JPH07227581A - Vacuum-cleaning and drying method and device therefor - Google Patents

Abstract

PURPOSE:To enhance the efficiency in cleaning a work by removing the deposit on the work in a heatable solvent such as petroleum solvent, pulling up the work, drying off the solvent depositing on the work and regenerating the solvent contg. the deposit by distillation. CONSTITUTION:A specified amt. of a petroleum solvent 2 is stored in a vacuum vessel 1, a work W to be cleaned is dipped in the solvent 2 in the vessel 1 by opening a lid 1a. The lid 1a is then closed, the vessel 1 is evacuated by a water-sealed vacuum pump 8, and an ultrasonic vibrator 5 is driven to ultrasonically clean the the work W in the solvent 2. The exhaust sucked in from the vessel 1 and contg. the mist and vapor of the solvent 2 is dissolved or mixed in the sealing water filled in the pump room and discharged into a gas-liq. separation tank 11 along with the sealing water through a gas-water mixture discharge pipe 9, and the soln. in the sealing water is recovered. The cleaned work W is then vacuum-dried in the vessel 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention cleans a member to be cleaned, such as metal or plastic parts, which has been contaminated, in a vacuum using a flammable solvent such as a petroleum solvent, and efficiently dries in the vacuum after cleaning. The present invention relates to a cleaning and drying method. The present invention also relates to a safe and highly reliable vacuum cleaning and drying apparatus to which such a cleaning and drying method utilizing vacuum is applied.

[0002]

2. Description of the Related Art Metal and plastic parts are used in various applications and have various shapes. Heretofore, as a cleaning agent for such parts, chlorofluorocarbon and triethane have been conventionally used as universal cleaning agents. However, in recent years, the use of CFCs and triethane has been restricted and prohibited internationally because the chlorine contained therein destroys ozone in the stratosphere. For this reason, in recent years, cleaning with water and a cleaning with a hydrocarbon-based solvent that are not likely to destroy ozone have begun to attract attention as alternative cleaning methods for CFCs and triethane. However, in the case of washing with water, although water itself as a solvent is inexpensive, there is a problem that a drainage facility and a pure water facility are required to prevent new environmental pollution, resulting in a large cost. Furthermore, in the case of washing with water,
The drying process cannot be performed quickly and water stains occur, which adversely affects the reliability of the parts. The surface tension of water is about 60 dyn.
Since there is also e / square · cm, it is not possible to penetrate into the close contact portion between the parts which are the objects to be cleaned or the fine holes by the usual cleaning method. Therefore, the dirt that adheres to the close contact parts between the parts and the fine holes is not cleaned. Such insufficient cleaning adversely affects the subsequent process. In addition, when the object to be cleaned is a metal part, there is a problem that rust prevention measures must be taken into consideration.

On the other hand, the cleaning with a hydrocarbon solvent is a cleaning using a cleaning agent mainly composed of an organic solvent like freon and triethane. However, like freon and triethane, it contains chlorine which destroys the ozone layer. Since it is not present, there is no fear of environmental destruction such as ozone layer destruction even if exhausted to the atmosphere. Moreover, since it is inexpensive and has a chemical structure similar to that of oil-based stains, it has a relatively high cleaning power even at room temperature. In addition, it has an advantage that stains are less likely to occur after it is completely dried and that it does not adversely affect the subsequent steps. However, 40-
Since it has a flash point of about 200 ° C., it has a problem of safety, and it has a problem of poor drying property because it has a high boiling point.
Further, since it has a flash point, it is very dangerous to use it by heating it in terms of safety. Therefore, there is a problem in that it cannot be said that the cleaning power for stains adhering to the close contact portion between the parts and the fine holes is sufficient. Further, some hydrocarbon-based solvents easily form an adsorption layer on the metal surface, and in order to remove them, it is necessary to dry at an energy higher than the adsorption energy, that is, a temperature higher than the boiling point of the solvent. However, it is extremely dangerous in terms of safety to heat a component to which such a flammable solvent adheres to a temperature above its boiling point (that is, above the flash point) in the atmosphere. Therefore, it has to be dried at a temperature lower than the flash point in the atmosphere, and there is a problem that the drying time and the drying quality are poor.

As a technique for solving the problem of cleaning and drying quality, Japanese Patent Application No. 4-199 previously filed by the present applicant.
There is 219. This technique involves cleaning and drying in a vacuum.

[0007] However, as a result of the examination in such a technique, the present inventor found out that it is difficult to sufficiently wash and dry the object depending on the shape and the washing mode of the article to be washed. It was also found that it is necessary to further consider issues such as space saving, safety, and cleaning / drying quality.

[0006]

SUMMARY OF THE INVENTION In view of these problems, an object of the present invention is that a flammable solvent represented by a petroleum solvent, which has a low flash point and a high boiling point, has a high detergency and a good dry quality. It is an object of the present invention to provide a vacuum cleaning and drying method capable of safely and efficiently cleaning and drying metal and plastic parts using an organic solvent as a cleaning agent. Another object is to provide a vacuum cleaning device and a vacuum drying device to which such a method is applied.

[0007]

[Means for Solving the Problems] A cleaning step of removing an object to be cleaned attached to a work in a flammable solvent such as a petroleum solvent, the work being pulled up from the flammable solvent, and the flammability attached to the work. There are a drying step for removing the solvent and a solvent regenerating step for regenerating the flammable solvent mixed with the cleaning object by distillation, and each of the steps is performed in a vacuum.

In the drying step, drying is carried out at a higher degree of vacuum than the degree of vacuum in the lower chamber in the upper compartment formed by vertically partitioning the internal space of the vacuum container for storing the flammable solvent. Good.

In the washing step, the flammable solvent is heated,
By reducing the pressure below the vapor pressure of the flammable solvent,
The work may be washed in the flammable solvent in a boiling state. The cleaning step includes a first cleaning step of immersing in the flammable solvent and a second cleaning step of pulling up from the combustible solvent and injecting the combustible solvent distilled and regenerated in the solvent regeneration step with a shower. You may By reducing the internal space of the vacuum container with a vacuum pump while heating the combustible solvent, by replacing the air in the vacuum container and the evaporated combustible solvent gas to reduce the oxygen partial pressure in the container A method of enhancing safety may be adopted.

Further, in the vacuum cleaning / drying method, the evaporated flammable solvent may be liquefied by a condenser provided between the vacuum pump and the vacuum container, and may be refluxed into the vacuum container. .

A method of shortening the drying time may be adopted by mounting the work on a holding table and circulating hot water inside the holding table. Also, a cleaning step of immersing the work in the flammable solvent at a first degree of vacuum,
A method of suddenly depressurizing the cleaning liquid to drain the cleaning liquid may be adopted by including a drying step of rapidly reducing the pressure to a second vacuum higher than the first vacuum.

