Ultrasonic radiation unit

Abstract

An ultrasonic radiation unit (21) is provided with a vibrating plate (12) and a plurality of vibrating body units (U1). The vibrator unit (U1) includes a plurality of ultrasonic vibrators (31), resonators (51), and a link plate (61) that transmits vibrations of the ultrasonic vibrators (31) to the resonators (51), the link plate (61) has a mountain portion (62) and a valley portion (63) on both side edges to alternately form a wide portion (64) and a narrow portion (65), and a bolt insertion hole (67) is provided in the center of the wide portion (64). Adjacent connecting plates (61) are disposed close to each other in a state in which the mountain sections (62) enter the valley sections (63), and the plurality of ultrasonic transducers (31) and resonators (51) are fastened and fixed to a plurality of bolts (15) protruding through a plurality of bolt insertion holes (67) in the connecting plates (61). According to the present invention, it is possible to realize, at low cost, an ultrasonic radiation unit having excellent corrosion resistance (long life) and excellent vibration displacement distribution uniformity (less cleaning irregularities).

Description

Technical Field

[0001] The present invention relates to an ultrasonic radiation unit that radiates ultrasonic waves from an ultrasonic transducer. Background Art

[0002] In the prior art, an ultrasonic cleaning device having an ultrasonic radiation unit that performs cleaning (ultrasonic cleaning) of an object to be cleaned by irradiating ultrasonic waves into a cleaning liquid has been put into practical use. Ultrasonic cleaning combines the physical action of ultrasonic waves and the chemical action of the cleaning liquid, acts on the details of an object to be cleaned having a complex shape, and can perform cleaning efficiently. Therefore, it is indispensable in the manufacture of precision mechanical parts, optical components, liquid crystal displays, semiconductors, etc.

[0003] Figure 15 The conventional ultrasonic cleaning device 200 shown includes a vibrating plate 201 also called a radiation plate. The vibrating plate 201 usually also serves as the bottom of the cleaning tank 202 and is formed of a stainless steel plate with a thickness of several millimeters. A plurality of bolt-fastened Langevin-type ultrasonic transducers 204 are joined to the non-radiating surface 203 of the vibrating plate 201 that constitutes the ultrasonic radiation unit. The surface of the vibrating plate 201 on the side opposite to the non-radiating surface 203 becomes the ultrasonic radiation surface 205. And, for example, in the case of using an ultrasonic radiation unit that generates ultrasonic waves of several tens of kHz, an ultrasonic cleaning device 200 that cleans an object to be cleaned 207 by a strong shock wave of cavitation caused by ultrasonic waves in the cleaning liquid 206 can be configured.

[0004] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2019-058883 ([ Figure 1 etc.)

[0005] However, when the cleaning area of the ultrasonic cleaning device 200 becomes wider, the radiation surface of the vibrating plate 201 also becomes larger. Therefore, when configuring the ultrasonic radiation unit, it is originally preferable to provide a plurality of ultrasonic transducers 204 on the vibrating plate 201 having a large radiation surface. However, if a plurality of ultrasonic transducers 204 are used to configure the ultrasonic radiation unit, the manufacturing cost of the device increases. On the other hand, if the number of ultrasonic transducers 204 commensurate with the size of the vibrating plate 201 is not provided, a gap (an area without a transducer) is generated between adjacent transducers. As a result, there is a problem that erosion 208 is generated on the vibrating plate 201 due to cavitation. In addition, there is also a problem of uneven cleaning due to non-uniformity of the vibration displacement distribution of the vibrating plate 201 (i.e., deviation of the sound pressure distribution).

[0006] Therefore, the inventors of the present application have proposed an ultrasonic radiation unit having a structure in which a rod-shaped resonator is disposed between a plurality of ultrasonic oscillators (for example, refer to Patent Document 1). According to this structure, it is possible to reduce the area where there are no oscillators or resonators on the non-radiating surface. However, even with such a structure, there is still a gap between the oscillator and the resonator, and it is not necessarily possible to sufficiently achieve a reduction in erosion and a uniformization of the vibration displacement distribution.

[0007] Furthermore, the inventors of the present application are studying the use of a connecting plate in the ultrasonic radiation unit having the above-described structure in which a rod-shaped resonator is disposed between a plurality of ultrasonic oscillators. That is, they are studying the use of a connecting plate that mechanically couples the ultrasonic oscillator and the resonator, and by means of this connecting plate, the ultrasonic oscillator and the resonator are provided on the non-radiating surface of the vibration plate, thereby transmitting the vibration of the ultrasonic oscillator to the resonator. However, even with such a structure, it is not easy to sufficiently densely arrange the ultrasonic oscillators or resonators. Summary of the Invention

[0008] The present invention has been made in view of the above problems, and an object thereof is to provide an ultrasonic radiation unit that achieves excellent erosion resistance (and thus a long life) and excellent uniformity of vibration displacement distribution (and thus less uneven cleaning) at low cost.

[0009] To solve the above problems, a first ultrasonic radiation unit provided by the present invention includes a vibration plate and a plurality of vibration body units. The vibration plate has a radiation surface for radiating ultrasonic waves, a non-radiating surface on the opposite side of the radiation surface, and a plurality of bolts protruding on the non-radiating surface; the plurality of vibration body units are configured in a form including a plurality of ultrasonic oscillators, a resonator disposed between the plurality of ultrasonic oscillators, and a connecting plate that mechanically couples the plurality of ultrasonic oscillators and the resonator to transmit the vibration of the plurality of ultrasonic oscillators to the resonator; the connecting plate is alternately formed with a plurality of wide portions and narrow portions by having ridges and valleys on both side edges, and a plurality of bolt insertion holes through which the plurality of bolts can be inserted are respectively provided in the central portions of the plurality of wide portions; adjacent connecting plates are arranged close to each other in an alternating manner such that the ridges enter the valleys; by fastening and fixing the plurality of ultrasonic oscillators and the resonator to the plurality of bolts protruding through the plurality of bolt insertion holes of the connecting plate, the plurality of vibration body units are provided on the non-radiating surface side.

