasonic transducers 31 are fastened and fixed to one connecting plate 61. Note that it may also be understood that by screwing the stud bolts 15 into the bolt insertion holes 56 of the transducer front plate 32, the connecting plate 61 is clamped and fixed in a state where it is sandwiched between the ultrasonic transducers 31 and the vibration plate 12.

[0030] Each ultrasonic transducer 31 of this embodiment shown in Fig. 1 etc. is a bolt-clamped Langevin type transducer of a longitudinal vibration type having a longitudinal primary vibration mode (single-unit resonant frequency 25 kHz) in which the longitudinal vibration component in the axial direction resonates at λ / 2 (λ: longitudinal vibration wavelength). Each ultrasonic transducer 31 vibrates at the same frequency.

[0031] 1, an ultrasonic oscillator 19 is electrically connected to each ultrasonic vibrator 31. The ultrasonic oscillator 19 supplies high-frequency power that continuously vibrates each ultrasonic vibrator 31. This high-frequency power drives each ultrasonic vibrator 31, and each ultrasonic vibrator 31 irradiates ultrasonic waves of 25 kHz (the resonance frequency when the ultrasonic vibrator 31 is bonded to the vibration plate 12) to the cleaning liquid W1 in the cleaning tank 11. In this embodiment, the ultrasonic output is set to 250 W, but is not particularly limited to this and can be set arbitrarily.

[0032] As shown in FIGS. 1 to 3, 5, and 6, each resonator rod 51 in this embodiment is a resonator that resonates at the same frequency as the ultrasonic transducer 31 (single resonant frequency of 25 kHz) and in a longitudinal vibration mode. The resonator rod 51 is circular and substantially cylindrical in plan view. The resonator rod 51 in this embodiment has the same diameter as the maximum diameter of the transducer front panel 32 and is slightly longer than the ultrasonic transducer 31. A bolt insertion hole 56, through which a stud bolt 15 is inserted, is provided in the center of the distal end of the resonator rod 51 and extends along the height direction. A plurality of stud bolts 15 protruding through the insertion hole 67 are screwed into the bolt insertion hole 56 of the resonator rod 51. This screw connection fastens each resonator rod 51 to one connecting plate 61. The resonator rod 51 is made of a metal material such as aluminum, aluminum alloy, stainless steel, or titanium alloy.

[0033] As shown in FIGS. 3 and 4 , the connecting plate 61 is a metal flat plate. The connecting plate 61 of this embodiment has a structure in which three regular hexagonal aluminum plates are arranged in a planar direction and connected together. The connecting plate 61 has multiple peaks 62 and multiple valleys 63 on both side edges. The peaks 62 and valleys 63 are generally V-shaped and are regularly arranged at equal intervals. As a result, the connecting plate 61 has three wide portions 64 and two narrow portions 65, with the wide portions 64 and narrow portions 65 alternately arranged. The connecting plate 61 can also be considered to have zigzag-shaped side edges on both sides (i.e., linear lines that bend at regular intervals and then reverse at each angle). In this connecting plate 61, the dimensions of the wide portions 64 are approximately twice the dimensions of the narrow portions 65. In the connecting plate 61 of this embodiment, a bolt insertion hole 67 through which a stud bolt 15 can be inserted is formed in the center of each of the three wide portions 64 (that is, the center of the regular hexagonal plate).

[0034] The thickness of the connecting plate 61 is not particularly limited and can be set arbitrarily, but is preferably 1 / 200 to 1 / 10 of the longitudinal vibration wavelength at the driving frequency of the ultrasonic waves. The reason for this is that if the connecting plate 61 is too thick, it may be difficult to couple the ultrasonic vibrator 31 and the resonant rod 51, and if it is too thin, bending vibrations are more likely to occur. In this embodiment, taking the above into consideration, the thickness of the connecting plate 61 is set to about 5 mm to 10 mm (i.e., about 1 / 20 to 1 / 10 of the longitudinal vibration wavelength).

