Horn-type ultrasonic cleaning device

Abstract

To provide a horn-type ultrasonic cleaning device capable of performing cleaning at different frequencies using a single horn.SOLUTION: In a horn-type ultrasonic cleaning device 1, when the frequency of vibrations whose maximum amplitude value line L1 extending along the Y direction is the center in the X direction on the XY plane is defined as a fundamental frequency f, output vibrations of first ultrasonic transducers 5 and second ultrasonic transducers 7, 17 are vibrations at frequencies f×n1 and f×n2, which are different integer multiples of the fundamental frequency f Hz. The first ultrasonic transducers are positioned on a maximum amplitude value line corresponding to the frequency f×n1, while the second ultrasonic transducers are positioned on a maximum amplitude value line corresponding to the frequency f×n2.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a horn type ultrasonic cleaning device. [Background technology]

[0002] An example of an ultrasonic cleaning device is disclosed in Patent Document 1. This device includes a cleaning tank in which the object to be cleaned is accommodated and liquid is stored, multiple ultrasonic vibration plates provided in the lower part of the cleaning tank, an ultrasonic oscillator for vibrating the ultrasonic vibration plates, and a control means for controlling the ultrasonic oscillator to ultrasonically clean the object to be cleaned. The multiple ultrasonic vibration plates are fixed to the wall that constitutes the cleaning tank.

[0003] In ultrasonic cleaning equipment using ultrasonic vibration plates, the vibration plate is fixed to the wall by adhesive or stud welding, so there is a problem that it cannot output large amplitude and power due to durability issues. Also, in order to vibrate the entire liquid in the cleaning tank, a considerable oscillator area (number of oscillators) is required compared to the plate area, and if the oscillator area is small, there is a problem that it is not possible to cause resonance of the medium. Furthermore, there is a problem that cleaning small workpieces in a large cleaning tank is inefficient in terms of input power.

[0004] In addition to the above, there is a horn-type ultrasonic cleaning device that does not rely on the resonance of the liquid and is not easily affected by the depth of the liquid in the cleaning tank or the shape of the cleaning tank. In this device, an ultrasonic horn that vibrates with an ultrasonic vibrator is immersed in the liquid in the cleaning tank to clean the workpieces in the cleaning tank. Horn-type ultrasonic cleaning devices use a large amplitude to enable powerful cleaning.

[0005] In actual cleaning sites, there are times when multiple stages of cleaning are applied to the workpiece. For example, rough cleaning is performed first to remove large dirt, followed by precision cleaning to remove small dirt. In this case, in horn-type ultrasonic cleaning devices, the frequency of the horn used is fixed and assigned to each horn, so that multiple stages of cleaning with different frequencies are performed by transferring the workpiece to multiple devices in sequence. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2019-217480 A Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made in view of the above, and has an object to provide a horn-type ultrasonic cleaning device that is capable of performing cleaning at different frequencies with a single horn. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, the present invention provides a horn-type ultrasonic cleaning device comprising an ultrasonic horn, a first ultrasonic vibrator and a second ultrasonic vibrator which apply vibrations to the ultrasonic horn, and an ultrasonic oscillator connected to the first ultrasonic vibrator and the second ultrasonic vibrator, the ultrasonic horn being a rectangular parallelepiped along three orthogonal axes, the XYZ axes being the vibration input and output surfaces, and the Z direction being the vibration transmission direction, the output vibrations of the first ultrasonic vibrator and the second ultrasonic vibrator being vibrations of different integer multiples of the fundamental frequency f Hz, where f is the frequency of vibration whose center in the X direction on the XY plane is the maximum amplitude line L1 extending along the Y direction, the first ultrasonic vibrator being disposed on the maximum amplitude line for the frequency f×n1 on the XY plane, and the second ultrasonic vibrator being disposed on the maximum amplitude line for the frequency f×n2 on the XY plane. Effect of the Invention

[0009] According to the present invention, cleaning at different frequencies can be performed with one horn. [Brief description of the drawings]

[0010] [Figure 1] 1 is an overall view of a horn-type ultrasonic cleaning device according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram showing an arrangement of a plurality of ultrasonic transducers in an ultrasonic horn according to the first embodiment. [Diagram 3] FIG. 2 is a perspective view showing a vibration mode of an ultrasonic horn according to the first embodiment. [Figure 4] FIG. 2 is a side view showing the vibration mode of the ultrasonic horn from the ZX end face direction in accordance with the first embodiment. [Diagram 5] FIG. 4 is a diagram showing the relationship between the vibration mode of the ultrasonic horn and the maximum amplitude value line in the first embodiment. [Figure 6] FIG. 11 is a diagram illustrating an arrangement of a plurality of ultrasonic transducers in an ultrasonic horn according to a second embodiment of the present invention. [Figure 7] FIG. 1 illustrates vibration modes for a modified shape of an ultrasonic horn. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of a horn-type ultrasonic cleaning device according to the present invention and a related method for installing a transducer (a method for determining an installation position) will be described with reference to the accompanying drawings. In the drawings, the same reference numerals indicate the same or corresponding parts.