When an object to be cleaned containing chlorine adheres to the work, after the cleaning step, a drying step for removing the flammable solvent adhering to the work is carried out while vacuuming by a vacuum pump. In the drying method, by introducing the gas exhausted by the vacuum pump into water through a pipe, a method is adopted in which chlorine derived from the chlorine-based extreme pressure agent contained in the exhausted gas is dissolved in water. You may.

Further, a cleaning / drying apparatus for cleaning and drying a work by using a flammable solvent such as a petroleum solvent as a cleaning agent, the vacuum container for vacuum cleaning and drying the work, and the inside of the vacuum container. A vacuum evacuation means for evacuation, a distillation regeneration means for distilling and regenerating the cleaning liquid, and a heating means for heating the cleaning agent, and vacuum cleaning of the workpiece in the vacuum container storing the heated cleaning agent, Vacuum drying may be performed.

Further, a gate valve for partitioning the inside of the vacuum container into upper and lower parts is provided, and an exhaust pipe by the evacuation means is connected to an upper part in the vacuum container partitioned by the gate valve, and an end of the exhaust pipe. The part may be immersed in the stored water outside the vacuum container.

Work raising / lowering means capable of holding a work in a lower part, an intermediate part and an upper part in the vacuum container, a gate valve for partitioning the inside of the vacuum container between the upper part and the intermediate part, A distillation regeneration means for regenerating the cleaning agent by vacuum distillation, and an exhaust pipe for the vacuum evacuation means is connected to an upper part of the vacuum container partitioned by the gate valve. An immersion cleaning chamber in which flammable solvent is stored is formed in the side portion, and a shower chamber in which a nozzle for spraying the cleaning agent distilled by the distillation regenerating means onto the work is formed in the intermediate portion is formed. Also, a vacuum cleaning / drying apparatus in which a vacuum drying chamber is formed in the upper portion by closing a gate valve may be used.

Further, the vacuum cleaning / drying apparatus may employ a method having a holding table for holding the work attached to the work lifting means and a means for heating the inside of the holding table with warm water. Further, it has a pressure adjusting means for connecting the vacuum vessel having a different degree of vacuum and the vacuum distillation means, or is connected to the side surface of the vacuum vessel at a portion higher than the liquid level of the cleaning agent stored in the vacuum vessel. An exhaust pipe by the evacuation means, a reflux pipe connected to the exhaust pipe and having a diameter smaller than that of the connection pipe connected to the side surface of the vacuum container at a portion higher than the liquid level of the cleaning agent, the vacuum container And a vacuum cleaning / drying device having a cooling means provided between the connection part of the reflux pipe and the reflux pipe, or a chlorine removing means provided in the pipe between the vacuum container and the distillation regeneration means. Good.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

First Embodiment FIG. 1 shows a vacuum cleaning apparatus to which the present invention is applied. In the figure, reference numeral 1 is a vacuum container that constitutes a vacuum cleaning / drying chamber, and a lid 1a that can be sealed is attached to the upper part. This vacuum cleaning / drying room 1 has a vacuum distiller 1
A petroleum-based solvent can be supplied through a supply pipe 17 connected to the No. 8. Further, the work W to be cleaned is installed in this by the lifting cylinder 15.
At the time of cleaning, as shown in FIG. 1, a fixed amount of petroleum solvent 2 is stored, and the work W is immersed therein. The work receiving table 16 of the work transfer function 15 is made of a hollow pipe, and hot water heated outside the vacuum container 1 can be circulated therein. An ultrasonic transducer 5 is attached to the outer bottom surface of the vacuum container 1. A discharge pipe 6 for the petroleum-based solvent stored inside is connected to the bottom of the vacuum container 1, and a drain valve 7 is attached to the discharge pipe 6. Further, an exhaust pipe 3 is connected to the upper side surface of the vacuum cleaning chamber 1. The exhaust pipe 3 is connected to a suction port 8 a of a water-sealed vacuum pump 8 via a valve 4.

The discharge port 8b of the water-sealed vacuum pump 8 is connected to a steam / water mixture drainage pipe 9. The water-sealed vacuum pump 8 is supplied with sealing water via a water supply pipe 10 by a sealing water supply mechanism (not shown).
The end of the water / water mixture drainage pipe 9 is the stored water 11a of the gas / liquid separation tank 11.
It has an opening inside. An exhaust pipe 12 extending upward is connected to the upper end of the gas-liquid separation tank 11, and a drain pipe 13 as an overflow pipe is connected to the side surface thereof. The drain pipe 13 extends horizontally and then downwardly, and is connected to the suction port 14 a of the oil-water separator 14. The oil discharge outlet 14b of the oil / water separator 14 is open to the oil recovery tank. The water from which oil has been removed is discharged from the drain outlet 14c.

In the vacuum cleaning / drying apparatus of this embodiment thus constructed, a predetermined amount of the petroleum solvent 2 is placed in the vacuum container 1 via the petroleum solvent supply pipe 17 connected to the vacuum distiller 18. And the workpiece W to be cleaned is immersed in the petroleum solvent 2 stored in the vacuum container 1 by opening the lid 1a. Then, the lid 1a is closed and the vacuum container 1 is hermetically closed. Then, the inside of the cleaning chamber 1 is evacuated by the water-sealed vacuum pump 8. After the predetermined vacuum state is formed, while maintaining the vacuum state, the ultrasonic vibrator 5 is driven to ultrasonically clean the workpiece W immersed in the petroleum solvent 2.

At this time, by providing the vacuum distiller 18 in the petroleum solvent supply system, the petroleum solvent can be used in a circulating manner, the cleaning quality can be improved even if the cleaning is repeated, and the flammability is increased. Since the petroleum solvent, which is a volatile substance, is used under reduced pressure throughout the pipe, it is extremely safe. The exhaust containing the mist or vapor of the petroleum solvent sucked from the inside of the vacuum container 1 is sucked from the suction port 8a of the water-sealed vacuum pump 8 and then the sealed water filled in the pump chamber. It is dissolved or mixed and discharged together with the sealed water from the discharge port to the steam / water discharge pipe 9. After passing through this air / water mixture drainage pipe 9, the sealed water is a gas-liquid separation tank 11.
It is discharged into the water stored inside. In this gas-liquid separation tank 11, the petroleum solvent in the sealed water is further dissolved or mixed in the stored water and recovered. Also, the oil contained therein separates and floats on the surface. The exhaust gas after the petroleum solvent is sufficiently removed is exhausted to the atmosphere through the exhaust pipe 12.