[0035] As shown in Figures 3 and 4, adjacent connecting plates 61 are arranged close to each other in a staggered manner, with the peaks 62 nested within the valleys 63. A certain gap 66 is provided between adjacent connecting plates 61. The size of this gap 66 is not limited, but is set to, for example, 0.1 mm or more, preferably 0.3 mm or more. If the gap 66 is too narrow, adjacent connecting plates 61 may come into contact with each other. In this case, the vibrations of adjacent vibrating body units U1 may interfere with each other, resulting in significant loss of vibration energy. The size of the gap 66 is set to, for example, 1 / 8 or less, preferably 1 / 15 or less, and more preferably 1 / 30 or less of the longitudinal vibration wavelength at the ultrasonic driving frequency. If the gap 66 is too wide, bending vibrations are more likely to occur, making it difficult to obtain uniform longitudinal vibrations. In this embodiment, taking the above into consideration, the gap 66 between the connecting plates 61 is set to about 1 mm to 2 mm (that is, about 1 / 100 to 1 / 50 of the longitudinal vibration wavelength).

[0036] The seven vibrating body units U1 in this embodiment are installed on the non-radiating surface 14 side of the diaphragm 12 by fastening the ultrasonic vibrators 31 and resonating rods 51 to a plurality of stud bolts 15 protruding through the bolt insertion holes 67 of the connecting plate 61. At this time, adjacent vibrating body units U1 are installed with a shift of half the pitch between the peaks 62 or the pitch between the valleys 63. As a result, the plurality of ultrasonic vibrators 31 belonging to different vibrating body units U1 are arranged in a staggered manner along the width direction of the vibrating body unit U1 (the arrangement direction of the vibrating body units U1). Similarly, the plurality of resonating rods 51 belonging to different vibrating body units U1 are also arranged in a staggered manner along the width direction of the vibrating body unit U1.

[0037] The ultrasonic vibrators 31 and resonator rods 51 constituting the vibrator unit U1 are formed to be smaller than the diameter of the inscribed circle of the regular hexagonal plate constituting the connecting plate 61, preferably to be 80% or more but less than 100% of the diameter of the inscribed circle of the regular hexagonal plate constituting the connecting plate 61. If the dimensions of the ultrasonic vibrators 31 and resonator rods 51 were equal to or larger than the diameter of the inscribed circle, the ultrasonic vibrators 31 and resonator rods 51 would protrude to the side of the connecting plate 61 and may come into contact with the adjacent connecting plate 61. Conversely, if the dimensions of the ultrasonic vibrators 31 and resonator rods 51 are too small, sufficient ultrasonic vibrations cannot be obtained. In consideration of this situation, in this embodiment, the dimensions of the ultrasonic vibrators 31 and resonator rods 51 are both set to approximately 95% of the diameter of the inscribed circle.

[0038] 8(a) and 8(b) are plan views illustrating a state in which adjacent connecting plates 61 are arranged close to each other in the vibrating body unit U1 of the embodiment. Fig. 9(a) and 9(b) are plan views illustrating a state in which adjacent connecting plates 61S are arranged close to each other in the vibrating body unit U1 of the comparative example 1.

[0039] Here, an arbitrarily selected specific vibrator unit U1 is defined as the “reference unit U1a,” and the vibrator unit U1 adjacent to the specific vibrator unit U1 is defined as the “adjacent unit U1b.” In this case, a straight line segment L1 is assumed to circumscribe the two ultrasonic vibrators 31 belonging to the reference unit U1a.

[0040] In the embodiment, as described above, the connecting plate 61 has a zigzag shape with multiple peaks 62 and multiple valleys 63 formed on its side edges, and adjacent connecting plates 61 have the peaks 62 nested within the valleys 63. Therefore, in the embodiment, when the base unit U1a and the adjacent unit U1b are arranged closely with a gap 66 between them, the outer circumferences of the two ultrasonic vibrators 31 and one resonator rod 51 belonging to the adjacent unit U1b intersect with the line segment L1 (see FIG. 8(b)). This means that in the embodiment, the ultrasonic vibrators 31 and the resonator rod 51 belonging to adjacent vibrator units U1 can be arranged very close to each other.

[0041] In contrast, in Comparative Example 1, the connecting plate 61S is rectangular, so the side edges are linear and there are no peaks 62 or valleys 63. Therefore, even when the reference unit U1a and the adjacent unit U1b are arranged closely with a gap 66 between them, the outer circumferences of the two ultrasonic vibrators 31 and one resonator rod 51 belonging to the adjacent unit U1b do not intersect with the line segment L1 (see FIG. 9(b)). This means that in Comparative Example 1, the ultrasonic vibrators 31 and the resonator rod 51 belonging to adjacent vibrator units U1 cannot be arranged as closely to each other as in the example.