[0012] Fig. 1 is an overall view of a horn-type ultrasonic cleaning device according to embodiment 1 of the present invention, and Fig. 2 is a diagram showing the arrangement of multiple ultrasonic transducers in an ultrasonic horn in this embodiment 1. In the figure, three mutually orthogonal axes, XYZ, indicate directions corresponding to Figs. 1 to 7.

[0013] The horn type ultrasonic cleaning device 1 according to the first embodiment includes an ultrasonic horn 3, a first ultrasonic transducer 5, a second ultrasonic transducer 7, and an ultrasonic oscillator 9. The first ultrasonic transducer 5 and the second ultrasonic transducer 7 are attached to the upper surface (one of the XY planes) of the ultrasonic horn 3. The first ultrasonic transducer 5 and the second ultrasonic transducer 7 are connected to the ultrasonic oscillator 9 by a connection line 11. As a more specific example, the first ultrasonic transducer 5 and the second ultrasonic transducer 7 are each a Langevin type transducer.

[0014] The ultrasonic horn 3 is a rectangular parallelepiped along three orthogonal axes, the XYZ axes. One XY surface of this rectangular parallelepiped (the upper surface in the figure) is a vibration input surface 21, and the other XY surface (the lower surface in the figure) is a vibration output surface 23. In addition, this rectangular parallelepiped has a vibration transmission direction in the Z direction (from top to bottom).

[0015] The overall length of the ultrasonic horn is adjusted to the resonant frequency of the transducer used, and the horn itself is designed to have the same resonant frequency. Due to the relationship between transverse waves and Poisson's ratio, when the size of the transverse direction (X direction) perpendicular to the vibration (longitudinal vibration in the Z direction) exceeds half the wavelength of the transverse sound velocity, the horn is affected by the resonance of the transverse waves and exhibits complex vibrations. In order to avoid the effects of transverse vibration, it is common to provide vertical grooves (slots, i.e. through holes or recesses) along the direction of transmission of the vertical vibration, and since the position, length, etc. have a subtle effect, it is now common to verify this with FEA analysis (Finite Element Analysis). In addition, the horn is designed to be completely free of the effects of transverse waves in the longitudinal direction (Y direction) by making the cross section of the horn in one direction in the longitudinal vibration transmission direction (Z direction) square. There are no length restrictions on the horn in the longitudinal direction, and no vertical groove processing is required inside.

[0016] When vibration is applied to the ultrasonic horn 3, there is a vibration in which the line obtained by extending the center of the X direction in the XY plane along the Y direction is the maximum amplitude line L1. If the frequency of this vibration is the fundamental frequency f (Hz) and the sound speed in metal for the metal constituting the ultrasonic horn 3 is C (m / s), one wavelength λ is C / f (m). The ZX end face of the ultrasonic horn 3 is a square, and the dimensions in the Z direction and the dimensions in the X direction are each λ / 2 (m). In this embodiment, the ZX end face of the ultrasonic horn 3 is a square of the smallest unit with one side length of λ / 2 (m), but the present invention is not limited to this, and any side of the square may be an integer multiple of λ / 2 (m).

[0017] In short, the multiple transducers in the present invention are arranged on the respective maximum amplitude value lines on the vibration input surface, which is the XY plane (top surface in the figure) of the ultrasonic horn. The output vibrations of the multiple transducers are vibrations with frequencies that are different integer multiples of the fundamental frequency f Hz, assuming that the line extending from the center in the X direction on the XY plane along the Y direction is the maximum amplitude value line L1, and the frequency of such vibration is the fundamental frequency f. These will be described with reference to Figs. 3, 4, and 5.

[0018] Fig. 3 is a perspective view showing the vibration mode of the ultrasonic horn in accordance with the present embodiment 1. Fig. 4 is a side view showing the vibration mode of the ultrasonic horn from the ZX end face direction in accordance with the present embodiment 1. Fig. 5 is a diagram showing the relationship between the vibration mode of the ultrasonic horn and the maximum amplitude value line in accordance with the present embodiment 1.