On the other hand, the oil content floating on the surface of the stored water in the gas-liquid separation tank 11 is discharged together with the overflow water through the drain pipe 13. Here, in the oil / water separator 14, the petroleum-based solvent and the oil component (wash residue) contained therein are recovered from the discharged water. The recovered oil and the like is recovered from the oil discharge outlet 14b into a recovery tank or the like. The liquid temperature of the stored water in the gas-liquid separation tank 11 may rise during operation. In order to prevent this, the cooling chiller 14c is arranged inside the gas-liquid separation tank 11, whereby the temperature rise of the stored water can be prevented. Further, by reducing the water temperature of the stored water, it is possible to enhance the effect of condensing the solvent vapor contained in the exhaust gas.

Next, as shown in FIG. 2, the cleaned work is vacuum dried in the vacuum container 1. Also in this case, the water-sealed vacuum pump 8 is driven to evacuate the inside of the vacuum container. Further, the mist or vapor of the petroleum solvent contained in the exhaust gas from the cleaning chamber is recovered in the same manner as the above-described cleaning.

As described above, in the vacuum cleaning / drying apparatus of this embodiment, the work W is cleaned in the vacuum atmosphere. Therefore, the effect that the air accumulated on the work is eliminated and the permeability of the cleaning agent is improved can be obtained. As a result, it is possible to surely clean blind holes, fine holes, downward holes and the like, or a large number of perforated parts, which were difficult to clean by the conventional cleaning method. Further, even when a large number of works are washed at once, it is possible to surely wash the contact portion between the works. Further, by cleaning the petroleum solvent in a vacuum state, dissolved air contained in the solvent in a large amount is bubbled, which is highly effective in cleaning the gaps such as the contact portion. Further, since the interfacial tension is lowered, the permeability is improved.

Further, by performing vacuum drying as in this example, the boiling point of the petroleum solvent stored in the vacuum container can be lowered. Therefore, the boiling point of the petroleum solvent can be lowered even at a low temperature. Further, not only the heat capacity of the work due to the lowering of the boiling point of the petroleum solvent and the heating of the solvent, but also the heating of the work by heating the work receiving table 16 with warm water can shorten the drying time safely. In a vacuum state, heat transfer due to radiation is extremely reduced, and thus such a heating method in which heat is directly conducted is extremely effective. FIG. 3 shows a schematic view of the plate heating device. Further, FIG. 4 shows a perspective cross-sectional view of a main part of the work cradle 16 for holding the work. For convenience, the accompanying equipment is not shown. The warm water heated by the heater 19 in the warm water tank 18 is transferred by the pump 20 to the water inlet 22 of the work cradle 16 through the tube 21. The warm water passes through the inside of the work cradle 16 to heat the work cradle 16 itself, so that the work cradle 1
It is discharged from the discharge port 23 of 6 and returns to the warm water tank 18.

Therefore, since the evaporation of the petroleum solvent is promoted, the drying property of the petroleum solvent can be remarkably improved as compared with the conventional method. Further, although solvent gas may remain as an adsorption layer on the surface of the work in air drying, such an adsorption layer can be removed by vacuum drying. Therefore, it is possible to solve the problem that the post-treatment of the work surface after drying, such as adhesion and coating, is adversely affected by the adsorption layer.

In addition, when cleaning easily corroded parts such as SPCC and cast iron, since cleaning and drying are performed in a vacuum having an extremely low oxygen concentration, corrosion may occur in the parts during the cleaning and drying process. There is no. In addition to these advantages, in this example, the inside of the vacuum container 1 is maintained at a predetermined degree of vacuum, so that the oxygen concentration is low and the airtight state is maintained. Further, since the pressure inside the cleaning / drying apparatus including the vacuum container is negative, even if there is a leak, petroleum-based solvents and solvent vapor will not leak outside. Furthermore, since the outlet of the vacuum container 1 is usually opened only after the drying is completed, the flammable solvent is rarely directly exposed to the atmosphere. Further, the opening and closing of the gate valve can be always kept vacuum by taking an interlock so that the gate valve does not open unless the drying chamber is in vacuum. Therefore, the safety is extremely high. Further, since the work is washed and dried in the same sealed vacuum container, the gas of the petroleum solvent stored therein does not leak outside. Therefore, there is an advantage that the external work environment can be kept safe and free from environmental pollution. In addition, the vacuum degree of the cleaning chamber decreases during operation,
That is, by providing a vacuum switch in the cleaning chamber or in the middle of piping to detect the rise in pressure, even if a leak should occur, it is possible to detect it before the solvent leaks to the outside of the device. You can deal with it.

Further, in this example, a water-sealed vacuum pump 8 is used as an exhaust system for evacuating the inside of the vacuum container 1, and a mist or vapor of a flammable petroleum solvent is dissolved in the sealed water. Alternatively, since they are discharged in a mixed state, the concentration of petroleum solvent gas contained in the exhaust system can be reduced. Therefore, also from this aspect, according to the apparatus of the present embodiment, the external environment can be kept safe and free from environmental pollution. In addition, since there is very little risk of the petroleum solvent leaking to the outside in this way, explosion-proof specifications, fire extinguishing equipment, etc. are unnecessary or can be kept to a minimum. Therefore, the cost of the device can be reduced.

In order to increase the suction force of the water-sealed vacuum pump, it is better to use a water-sealed vacuum pump with an air ejector. In order to further increase the suction force, a mechanical booster pump may be connected in front of the water-sealed vacuum pump. In this embodiment, the cleaning apparatus and the drying apparatus are provided as separate tanks, and in order to obtain higher cleaning quality, a horizontal vacuum cleaning / drying apparatus having a plurality of cleaning tanks by arranging several cleaning tanks of FIG. 1 ( For example, it is also very effective to use two cleaning tanks for rough cleaning and finish cleaning and one drying tank shown in FIG. Further, the shape of the work cradle 16 is not limited to that of the present embodiment, and may be any one as long as hot water can be circulated inside the work cradle.

Second Embodiment In the cleaning apparatus of FIG. 1, when the petroleum-based solvent is heated, especially when it is used in a boiling state, the petroleum-based solvent evaporates and is discharged to the outside of the vacuum container through the vacuum pump. The reduction of the solvent in the vacuum container becomes remarkable. The reduction of the solvent leads to an increase in cleaning cost and an increase in the maintenance and management of the equipment because the petroleum solvent must be constantly replenished. For this reason, in this embodiment, it is further preferable to provide an oil trap in the preceding stage of the exhaust system for evacuating the inside of the vacuum container.