[0042] Next, the operation of the ultrasonic cleaning device 10 of this embodiment will be described.

[0043] First, the ultrasonic cleaning device 10 is driven, and high-frequency power is supplied from the ultrasonic oscillator 19 to the multiple ultrasonic vibrators 31, causing each ultrasonic vibrator 31 to vibrate continuously. As a result, ultrasonic waves are irradiated into the cleaning solution W1 from the ultrasonic vibrators 31. At this time, cavitation occurs in the cleaning solution W1 in association with the irradiation of ultrasonic waves, and the object 17 to be cleaned is cleaned by the impact of the cavitation bursting.

[0044] Next, an evaluation test of the ultrasonic wave emitting unit 21 and the results thereof will be described.

[0045] In this evaluation test, measurement samples were prepared as follows. An ultrasonic emitting unit identical to the ultrasonic emitting unit 21 of this embodiment was prepared and designated as the Example. The ultrasonic emitting unit 21 of the Example is described in the right column of the table in FIG. 7 as "(c) BLT + resonant rod + connecting plate connection." An ultrasonic emitting unit was prepared in which the connecting plate 61 was omitted from the ultrasonic emitting unit 21 of this embodiment and designated as Comparative Example 2. The ultrasonic emitting unit 21 of Comparative Example 2 is described in the middle column of the table in FIG. 7 as "(b) BLT + resonant rod connection." An ultrasonic emitting unit was prepared in which the connecting plate 61 and resonant rod 51 were omitted from the ultrasonic emitting unit 21 of this embodiment and designated as Comparative Example 3. The ultrasonic emitting unit 21 of Comparative Example 3 is described in the left column of the table in FIG. 7 as "(a) BLT connection."

[0046] Next, the vibration displacement distribution under water load was analyzed for the diaphragm 12 of the ultrasonic emitting unit of each measurement sample (Example, Comparative Example 2, and Comparative Example 3) using a conventionally known finite element method. In this analysis, a diaphragm 12 measuring 390 mm long, 240 mm wide, and 2.5 mm thick was used, and the ultrasonic emitting unit was configured by mounting 14 ultrasonic vibrators 13 (manufactured by Honda Electronics Co., Ltd., "HEC-45282") with a nominal frequency of 28 kHz on the non-radiating surface 14 of the diaphragm 12. The driving power of each ultrasonic vibrator 13 was 600 W.

[0047] As a result, it was confirmed that Comparative Example 2 had less unevenness in the vibration displacement distribution than Comparative Example 3, and that the Examples had less unevenness in the vibration displacement distribution than Comparative Example 2. Therefore, it was confirmed that the uniformity of the vibration displacement distribution was highest for "(c) BLT + resonant rod + connecting plate connection", followed by "(b) BLT + resonant rod connection", and lowest for "(a) BLT connection".

[0048] Therefore, according to this embodiment, the following effects can be obtained.

[0049] (1) The ultrasonic radiation unit 21 of this embodiment is constructed using multiple vibrator units U1, each of which mechanically connects two ultrasonic vibrators 31 and one resonator rod 51 via a connecting plate 61. Therefore, the resonator 51 is excited by a resonance phenomenon associated with the vibration of the ultrasonic vibrator 31. At this time, the connecting plate 61 functions as a radiation plate for the vibrator consisting of the two ultrasonic vibrators 31 and the resonator rod 51, thereby achieving uniform longitudinal vibration over a relatively wide radiation surface. Furthermore, adjacent connecting plates 61 are arranged close to each other in a staggered manner, with the peaks 62 nested within the valleys 63. This allows the ultrasonic vibrators 31 and the resonator rods 51 to be arranged sufficiently densely. As a result, bending vibrations occurring in the gaps 66 between the vibrator units U1 are suppressed, reducing erosion of the vibrating plate 12 and reducing wear of the vibrating plate 12, thereby extending the device's lifespan. Furthermore, a uniform vibration displacement distribution is more easily achieved, reducing the occurrence of uneven cleaning. As a result, an excellent ultrasonic cleaning device 10 capable of uniform cleaning can be provided.