[0010] Therefore, according to the first ultrasonic radiation unit, since a plurality of vibrating body units, in which a plurality of ultrasonic transducers and resonators are mechanically coupled via a connection plate, are used, the transducers are excited by a resonance phenomenon accompanying the vibration of the ultrasonic transducers. At this time, since the connection plate functions as a radiation plate of a vibrating body composed of a plurality of ultrasonic transducers and resonators, uniform longitudinal vibration can be obtained on a relatively wide radiation surface. Moreover, adjacent connection plates are arranged close to each other in a mutually staggered manner such that a peak portion enters a valley portion, so that ultrasonic transducers or resonators can be arranged sufficiently closely. As a result, bending vibration generated in the gap between the vibrating body units is suppressed, generation of erosion in the vibrating plate is reduced, and a uniform vibration displacement distribution is easily obtained.

[0011] In addition, since the resonator has a simpler structure than an ultrasonic transducer composed of multiple components, it can be manufactured at a relatively low cost. Since the connection plate also has a relatively simple structure, it can be manufactured at a relatively low cost by sheet metal processing such as stamping or laser processing. Therefore, for example, in an ultrasonic radiation unit having a vibrating plate that requires a wide cleaning area, instead of arranging a plurality of ultrasonic transducers, by using inexpensive resonators and connection plates, a device with excellent erosion resistance and uniformity of vibration displacement distribution can be realized at low cost.

[0012] The second ultrasonic radiation unit provided by the present invention is such that, in the first ultrasonic radiation unit, a plurality of the ultrasonic transducers and the resonators are each arranged in a zigzag pattern along the width direction of the vibrating body unit.

[0013] The third ultrasonic radiation unit provided by the present invention is such that, in the second ultrasonic radiation unit, when a specific vibrating body unit is taken as a reference unit and a vibrating body unit adjacent to the specific vibrating body unit is taken as an adjacent unit, when imagining a line segment circumscribing a plurality of the ultrasonic transducers belonging to the reference unit, the outer peripheries of the ultrasonic transducers and the resonators belonging to the adjacent unit cross the line segment.

[0014] The fourth ultrasonic radiation unit provided by the present invention is such that, in the third ultrasonic radiation unit, the peak portions and the valley portions are regularly formed at equal intervals.

[0015] The fifth ultrasonic radiation unit provided by the present invention is such that, in any one of the first to fourth ultrasonic radiation units, the connection plate has a structure in which a plurality of regular hexagonal plates are arranged and connected integrally in a planar direction.

[0016] The sixth ultrasonic radiation unit provided by the present invention is such that, in any one of the first to fourth ultrasonic radiation units, adjacent connection plates are arranged close to each other with a gap of 0.1 mm or more and 1 / 8 or less of the longitudinal vibration wavelength therebetween.

[0017] The seventh ultrasonic radiation unit provided by the present invention is any one of the first to fourth ultrasonic radiation units, wherein the thickness of the connection plate is 1 / 200 or more and 1 / 10 or less of the longitudinal vibration wavelength.

[0018] As described above, according to the first to seventh ultrasonic radiation units, an ultrasonic radiation unit with excellent erosion resistance (and thus long life) and excellent uniformity of vibration displacement distribution (and thus less cleaning unevenness) can be achieved at low cost. Description of the Drawings

[0019] Figure 1 It is a schematic structural diagram showing the ultrasonic cleaning device of the first embodiment. Figure 2 It is a partially exploded perspective view showing the ultrasonic radiation unit of the diaphragm type of the first embodiment. Figure 3 It is a top view showing the ultrasonic radiation unit of the diaphragm type of the first embodiment. Figure 4 It is a perspective view showing the connection plate used in the ultrasonic radiation unit of the first embodiment. Figure 5 It is a side view showing the state before assembly of the ultrasonic radiation unit of the first embodiment. Figure 6 It is a side view showing the state after assembly of the ultrasonic radiation unit of the first embodiment. Figure 7 It is a table showing the vibration displacement analysis results of Comparative Example 1, Comparative Example 2, and the Example. Figure 8A 、 Figure 8B It is a top view for explaining the state in which adjacent connection plates are arranged close to each other in the vibrating body unit of the Example. Figure 9A 、 9B It is a top view for explaining the state in which adjacent connection plates are arranged close to each other in the vibrating body unit of Comparative Example 3. Figure 10 It is a perspective view showing the ultrasonic radiation unit of the diaphragm type of the second embodiment. Figure 11 It is a top view showing the ultrasonic radiation unit of the diaphragm type of another embodiment. Figure 12 It is a side view showing the state after assembly of the ultrasonic radiation unit of another embodiment. Figure 13A 、 Figure 13B It is a top view for explaining the state in which adjacent connection plates are arranged close to each other in the vibrating body unit of another embodiment. Figure 14A and Figure 14B is a top view for explaining a state in which adjacent connection plates in a vibrating body unit of another embodiment are arranged close to each other. Figure 15 is a schematic structural diagram showing an ultrasonic cleaning device of the prior art. Detailed Description of the Invention

[0020] (First Embodiment) Hereinafter, based on Figure 1 to FIG. 9, a first embodiment in which the present invention is embodied as an ultrasonic cleaning device will be described in detail.

