JPH0437754B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ultrasonic cleaning device, and more particularly to an improvement in a cleaning liquid deaeration device.

[Conventional technology]

As is well known, in workpiece cleaning equipment, it is often used to radiate ultrasonic waves into the cleaning liquid and generate cavitation to clean the workpiece. It has also been confirmed that irradiation of ultrasonic waves causes better cavitation and improves cleaning efficiency. Therefore, cleaning apparatuses having cleaning liquid deaerating means have been proposed. For example, devices described in Japanese Utility Model Application Publication No. 50-66476 and Japanese Utility Model Application Publication No. 50-81064 are known. That is, it includes a cleaning tank and a heating tank, and the cleaning liquid is heated in the heating tank, deaerated, and sent to the cleaning tank, that is, the cleaning liquid is circulated between the cleaning tank and the heating tank.

[Problem to be solved by the invention]

By the way, in order to maintain the degassed state of the cleaning liquid in the cleaning tank under conditions where the atmosphere is open, it is necessary to consider not only the equipment used during deaeration, but also the process to maintain the degassed state after deaeration. As a device in this sense, the following points must be taken into consideration.

Efforts must be made to prevent air from dissolving into the cleaning liquid from the interface between the cleaning liquid and the atmosphere after deaeration.

Whether or not a deaeration method is used that is faster than the rate at which the atmosphere (air) dissolves into the cleaning liquid from the interface between the cleaning liquid and the atmosphere after deaeration.

There are two points.

Looking at the above two conventional technologies from this point,
In both conventional technologies, the cleaning liquid is heated in a heating tank and degassed, but basically the heated cleaning liquid after deaeration is circulated between the cleaning tank and the cleaning tank. The heated cleaning liquid immediately mixes with the cooled liquid. That is, although the liquid in the cleaning tank enters the tank heated, it is immediately cooled down. Once cooled,
Atmospheric air easily dissolves from the interface, making it impossible to maintain a degassed state. That is, when cleaning a workpiece, the emitted ultrasonic waves ripple the interface and air is taken in from there, but since the workpiece is cooled, the air dissolves more easily. In addition, since it is actively cooled, it is easier for air to enter. Therefore, even if heated and degassed, air is dissolved in the cleaning liquid during the cleaning stage, and cavitation due to ultrasonic radiation under degassed conditions cannot be expected to occur effectively. Therefore,
The intended purpose of improving the cleaning effect under deaeration may not be achieved.

〔the purpose〕

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a means for better maintaining the deaerated state of the cleaning liquid even when cleaning a workpiece in a cleaning tank after the cleaning liquid has been deaerated. More specifically, it is difficult for air to dissolve from the interface into the cleaning liquid after degassing the cleaning tank, and the degassing state of the cleaning liquid is maintained even when cleaning the workpiece, thereby preventing cavitation from occurring during ultrasonic irradiation. It is an object of the present invention to provide a means for improving the cleaning effect of a workpiece.

[Means to solve the problem]

In order to achieve the above object, the present invention has the following technical means. That is, the present invention provides an ultrasonic cleaning system comprising a cleaning tank filled with a cleaning liquid for immersing an object to be cleaned, an ultrasonic vibrator that emits ultrasonic waves into the cleaning liquid, and an oscillator that operates the ultrasonic vibrator. The apparatus includes a deaerator for degassing gas dissolved in the cleaning liquid so that cavitation is generated in the cleaning liquid when ultrasonic waves are radiated to the cleaning liquid in the cleaning tank. In an ultrasonic cleaning device; the deaeration device is installed next to the cleaning tank, and when the object to be cleaned is put into the cleaning tank, it releases overflow cleaning liquid in an amount corresponding to the volume of the object to be cleaned. An overflow recovery tank is provided next to the cleaning tank to receive the overflow, and when the cleaning liquid returned from the overflow recovery tank is allowed to flow in sequentially, the inflow amount of cleaning liquid overflows into the cleaning tank. Equipped with a boiling tank to allow water to flow into the
The ultrasonic cleaning apparatus is characterized in that the boiling tank is provided with a heater that heats the cleaning liquid so that dissolved gas having a lower boiling point than the cleaning liquid can be evaporated and the dissolved gas can be separated at the boiling point.

