JPS6232634Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to an ultrasonic cleaning device.

Ultrasonic cleaning devices of various shapes are used. Broadly speaking, as shown in Fig. 1, a hole 3 is provided in the center of the bottom wall 2 of the cleaning tank 1, a flange 4 is fixed to the outer periphery of this hole 3 by welding, etc., and a vibrating body 5 made of stainless steel is fixed. are in contact with each other through a packing 6, and the outside of the vibrating body 5 is fixed with a plurality of screws 9 through a packing 7 and a presser flange 8, and a plurality of ultrasonic transducers 10, . . . are attached to the outside of the vibrating body 5. ... was fixed.

In addition, in the apparatus shown in FIG. 2, a flange 4 is fixed to the outer circumference of the lower end of a rectangular cleaning tank 1' whose four corners are circular arcs, and a circular arc portion 11 is attached to the bottom inner peripheral surface of the flange 4 through a packing 6. A shallow dish-shaped stainless steel vibrating body 5' is fixed. Since the other parts are the same as those in FIG. 1, the same reference numerals are given and the explanation will be omitted.

Furthermore, the apparatus shown in FIG. 3 has a plurality of ultrasonic transducers 10, . and the bottom wall 13, and cover this with the bottom wall 13.
into a cleaning tank 1'' with a support 1 at the bottom 2.
It is supported through 4.

In each of the various ultrasonic cleaning devices described above, the vibrating body is made of stainless steel. This stainless steel has the disadvantage of large vibration loss due to ultrasonic vibration, but since the liquid used for cleaning is usually alkaline or alkaline solvent, tofu water, pure water, etc., stainless steel is used in consideration of corrosion resistance. is used.

However, although it has corrosion resistance against chemical solutions,
Corrosion resistance due to erosion caused by cavitation caused by ultrasonic waves is not necessarily sufficient.

In order to avoid the above-mentioned erotation, the fourth
A vibrating body in which a hard chromium layer B is electroplated on the radiating surface of a stainless steel plate A as shown in the figure has come to be used. Although this vibrator can improve its erosion resistance, since the hard chromium layer B is formed by electroplating, the outer periphery is thick, making installation difficult.

In addition, the range of applications for ultrasonic cleaning has recently expanded,
A wide variety of liquids are used, and particularly in the semiconductor field, acids such as hydrochloric acid, sulfuric acid, and nitric acid are increasingly used as processing liquids, and the problem has arisen that the chromium layer has no acid resistance and cannot be used.

As a means to solve the problem of acid resistance, it has been proposed that the entire vibrating body is made of ceramic. This vibrating body must be thick in order to have the strength necessary to support the weight of the cleaning liquid.
Therefore, a plate thickness of around 10 mm is usually required.

Since the vibrating body generally vibrates with its surroundings fixed, the vibrating body 5 has the following characteristics, as shown in FIG.
It will be displaced in a vertically curved state. When the vibrating body is displaced upward, the liquid contact surface (radiation surface) above the neutral plane of the vibrating body has the maximum extensional strain, and the lower end surface has the maximum compressive strain.

Now, when the displacement of the vibrating body is maximum due to ultrasonic vibration, the radius of curvature of the neutral axis is R, and the plate thickness is t.
Then, the strain ε becomes ε=t/2/R (1), and it can be seen that the smaller the thickness t, the smaller the strain per displacement.

Further, if the longitudinal coefficient of the material is E, then the stress σ is as follows: σ=ε·E=E·t/2/R (2).

Generally, the fatigue limit of a material is as shown in FIG. 6 with respect to the stress σ applied to it.

Therefore, when the vibrating body is vibrated with the same amplitude, the thinner the plate thickness, the smaller the stress applied to it, and the more it can withstand repeated stress.

Furthermore, the fact that the stress applied to the vibrating body during vibration is large means that a large amount of power is required to vibrate the vibrating body alone, resulting in wasted energy.

Therefore, the conventional vibrating body made of ceramic with grooves has a thickness of 10 mm, which causes large distortion.
Since the stress is large, it cannot withstand repeated stress and has the disadvantage that it consumes a large amount of energy.

Furthermore, if there are pinholes, bubbles, etc. in the ceramic, cracks will occur at those locations and the ceramic will break. This means that only a special type of high-density ceramic can be used, making it expensive.

Therefore, an object of the present invention is to provide an ultrasonic cleaning device that has chemical resistance, does not cause erosion due to cavitation, and has good workability.

The structure of the present invention will be explained in detail based on the embodiment shown in FIG. 7. Ceramic is coated on the radiation surface side of a metal plate A to form a ceramic layer C. Ultrasonic vibrator 1
0, .

Note that a ceramic layer may also be provided on the anti-radiation side of the metal plate A.

As a means for forming the ceramic layer C, various thermal spraying means as described below can be used.

1 Plasma electric arc method 2 Gas powder method 3 Gas melt wire method 4 Electric melt wire method 5 Gas melt rod method In addition, when coating is done by thermal spraying, the coating is hard, dense, and has high density between particles and with the base material.
High binding strength is known.

The shape of the vibrating body D is not limited to that shown in the drawings, but may be formed into the shapes shown in FIGS. 2 and 3, which illustrate conventional examples.

The present invention is constructed as described above, and the ceramic layer C is provided on the radiation surface of the metal plate A that constitutes the vibrating body that comes into contact with the cleaning liquid in the cleaning tank.
It has excellent acid resistance, alkali resistance, pure water resistance, etc., and can prevent erosion due to cavitation.

Furthermore, since it is constructed from a multi-layer structure consisting of the metal plate A and the ceramic layer C, the plate does not need to be as thick as the conventional ceramic plate, and the ceramic layer C can be made thinner. As a result, there is no need to consider the occurrence of cracks due to pinholes and bubbles, and commonly used ceramics can be used.

Furthermore, the ceramic layer has both erosion and corrosion resistance properties, so by coating the entire metal plate, there is no need to consider the corrosion resistance of the metal plate, and aluminum, which has low vibration loss as a metal plate, Titanium or the like can be used, and vibrations can be transmitted effectively.

In addition, since the ceramic layer can be formed uniformly, it can be easily attached to the cleaning tank without requiring any special measures.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an example of a conventional ultrasonic cleaning device, Fig. 2 is a sectional view of another conventional example, Fig. 3 is another sectional view, and Fig. 4 is a sectional view of another example of a vibrating body. Figure 5 is an explanatory diagram of the vibration state of the vibrating body, Figure 6 is an explanatory diagram showing the relationship between stress and the number of repetitions, and Figure 7 is an explanatory diagram showing the relationship between stress and the number of repetitions.
The figures each show a sectional view of an embodiment of a vibrating body used in an ultrasonic cleaning device according to the present invention. In the figure, A is a metal plate, C is a ceramic layer, and D is a vibrating body.

Claims (1)

[Scope of utility model registration request] An ultrasonic cleaning device characterized in that a ceramic layer C is coated on the radiation surface of the metal plate A on the cleaning liquid side that is in contact with the cleaning liquid in the cleaning tank 1, and an ultrasonic vibrator 10 is provided on the anti-radiation surface of the metal plate A. .