[0021] As Figures 1 to 3 shown, the ultrasonic cleaning device 10 includes a metal cleaning tank 11 for storing a cleaning liquid W1 and an ultrasonic radiation unit 21. A plurality of bolt holes 11a are provided at the lower end of the cleaning tank 11. The vibrating plate 12 in the ultrasonic radiation unit 21 forms the bottom of the cleaning tank 11 and is a substantially rectangular plate-shaped metal plate (a stainless steel plate in this embodiment) with a length of 390 mm in the longitudinal direction, a width of 240 mm in the transverse direction, and a thickness of 2.5 mm. That is, the ultrasonic radiation unit 21 of this embodiment is a vibrating plate type ultrasonic radiation unit in which the vibrating plate 12 is arranged at the lower end of the cleaning tank 11 via a seal 1, and the vibrating plate 12 is screwed and fixed with bolts 2 and nuts 3. The vibrating plate 12 has a radiation surface 13 for radiating ultrasonic waves and a non-radiation surface 14 on the opposite side of the radiation surface 13. Stud bolts 15 are protrudingly provided at a plurality of positions on the non-radiation surface 14 of the vibrating plate 12 (refer to Figure 2 and Figure 5 ). A plurality of fixing holes 16 are provided at equal intervals in the entire circumference on the outer peripheral portion of the vibrating plate 12.

[0022] As Figure 2 and Figure 3As shown in etc., the ultrasonic radiation unit 21 has the diaphragm 12 and a plurality of vibrating body units U1. The number of the vibrating body units U1 is not particularly limited, but is 7 in the present embodiment. Each vibrating body unit U1 includes a plurality of ultrasonic oscillators 31, a resonance bar 51 (resonator) disposed between the plurality of ultrasonic oscillators 31, and a connection plate 61 as a vibration transmission body. Specifically, in the present embodiment, each vibrating body unit U1 has a structure in which one resonance bar 51 is disposed between two ultrasonic oscillators 31. The connection plate 61 mechanically couples the two ultrasonic oscillators 31 and one resonance bar 51, and functions to transmit the ultrasonic vibrations generated by the two ultrasonic oscillators 31 to the resonance bar 51. Moreover, the ultrasonic cleaning device 10 of the present embodiment using the vibrating body unit U1 is configured to clean the surface of the object to be cleaned 17 (refer to Figure 1 ) accommodated in the cleaning tank 11 by irradiating ultrasonic waves from each ultrasonic oscillator 31 into the cleaning liquid w1 in the cleaning tank 11.

[0023] As Figure 2 , Figure 5 , Figure 6 shown, each ultrasonic oscillator 31 is a device for irradiating ultrasonic waves, and is composed of an oscillator front panel 32, an oscillator back panel 33, a drive unit 41, and an oscillator assembly bolt 34. That is, each ultrasonic oscillator 31 of the present embodiment is a bolt-fastened convex type oscillator (BLT). The oscillator front panel 32 is disposed on the front end side of the ultrasonic oscillator 31. The oscillator front panel 32 has a circular shape in plan view and is substantially cylindrical. Moreover, the circular radiation surface of the oscillator front panel 32 is joined to the upper surface side of the connection plate 61 via an adhesive such as an epoxy resin system. In addition, the lower surface side of the connection plate 61 is joined to the non-radiation surface 14 of the diaphragm 12 via an adhesive such as an epoxy resin system. In addition, the oscillator front panel 32 is formed of a metal material such as aluminum, aluminum alloy, stainless steel, or titanium alloy.

[0024] The oscillator back panel 33 is disposed on the rear end side of the ultrasonic oscillator 31. The oscillator back panel 33 has a circular shape in plan view and is substantially cylindrical, and is set to be one size smaller than the oscillator front panel 32 in the present embodiment. The drive unit 41 is formed by alternately laminating two piezoelectric elements 42 and two electrode plates 43, and is clamped between the oscillator front panel 32 and the oscillator back panel 33. In addition, the oscillator back panel 33 is formed of a metal material such as aluminum, aluminum alloy, stainless steel, or titanium alloy.

[0025] The piezoelectric element 42 is annular, and the electrode plate 43 is substantially annular with a tab portion in part, so the drive unit 41 has a bolt insertion hole 44 penetrating through its center. Each piezoelectric element 42 is polarized in the thickness direction.

[0026] In addition, the piezoelectric element 42 of the present embodiment is not particularly limited and is formed of a ceramic piezoelectric material containing Pb (lead) such as lead zirconate titanate (PzT). In addition, the piezoelectric element 42 may also be formed of a lead-free ceramic piezoelectric material. Specifically, it may also be formed of a niobium-based ceramic piezoelectric material.

[0027] As Figure 5 , Figure 6 shown, an internal threaded hole 35 extending in the height direction of the oscillator front panel 32 ( Figure 5 , Figure 6 is the vertical direction in this case) is formed at the center of the rear end side of the oscillator front panel 32. This internal threaded hole 35 does not penetrate the oscillator front panel 32. That is, this internal threaded hole 35 only opens at the back of the oscillator front panel 32. On the other hand, at the center of the front end side of the oscillator front panel 32, a bolt insertion hole 56 for inserting the double-headed bolt 15 is provided so as to extend in the height direction.