An example of a vacuum cleaner having an oil trap is shown in FIGS. An exhaust pipe 3 is connected to a side surface above the vacuum cleaning chamber 1 (above the liquid surface of the petroleum solvent 2) in FIG. 5A. The exhaust pipe 3 is connected to a suction port 8 a of a water-sealed vacuum pump 8 via a valve 4. An oil trap 24 is provided in the middle of the exhaust pipe 3. Piping 3 between the oil trap 24 and the vacuum container 1
There is a cooler around. This may be water cooled or air cooled.
Below the oil trap 24 is a drain pipe 27 via a discharge valve 26.

The petroleum solvent evaporated in the vacuum container 1 is cooled and liquefied by the cooler 25 provided around the exhaust pipe 3. The liquefied petroleum solvent is the oil trap 24.
And drained from the drain pipe 27 as appropriate. By adopting such a configuration, the concentration of the petroleum solvent in the exhaust reaching the water-sealed vacuum pump 8 can be suppressed.

Further, as shown in FIG. 5 (b), the drain pipe 27 may be connected to a position lower than the liquid level of the petroleum solvent in the vacuum container 1. In this case, the inner diameter of the drain pipe is made smaller than the inner diameter of the exhaust pipe 3. With such a configuration, the trapped petroleum solvent can be easily returned to the inside of the vacuum container 1 without exposing the inside of the vacuum container 1 to the atmosphere after being liquefied. At this time, the drain pipe 27
Is filled with the petroleum solvent to the same level as the liquid surface of the petroleum solvent in the vacuum container 1. The drain pipe 27 in FIG.
The reason why the diameter is smaller than the diameter of the exhaust pipe 3 is to prevent the petroleum solvent from flowing into the water-sealed vacuum pump 8 from the drain pipe 27 during evacuation.

The drain pipe 27 may be connected to the drain pipe 6 of the vacuum container 1 as shown in FIG. 5 (c). Although not shown in the figures other than this example, a valve is provided in the middle of the drain pipe so that the flow rate of the drain pipe 27 can be reduced, or when vacuuming is performed, this valve is closed and the valve is opened after the vacuuming is completed to liquefy the petroleum solvent It may be configured to return to the vacuum container, or a check valve may be provided in the middle of the drain pipe 27 so that it is closed during evacuation and opened after the evacuation is completed.

Third Embodiment Next, FIGS. 6 and 7 show modifications of the apparatus shown in FIG. 1, respectively. First, in the apparatus shown in FIG.
Valve 28 for dividing the internal space of the car into upper and lower parts
Is installed. The upper space of the vacuum container 1 partitioned by the gate valve 28 is used as a vacuum drying chamber, and the exhaust pipe 3 is connected to the side surface thereof.

In the apparatus of this example, the gate valve 28
Is opened as shown by the solid line in FIG. 6, and the work W is subjected to immersion ultrasonic cleaning. Lifting cylinder 15 after cleaning
The work W is pulled up above the partition position by the gate valve 28, and is held at the broken line position in the figure. After that, the gate valve 28 is pulled out as shown by the broken line in the figure, and the inside of the vacuum container 1 is divided into upper and lower parts. At this time, the vacuum drying chamber and the vacuum cleaning chamber in the upper space of the vacuum container 1 are physically completely separated. After this, the work W is vacuum dried in the upper vacuum drying chamber. Other operations are similar to those of the device shown in FIG.

According to the apparatus thus constructed, the volume of the vacuum drying chamber can be reduced. Further, when the gate valve is closed, the petroleum solvent accumulated at the bottom of the vacuum container does not enter the upper vacuum drying chamber. Therefore, the degree of vacuum in the vacuum drying chamber can be increased, and the drying time can be shortened. Further, when the dried work is taken out, the petroleum solvent in the vacuum container is separated from the atmosphere by the gate valve, so that the petroleum solvent is not exposed to the atmosphere. Therefore, the petroleum solvent can be prevented from evaporating into the atmosphere, and the external environment can be kept safe and free from pollution. In addition, although not shown, if a valve capable of leaking to the extent that the degree of vacuum is not extremely lowered during vacuum drying is provided, the partial pressure of the solvent gas in the drying chamber will be reduced, so that the drying property will be further improved. You can Atmosphere may be used, but it is better if nitrogen is leaked.

The apparatus shown in FIG. 7 is provided with a petroleum solvent circulation system for vacuum distillation regeneration of the petroleum solvent in the vacuum vessel. As shown in the figure, the discharge pipe 6 connected to the bottom surface of the vacuum container is connected to the side surface of the distillation tank 32 via a pressure adjusting valve 29 (a), a pressure pump 30 and a valve 31.

A float 33 for controlling the liquid level is installed in the distillation tank 32, and the opening / closing control of the valve is controlled so that the liquid level of the petroleum solvent stored in the tank becomes a constant level. Do it. A heating source is installed on the bottom surface of the tank 32 to heat the petroleum solvent. A discharge pipe 35 for discharging the distillation residue remaining on the bottom of the distillation tank is connected to the discharge pipe 3
5 is connected to the recovery layer side (not shown) via a valve 36. A solvent vapor supply pipe 37 is connected to the upper end of the tank 32. The solvent vapor supply pipe 37 is connected to a heat exchanger 38 for liquefying the solvent vapor. The heat exchanger 38 again stores the liquefied solvent in the vacuum container 1
A supply pipe 39 for refluxing the inside is connected. This supply pipe 39 is provided with a pressure pump 40 and a pressure adjusting valve 29.
It is connected to the side surface of the vacuum container 1 via (a).

In the thus constructed apparatus of this example, the petroleum solvent in the vacuum container is recovered in the distillation tank, and vacuum distillation / regeneration is performed there. The solvent vapor that has been regenerated is liquefied again in the heat exchanger and is returned to the vacuum pump. Therefore, according to this example, the cleaning life of the petroleum solvent in the vacuum tank and deterioration such as oxidation can be prevented, and the cleaning quality of the work can be maintained for a long time.

Fourth Embodiment Next, FIG. 8 shows a modification of the apparatus shown in FIG. Similar to FIG. 6, the apparatus shown in FIG. 8 is provided with a gate valve 28 for vertically dividing the internal space of the vacuum container 1 into two parts. The upper space of the vacuum container 1 partitioned by the gate valve 28 is used as a vacuum drying chamber, and the exhaust pipe 3 is connected to the side surface thereof. The lower space of the vacuum container 1 is divided into a portion for immersion cleaning and a portion for shower cleaning as a vacuum cleaning chamber. A shower nozzle 41 connected to a vacuum distiller is provided on the side surface of the vacuum container in the shower cleaning section. From this shower nozzle 41, the clean petroleum solvent distilled in the vacuum distiller 32 is jetted. A discharge pipe 6 is provided on the bottom surface of the vacuum container 1 for sending the petroleum solvent, which is contaminated by the cleaning of the work W, to the vacuum distiller 32.