[0019] When vibrations of 0.5 wavelength of frequency f (Hz), which is 1 times the fundamental frequency f (Hz), vibrations of 1.0 wavelength of frequency 2f (Hz), which is twice the fundamental frequency f (Hz), and vibrations of 1.5 wavelength of frequency 3f (Hz), which is 3 times the fundamental frequency f (Hz), are applied to ultrasonic horns 31, 32, and 33 of the same size and shape in a state where vibrations are not applied, the vibration modes are as shown in Figures 3 and 4 according to the finite element method. Note that the deformations shown in the figures are exaggerated to prioritize understanding from the figures, and in reality, the displacements in the X and Z directions are on the order of several microns to several tens of microns.

[0020] For example, in a vibration mode of 0.5 wavelengths (λ / 2(m)) of frequency f(Hz), which is one time the fundamental frequency f(Hz), the central part in the X direction on the XY plane shows the maximum repetition of convex and concave deformations, that is, this part shows the maximum amplitude. If we consider the Y direction as well, as shown in FIG. 5, in a vibration mode of 0.5 wavelengths (λ / 2(m)) of frequency f(Hz), which is one time the fundamental frequency f(Hz), a maximum amplitude line L1 appears extending from the center of the X direction on the XY plane along the Y direction. Similarly, in a vibration mode of 1.0 wavelengths of frequency 2f(Hz), which is twice the fundamental frequency f(Hz), two maximum amplitude lines L2 appear on the XY plane as the part showing the maximum repetition of convex and concave deformations, and further, in a vibration of 1.5 wavelengths of frequency 3f(Hz), which is three times the fundamental frequency f(Hz), three maximum amplitude lines L3 appear on the XY plane. The maximum amplitude value line is the part that shows the maximum repeated convex and concave deformation in that vibration mode. Also, in Fig. 5, the solid line and the dotted line of the maximum amplitude value line show that they are in opposite phase to each other. If the positive phase and the negative phase are used simultaneously, they are controlled by the ultrasonic oscillator 9.

[0021] In the present invention, multiple transducers are pre-assigned to apply vibrations of any of different integer multiples of the fundamental frequency fHz to the ultrasonic horn, and each transducer is positioned on a maximum amplitude line corresponding to its assigned integer multiple frequency.

[0022] Specifically, in the first embodiment, the first ultrasonic transducer 5 and the second ultrasonic transducer 7 are used to apply vibrations of a frequency f (Hz) that is one time the fundamental frequency f (Hz) and vibrations of a frequency 2f (Hz) that is twice the fundamental frequency f (Hz) to the ultrasonic horn 3. The combination of f (Hz) and 2f (Hz) may be a combination of 20 (kHz) and 40 (kHz), or a combination of 30 (kHz) and 60 (kHz). As shown in Figs. 2 and 5, the first ultrasonic transducer 5 is disposed on the first maximum amplitude line L1 on the XY plane, and the second ultrasonic transducer 7 is disposed on the second maximum amplitude line L2 on the XY plane.

[0023] In the horn type ultrasonic cleaning device 1 configured as above, two ultrasonic transducers, a first ultrasonic transducer 5 and a second ultrasonic transducer 7, which apply vibrations of different frequencies to one ultrasonic horn 3, are mounted, and the ultrasonic horn 3 is immersed in liquid in a cleaning tank (not shown). The workpiece to be cleaned is placed in the liquid in the cleaning tank. For example, first, only the first ultrasonic transducer 5 is driven to perform the first cleaning, and then only the second ultrasonic transducer 7 is driven to perform the second cleaning.

[0024] According to the horn type ultrasonic cleaning device of the present embodiment, cleaning with different cavitation sizes (cleaning with different vibration frequencies) can be performed with one ultrasonic horn while the workpiece is set in one cleaning tank, without transferring the workpiece from one cleaning tank to another, or without inserting, using, and removing one ultrasonic horn (ultrasonic vibrator) into one cleaning tank and then inserting and using another ultrasonic horn (ultrasonic vibrator). Therefore, with one ultrasonic horn while the workpiece is set in one cleaning tank, cleaning can be performed to remove large dirt first, and then precision cleaning can be performed to remove small dirt by increasing the frequency and reducing the cavitation size. At that time, since the driving point of the ultrasonic horn is located on the maximum amplitude value line of the vibration mode, the vibration of each frequency is utilized with high efficiency. In addition, since it is a horn type ultrasonic cleaning, unlike the vibrator plate type, it does not use the resonance of the liquid, and compared to the vibrator plate type, it can produce a large amplitude and generate strong cavitation in a specific area, thereby performing efficient cleaning. In other words, it is possible to perform cleaning with strong cavitation in a specific area, and at the same time, it is possible to perform cleaning with different frequencies with a single horn. Furthermore, the ultrasonic horn of this embodiment has the advantage that there is no restriction on the length in the longitudinal direction, and no longitudinal groove processing is required inside.