[0028] The internal threaded hole 35 of the oscillator front panel 32 communicates with the bolt insertion hole 44 of the drive unit 41. On the other hand, a through hole 36 extending in the height direction of the oscillator back plate 33 ( Figure 3 is the vertical direction in this case) is formed at the center of the oscillator back plate 33. The through hole 36 opens at the front and communicates with the bolt insertion hole 44, and also opens at the back. In addition, the oscillator assembly bolt 34 having an external thread formed on its outer peripheral surface is inserted from the side of the oscillator back plate 33, and its front end reaches the internal threaded hole 35 on the side of the oscillator front panel 32 via the through hole 36 and the bolt insertion hole 44. That is, the front end of this oscillator assembly bolt 34 stops in the middle of the oscillator front panel 32 and does not reach the vibration plate 12. This oscillator assembly bolt 34 is screwed into the internal threaded hole 35. Moreover, by screwing the nut 38 onto the protruding portion of the oscillator assembly bolt 34 inserted through the oscillator back plate 33, the oscillator front panel 32, the drive unit 41, and the oscillator back plate 33 are fastened and fixed to each other and integrated. In addition, the metal material forming the oscillator assembly bolt 34 and the nut 38 is arbitrary, but stainless steel is used here.

[0029] A plurality of bolt insertion holes 67 are provided through the connection plate 61, and the plurality of bolts 15 protruding through these bolt insertion holes 67 are screwed into the bolt insertion holes 56 of the oscillator front panel 32. By this screwing, the two ultrasonic oscillators 31 are fastened and fixed to one connection plate 61. In addition, the connection plate 61 may also be fastened and fixed in a state of being sandwiched between the ultrasonic oscillator 31 and the vibration plate 12 by screwing the bolt insertion holes 56 of the oscillator front panel 32 and the stud bolt 15.

[0030] Figure 1Each ultrasonic oscillator 31 of the present embodiment shown in the figure has a longitudinal vibration type bolt-fastening type oscillator with a longitudinal primary vibration mode (monomer resonance frequency: 25 kHz) in which the longitudinal vibration component in the axial direction resonates at λ / 2 (λ: longitudinal vibration wavelength). Each ultrasonic oscillator 31 is an oscillator that vibrates at the same frequency as each other. In addition, as Figure 1 shown, an ultrasonic oscillator 19 is electrically connected to each ultrasonic oscillator 31. The ultrasonic oscillator 19 supplies high-frequency power that causes each ultrasonic oscillator 31 to vibrate continuously. Using this high-frequency power, each ultrasonic oscillator 31 is driven, and ultrasonic waves of 25 kHz (resonance frequency in a state where the ultrasonic oscillator 31 is joined to the vibration plate 12) are irradiated into the cleaning liquid W1 in the cleaning tank 11 from each ultrasonic oscillator 31. In addition, in the present embodiment, the output of the ultrasonic waves is 250 W, but it is not particularly limited thereto and can be arbitrarily set.

[0032] As Figures 1 to 3 、 Figure 5 、 Figure 6 shown, each resonance rod 51 in the present embodiment is a resonator that resonates at the same frequency (monomer resonance frequency: 25 kHz) and longitudinal vibration mode as the ultrasonic oscillator 31. The resonance rod 51 has a circular shape when viewed from above and is substantially cylindrical. The resonance rod 51 in the present embodiment has the same diameter as the maximum diameter of the oscillator front panel 32 and is formed slightly longer than the ultrasonic oscillator 31. A bolt insertion hole 56 for inserting the double-headed bolt 15 is provided at the center of the front end side of the resonance rod 51 so as to extend in the height direction. Moreover, a plurality of double-headed bolts 15 protruding through the insertion hole 67 are screwed into the bolt insertion hole 56 of the resonance rod 51. By this screw connection, one resonance rod 51 is firmly fixed to one connection plate 61. In addition, the resonance rod 51 is formed of a metal material such as aluminum, aluminum alloy, stainless steel, or titanium alloy.

[0033] As Figure 3 、 Figure 4As shown, the connecting plate 61 is a component composed of a flat plate made of metal. The connecting plate 61 in this embodiment has a structure in which three aluminum regular hexagonal plates are arranged and integrally connected in the plane direction. The connecting plate 61 has a plurality of mountain portions 62 and a plurality of valley portions 63 at both side edges. The mountain portions 62 and the valley portions 63 are portions formed in a substantially Japanese hiragana く shape, and are regularly formed at equal intervals. As a result, the connecting plate 61 has three wide portions 64 and two narrow portions 65, and has a structure in which these wide portions 64 and narrow portions 65 are alternately formed. In addition, it can also be understood that the connecting plate 61 has serrated (i.e., linear with an angle formed at a certain interval and folded back and bent in the opposite direction each time) side edges on both sides. In this connecting plate 61, the size of the wide portion 64 is about twice the size of the narrow portion 65. In addition, in the connecting plate 61 of this embodiment, bolt insertion holes 67 through which the double-headed bolts 15 can be inserted are respectively provided at the central portions of the three wide portions 64 (i.e., the central portions of the regular hexagonal plates).