In the apparatus of this example, the gate valve 28
Is opened as shown by the solid line in FIG. 8, and the work W is subjected to immersion ultrasonic cleaning. After the immersion ultrasonic cleaning is finished, the work W is raised to the position of the shower nozzle 41 by the elevating cylinder 15. At this time, the work W can be sufficiently rinsed by directly injecting the petroleum solvent distilled by the vacuum distiller 32 onto the work W. After cleaning, the work cylinder W is moved to the gate valve 28 by the lifting cylinder 15.
It is pulled up above the partition position by and is held at the broken line position in the figure. After that, the gate valve 28 is pulled out as shown by the broken line in the figure, and the inside of the vacuum container 1 is divided into upper and lower parts. At this time, the vacuum drying chamber and the vacuum cleaning chamber in the upper space of the vacuum container 1 are physically completely separated. After this, the work W is vacuum dried in the upper vacuum drying chamber. Other operations are similar to those of the device shown in FIG. At this time, the vacuum pump is further operated to raise the degree of vacuum higher than the degree of vacuum at the time of cleaning, so that the evaporation of the petroleum solvent can be further promoted and the drying time can be shortened. Further, by adopting a heating plate for the work cradle 16 as shown in FIG. 4, the drying time can be further shortened.

Further, according to the apparatus constructed as described above, even if the petroleum solvent for immersion cleaning is slightly soiled by repeated cleaning, the clean solvent distilled by the vacuum still 32 is sprayed onto the work by the shower. Because you can
Finish cleaning can be performed, and the cleaning quality is further improved. Also, the volume of the vacuum drying chamber can be reduced. Further, when the gate valve is closed, the petroleum solvent accumulated at the bottom of the vacuum container 1 does not enter the upper vacuum drying chamber. Therefore, the degree of vacuum in the vacuum drying chamber can be increased, and the drying time can be shortened. Further, when the work after drying is taken out, the petroleum solvent in the vacuum container 1 is separated from the atmosphere by closing the gate valve 28, so that the petroleum solvent is not exposed to the atmosphere. Therefore, the petroleum solvent can be prevented from evaporating into the atmosphere, and the external environment can be kept safe and free from pollution.

Further, an oil trap as shown in FIGS. 5 (a) to 5 (c) is provided in front of the vacuum pump of the exhaust system as shown in FIG.
Even when the petroleum-based solvent is heated to near the boiling point during cleaning, the reduction of the petroleum-based solvent due to evaporation can be suppressed to a minimum.

Fifth Embodiment FIG. 9 shows a modification of the apparatus shown in FIG. The apparatus shown in FIG. 8 is a mechanism for heating the petroleum solvent regenerated by vacuum distillation and returning it to the inside of the vacuum container 1, and a pressure adjusting mechanism when the vacuum degree of the vacuum distiller is lower than the vacuum degree of the vacuum cleaning chamber. Is attached. As shown in the figure, the discharge pipe 6 connected to the bottom surface of the vacuum container is connected to the side surface of the distillation tank 32 via the check valve 52, the pressure feed pump 30, the valve 31, and the liquid level adjuster 42.

A float 33 for controlling the liquid level is installed in the distillation tank 32, and the opening / closing control of the valve is performed so that the liquid level of the petroleum solvent stored in the tank is at a constant level. Do it. A heating source is installed on the bottom surface of the tank 32 to heat the petroleum solvent. A discharge pipe 35 for discharging the distillation residue remaining on the bottom of the distillation tank is connected to the discharge pipe 3
5 is connected to the side of a recovery tank (not shown) via a valve 36.

A solvent vapor supply pipe 37 is connected to the upper end of the tank 32. This solvent vapor supply pipe 37 is
It is connected to a heat exchanger 38 for liquefying the solvent vapor. The heat exchanger 38 is connected to a water separator 43 for separating water in the liquefied solvent. The water separator 43 separates water and petroleum solvent while circulating with a pressure pump 44. A solvent outlet 43a is provided on the side surface of the water separator 43, and the outlet 43a is connected to the solvent heating tank 45 by a pipe via a flow rate adjusting valve 51. The solvent heating tank 45 includes a pressure gauge 46 and a pressure switch 4.
7 and a heating tube 48 for temperature adjustment are provided. The temperature adjusting heating tube 48 can pass steam. The lower portion of the solvent heating tank 45 is connected to a supply pipe 39, and the supply pipe has an opening / closing valve 4 interlocked with a pressure switch 47.
9. The vacuum container 1 is connected via a shower / circulation switching valve 50.

The petroleum solvent distilled in the vacuum distiller 32 is stored in the solvent heating tank 45 after water is separated in the water separator 43. The pressure of the solvent heating tank 45 increases as the amount of the solvent stored in the solvent heating tank 45 increases.
If the pressure switch 47 is set so that the opening / closing valve 49 operates at a certain constant pressure, the opening / closing valve 49 opens and the solvent that has been distilled and regenerated flows into the vacuum container. When the solvent flows into the vacuum container 1, the amount of the solvent in the solvent heating tank 45 decreases and the pressure decreases. At this time, the same operation can be repeated by closing the open / close valve with the pressure switch 47.

As described above, when the vacuum degree of the solvent heating tank 45 or the vacuum distiller 32 is lower than that in the vacuum cleaning chamber, the solvent can be supplied to the vacuum container without providing a pump in the supply pipe 39. .

Further, according to the present embodiment, the entire pipe can be kept in a vacuum state, so that the safety is extremely high.

Sixth Embodiment Next, an embodiment of a cleaning method using the cleaning / drying apparatus shown in FIG. 9 will be described. FIG. 11 shows a timing chart. The horizontal axis of FIG. 11 represents time, where A represents the degree of vacuum in the vacuum cleaning chamber and B represents the degree of vacuum in the vacuum drying chamber.