[0025] The contents of the present invention have been specifically described above with reference to preferred embodiments. However, it is obvious that a person skilled in the art can adopt various modifications based on the basic technical concept and teachings of the present invention.

[0026] For example, in the present invention, the multiple transducers may be assigned to apply vibrations of different integer multiples of the fundamental frequency fHz to the ultrasonic horn, and are not limited to the assignment of vibrations of frequency f(Hz) which is 1x (n1=1) the fundamental frequency f(Hz) and frequency 2f(Hz) which is 2x (n2=2). Therefore, as another example, as shown in FIG. 6, in the second embodiment, a first ultrasonic transducer 5 and a second ultrasonic transducer 17 are applied to the ultrasonic horn 3 to obtain vibrations of frequency f(Hz) which is 1x (n1=1) the fundamental frequency f(Hz) and frequency 3f(Hz) which is 3x (n2=3). As a combination of f(Hz) and 3f(Hz), a combination of 20(kHz) and 60(kHz) can be given. 2 and 6, the first ultrasonic transducer 5 is disposed on the first maximum amplitude line L1 on the XY plane, and the second ultrasonic transducer 17 is disposed on the third maximum amplitude line L3 (which ultimately overlaps with the first maximum amplitude line L1) on the XY plane. In this configuration, the first ultrasonic transducer 5 and the second ultrasonic transducer 17 are disposed symmetrically with respect to the first maximum amplitude line L1 and the third maximum amplitude line L3, which are on the same line in a plan view.

[0027] It is also possible to use an ultrasonic horn in which the ZX end face has two consecutive squares in the X direction, the minimum unit with a side length of λ / 2 (m), as shown in Fig. 7. This is a ZX end face with an X direction dimension of one wavelength λ and a Z direction dimension of 0.5 wavelength λ / 2, and the vibration modes due to vibration at a frequency f (Hz) that is 1 time the fundamental frequency f (Hz), vibration at a frequency 2f (Hz) that is twice the fundamental frequency f (Hz), and vibration at a frequency 3f (Hz) that is 3 times the fundamental frequency f (Hz) are as shown in Fig. 7. From these vibration modes, maximum amplitude value lines for vibration at each frequency are also obtained, and each ultrasonic transducer is positioned on the corresponding maximum amplitude value line. [Explanation of symbols]

[0028] 1 Horn type ultrasonic cleaning device 3 Ultrasonic Horn 5 First ultrasonic transducer 7, 17 Second ultrasonic transducer 9. Ultrasonic Oscillator 11 Connecting wire 21 Vibration input surface 23 Vibration output surface

Claims

1. An ultrasonic horn; a first ultrasonic transducer and a second ultrasonic transducer that apply vibrations to the ultrasonic horn; an ultrasonic oscillator connected to the first ultrasonic transducer and the second ultrasonic transducer; The ultrasonic horn is a rectangular parallelepiped along three orthogonal axes, that is, an XYZ axis, the XY plane being a vibration input plane and a vibration output plane, and the Z direction being a vibration transmission direction. The output vibrations of the first ultrasonic transducer and the second ultrasonic transducer are vibrations having frequencies f×n1 and f×n2 that are different integer multiples of the fundamental frequency f Hz, where f is the frequency of the vibration whose center in the X direction on the XY plane is the maximum amplitude value line L1 extending along the Y direction, and The first ultrasonic transducer is disposed on a maximum amplitude line for the frequency f×n1 on the XY plane, The second ultrasonic transducer is disposed on a maximum amplitude line for the frequency f×n2 on the XY plane. Horn type ultrasonic cleaning device.

2. The frequency f×n1 is 1 times the fundamental frequency f, and is the fundamental frequency f itself. The frequency f×n2 is two or three times the fundamental frequency f; 2. The horn type ultrasonic cleaning device according to claim 1.

3. The first ultrasonic transducer and the second ultrasonic transducer are arranged, in a plan view, to be line-symmetric with respect to the maximum amplitude value line L1.

2. The horn type ultrasonic cleaning device according to claim 1.

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