[0050] Furthermore, the cylindrical resonator 51 of this embodiment, which is made of a single material, has a simpler structure than the ultrasonic vibrator 31, which is made up of multiple types of parts, and can therefore be manufactured relatively inexpensively. The connecting plate 61 of this embodiment also has a relatively simple structure, and can therefore be manufactured relatively inexpensively by sheet metal processing such as punching and laser processing. Therefore, even in an ultrasonic emission unit 21 equipped with a vibrating plate 12 that requires a wide cleaning area, for example, by using an inexpensive resonator rod 51 and connecting plate 61 instead of arranging multiple ultrasonic vibrators 31, a device with excellent erosion resistance and uniformity of vibration displacement distribution can be realized at low cost.

[0051] (2) In the ultrasound emitting unit 21 of this embodiment, the ultrasonic vibrators 31 and the resonator rods 51 are all arranged in a staggered pattern along the width direction of the vibrator unit U1. In addition, the outer peripheries of the ultrasonic vibrators 31 and the resonator rods 51 belonging to the adjacent unit U1b intersect with a line segment L1 circumscribing the two ultrasonic vibrators 31 belonging to the base unit U1a. With this configuration, it becomes relatively easy to arrange the ultrasonic vibrators 31 and the resonator rods 51 closely to each other.

[0052] (3) In this embodiment, the peaks 62 and valleys 63 are regularly formed at equal intervals. Therefore, when adjacent connecting plates 61 are arranged close to each other in a staggered manner so that the peaks 62 are inserted into the valleys 63, a narrow gap 66 of approximately constant size can be formed between them. Incidentally, in the above-described comparative example 1, the gap 66 between adjacent vibrating body units U1 is linear, and thus bending vibrations are easily excited along the linear gap 66. Therefore, heat generation and stress damage are a concern depending on the vibration level. Therefore, it is considered necessary to suppress bending vibrations in practical use. In contrast, in this embodiment, the gap 66 between adjacent vibrating body units U1 is nonlinear (zigzag) and narrow, and therefore bending vibrations are less likely to be excited, unlike in comparative example 1. Therefore, there is an advantage in that there are no concerns about heat generation and stress damage.

[0053] (4) For example, Japanese Patent Publication No. 7171117 discloses an ultrasonic emitting unit constructed using a block-shaped base member in which the front portion of a resonating rod and the front portion of an ultrasonic vibrator are integrated. This ultrasonic emitting unit has the advantage of being excellent in both uniformity of vibration distribution and erosion resistance. On the other hand, it has the disadvantage that the cost of cutting to form narrow grooves in the base member is relatively high, resulting in high manufacturing costs for the device. In contrast, the connecting plate 61 used in this embodiment can be manufactured relatively inexpensively as described above, and therefore has the advantage of not leading to high costs for the device.

[0054] [Second embodiment]

[0055] Next, an ultrasonic radiating unit 121 according to a second embodiment of the present invention will be described in detail with reference to Fig. 10. Note that only the configurations different from those of the ultrasonic radiating unit 21 according to the first embodiment will be described here, and the common configurations will be denoted by the same component numbers and will not be described in detail.

[0056] In the first embodiment, a substantially trapezoidal region R1 (see FIG. 2, etc.) on the non-radiating surface 14 of the diaphragm 12, which is on an extension of the length direction of the vibrating body unit U1 and does not include the connecting plate 61, exists, but no particular structure is provided there. In contrast, in the ultrasonic emitting unit 121 of the present embodiment, stud bolts 15 are also provided protruding from the region R1. Resonating rods 59 serving as second resonators are fastened and fixed to these stud bolts 15. The substantially trapezoidal region R1 has an area approximately half that of the regular hexagonal plate constituting the connecting plate 61. In order to install the resonating rod 59 in the region R1, the resonating rod 59 has a diameter somewhat smaller than that of the resonating rod 51 (first resonator) belonging to the vibrating body unit U1.