As the cleaning agent, ACTREL 1140L (manufactured by Exxon Chemical Co., Ltd.) is used. The basic physical properties of this petroleum-based cleaning agent are a flash point of 43 ° C and a boiling point of 155-155.
195 ° C, surface tension 24.4 dyne / square ・
cm, latent heat of vaporization 70.0 (ratio to triethane 1.21). The vapor pressure curve of this detergent is shown in FIG. As the cleaning work, a SUS short lead material (40 mm × 150 mm) for a lead frame is used. In this work,
Cutting oil containing chlorine-based extreme pressure agent as dirt (JIS 2 11
No.) is attached. The object to be cleaned was a stack of 20 objects to be cleaned. This work is set on the work cradle in FIG. 9 (FIG. 11-1), and the lid of the vacuum container is closed (FIG. 1).
1.2). Since the gate valve is closed at this time,
The vacuum degree in the vacuum cleaning chamber is 50 Torr. By vacuuming with a vacuum pump (Fig. 11-2-3), the vacuum degree in the vacuum drying chamber is the same as the vacuum cleaning chamber, 50 Torr.
After setting to r, the gate valve is opened (Fig. 11.4), and the work is immersed in the cleaning liquid stored in the vacuum cleaning chamber (Fig. 11.5). The temperature of the cleaning liquid at this time is maintained at 80 ° C. After that, ultrasonic cleaning is performed for 5 minutes with an ultrasonic oscillator of 40 KHz (Fig. 11-5-6). At this time, the work is oscillated at a span of 10 cm for 5 sec / stroke. After ultrasonic cleaning, the work is pulled up from the surface of the cleaning liquid, and the cleaning agent regenerated by the vacuum distiller is sprayed onto the work by a shower (Fig. 11-6-7). After that, the work is pulled up to the vacuum drying chamber (Fig. 11 ・
7) Close the gate valve (Fig. 11 ・ 8). Next, the vacuum pump is evacuated and the vacuum degree in the vacuum drying chamber is set to 1
Set to 0 Torr (Fig. 11.9). The work surface is heated to about 80 ° C. by the residual heat of the cleaning liquid. Since the surface of the work has a higher temperature than the boiling point of 51 ° C. at 10 Torr of the cleaning liquid, the cleaning liquid attached to the surface of the work evaporates. However, since this cleaning liquid has a latent heat of vaporization of about 70.0, the surface temperature of the work may gradually decrease as the cleaning liquid on the surface of the work evaporates, and the drying property may deteriorate. 8 in the work cradle to prevent this
By circulating hot water at 0 ° C, the temperature drop of the work is suppressed. After drying for 5 minutes (Figs. 11-9-10), air was leaked to the vacuum drying chamber (Figs. 11-10-11).
Open the lid of the vacuum container and take out the work (Fig. 11.1).
2).

For this work, the amount of adhered dirt before cleaning was determined in advance by carbon tetrachloride extraction, and the amount of adhered after cleaning was determined by the same method, and the cleaning rate was calculated from the following formula. Cleaning rate = (adhesion amount before cleaning−adhesion amount after cleaning) / adhesion amount before cleaning × 100

As a result, the cleaning rate was 96%, and cleaning was completed almost completely. Further, in the above experiment, it was 83% when the temperature of the cleaning liquid was 25 ° C. Further, when the degree of vacuum in the vacuum cleaning chamber was 760 Torr (atmospheric pressure) (other conditions were the same), it was 64%. Further, when the degree of vacuum in the vacuum cleaning chamber is set to 760 Torr, that is, atmospheric pressure, and the liquid temperature of the cleaning liquid is 25 ° C., it becomes 31%. By further heating the cleaning liquid in vacuum as in the present embodiment, the cleaning property can be improved. Is much improved. Moreover, the cleaning liquid does not remain at all visually. (The work of this experiment does not affect the subsequent process if the cleaning rate is 80% or more.)

Further, in the above-mentioned embodiment, when the vacuum degree of the vacuum cleaning chamber is 20 Torr, the boiling point of this cleaning liquid at this pressure is 68 ° C., so that the cleaning liquid is in a boiling state. If the washing and drying are performed under the other conditions in the boiling state according to the above-described embodiment, the washing rate is 97%.
The timing chart at this time is shown in FIG. In this case, when cleaning is not performed, the degree of vacuum in the vacuum cleaning chamber is lowered to such an extent that the cleaning liquid does not boil. The Greek letters on the horizontal axis indicate the same steps as those in FIG.
11 is different from FIG. 11 in that the gate valve is opened when the degree of vacuum in the vacuum drying chamber becomes almost the same as that in the vacuum cleaning chamber, and when the vacuum cleaning is completed, the vacuum in the vacuum cleaning chamber and the vacuum drying chamber is reduced. The point is to lower the degree once. With such a configuration, the cleaning liquid does not boil when it is not cleaned, and evaporation of the cleaning liquid can be suppressed.

By thus heating in a vacuum state, the cleaning power is remarkably improved. In particular, it has been found that the washing power is further improved by heating the washing liquid to a temperature above the boiling point of a certain degree of vacuum. It is clear from the results of the above cleaning rate that increasing the degree of vacuum is more than increasing chemical energy by applying heat.

An example in which a similar experiment was performed with a work having another shape will be shown below. The workpiece is a copper-based part having uncompleted holes. The size of the work piece is 0.8m inside diameter
m, the outer diameter is 1.2 mm, and the length is 20 mm. 1000 parts were put in a basket and tested by the above-mentioned washing and drying method. As a result, in the above experiment, the temperature of the cleaning liquid was 8
When the temperature is 0 ° C and the vacuum degree is 50 Torr, the cleaning rate is 81
%, And the washing was almost completely completed. It was 53% when the temperature of the cleaning liquid was 25 ° C. Further, when the vacuum cleaning chamber was set to atmospheric pressure (other conditions were the same), it was 23%. Further, when the vacuum cleaning chamber is set to atmospheric pressure and the temperature of the cleaning liquid is 25 ° C., it becomes 11%, and the cleaning property is remarkably improved by heating the cleaning liquid in vacuum as in this embodiment. Moreover, the cleaning liquid does not remain at all visually.

Further, in the above-mentioned embodiment, when the vacuum degree of the vacuum cleaning chamber is 20 Torr, the boiling point of this cleaning liquid at this pressure is 68 ° C., so that the cleaning liquid is in a boiling state. When the washing and drying are performed under the other conditions in this boiling state according to the above-mentioned embodiment, the washing rate is 92%.

When the degree of vacuum is raised all at once after the end of cleaning, the cleaning agent adhering to the work is boiled and scattered to be drained. By bumping and scattering the cleaning liquid in this way, the amount of the cleaning agent adhering to the workpiece is significantly reduced immediately after raising the degree of vacuum, and the remaining cleaning agent is evaporated after that, so gradually. It is possible to shorten the drying time as compared with the case where the degree of vacuum is increased. The exhaust speed at this time is preferably about 100 cubic m / hr.

Seventh Example An example of explosive properties in a vacuum container is shown below.

