JPS5855835B2 - Ultrasonic cleaning method for continuous linear thin materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultrasonic cleaning method for relatively thin objects such as wire rods and hoop materials that can be continuously reduced in feed.

Conventionally, when continuously cleaning wires or hoop materials (for example, iron bands) using ultrasonic waves, an ultrasonic vibrator 2 or 21 is attached, and high frequency power is applied to this vibrator from a high frequency oscillator 4 via a cable 3 to radiate ultrasonic vibrations into the cleaning liquid 5.

If the object to be cleaned, such as a wire or hoop material 6, is passed through this ultrasonic sound field at a speed commensurate with the strength of the sound field and the degree of contamination, a cleaning effect proportional to the length of passage can be obtained.

In general, the cleaning effect is better when the object to be cleaned is placed as close to the radiation surface of the vibrator as possible, and by doing so, the depth of the cleaning liquid can be made shallow enough that the object to be cleaned is just submerged under the surface of the cleaning liquid. It is known that it is economical because it requires less cleaning liquid and less high-frequency power input.

However, in order to do so, for example 7.7' in Fig.
, γ′, 7# It is necessary to install guide rollers to push down the object passing through the top of the washing tank to near the bottom of the tank, but the less flexible the object, the lower the bending angle. is large and cannot be bent very much, so as a result, it is necessary to lengthen the sloping part pushed down, and the length of the cleaning tank itself also increases, resulting in an increase in the size of the entire equipment.

Furthermore, in the case of a very hard object to be cleaned, it is impossible to even bend it, so the push-down method using guide rollers cannot be adopted.

Next, in order to avoid the above-mentioned drawbacks, there is a method of washing while transporting the material in a straight line.

FIG. 2 is a diagram showing the basic configuration of this system, and the symbols in the diagram are the same as those in FIG. 1.

In this method, holes 8 and 8' are formed in the side wall of the tank to be cleaned, and the object to be cleaned is transported linearly through the tank 1, but the center of the hole is aligned with the center of the object to be cleaned. Therefore, if the cleaning liquid leaks from the holes 9 and 9', the liquid level will drop by the time the object to be cleaned is exposed above the liquid level.

Therefore, the hole is usually covered with a soft cloth to avoid leaving any scratches on the object to be cleaned, to reduce leakage, and to drain the amount of fluid into the fluid replenishment port 1.
Replenish from 0 to prevent the liquid level from dropping below a certain level.

Note that this turbidity removing liquid is normally collected in a replenishment tank (not shown).

A common drawback of the above two conventional methods is that they utilize a diffuse sound field 11 of the sound source, as shown in FIG.

That is, the strength of the sound field decreases as it moves away from the radiation surface of the vibrator.

Needless to say, once emitted ultrasonic vibrations undergo multiple reflections on the liquid surface and the cleaning tank wall, but in general, the reflection at the liquid surface is the largest, creating a distinct standing wave between the transducer surface and the liquid surface, and the location of the strong vibration. It is normal to pass the object to be cleaned through it.

However, the strength at that position cannot exceed the strength at the radiation surface of the vibrator.

In order to improve the cleaning effect with this X, it is necessary to increase the sound pressure at the location of the object to be cleaned and to strengthen the cavitation that contributes to cleaning, but this also needs to be stronger than the vibration level. However, if the sound pressure is increased above a certain level, cavitation on the vibrating surface will prevent the sound waves from proceeding, and the sound pressure at the object to be cleaned will drop sharply.

Therefore, with this method, the sound pressure and the intensity of cavitation cannot be increased beyond a certain level, and the cleaning effect is also limited.

Furthermore, as described above, since the object to be cleaned is long and narrow and the area to be cleaned is narrow, the capacity of the cleaning tank required is large, and it is necessary to increase the power of the ultrasonic waves applied.

In combination with the limitation of sound pressure level, the power density per surface area of the object to be cleaned is small considering the amount of power input.
It must be said that this is an extremely inefficient cleaning method.