[0057] The ultrasonic emitting unit 121 configured as described above can reduce erosion and cleaning unevenness on the diaphragm 12, as in the first embodiment, and can be manufactured relatively inexpensively. In addition, the vibration displacement distribution in the specific region is less likely to be uneven than in the first embodiment, making the vibration displacement distribution even more uniform. It is also conceivable to extend the connecting plate 61 to the trapezoidal region R1 and install the resonating rod 59 through the extended portion. However, this configuration would not sufficiently reduce the unevenness in the vibration displacement distribution in the specific region, so in this embodiment, the resonating rod 59 is installed directly in the region R1.

[0058] The above embodiment may be modified as follows.

[0059] While each vibrator unit U1 in the above embodiment is configured to include two ultrasonic vibrators 31 and one resonator 51, with one resonator 51 disposed between the two ultrasonic vibrators 31, this is not limiting. For example, like a vibrator unit 131 of another embodiment shown in Figures 11 and 12, it may be configured to include three ultrasonic vibrators 31 and two resonators 51, with one resonator 51 disposed between the two ultrasonic vibrators 31.

[0060] In the above embodiment, the vibrator unit U1 is configured using a resonator rod 51 that is circular and substantially cylindrical in plan view, but is not limited to this. For example, the vibrator unit U1 may be configured using a resonator rod that is rectangular and substantially prismatic in plan view.

[0061] In the above embodiment, the vibrator unit U1 was configured using a connecting plate 61 having zigzag-shaped side edges formed by the formation of multiple, approximately L-shaped peaks 62 and multiple, approximately L-shaped valleys 63. However, this is not limiting. For example, as in another embodiment of the vibrator unit U1 shown in FIGS. 13(a) and 13(b), the vibrator unit U1 may be configured using a connecting plate 61A having gently curved, wavy-shaped side edges formed by the formation of multiple peaks 62 and multiple valleys 63 in an arc shape. Even in this case, adjacent connecting plates 61A, 61A can be arranged very close to each other with the peaks 62 nested in the valleys 63. Alternatively, the vibrator unit U1 may be configured using a connecting plate 61B shaped like the vibrator unit U1 of another embodiment shown in FIGS. 14(a) and 14(b). Similarly, even in this case, adjacent connecting plates 61B, 61B can be arranged very close to each other with the peaks 62 nested in the valleys 63.

[0062] In the above embodiment, the stud bolt 15, which is a bolt without a head, is used as the bolt that protrudes from the non-radiating surface 14 of the diaphragm 12. However, a bolt with a head, such as a hexagonal bolt, a hexagonal socket head bolt, or a butterfly bolt, may also be used as the bolt that protrudes from the non-radiating surface 14.

[0063] In the above embodiment, the ultrasonic emitting units 21, 121, 131 of the vibration plate type are attached to the bottom of the cleaning tank 11 in the ultrasonic cleaning device 10 via the packing 1, but the present invention is not limited to this. For example, the ultrasonic emitting units 21, 121, 131 may be of the cleaning tank type that are attached to stud bolts protruding from the non-radiating surface of the bottom plate of the cleaning tank 11. Alternatively, the ultrasonic emitting units 21, 121, 131 may be of the throw-in type that are thrown into the cleaning liquid W1 in the cleaning tank 11 for use.

[0064] While the ultrasonic emission units 21, 121, and 131 in the above-described embodiments were applied to the ultrasonic cleaning device 10, which uses ultrasonic waves to perform cleaning, they may also be applied to devices performing processes other than cleaning, such as extraction, emulsification, dispersion, mixing, stirring, crushing, and atomization. Specifically, for example, when applied to an ultrasonic emulsification device, emulsions can be highly refined to nanoparticles, providing long-term stability and reducing the need for surfactants. Furthermore, when applied to an ultrasonic dispersion device, nanoparticles (metal nanoparticles, carbon nanotubes, ceramic nanoparticles, magnetic nanoparticles, etc.) can be highly efficiently dispersed. Furthermore, the ultrasonic emission units may be embodied as ultrasonic processing devices that utilize chemical action. In this case, cavitation can be efficiently generated uniformly and over a wide area, thereby increasing the amount of radicals, such as OH radicals, generated by the high-temperature and high-pressure field that occurs when bubbles collapse. This increases the efficiency of sonochemical reactions caused by radical species, enabling efficient decomposition and detoxification of harmful substances, sterilization, and polymer polymerization.

[0065] Next, in addition to the technical ideas set forth in the claims, the technical ideas grasped by the above-described embodiments will be listed below.