In the cleaning / drying apparatus shown in FIG. 9, ACTREL 1140L (manufactured by Exxon Chemical Co., Ltd.) is used as a cleaning agent, and a SUS short-sheath material (40 mm × 150 mm) for a lead frame is used as a cleaning work. This work contains cutting oil containing chlorine-based extreme pressure agent as dirt (JI
S2 type 11) is attached. The object to be cleaned was a stack of 20 objects to be cleaned. This work is placed on the work cradle in FIG. 9 and the lid of the vacuum container is closed. At this time, since the gate valve is closed, the degree of vacuum in the vacuum cleaning chamber is 50 Torr. The vacuum degree in the vacuum drying chamber is set to 50 Torr, which is the same as that in the vacuum cleaning chamber, by evacuating with a vacuum pump, and then the gate valve is opened to immerse the workpiece in the cleaning liquid stored in the vacuum cleaning chamber. The temperature of the cleaning liquid at this time is maintained at 80 ° C. After that, 4
5 ultrasonic cleaning with 0 KHz ultrasonic oscillator / vibrator
Do it for a minute. At this time, the workpiece is 5 cm with a span of 10 cm.
Swing ec / stroke. After ultrasonic cleaning, the work is pulled up from the surface of the cleaning liquid, and the cleaning agent regenerated by the vacuum distiller is sprayed onto the work by a shower. After that, the work is pulled up to the vacuum drying chamber and the gate valve is closed. Next, the vacuum pump is evacuated to bring the vacuum degree in the vacuum drying chamber to 10 Torr. The work surface is heated to about 80 ° C. by the residual heat of the cleaning liquid. Further, by circulating hot water of 80 ° C. in the work cradle, the temperature decrease of the work is suppressed. After drying for 5 minutes, air is leaked to the vacuum drying chamber, the lid of the vacuum container is opened, and the work is taken out. At this time, when the oxygen concentration in the vacuum container is measured, it is 0.1 ppm or less in the entire washing and drying process. This is because in addition to the vacuum state (50 Torr), the cleaning liquid is evaporated by heating the cleaning liquid and the air in the space in the vacuum container is replaced by the vaporized cleaning liquid.

That is, when vacuuming is performed, the calculated value is 5
At 0 Torr, the oxygen concentration is about 0.02%. However, although it was conventionally considered very dangerous to heat the combustible solvent by heating and evacuation, it can be said that this method is rather safe. As described above, the flammable cleaning liquid is heated while being evacuated by the vacuum pump, so that oxygen in the vacuum container is replaced and a non-explosive state is established. In this way, heating the cleaning liquid not only improves the cleaning and drying quality, but also exhibits an excellent effect on safety. Even if the temperature is not 80 ° C. as in the embodiment, the solvent is evaporated at a temperature higher than room temperature, which is sufficient to replace the solvent in the vacuum container, which is sufficient. Strictly speaking, it suffices that the cleaning liquid can be maintained at a constant temperature equal to or higher than room temperature without heating. The reason is that when not heated, the liquid temperature of the cleaning liquid is lowered by the heat of vaporization due to evaporation, so that the amount of evaporation is reduced and oxygen cannot be sufficiently replaced. Therefore, sufficiently high safety can be secured by heating to the extent that this reduction is prevented.

Eighth Embodiment Further, when a low boiling point compound, especially a chlorine compound such as chlorinated paraffin (boiling point: about 120 ° C.) is contained in the dirt as in this Example, a vacuum distiller is sufficient. Cannot be removed. As a result, chlorine compounds are mixed in the cleaning liquid,
Problems such as work discoloration and corrosion occur. This is particularly noticeable when the work uses a copper-based material. Also, if this chlorine is released to the atmosphere, it becomes an environmental problem. In order to prevent this, in this embodiment, a water-sealed vacuum pump is used as an exhaust system for evacuating the inside of the vacuum container as shown in FIG. 9, and a mist or vapor of a flammable petroleum solvent is used. Since it is discharged in a state of being dissolved or mixed in the sealed water, the concentration of petroleum solvent gas contained in the exhaust system is reduced and
Since chlorine compounds are water-soluble, they dissolve in sealed water.

Since the chlorine compound has a lower boiling point than that of the petroleum solvent, it is more likely to evaporate than the petroleum solvent. Therefore, the chlorine compound is discharged out of the vacuum container by drawing a vacuum while heating. Further, in order to prevent the chlorine compound from being discharged into the atmosphere, it is made into fine bubbles and dispersed in water. By this operation, the chlorine in the discharged exhaust gas is reduced to a level that does not pose a problem. As an additional effect, since chlorine is dispersed in the water in the gas-liquid separation tank, corrosion of this water can be prevented without adding a preservative, and maintenance and cost can be reduced. You can

Ninth Embodiment Another method for solving the problem in the seventh embodiment will be described in detail. FIG. 13 is a modification of FIG. A chlorine removing device 53 is attached to the cleaning / drying device of FIG. FIG.
Using the washing and drying equipment of the
140L (manufactured by Exxon Chemical Co., Ltd.) is used as a cleaning work as a lead frame SUS short board material (40 m).
m × 150 mm) is used. Cutting oil containing a chlorine-based extreme pressure agent (JIS 11 No. 2) adheres to this work as dirt. The object to be cleaned was a stack of 20 objects to be cleaned. Place this work on the work cradle in the figure and close the lid of the vacuum container. At this time, since the gate valve is closed, the degree of vacuum in the vacuum cleaning chamber is 50 Torr.
The vacuum degree in the vacuum drying chamber is set to 50 Torr, which is the same as that in the vacuum cleaning chamber, by evacuating with a vacuum pump, and then the gate valve is opened to immerse the workpiece in the cleaning liquid stored in the vacuum cleaning chamber. The temperature of the cleaning liquid at this time is maintained at 80 ° C. Then, ultrasonic cleaning is performed for 5 minutes with a 40 KHz ultrasonic oscillator / vibrator. At this time, the work is oscillated at a span of 10 cm for 5 sec / stroke. After ultrasonic cleaning, the work is pulled up from the surface of the cleaning liquid, and the cleaning agent regenerated by the vacuum distiller is sprayed onto the work by a shower. After that, the work is pulled up to the vacuum drying chamber and the gate valve is closed. Next, the vacuum pump is evacuated and the vacuum degree in the vacuum drying chamber is set to 1
Set to 0 Torr. 8 on the surface of the work due to residual heat of the cleaning liquid
It is heated to about 0 ° C. 80 in the work cradle
By circulating hot water at ℃, the temperature drop of the work is suppressed. After drying for 5 minutes, air is leaked to the vacuum drying chamber, the lid of the vacuum container is opened, and the work is taken out. The flow of the cleaning liquid during this series of cleaning / drying steps is as follows. The cleaning liquid stored in the vacuum container is mixed with a cutting oil containing a chlorine-based extreme pressure agent through a series of cleaning. This chlorine-based extreme pressure agent contains 2.5% chlorine. The cleaning agent containing chlorine or the like is transferred to a vacuum distiller. 10 in a vacuum distiller under reduced pressure of about 80 Torr
It is distilled at 0 ° C. The boiling point of the cleaning agent is 155 to 195 ° C,
Since chlorine is present in the form of chlorinated paraffins, the boiling point of this compound is approximately 120 ° C., so that the chlorinated paraffins are distilled first, followed by the detergent. The other components of the cutting oil have a boiling point of 200 ° C. or higher and are discharged as a distillation residue. Therefore, the chlorinated paraffin remains in the distilled cleaning agent without being separated. Chlorine can be removed by passing this cleaning agent through a chlorine removing device. This chlorine removing device is composed of an activated carbon adsorption tower or a water mixer that utilizes the dissolution of chlorine in water. The water mixer has a structure in which water and a detergent are stirred to extract chlorine in the detergent into water.