As mentioned above, in order to clean thin objects such as wire rods and hoops with S, the usage rate of ultrasonic power is low even if multiple objects to be cleaned are passed through the cleaning tank at the same time. Since the cleaning speed is slow, it is uneconomical to lengthen the cleaning period and increase the ultrasonic power, so there are few examples of practical use.

The present invention was originally developed to eliminate the drawbacks of the conventional method, but it (1) increases the ultrasonic power utilization rate by reducing the ratio of cleaning liquid to ultrasonic power; Increasing the sound pressure level, (3X1), (2) increasing the processing amount per ultrasonic power and increasing the processing speed, (4) using a method of transferring wire rods, hoop materials, etc. in a straight line, ( 5) The field of application is high-speed, high-quality in-line cleaning of wire rods and hoop materials, specifically, for example, cleaning of piano wire before bright annealing.

Next, the present invention will be explained in detail by way of examples.

FIG. 4 is a diagram illustrating an example of the configuration and operation of an ultrasonic vibrator that is the basis of the present invention.

In FIG. 4a, 12 is a pipe made of an elastic material such as steel, and 13 is a rod made of the same material.

The rod 13 is joined to the center of the pipe 12 so that their axes are perpendicular to each other.

14 is a junction point. When ultrasonic vibrations are applied to the rod 13 in the axial direction, that is, longitudinal ultrasonic vibrations are applied, the vibrations are transmitted to the pipe 12.

If the diameter of the pipe is such that it resonates with the ultrasonic frequency, the pipe will often vibrate when breathing.

This respiratory vibration is transmitted in the axial direction of the pipe 12.

If the length of the pipe 12 is a value that resonates with the frequency of the ultrasonic wave, a standing wave of respiratory vibration is generated in the axial direction.

Figure 4 shows the standing wave in the axial direction of the pipe 12 at the point when the longitudinal vibration, that is, the compressional wave becomes sparse, at the junction point 14 of the rod 13 (hereinafter referred to as the transmission rod) with the pipe 12; Figure 4C shows the standing wave at the time when the compression wave becomes dense.

These vibrations are repeated according to the frequency of the driving ultrasonic wave of the transmission rod 13.

In Figure 4, L2, L3, L1', L2! ',
L, 7. N, TsuN2fuN3riN,' , N2' ,
N3' indicates the position of the antinode and node of the amplitude of the standing wave, and is obvious from the figure.

Now, the above relationship can be approximated by the following formula.

Now, the frequency of the driving ultrasonic wave is f (KHz), the sound speed of the longitudinal wave inside the elastic body is C (cm/sec), the wavelength of the ultrasonic wave inside the elastic body is λ (cm, ), and the average diameter of the pipe 12 is D (of ), the circumference πD of the pipe 12 is calculated from the wavelength of the standing wave λ′ξλ by λ′/2ξc / 2 f (2) For example, if the elastic body is steel, it is 0250105 cm, /se
c, when f=28KHz, D#5.7crIL, λ'/2=9m from both equations (principal 1) and (2).

Therefore, taking the case shown in Figure 4 as an example, the total length of the pipe 12 is 9CIrLX5=45
becomes.

From these, the average diameter is 5.7CrrL and the length is 45C1rL.
It can be seen that when a steel pipe is driven by ultrasonic vibrations of 28 KHz from the center, breathing vibrations are generated at five locations in the axial direction.

Note that the breathing motion is a motion in which the diameter of the pipe 12 periodically expands and contracts as shown in the cross-sectional views a, b, and c shown on the right side of Figure 4. When a pipe is filled with a liquid that causes breathing vibrations due to waves, the sound field in the pipe is concentrated on the axis of the pipe, and if a wire or hoop material is passed along this axis, a strong sound field will be generated above it. A sound field is created and the cleaning process is effectively performed.

FIG. 5 is a side view of the configuration of an ultrasonic cleaning apparatus of the present invention utilizing the principle of FIG. 4, where A is a cross-sectional view and B is a top view.

However, the high frequency oscillation source and the like are omitted.

In this figure, reference numerals 12 and 13 are the elastic pipes and rods explained in FIG.
20 and connect both ends in a watertight manner.

