JPH043667Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to an ultrasonic cleaning machine capable of cleaning using high frequency oscillation of 100kHz or more.

(Prior Art) As is well known, an ultrasonic cleaning machine includes a cleaning tank containing a cleaning liquid, an ultrasonic diaphragm disposed at the bottom of the cleaning tank, and an ultrasonic diaphragm that excites the ultrasonic diaphragm. It has an ultrasonic oscillator.

The ultrasonic diaphragm generally consists of an ultrasonic vibrator bonded and fixed to a stainless steel vibrating substrate. Normally, the thickness of the vibrating substrate in the ultrasonic diaphragm is very small (approximately 1/100 or less ).

In addition, in general, in order to cause an ultrasonic diaphragm to resonate and vibrate efficiently, it is required that the length of one side of the oscillating substrate, which is a rectangle or square, be equal to or less than 1/4 wavelength of the resonant frequency. There is.

A drive oscillation signal of a single frequency is applied from an ultrasonic oscillator to the ultrasonic diaphragm (ultrasonic vibrator) configured in this way, and the ultrasonic waves generated by the ultrasonic diaphragm are directed toward the object to be cleaned in the cleaning liquid. The object to be cleaned has been cleaned by irradiation.

(Problem to be solved by the invention) However, in the above-mentioned conventional ultrasonic cleaner, when the frequency of the drive oscillation signal is set to a high frequency of 100kHz or more, the vibrating substrate becomes extremely thin. At 1MHz, the plate thickness is
It will be less than 0.1mm. If the plate thickness becomes thinner like this,
The mechanical strength of the ultrasonic diaphragm becomes weak, and when the ultrasonic diaphragm is attached to the bottom of the cleaning tank, the ultrasonic diaphragm may be deformed due to the liquid pressure.
There is a problem that the ultrasonic vibrator bonded to the vibrating substrate may peel off, or in the worst case, the ultrasonic vibrating plate may be torn. Further, when the thickness of the vibrating substrate becomes thinner, the vibrating substrate becomes easily deformed when an ultrasonic transducer is bonded to the vibrating substrate, and therefore, there is a problem in that the bonding work becomes difficult to perform.

Of course, in order to increase the mechanical strength of the ultrasonic diaphragm, it is possible to take measures such as reinforcing it or reducing the area of the ultrasonic diaphragm. There is a problem that vibration unevenness occurs between the two, and if the area of the ultrasonic diaphragm is reduced, new problems occur such as a reduction in the vibration energy transmitted to the cleaning liquid.

Further, when a conventional ultrasonic diaphragm is driven at a high frequency of 100 kHz or more, it is not practical to make the length of one side of the ultrasonic diaphragm less than 1/4 wavelength.

For this reason, the length of one side is usually set to 1/4 wavelength or more, but this poses a problem, especially in the case of thick plates, because the attenuation of resonance vibration becomes large, making it impossible to achieve efficient ultrasonic vibration.

Furthermore, in conventional devices, the ultrasonic diaphragm is vibrated by a drive oscillation signal of a single frequency, so there is a problem that it cannot handle many types of dirt on the object to be cleaned, and its uses are limited. Ta.

This invention was made to solve the above-mentioned conventional problems, and its purpose is to increase mechanical strength and efficiently generate even vibration energy despite the high drive frequency specifications. An object of the present invention is to provide an ultrasonic cleaning machine that can generate and clean many types of dirt.

(Means for solving the problems) In order to achieve the above object, the present invention is constructed as follows. That is, the present invention provides an ultrasonic cleaning machine comprising: an ultrasonic oscillator that outputs a driving oscillation signal; and an ultrasonic diaphragm that receives the driving oscillation signal and irradiates ultrasonic waves into a cleaning liquid in a cleaning tank. , the ultrasonic oscillator is an ultrasonic oscillator capable of outputting a drive oscillation signal of either the fundamental frequency or an odd multiple frequency thereof, and the ultrasonic diaphragm has at least one side length at a resonant frequency in the plate thickness direction. The ultrasonic cleaner has a wavelength of 1/4 wavelength or more, and a plate thickness that is an integral multiple of approximately 1/2 wavelength of the resonant frequency.

(Function) In the present invention having the above configuration, when the ultrasonic vibrator is excited by a multi-frequency oscillator, the thickness of the ultrasonic diaphragm is formed to be an integral multiple of approximately 1/2 wavelength of the resonant frequency. Therefore, even if the thickness of the ultrasonic diaphragm increases, the ultrasonic diaphragm vibrates almost at its own resonant frequency.

Furthermore, even if the length of one side of the ultrasonic diaphragm is increased to 1/4 wavelength or more of the resonant frequency, the ultrasonic diaphragm vibrates at approximately the resonant frequency as described above, so the ultrasonic diaphragm vibrated by the drive frequency signal There is almost no phase difference between the vibration waves of each part of the sonic diaphragm.