[Effect]

According to the above configuration, the cleaning liquid 8 containing gas is continuously sent from the steam tank 4 via the steam condenser 11 and the water separator 13 to the boiling tank 3 which is a deaerator. The dissolved gas having a lower boiling point than the cleaning liquid 8 and the cleaning liquid 8 are separated, and only the cleaning liquid 8 having a low gas solubility is returned to the cleaning tank 2 again.

When the cleaning liquid is returned to the cleaning tank 2, the cleaning liquid that has entered the boiling tank 3 overflows the boiling tank and enters the cleaning tank 2. That is, the upper surface of the cleaning liquid in the cleaning tank 2 flows in. Therefore, the cleaning liquid in the cleaning tank 2 is not disturbed greatly, and the state of the cleaning liquid in the cleaning tank 2 is such that the upper part is heated by the boiling tank 3 and a relatively high temperature layer is formed, and the lower part is relatively high temperature. A layer of extremely low temperature is formed. That is, a double layer consisting of an upper high-temperature layer and a lower low-temperature layer is formed, and the space between them is stable.

Therefore, when the transducer 6 is activated to emit ultrasonic waves, cavitation occurs. Moreover, since the bubbles existing in the liquid do not expand, cavitation occurs more easily. Also, the impact energy caused by the destruction of the cavity under compression during cavitation reaches the object to be cleaned without being hindered by the bubbles. Therefore, the cleaning effect is good.

In particular, when looking at the state of the cleaning liquid in cleaning tank 2, the upper part is formed as a relatively high-temperature layer, and the high-temperature layer is originally degassed in the previous stage and is maintained at a high temperature, so it is not cooled. In addition, since the above-mentioned high-temperature layer is stable above the lower low-temperature layer, air will not dissolve from the interface into this low-temperature layer. For this reason, the degassed state is maintained for a long time, improving the efficiency of cavitation generation during degassing during cleaning of the workpiece by ultrasonic radiation, and the resulting cleaning efficiency.

Even when a workpiece is put into the cleaning tank 2, the cleaning liquid corresponding to the volume of the workpiece overflows from the cleaning tank 2 and enters the collection tank 8. In other words, the cleaning liquid in the cleaning tank 2 does not flow. It is useful for forming high and low temperature layers on the top and bottom after cleaning.

〔Example〕

Next, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 in the figure indicates an ultrasonic cleaning device, and this device 1
is composed of a cleaning tank 2, a boiling tank 3, a steam tank 4, and a steam condenser 5.

The cleaning tank 2 consists of a single tank, and this cleaning tank 2
A piezoelectric ultrasonic transducer 6 connected to an oscillator (not shown) is disposed.

Further, the boiling tank 3 is disposed upstream of the supply side of the cleaning liquid 8 of the cleaning tank 2, and a heater 7 is piped to the boiling tank 3 to heat the cleaning liquid 8 at a temperature close to but below the boiling point. has been done. In this example, an example of Freon 113 among various cleaning liquids 8 is shown, and since the boiling point of this Freon 113 is 47.6°C, the boiling tank 3 is heated by the heater 7. The temperature is set at around 47℃.
Therefore, dissolved gases having a boiling point lower than the boiling point of the chlorofluorocarbon 113, which is the cleaning liquid 8, are separated by boiling point separation.

By the way, the boiling tank 3 is provided beside the cleaning tank 2, and an amount of cleaning liquid returned to the boiling tank 3 overflows and flows into the cleaning tank 2. At this time, the cleaning liquid does not flow into the upper surface of the cleaning tank 2 and disturb the cleaning liquid in the cleaning tank 2.

Further, the steam tank 4 is disposed upstream of the cleaning liquid 8 supply side of the boiling tank 3, and a heater 9 is piped to the steam tank 4. This heater 9
The cleaning liquid 8 is heated to a boiling point or higher and evaporated.