[0066] (1) In claim 1, etc., the vibration plate and the connecting plate are joined in surface contact via an adhesive, and the ultrasonic vibrator and the resonator are joined in surface contact with the connecting plate via the adhesive. (2) In claim 1, etc., the ultrasonic vibrator is a longitudinal vibration type vibrator that vibrates in a longitudinal vibration mode, and the resonator is a resonator that resonates at the same frequency and in the same longitudinal vibration mode as the ultrasonic vibrator. (3) In claim 1, the ultrasonic vibrator and the resonator are smaller in diameter than the inscribed circle of the regular hexagonal plate that constitutes the connecting plate. (4) In claim 1, the ultrasonic vibrator and the resonator are 80% or more and less than 100% of the diameter of the inscribed circle of the regular hexagonal plate that constitutes the connecting plate. (5) In claim 1, etc., one of the vibrating body units is configured by disposing one of the resonators between two of the ultrasonic vibrators. (6) In claim 1, etc., the resonator is a resonator rod longer than the ultrasonic vibrator. (7) In claim 1, etc., the bolt is provided to protrude from an area on an extension line of the length of the vibrating body unit where the connecting plate is not present, and a small-diameter resonator is fastened and fixed to the bolt. [Explanation of symbols]

[0067] 12...Diaphragm 13...Radiation surface 14...Non-radiative surface 15...Stud bolt as a bolt 21, 121, 131...Ultrasonic emission units 31...Ultrasonic vibrator 51...(first) resonator rod 59... Resonating rod as second resonator 54...Bolt insertion hole 61, 61A, 61B...Connection plate 62...Yamabe 63... Valley 64...Wide part 65…Narrow part 66...gap 67...Bolt insertion hole L1...line segment t1...Thickness of connecting plate U1...Vibration unit U1a...Reference unit U1b: Adjacent unit

Claims

1. a vibration plate having a radiation surface that radiates ultrasonic waves and a non-radiating surface located opposite the radiation surface, with a plurality of bolts protruding from the non-radiating surface; a plurality of vibrating body units each including a plurality of ultrasonic vibrators, a resonator disposed between the plurality of ultrasonic vibrators, and a connecting plate that mechanically couples the plurality of ultrasonic vibrators and the resonator to transmit vibrations of the plurality of ultrasonic vibrators to the resonator; Equipped with The connecting plate has peaks and valleys on both side edges, thereby forming a plurality of wide portions and narrow portions alternately, and a plurality of bolt insertion holes through which the plurality of bolts can be inserted are respectively provided in the centers of the plurality of wide portions, The adjacent connecting plates are arranged close to each other in a staggered manner so that the peaks are inserted into the valleys, The plurality of ultrasonic vibrators and the resonators are fastened and fixed to the plurality of bolts protruding through the plurality of bolt insertion holes of the connecting plate, so that the plurality of vibrating body units are installed on the non-radiating surface side. An ultrasonic wave emitting unit characterized by:

2. 2. The ultrasonic radiation unit according to claim 1, wherein the plurality of ultrasonic vibrators and the plurality of resonators are arranged in a staggered pattern along the width direction of the vibrating body unit.

3. The ultrasonic radiation unit described in claim 2, characterized in that when a specific vibrating body unit is taken as a reference unit and the vibrating body unit adjacent to the specific vibrating body unit is taken as an adjacent unit, when a line segment circumscribing the multiple ultrasonic vibrators belonging to the reference unit is imagined, the outer peripheries of the ultrasonic vibrators and resonators belonging to the adjacent unit intersect with the line segment.

4. 4. The ultrasonic wave emitting unit according to claim 3, wherein the peaks and valleys are regularly formed at equal intervals.

5. 5. The ultrasonic wave emitting unit according to claim 1, wherein the connecting plate has a structure in which a plurality of regular hexagonal plates are arranged in a planar direction and connected together.

6. 5. The ultrasonic wave emitting unit according to claim 1, wherein the adjacent connecting plates are closely arranged with a gap of 0.1 mm or more and 1 / 8 or less of the longitudinal vibration wavelength therebetween.

7. 5. The ultrasonic wave emitting unit according to claim 1, wherein the thickness of the connecting plate is not less than 1 / 200 and not more than 1 / 10 of the longitudinal vibration wavelength.

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