In this way, in the ultrasonic diaphragm of the present invention, even if the driving frequency is increased, there is no need to reduce the plate thickness accordingly, so it is possible to maintain a constant mechanical strength, and the efficiency due to high frequency is improved. It becomes possible to generate vibrational energy.

Then, excite the ultrasonic diaphragm at the fundamental frequency (the smallest frequency among the resonant frequencies) as necessary.
Since the frequency can be appropriately switched to a desired odd multiple frequency, it is possible to effectively clean various stains on the object to be cleaned.

(Example) Hereinafter, an example of the present invention will be described based on the drawings. Figure 1 shows the first ultrasonic cleaning machine according to the present invention.
A mechanical block diagram showing the embodiment is shown, and FIG. 2 shows a block diagram common to each embodiment.

In the figure, an opening 4 is provided in the bottom plate 3 of a cleaning tank 2 that accommodates a cleaning liquid 1, and an ultrasonic diaphragm 6, which is characteristic of this embodiment, is connected to a bolt 7 through a gasket 5 in this opening. The opening 4 is hermetically closed.

The ultrasonic diaphragm 6 has an ultrasonic vibrator 9 fixed to a vibrating substrate 8 with an adhesive 10,
A driving oscillation signal is applied from a multi-frequency oscillator 11 to the ultrasonic vibrator 9, and based on the excitation of the ultrasonic vibrator 9, ultrasonic waves are irradiated from the ultrasonic diaphragm 6 into the cleaning liquid 1. There is.

Incidentally, the thickness t of the vibrating substrate 8 of the characteristic ultrasonic diaphragm 6, that is, the ultrasonic diaphragm 6, is set to be an integral multiple of the 1/2 wavelength of the approximate driving frequency (frequency of the driving oscillation signal).

That is, t = 1/2λN where λ: wavelength N: integer In this case, since the driving frequency is made to match the resonant frequency of the vibration (longitudinal vibration) in the thickness direction of the ultrasonic diaphragm 6, the plate thickness t is set at the resonance frequency. It is an integral multiple of 1/2 wavelength of the frequency.

For example, in the case of the vibrating substrate 8, the sound speed of ultrasonic waves propagating through the vibrating substrate 8 is 5100 (m/s), so if the driving frequency is 1MHz, the 1/2 wavelength is 2.55 m/s.
mm, so the plate thickness t should be an integral multiple of that.

By setting the plate thickness like this, this can be
When driven at 1 MHz, the vibrating substrate 8 resonates, so the acoustic loss is smaller than when using a conventional vibrating substrate with a thickness of about 1/100 of the wavelength, that is, 50 μm.

Furthermore, even when the driving frequency is high, there is no need to make the plate thickness extremely thin, so it is possible to design the plate to have strong mechanical strength. The adhesion work becomes easier, and the conventional problem of deformation of the ultrasonic diaphragm 6 due to the hydraulic pressure of the cleaning liquid is completely eliminated.

Further, when the shape of the vibrating substrate 8 in this embodiment is a square, the length of at least one side is set to be equal to or more than 1/4 wavelength of the resonance frequency (drive frequency). On the other hand, when the thin plate 2 is shaped like a disk, its diameter is formed to be equal to or larger than 1/4 wavelength.

In the case of this embodiment, since the plate thickness is formed to be an integral multiple of 1/2 wavelength of the resonant frequency as described above, resonant vibration can occur even if the length of at least one side of the vibrating substrate 8 is 1/4 wavelength or more. Therefore, there is almost no phase shift in the vibration waves in each part of the ultrasonic diaphragm 6, and as a result, it is possible to generate efficient and uniform ultrasonic vibrations from the ultrasonic diaphragm 6 over the entire surface. becomes.

Therefore, according to the ultrasonic diaphragm 6 of this embodiment, it is possible to generate high-energy ultrasonic waves with a high frequency of 100 kHz or more, which was difficult in the conventional example, and thereby, the influence of lateral vibration can be suppressed. It is possible to exhibit an excellent cleaning effect with almost no damage.

By the way, the multi-frequency oscillator 11 in this embodiment
is an oscillation circuit that oscillates the fundamental frequency (the smallest frequency among the resonant frequencies) ₀ , and the fundamental frequency _0.
It has an oscillation circuit that oscillates a desired odd multiple frequency m ₀ (m is an odd number of 3 or more), and switches the frequency of the drive oscillation signal output from the multi-frequency oscillator 11 manually or automatically by a desired method. configured to be possible. Therefore, by switching the frequency of the drive oscillation signal, the object to be cleaned (not shown) in the cleaning liquid 1 is irradiated with ultrasonic waves of different frequencies, thereby causing various effects on the object to be cleaned. Even if dirt is attached, it can be efficiently cleaned. In this case, it is conceivable to irradiate the cleaning liquid 1 with a frequency that is an even number multiple of the fundamental frequency ₀ , but in that case, harmonic components will have an adverse effect on the cleaning effect, so this is not preferable.

In the case of the odd multiple frequency, there is no adverse effect of harmonic components and an excellent cleaning effect can be obtained.