As is clear from Figure B, the tanks 15 and 1s' are divided into two chambers, front and rear, by partition walls 17 and 17', respectively.

Also, one of the two partitions (17' in this example)
The height of the pipe 17 shall be lower than that of the other pipe 17, but the height of the pipe 12 shall be kept higher than that of the pipe 12.

Furthermore, through holes 18 and 18' are provided on the axis of the pipe 12 in the wall on the side opposite to the pipe connection side of the tanks 15 and 15', and through holes 19 and 19' are provided in the partition walls 17 and 17', respectively. .

Drain pipes 20 and 20' for draining liquid are provided at the bottoms of the outer partitions of the tanks 15 and 15' into which the pipe 12 is not inserted, respectively, and the drained liquid is led to a liquid storage tank 22 by a pipe 21.

Now, tanks 15, 15' and pipe 12 have a tank 22.
The liquid 23 inside is sucked up by the pipe 25 of the pump 24 and flows in through the supply pipe 26.

The internal liquid of tanks 15 and 15' is supplied through through holes 19 and 19, respectively.
When the liquid level in the tank decreases, the liquid 23 is sucked up by the pump 24, and in this example, the pipe 12 in the tank 15. The liquid flow is such that the liquid overflows through the holes 19 and 19'.

That is, the liquid fills the inside of the pipe 12 and then flows from the tank 15 to the tank 15' where the height of the partition wall is low.

Therefore, the wire rod or hoop material 27 to be processed is inserted into the through hole 1.
If the ultrasonic vibration is applied from the transmission rod 13 by passing it through the pipe 12 in the axial direction via the rods 8, 19, 19', and 18, the material to be treated 27 can be subjected to the desired treatment.

For example, in the case of cleaning, if a cleaning liquid is used as the processing liquid and the direction of the material to be treated is continuously moved from left to right in Figure 5, the material to be treated will always be fresh at the outlet as shown in the figure. S cleaning is performed continuously while being exposed to a liquid (liquid from pipe 26).

, Now, the problem with S is pipe 12 and tank 15.
, 15' and the through parts 16, 16' in a watertight manner.

Watertightness can be obtained by simple brazing or welding, but this means mechanically clamping the pipe that is supposed to vibrate to suppress the vibration.

To eliminate this drawback, for example, N3 in FIG. If they are coupled at a node of respiratory vibration such as N3', the suppressive effect can be considerably reduced.

However, this position is the antinode (lo) of the vibration of the longitudinal standing wave in the axial direction.
op), so the suppressing effect works and is a problem.

In the present invention, this coupling method is constructed as shown in FIG. 6, and watertightness is achieved by a rubber elastic O-ring.

In FIG. 6, reference numeral 12 denotes a pipe, and only the 01J ring receiver 28 (only the penetrating portion 16 side is shown) at the end of the pipe.

There is 28' on the penetrating portion 16' side. The same applies to 29 to 32, but the portions in contact with (not shown) are mechanically finished.

The O-ring support 28A is watertightly joined to the through-hole portion 16 of the tank.

This O-ring holder has a portion where the O-ring 28 is accommodated, that is, an O-ring chamber 29 and a threaded portion 30.

Attach both ends of the pipe 120 to the O-ring receivers 28A and 28'A with O-rings 28 and 28', respectively, and attach the bush 31
, 31' are screwed in with the screws 32, 32' and the O-rings 28, 2B' are crimped, so that the pipe 12 is watertightly connected to the tanks 15, 15'.

According to this method, the position of the O-ring 28°28' is adjusted to the node N.
2. If it is set near N2', the pipe and tank can be brought into close contact without suppressing shaking, and assembly and disassembly are also easy.

FIG. 7 is a sectional view showing the configuration of a joint when a plurality of pipes 12 are connected in series.If the O-ring support 28A is modified as shown in 33, a watertight connection can be easily achieved.

In FIG. 7, 34 and 35 are bushes, and 36 and 37 are O-rings.

In FIG. 4, the connecting position 14 of the vibrating rod 13 to the pipe 12 is set at the center of the pipe 12, but in reality, it is not necessary to limit it to the central point, and it can be connected to a point such as the abdomen of the vibration (for example, L2, L2 ', L3. L3', etc.) - Needless to say, it's good.