[0034] In addition, the thickness of the connecting plate 61 is not particularly limited and can be arbitrarily set. For example, it is preferably 1 / 200 or more and 1 / 10 or less of the longitudinal vibration wavelength at the driving frequency of the ultrasonic wave. The reason is that if the connecting plate 61 is too thick, it may be difficult to combine the ultrasonic oscillator 31 and the resonance bar 51, and if it is too thin, flexural vibration is likely to occur. In this embodiment, based on the above matters, 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 Figure 3 , Figure 4 shown, adjacent connecting plates 61 are arranged close to each other in different states such that the mountain portions 62 enter the valley portions 63. In addition, a certain gap 66 is ensured between adjacent connecting plates 61. The size of this gap 66 is not limited. For example, it is set to 0.1 mm or more, and preferably set to 0.3 mm or more. If the gap 66 is too narrow, the connecting plates 61 may come into contact with each other when arranged adjacent to each other. In this case, the vibrations of adjacent vibrating body units U1 interfere with each other, and the loss of vibration energy may become large. In addition, the size of the gap 66 is set to, for example, 1 / 8 or less of the longitudinal vibration wavelength at the driving frequency of the ultrasonic wave, preferably 1 / 15 or less, and more preferably 1 / 30 or less. This is because if the gap 66 is too large, flexural vibration is likely to occur, and it is difficult to obtain uniform longitudinal vibration. In this embodiment, based on the above matters, the gap 66 between the connecting plates 61 is set to about 1 mm to 2 mm (i.e., about 1 / 100 to 1 / 50 of the longitudinal vibration wavelength).

[0036] Moreover, the seven vibrating element units U1 in the present embodiment are provided on the non-radiating surface 14 side of the vibrating plate 12 by fastening and fixing the ultrasonic vibrator 31 and the resonance bar 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 element units U1 are arranged in a state where they are offset by half of the pitch between the peak portions 62 or the pitch between the valley portions 63. As a result, the plurality of ultrasonic vibrators 31 belonging to different vibrating element units U1 are arranged in a staggered state along the width direction (the arrangement direction of the vibrating element units U1) of the vibrating element units U1. Similarly, the plurality of resonance bars 51 belonging to different vibrating element units U1 are also arranged in a staggered state along the width direction of the vibrating element units U1.

[0037] The ultrasonic vibrator 31 and the resonance bar 51 constituting the vibrating element unit U1 are formed to be smaller than the diameter of the inscribed circle of the regular hexagon plate constituting the connecting plate 61, and are preferably formed to be 80% or more and less than 100% of the diameter of the inscribed circle of the regular hexagon plate constituting the connecting plate 61. This is because if the sizes of the ultrasonic vibrator 31 and the resonance bar 51 are equal to or larger than the diameter of the inscribed circle, the ultrasonic vibrator 31 and the resonance bar 51 may protrude to the side of the connecting plate 61 and come into contact with the adjacent connecting plate 61. On the contrary, if the sizes of the ultrasonic vibrator 31 and the resonance bar 51 are too small, sufficient ultrasonic vibration cannot be obtained. In view of such a situation, in the present embodiment, the sizes of both the ultrasonic vibrator 31 and the resonance bar 51 are set to about 95% of the diameter of the inscribed circle.

[0038] Figure 8A and Figure 8B are top views for explaining the state in which adjacent connecting plates 61 are arranged close to each other in the vibrating element unit U1 of the embodiment. Figure 9A and Figure 9B are top views for explaining the state in which adjacent connecting plates 61S are arranged close to each other in the vibrating element unit U1 of Comparative Example 1.

[0039] Here, a randomly selected specific vibrating element unit U1 is defined as the "reference unit U1a", and the vibrating element unit U1 adjacent to the specific vibrating element unit U1 is defined as the "adjacent unit U1b". In this case, a linear segment L1 circumscribing two ultrasonic vibrators 31 belonging to the reference unit U1a is envisaged.

[0040] In the embodiment, as described above, the connecting plate 61 has a serrated shape in which a plurality of mountain portions 62 and a plurality of valley portions 63 are formed at the side edge portions, and adjacent connecting plates 61 are in a state where the mountain portion 62 enters the valley portion 63. Therefore, in the embodiment, when the reference unit U1a and the adjacent unit U1b are disposed close to each other through the gap 66, the outer circumferences of the two ultrasonic oscillators 31 and one resonance bar 51 belonging to the adjacent unit U1b are in a crossed state with respect to the line segment L1 (see Figure 8B ). This means that in the embodiment, the ultrasonic oscillators 31 and the resonance bars 51 belonging to the adjacent vibrating body units U1 can be disposed very close to each other.

[0041] On the contrary, in Comparative Example 1, since the connecting plate 61S is rectangular, the side edge portion is a straight line, and there are no mountain portions 62 and valley portions 63. Therefore, even when the reference unit U1a and the adjacent unit U1b are disposed close to each other through the gap 66, the outer circumferences of the two ultrasonic oscillators 31 and one resonance bar 51 belonging to the adjacent unit U1b do not cross with respect to the line segment L1 (see Figure 9B ). This means that in Comparative Example 1, the ultrasonic oscillators 31 and the resonance bars 51 belonging to the adjacent vibrating body units U1 cannot be disposed as close to each other as in the embodiment.

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

[0043] First, the ultrasonic cleaning apparatus 10 is driven, and high-frequency power is supplied from the ultrasonic oscillator 19 to the plurality of ultrasonic oscillators 31, causing each ultrasonic oscillator 31 to vibrate continuously. As a result, ultrasonic waves are irradiated from the ultrasonic oscillators 31 into the cleaning liquid W1. At this time, with the irradiation of the ultrasonic waves, cavitation bubbles are generated in the cleaning liquid W1, and the object to be cleaned 17 is cleaned by the impact of the rupture of these bubbles.

[0044] Next, the evaluation test of the ultrasonic radiation unit 21 and its results will be described.