FIG. 3 shows the configuration of a second embodiment of the present invention. The difference between the second embodiment and the first embodiment is that an ultrasonic transducer 9 is directly adhesively fixed to the bottom plate 3 of the cleaning tank 2 without providing an opening in the bottom plate 3. . In the second embodiment, the bottom plate 3 also serves as the vibration substrate 8, and therefore the bottom plate 3 at the fixed part of the ultrasonic transducer 9
The plate thickness is formed to be an integral multiple of 1/2 wavelength of the resonant frequency, and the length of at least one side of the plate thickness is formed to be 1/4 wavelength or more of the resonant frequency.

In this way, by using the bottom plate 3 as the vibrating substrate 8 having the dimensions and shape described above, it is possible to achieve effective ultrasonic cleaning using a high-frequency drive oscillation signal, similar to the first embodiment.

FIG. 4 shows the configuration of a third embodiment of the present invention. The third embodiment relates to a so-called immersion type ultrasonic cleaner, in which a vibrating box 12 is inserted into a cleaning liquid 1 in a cleaning tank 2.

The vibration box 12 includes an airtight hollow box body 13, and an upper plate 13a of the hollow box body 13 from the inside of the hollow box body 13.
The ultrasonic transducer 9 is adhesively fixed to the ultrasonic transducer 9.

A cable introduction pipe 14 is airtightly connected to the side of the hollow box 13, and a cable 15 introduced into the cable introduction pipe 14 is used to connect the multifrequency oscillator 11 to the ultrasonic transducer 9. A drive oscillation signal is applied.

In the third embodiment, the upper plate 13a of the hollow box body 13 also serves as the vibration substrate 8, and the upper plate 13a
As in the case of the bottom plate 3 of the second embodiment, the ultrasonic transducer fixing part has a desired vibration region (at least the length of one side is (A region where the wavelength is 1/4 wavelength or more of the resonant frequency)
is formed.

Therefore, also in the case of the third embodiment, the first
It is possible to achieve effective ultrasonic cleaning using a high frequency driving oscillation signal as in the embodiments 1 and 2.

(Effects of the invention) Since the present invention has the configuration and operation described above, it is possible to reduce the plate thickness not only when the driving frequency is low but also when the driving frequency is high such as 100 kHz or more. It can be made thick enough.

Therefore, the mechanical strength of the ultrasonic diaphragm is increased, and the ultrasonic diaphragm is prevented from being abnormally deformed or damaged by the hydraulic pressure of the cleaning liquid.

In addition, since no abnormal deformation or breakage occurs in this way, there is no need to be extra careful when bonding the ultrasonic transducer, so that the bonding workability can be improved. Furthermore, the life span against erosion on the ultrasonic diaphragm that occurs during ultrasonic irradiation can be made very long.

In addition, in this invention, the thickness of the ultrasonic diaphragm is selected so that it resonates efficiently at its driving frequency, that is, the resonant frequency of the ultrasonic diaphragm. Acoustic loss is also reduced compared to Moreover, since the multi-frequency oscillator can arbitrarily switch between a drive oscillation signal having the fundamental frequency and a drive oscillation signal having an odd multiple frequency of the fundamental frequency, the object to be cleaned can be cleaned with ultrasonic waves of different frequencies. The effect is extremely large.

Furthermore, even if the length of at least one side of the ultrasonic diaphragm is set to 1/4 wavelength or more of the resonant frequency, there is almost no phase shift of the vibration waves in each part of the ultrasonic diaphragm, so it is efficient and can be applied over the entire surface. Therefore, uniform vibration waves can be generated.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the configuration of a first embodiment of the present invention, FIG. 2 is a block diagram common to each embodiment of the present invention, and FIG. 3 is a second embodiment of the present invention. FIG. 4 is a sectional view showing the structure of a third embodiment of the present invention. 1...Cleaning liquid, 2...Cleaning tank, 3...Bottom plate, 4
...Opening, 5...Packing, 6...Ultrasonic diaphragm, 7...Bolt, 8...Vibration board, 9...Ultrasonic vibrator, 10...Adhesive, 11...Multi-frequency oscillator, 12 ... Vibration box, 13 ... Hollow box body, 13a
...Top plate, 14...Cable introduction pipe, 15...Cable.

Claims (1)

[Scope of utility model registration request] An ultrasonic cleaning machine comprising: an ultrasonic oscillator that outputs a driving oscillation signal; and an ultrasonic diaphragm that receives the driving oscillation signal and irradiates ultrasonic waves into a cleaning liquid in a cleaning tank; It consists of a multi-frequency oscillator that can output drive oscillation signals at both the fundamental frequency and its odd multiples, and the ultrasonic diaphragm has at least one side length that is at least 1/4 wavelength at the resonant frequency in the plate thickness direction. An ultrasonic cleaning machine having a plate thickness that is an integral multiple of approximately 1/2 wavelength of the resonant frequency.