A steam condensing section 5 around which a steam condensing pipe 11 is disposed is provided in the upper part 10 of the above-mentioned cleaning tank 2, boiling tank 3, and steam tank 4.

Cleaning liquid 8 condensed by the steam condensing section 5
is sent to the water separator 13 via the connecting pipe 12.
Then, water is separated by this water separator 13. The water separated at this time is mainly adhering water that adheres immediately when the object to be cleaned (workpiece) is placed in the cleaning tank 2. The cleaning liquid 8 from which water has been separated by the water separator 13 is sent to the boiling tank 3 via the cleaning liquid introduction pipe 14. Then, only the cleaning liquid 8 separated by boiling point separation is introduced into the cleaning tank 2 again. Further, an overflow recovery tank 16 is connected to the front portion 15 of the cleaning tank 2. The cleaning tank 2 is filled with the cleaning liquid 8 up to the upper end, so when a workpiece is loaded, the cleaning liquid 8 corresponding to the volume of the workpiece will overflow, and this overflowing cleaning liquid 8 will be collected by the collection tank 16. , is introduced into the steam tank 4 via the recovery pipe 17.

Further, a filtration pipe 20 is connected to one 19 side of the bottom 18 of the cleaning tank 2, and a pump 2 is connected to this filtration pipe 20.
1. A filter (not shown) and a cooler 22 are provided, and the other end of the filtration tube 20 is connected to the bottom 18 of the cleaning tank 2.
It is piped to the other 23 side.

The cleaning liquid 8 in the cleaning tank 2 is circulated by a pump 21 through a filtration pipe 20, and foreign matter (dust, deposits, oil), etc. in the cleaning liquid 8 is removed by a filter, and at the same time, it is superimposed by the cooler 22. The temperature of the cleaning liquid 8 is maintained constant by cooling the heat generated by the sound waves.

Although the cleaning liquid 8 described above is exemplified using Freon 113, it is possible to use a cleaning liquid other than Freon 113. Namely, Freon 112, isopropyl alcohol (IPA), ethanol, methylene chloride,
Trichlorethylene, perchlorethylene, 111 trichloroethane, azeotropes thereof, water, and the like can also be used.

Next, an example of how this embodiment is used will be explained.

First, an object to be cleaned (workpiece) is placed in the cleaning tank 2, and the ultrasonic vibrator 6 is activated there to clean it.

That is, by putting the object to be cleaned (workpiece) into the cleaning tank 2, the cleaning liquid 8 in the cleaning tank 2 overflows, and the overflowing cleaning liquid 8 enters the recovery tank 16 and is collected through the recovery pipe 17. and introduced into the steam tank 4. Since the inflow is caused by this overflow, no flow occurs in the cleaning liquid in the cleaning tank 2 and the cleaning liquid in the cleaning tank 2 is not disturbed greatly. Now, the cleaning liquid 8 introduced into the steam tank 4 is heated by a heater 9, becomes vapor, and is returned to liquid again by a condensing pipe 11 of a vapor condensing section 5 located in an upper part 10. Then, it is introduced into a water separator 13 via a connecting pipe 12, and water is separated.
The cleaning liquid 8 from which water has been separated is introduced into the boiling tank 3 via the cleaning liquid introduction pipe 14. At this time, the cleaning liquid 8 is heated by the heater 7 and the dissolved gases having a boiling point lower than that of the cleaning liquid 8 are degassed by boiling point separation. Only the degassed cleaning liquid 8 is introduced into the cleaning tank 2.

At this time, since the water overflows from the boiling tank 8 and enters the cleaning tank 2, the state of the cleaning liquid in the cleaning tank 2 is not disturbed significantly. That is, the state of the cleaning liquid in the cleaning tank 2 is such that a high temperature cleaning layer heated by the boiling tank 8 is formed in the upper region, and a low temperature layer is formed in the lower region. Here, by putting the work into the cleaning liquid in the cleaning tank 2 and activating the ultrasonic vibrator 6 to radiate ultrasonic waves to the cleaning liquid 8, a good cavitation effect can be obtained at all times, and therefore a good cavitation effect can be obtained. It can provide cleaning power.