[0045] In this evaluation test, a measurement sample was prepared as follows. A device identical to the ultrasonic radiation unit 21 of the present embodiment was prepared and used as an example. In addition, the ultrasonic radiation unit 21 of the example is described in the right column of the table in Figure 7 as "(c) BLT + resonance bar + connecting plate connection". In addition, an ultrasonic radiation unit in which the connecting plate 61 was omitted was prepared from the ultrasonic radiation unit 21 of the present embodiment and used as Comparative Example 2. In addition, the ultrasonic radiation unit 21 of Comparative Example 2 is in Figure 7The middle column in the table is recorded as "(b) BLT + resonance bar connection". Furthermore, an ultrasonic radiation unit that omits the connection plate 61 and the resonance bar 51 is prepared from the ultrasonic radiation unit 21 of the present embodiment, and this is used as Comparative Example 3. In addition, the ultrasonic radiation unit 21 of Comparative Example 3 is recorded as "(a) BLT connection" in the left column of the Figure 7 table.

[0046] Next, by analysis using the conventionally well-known finite element method, in the vibration plate 12 of the ultrasonic radiation unit of each measurement sample (Example, Comparative Example 2, Comparative Example 3), the vibration displacement distribution under the water load state was analyzed. In addition, in this analysis, a vibration plate 12 with a length of 390 mm, a width of 240 mm, and a thickness of 2.5 mm was used, and 14 ultrasonic transducers 13 (manufactured by Honda Electronics Co., Ltd., "HEC-45282") with a frequency of 28 kHz (nominal) were mounted on the non-radiating surface 14 of the vibration plate 12 to form an ultrasonic radiation unit. The driving power of each ultrasonic transducer 13 is 600 W.

[0047] As a result, compared with Comparative Example 3, it was confirmed that the non-uniformity of the vibration displacement distribution in Comparative Example 2 decreased, and compared with Comparative Example 2, the non-uniformity of the vibration displacement distribution in the Example decreased. Therefore, regarding the uniformity of the vibration displacement distribution, it was confirmed that the result of "(c) BLT + resonance bar + connection plate connection" was the highest, followed by "(b) BLT + resonance bar connection" being relatively high, and "(a) BLT connection" being the lowest.

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

[0049] (1) The ultrasonic radiation unit 21 of the present embodiment is configured using a plurality of vibrating body units U1 in which two ultrasonic transducers 31 and one resonance bar 51 are mechanically coupled via a connection plate 61. Therefore, due to the resonance phenomenon accompanying the vibration of the ultrasonic transducer 31, the transducer 51 is excited. At this time, since the connection plate 61 functions as a radiation plate of a vibrating body composed of two ultrasonic transducers 31 and the resonance bar 51, uniform longitudinal vibration can be obtained over a relatively wide radiation surface. Moreover, adjacent connection plates 61 are arranged close to each other in a state where the peak portion 62 enters the valley portion 63 in an interlaced manner. Therefore, the ultrasonic transducers 31 and the resonance bar 51 can be arranged sufficiently closely. As a result, the bending vibration generated in the gap 66 between the vibrating body units U1 can be suppressed, the generation of erosion in the vibration plate 12 becomes less, and the vibration plate 12 is less likely to wear, so that the long life of the device can be achieved. In addition, a uniform vibration displacement distribution can be easily obtained, and the generation of cleaning non-uniformity can be reduced. As a result, an excellent ultrasonic cleaning device 10 capable of performing uniform cleaning can be provided.

[0050] In addition, the cylindrical resonator 51 of the present embodiment, which is made of a single material, has a simpler structure than the ultrasonic vibrator 31, which is made of multiple parts, and can therefore be manufactured relatively cheaply. Since the connecting plate 61 of the present embodiment also has a relatively simple structure, it can be manufactured relatively cheaply by sheet metal processing such as punching or laser processing. Therefore, for example, in an ultrasonic radiating unit 21 having a vibration plate 12 that requires a wide cleaning area, instead of configuring a plurality of ultrasonic vibrators 31, by using an inexpensive resonant rod 51 and a connecting plate 61, a device having excellent corrosion resistance and uniformity of vibration displacement distribution can be realized at a low cost.

[0051] (2) In the ultrasonic radiating unit 21 of the present embodiment, the plurality of ultrasonic vibrators 31 and the resonance rods 51 are arranged in a staggered manner along the width direction of the vibrator unit U1. In addition, the outer periphery of the ultrasonic vibrators 31 and the resonance rods 51 belonging to the adjacent unit U1b intersects with the line segment L1 circumscribed to the two ultrasonic vibrators 31 belonging to the reference unit U1a. By adopting these structures, it is relatively easy to arrange the ultrasonic vibrators 31 and the resonance rods 51 closely to each other.

[0052] (3) In the present embodiment, the peaks 62 and the 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 enter the valleys 63, a narrow gap 66 of approximately constant size can be provided between them. Incidentally, in the above-mentioned comparative example 1, since the gap 66 between adjacent vibration body units U1 is linear, it is easy to excite flexural vibration along the linear gap 66. Therefore, depending on the vibration level, there is a concern about the generation of heat and stress damage. Therefore, it is considered necessary to suppress bending vibration in practical application. In contrast, in the present embodiment, since the gap 66 between adjacent vibration body units U1 is nonlinear (sawtooth-shaped) and narrow, unlike comparative example 1, flexural vibration is difficult to be excited. Therefore, there is an advantage that there is no concern about the generation of heat or stress damage.