As is clear from the above explanation, the effect of the present invention is (1) The device becomes simpler (compact).

In particular, in practice, it is common to process multiple wire rods and hoop materials in parallel, and even if multiple processing devices are arranged in parallel, the occupied area is small.In other words, if the width W of the front and rear tanks is made slightly larger than the diameter of the pipe, (It is convenient to arrange them in parallel.)

(2) It is easy to connect pipes in series, and processing capacity can be increased by connecting multiple ultrasonic vibrators shown in Figure 4 in series as shown in Figure 7 and providing tanks 15 and 15' at both ends. can.

(3) The liquid is flowed only inside the pipe and there is no loss of ultrasonic energy to the outside, making it highly effective.

(4) The power density is high because the amount of liquid per vibration area of the pipe is much smaller than in conventional ultrasonic tanks (because the ratio of the volume to area of the cylinder is small).

(5) Power is particularly concentrated on the central axis of the pipe.

(6) Pipes can be replaced easily.

(7) There is little acoustic loss in the watertight part of the pipe end.

The practical effects of the present invention are obvious.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram of an example of a conventional ultrasonic cleaning device for a thin linear object, Fig. 2 is a structural diagram of another example, Fig. 3 is an explanatory diagram of the diffusion of the sound source, and Fig. 4 is the invention of the present invention. Fig. 5 is an example of the structure of the device of the present invention, Fig. 6 is a cross-sectional view of an example of a watertight joint between the vibration pipe and the cleaning liquid tank, and Fig. 7 The figure is a sectional view of an example of a watertight joint when pipes are joined in series. 1...Cleaning tank, 2,2/-...Ultrasonic vibrator, 3...High frequency cable, 4...
High frequency oscillator, 5...Cleaning liquid, 6...
Item to be cleaned, 7~7"...Roller, 8.81...
...hole, 9,9'...leakage, 10...
... Replenishment liquid 11 ... Diffusion sound field, 12 ...
・Elastic pipe, 13...Elastic rod, 14
・・・・・・Joint point of pipe and rod, 15, 15'...
...Tank, 16,16'...Through hole, 1
7, 17'...Partition wall, 1B, 18',
19゜19/-...Through hole, 20,20'-...
...Drain pipe. 21...Piping, 22...Liquid storage tank, 23
...Liquid, 24...Pump, 25...
... Suction pipe, 26 ... Supply pipe, 2
7... Wire rod, hoop material to be processed, 28, 36
, 37... O-ring, 28A. 33... O-ring receiver, 29... O-ring chamber, 30... Screw, 31, 34, 3501
061.787°32...screw.

Claims (1)

[Claims] 1. At one point in the vibration abdomen of an elastic pipe that generates breathing vibrations around the circumference and standing wave vibrations along the central axis at the same resonant frequency, a transmission rod with a diameter smaller than the pipe is placed at a right angle g to the axis of the pipe. One or more pipe-shaped vibrating bodies are connected to each other so as to be driven by high-frequency power at the above-mentioned resonance frequency from the transmission rod, and inside which the fine material to be cleaned and the cleaning liquid flow in a fixed direction along the axis. A vibrating body that is airtightly engaged with the vibrating body in series, and two cleaning liquid tanks that are installed at both ends of the pipe of the pipe-like vibrating body and that are watertightly connected by penetrating the pipe near the nodes of standing wave vibration of the pipe. Each tank is divided into two chambers in a direction perpendicular to the axial direction of the pipe-shaped vibrating body, and the cleaning liquid is supplied to the chamber on the pipe-joining side of one tank, flows through the pipe-shaped vibrating body, and enters the tank at the other end. The cleaning liquid is circulated by a pump by overflowing from the pipe joint chamber to another chamber, and both tanks have through holes in their respective walls aligned with the axis of the pipe. A method for ultrasonic cleaning of continuous linear fine materials, characterized in that the thin materials are continuously moved through pipes and through holes located in a straight line.