That is, the cleaning liquid is degassed in the boiling tank 8, the upper part of the cleaning liquid in the cleaning tank is a relatively high-temperature layer and air is less likely to dissolve therein than the interface with the atmosphere, and the lower low-temperature layer is stable. Since contact with the atmosphere is blocked by the upper high-temperature layer and air is difficult to dissolve, the deaeration state of the cleaning liquid in the cleaning tank 2 is maintained well, so cavitation can be better prevented. This improves cleaning efficiency.

Further, in this example, the cleaning liquid 8 in the cleaning tank 2 is circulated by the pump 21 through the filter pipe 20, and foreign matter (dust, deposits, oil), etc. in the cleaning liquid 8 is removed by a filter, and the cleaning liquid 8 is circulated by the pump 21 through the filter tube 20. By connecting 22, the heat generated by the ultrasonic waves is removed, and therefore the temperature of the cleaning liquid 8 is maintained at a substantially constant level. As a result, cavitation can be improved. Therefore, the cleaning effect can be further improved.

Furthermore, by using the boiling tank 3 as the degassing means, the structure of the device 1 itself can be simplified, making it more compact and space-saving.In addition, when the device 1 is used continuously, This allows for further space savings.

〔Effect of the invention〕

As described in detail above, according to the present invention, the cleaning liquid before entering the cleaning tank is degassed in the boiling tank. Because it can be washed,
Not only does it have a good cleaning effect, but especially when the cleaning liquid enters the cleaning tank from the boiling tank, it overflows from the cleaning tank and flows into the upper surface of the cleaning tank.
The cleaning liquid in the cleaning tank is not disturbed to a large extent, and therefore the state of the cleaning liquid in the cleaning tank is a relatively high temperature layer at the top and a low temperature layer at the bottom, and this state is stable. Therefore, in high-temperature cleaning liquids that have an interface with air, air is less likely to dissolve from the interface than in low-temperature ones, and the lower low-temperature layer is blocked from air by the upper high-temperature layer. Therefore, the above deaerated state is maintained for a long time due to the fact that air is difficult to dissolve. Therefore, cavitation generation under deaerated conditions is better realized, and the cleaning effect is advantageous.

[Brief explanation of drawings]

The accompanying drawings show an embodiment of the present invention and are a configuration diagram of a cleaning device. In addition, in the figure, 2... washing tank, 3... boiling tank, 4...
...Steam tank, 8...Cleaning liquid, 11...Steam condenser,
13...water separator, 16...recovery tank, 18...bottom, 21...pump, 22...cooler, respectively.

Claims (1)

[Claims] 1. Consisting of a cleaning tank filled with a cleaning liquid for immersing an object to be cleaned, an ultrasonic vibrator that emits ultrasonic waves into the cleaning liquid, and an oscillator that operates the ultrasonic vibrator. An ultrasonic cleaning device for degassing gas dissolved in the cleaning liquid so as to generate cavitation in the cleaning liquid when ultrasonic waves are emitted to the cleaning liquid in the cleaning tank. In the ultrasonic cleaning device having the device; the deaerator is provided beside the cleaning tank,
When the object to be cleaned is put into the cleaning tank, there is an overflow recovery tank for receiving an amount of overflow cleaning liquid corresponding to the volume of the object to be cleaned, and an overflow recovery tank installed next to the cleaning tank to receive the overflow cleaning liquid from the overflow recovery tank. When the washed cleaning solution is made to flow in sequentially,
A boiling tank is provided for overflowing the amount of cleaning liquid that flows into the cleaning tank, and the boiling tank is equipped with a boiling tank that evaporates dissolved gases lower than the boiling point of the cleaning liquid and separates the dissolved gases at their boiling points. 1. An ultrasonic cleaning device characterized in that a heater for heating a cleaning liquid is provided. 2. The ultrasonic cleaning device according to claim 1, characterized in that a water separator 13 is provided upstream of the boiling tank 3. 3 A steam condenser 11 is installed upstream of the water separator 13.
2. The ultrasonic cleaning apparatus according to claim 1, further comprising a steam tank 4 and a steam tank 4.