[0053] (4) Here, for example, Japanese Patent Gazette No. 7171117 discloses an ultrasonic radiating unit composed of a block-shaped base member in which the front side portion of a resonance rod and the front side portion of an ultrasonic vibrator are integrated. Moreover, this ultrasonic radiating unit has the advantages of excellent uniformity of vibration distribution and corrosion resistance. On the other hand, however, the cutting processing cost is relatively high when forming a narrow groove in the base member, resulting in a disadvantage that the manufacturing cost of the device becomes high. In contrast, the connecting plate 61 used in the present embodiment can be manufactured relatively cheaply as described above, and therefore has the advantage of not being associated with the high cost of the device.

[0054] (Second Implementation Method)

[0055] Next, based on Figure 10 The ultrasonic radiation unit 121 of the second embodiment embodying the present invention will be described in detail. In addition, structures different from those of the ultrasonic radiation unit 21 of the first embodiment will be described herein, and for common structures, only the same reference numerals will be given and detailed descriptions will be omitted.

[0056] In the above-described first embodiment, on the non-radiating surface 14 of the diaphragm 12, there is a substantially trapezoidal region R1 (see Figure 2 etc.) that is located on the extension line of the length direction of the vibrating body unit U1 and has no connecting plate 61, but no structure is particularly provided there. In contrast, in the ultrasonic radiation unit 121 of the present embodiment, stud bolts 15 are also protrudingly provided in the region R1. Further, a resonance bar 59 serving as a second resonator is fastened and fixed to these stud bolts 15. In addition, the substantially trapezoidal region R1 has an area approximately half that of the regular hexagonal plate constituting the connecting plate 61. In order to provide the resonance bar 59 in the region R1, the resonance bar 59 is smaller than the resonance bar 51 (first resonator) belonging to the vibrating body unit U1.

[0057] According to the ultrasonic radiation unit 121 having the above-described structure, as in the case of the first embodiment, erosion and cleaning unevenness generated on the diaphragm 12 can be reduced, and it can be manufactured at a relatively low cost. In addition, compared with the case of the above-described first embodiment, unevenness in the vibration displacement distribution in a specific region is less likely to occur, and the vibration displacement distribution can be made more uniform. Incidentally, it is also possible to consider a structure in which the connecting plate 61 is expanded to the substantially trapezoidal region R1 and the resonance bar 59 is provided via the expanded portion. However, if such a structure is adopted, unevenness generated in the vibration displacement distribution in a specific region cannot be sufficiently reduced. Therefore, in the present embodiment, a structure in which the resonance bar 59 is directly provided with respect to the region R1 is intentionally adopted.

[0058] In addition, the above-described embodiment can be modified as follows.

[0059] Each of the vibrating body units U1 in the above-described embodiment includes two ultrasonic oscillators 31 and one resonator 51, and one resonator 51 is disposed between the two ultrasonic oscillators 31, but is not limited thereto. For example, as in Figure 11 、 Figure 12 the oscillator unit 131 of another embodiment shown, it may include three ultrasonic oscillators 31 and two resonators 51, and one resonator 51 is disposed between the two ultrasonic oscillators 31.

[0060] In the above-described embodiment, the resonance rod 51, which has a circular shape in plan view and is substantially cylindrical, is used to form the vibrating body unit U1, but it is not limited thereto. For example, of course, a resonance rod having a rectangular shape in plan view and being substantially prismatic may be used to form the vibrating body unit U1.

[0061] In the above-described embodiment, the connecting plate 61 having both side edges with a sawtooth shape is used to form the vibrating body unit U1 by forming a plurality of mountain portions 62 each having a substantially Japanese hiragana く shape and a plurality of valley portions 63 each having a substantially Japanese hiragana く shape, but it is not limited thereto. For example, as Figure 13A , Figure 13B shown in the vibrating body unit U1 of another embodiment, the vibrating body unit U1 may be formed by forming a plurality of mountain portions 62 and a plurality of valley portions 63 into an arc shape and using a connecting plate 61A having both side edges with a wavy line shape formed by a gentle curve. Even in this case, adjacent connecting plates 61A, 61A can be arranged very close to each other with the mountain portion 62 entering the valley portion 63. Alternatively, a connecting plate 61B having a shape like that of the vibrating body unit U1 of other embodiments shown in Figure 14A , Figure 14B may be used to form the vibrating body unit U1. Similarly, even in this case, adjacent connecting plates 61B, 61B can be arranged very close to each other with the mountain portion 62 entering the valley portion 63.

[0062] In the above-described embodiment, the double-headed bolt 15, which is a bolt without a head, is used as the bolt protruding from the non-radiating surface 14 of the vibrating plate 12. However, a bolt with a head such as a hexagon bolt, a hexagon bolt with a hole, or a wing bolt may also be used as the bolt protruding from the non-radiating surface 14.

[0063] In the above-described embodiment, the vibrating plate type ultrasonic radiation units 21, 121, 131 are used by being installed via a seal 1 at the bottom of the cleaning tank 11 of the ultrasonic cleaning device 10, but it is not limited thereto. For example, the ultrasonic radiation units 21, 121, 131 may also be of the cleaning tank type installed with respect to stud bolts protruding from the non-radiating surface of the bottom plate of the cleaning tank 11. Alternatively, the ultrasonic radiation units 21, 121, 131 may also be of the type that is put into the cleaning liquid W1 in the cleaning tank 11 for use.

[0064] The ultrasonic radiation units 21, 121, and 131 of the above-described embodiments are applicable to the ultrasonic cleaning device 10 that uses ultrasonic waves for cleaning. However, in addition to cleaning, they can also be applicable to devices that perform processes such as extraction, emulsification, dispersion, mixing, stirring, crushing, and atomization. Specifically, for example, when the ultrasonic radiation unit is applied to an ultrasonic emulsification device, the emulsion can be efficiently refined into nanoparticles, and effects such as long-term stabilization and surfactant reduction can be expected. In addition, when the ultrasonic radiation unit is applied to an ultrasonic dispersion device, nanoparticles (such as metal nanoparticles, carbon nanotubes, ceramic nanoparticles, and magnetic nanoparticles) can be efficiently dispersed. Furthermore, the ultrasonic radiation unit can be embodied as an ultrasonic treatment device that utilizes chemical action. In this case, since cavitation can be generated uniformly and efficiently over a wide range, the amount of free radicals such as OH radicals generated in the high-temperature and high-pressure field when the bubbles are crushed can be increased. Therefore, the reaction efficiency of chemical reactions caused by free radical species can be improved, and processes such as decomposition and detoxification of harmful substances, sterilization, and polymer polymerization can be efficiently performed.

[0065] In addition, in addition to the technical ideas described in the claims, the following technical ideas grasped from the above-described embodiments are listed.

[0066] (1) As described in Technical Solution 1 and the like, the vibration plate and the connection plate are joined in surface contact with an adhesive, and the ultrasonic oscillator, the resonator, and the connection plate are joined in surface contact with the adhesive. (2) The resonator according to Technical Solution 1, wherein the ultrasonic oscillator is a longitudinal vibration type oscillator that vibrates in a longitudinal vibration mode, and the resonator is a resonator that resonates at the same frequency and longitudinal vibration mode as the ultrasonic oscillator. (3) The ultrasonic oscillator and the resonator according to Technical Solution 1 and the like are smaller than the diameter of the inscribed circle of the regular hexagonal plate constituting the connection plate. (4) The ultrasonic oscillator and the resonator according to Technical Solution 1 and the like are 80% or more and less than 100% of the diameter of the inscribed circle of the regular hexagonal plate constituting the connection plate. (5) The vibrating body unit according to Technical Solution 1, wherein one resonator is disposed between two ultrasonic oscillators in one vibrating body unit. (6) The resonance bar according to Technical Solution 1, wherein the resonance bar is a resonance bar that is longer than the ultrasonic oscillator. (7) As described in Technical Solution 1 and the like, on the extension line in the length direction of the vibrating body unit, the bolt is protrudingly provided in a region without the connection plate, and a small-diameter resonator is fixedly fastened to the bolt. Explanation of Reference Numerals

[0067] 12…Vibrating plate 13…Radiating surface 14…Non-radiating surface 15…Stud bolt as a bolt 21, 121, 131…Ultrasonic radiation unit 31…Ultrasonic oscillator 51…Resonance rod as (first) resonator 59…Resonance rod as second resonator 54…Bolt insertion through-hole 61, 61A, 61B…Connecting plate 62…Mountain part 63…Valley part 64…Wide part 65…Narrow part 66…Gap 67…Bolt insertion through-hole L1…Line segment t1…Connecting plate thickness U1…Vibrating body unit U1a…Reference unit U1b…Adjacent unit

Claims

1. An ultrasonic radiating unit, characterized in that: It has a vibration plate and a plurality of vibration body units. The vibration plate has a radiation surface for radiating ultrasonic waves, a non-radiation surface located on the opposite side of the radiation surface, and a plurality of bolts protruding from the non-radiation surface; The plurality of vibrating body units are constituted in the form of a plurality of ultrasonic vibrators, a resonator arranged between the plurality of ultrasonic vibrators, and a connecting plate that mechanically combines the plurality of ultrasonic vibrators and the resonator to transmit the vibrations of the plurality of ultrasonic vibrators to the resonator; The connecting plate has a plurality of wide width portions and narrow width portions alternately formed by having mountain portions and valley portions at both side edges, and a plurality of bolt insertion holes through which the bolts can be inserted are respectively provided at the center of the plurality of wide width portions; The adjacent connecting plates are arranged close to each other in an alternating manner so that the peaks enter the valleys; the plurality of ultrasonic vibrators and the resonators are fastened to the plurality of bolts protruding through the plurality of bolt insertion holes of the connecting plates, and the plurality of vibration body units are arranged on the non-radiating surface side.

2. The ultrasonic radiating unit according to claim 1, characterized in that: The plurality of ultrasonic vibrators and the resonators are arranged in a zigzag pattern along the width direction of the vibrator unit.

3. The ultrasonic radiating unit according to claim 2, characterized in that: When a specific vibrator unit is taken as a reference unit and the vibrator unit adjacent to the specific vibrator unit is taken as an adjacent unit, when a line segment circumscribed to the plurality of ultrasonic vibrators belonging to the reference unit is envisioned, the peripheries of the ultrasonic vibrators and the resonators belonging to the adjacent unit intersect with respect to the line segment.

4. The ultrasonic radiating unit according to claim 3, characterized in that: The mountain portions and the valley portions are regularly formed at equal intervals.

5. The ultrasonic radiating unit according to any one of claims 1 to 4, characterized in that: The connection plate has a structure in which a plurality of regular hexagonal plates are arranged in a plane direction and connected to form an integral whole.

6. The ultrasonic radiating unit according to any one of claims 1 to 4, characterized in that: The adjacent connecting plates are arranged closely to each other with a gap of not less than 0.1 mm and not more than 1 / 8 of the longitudinal vibration wavelength therebetween.

7. The ultrasonic radiating unit according to any one of claims 1 to 4, characterized in that: 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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