In FIG. 13, the chlorine removing device is provided at the outlet of the vacuum distiller, but it is not limited to this place and may be provided at any place of the pipe between the vacuum distiller and the vacuum vessel. Further, the cleaning / drying device is not limited to that shown in FIG. 6, and another cleaning / drying device such as that shown in FIG. 1 may be used.

The vacuum cleaning / drying apparatus and the cleaning / drying method of the present invention are not limited to petroleum-based solvents, but may be 20 Torr.
A liquid substance that evaporates under a reduced pressure of r under a temperature condition of about 100 ° C., preferably a cleaning agent mainly composed of an organic solvent having a boiling point of 120 to 200 ° C. under normal pressure can be applied.

[0068]

As described above, in the method and apparatus of the present invention, in order to solve the problems of safety and dryness when a flammable solvent such as a petroleum solvent is used as a cleaning liquid, the above-mentioned vacuum is used. Cleaning and vacuum drying are performed. By thus performing the vacuum cleaning / drying and the distillation regeneration of the cleaning liquid by circulation, the cleaning quality is not deteriorated even if the cleaning is repeatedly performed. Further, the cleaning, drying and regeneration of the cleaning liquid can be performed without exposing the combustible solvent as the cleaning liquid to the atmosphere at all, which is safe and avoids pollution of the working environment.

By heating the cleaning liquid and vacuum-cleaning it, the permeability of the solvent is improved. As a result, it is possible to surely clean the uncompleted holes, the fine holes, the downward holes, the close contact parts such as the gaps between the works, or the porous parts, which have been difficult to clean sufficiently in the past. Further, by heating the cleaning liquid, it is possible to reliably replace the oxygen in the container with the cleaning liquid gas, so that even if the works rub against each other, there is no possibility of ignition or explosion. Therefore it is very safe.

By further performing vacuum drying, the boiling point of the flammable solvent is lowered and the solvent can be evaporated even at a low temperature. In addition, solvent gas may remain as an adsorption layer, but by heating the work cradle, it is possible to suppress the temperature drop due to solvent evaporation of the work, and to obtain such an adsorption layer reliably and in a short time. be able to. Further, since it is possible to drain the liquid by bumping by raising the degree of vacuum all at once during drying, it is possible to shorten the drying time.

Further, in the case of cleaning a part such as a metal part which is likely to be rusted, since the cleaning and drying are performed in a vacuum having a low oxygen concentration and in an atmosphere replaced with a cleaning liquid gas, the parts are not cleaned in the cleaning and drying steps. There is also an advantage that rust does not occur in the.

Next, in the case where the gate valve is used to partition the upper and lower parts into the same vacuum container and the upper side is used as a drying chamber, the degree of vacuum at the time of washing and the time of drying can be changed, that is, drying. The drying time can be shortened by making the degree of vacuum during drying higher than that during washing in order to improve the property. Further, when the work is taken out of the vacuum container after drying, the side where the solvent is stored in the container is closed by the gate valve, so there is no risk of the solvent leaking into the atmosphere. Therefore, there is an advantage that it is safe and there is no fear of air pollution.

Even if the dirt containing chlorine is washed, it is possible to remove chlorine in the vacuum container or in the middle of the piping, so that there is no fear of adversely affecting the parts. In addition, when exhausting with a water-sealed vacuum pump and removing chlorine by bubbling in water, a suitable amount of chlorine dissolves in the water in the sealed water and the water / water separation tank. A long-term antiseptic effect can be obtained without adding.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a vacuum cleaning apparatus to which the method of the present invention is applied.

FIG. 2 is a schematic configuration diagram showing a vacuum drying device to which the method of the present invention is applied.

FIG. 3 is a schematic configuration diagram showing a case where a configuration in which a plate heating device is attached is adopted in the device of FIG.

4 is a perspective view including a cross section of a main part of a work cradle in the apparatus of FIG.

5 is a schematic configuration diagram showing a vacuum cleaning device provided with an oil trap in the device of FIG.

6 is a schematic configuration diagram showing a case in which a configuration in which a gate valve is attached to the apparatus of FIG. 1 so that the inside of a vacuum container can be divided into upper and lower portions is adopted.

7 is a schematic configuration diagram showing a case in which a configuration in which a solvent vacuum distillation regeneration mechanism is additionally provided in the apparatus of FIG. 6 is adopted.

8 is a schematic configuration diagram showing a case where a mechanism for directly showering a solvent regenerated by distillation onto a work is adopted in the apparatus of FIG.

9 is a schematic configuration diagram showing a case where a pressure adjusting mechanism is adopted in the device of FIG.

FIG. 10 is a diagram showing a vapor pressure curve of a cleaning agent used in this example.

FIG. 11 is a diagram showing a series of timing charts to which the method of the present invention is applied.

FIG. 12 is a diagram showing another timing chart to which the method of the present invention is applied.

13 is a schematic configuration diagram showing a case where a configuration in which a chlorine removal mechanism is attached to the apparatus of FIG. 9 is adopted.

[Explanation of symbols]

 1 ... Vacuum container 1a ... Lid W ... Workpiece 2 ... Petroleum solvent 3 ... Exhaust pipe 4 ... Valve 5 ... Ultrasonic transducer 6 ... Discharge pipe 7 ... ..Drain valve 8 ... Water-sealed vacuum pump 8a ... Suction port 9 ... Air / water mixed water distribution pipe 10 ... Water supply pipe 11 ... Gas-liquid separation tank 11a ... Reservoir water 12. ..Exhaust pipe 13 ... Drain pipe 14 ... Oil-water separator 14c ... Cooling chiller 15 ... Lifting cylinder 16 ... Work cradle 17 ... Supply pipe 18 ... Hot water tank 19. ..Heater 20 ... Pump 21 ... Tube 22 ... Water inlet 23 ... Discharge port 24 ... Oil trap 25 ... Cooler 26 ... Discharge valve 27 ... Drain pipe 28・ ・ ・ Gate valve 29 ・ ・ ・ Pressure control valve 30 ・ ・ ・ Pressure pump 3 ... Valve 32 ... Tank 33 ... Float 34 ... Heating source 35 ... Exhaust pipe 36 ... Valve 37 ... Solvent vapor supply pipe 38 ... Heat exchanger 39 ... Supply pipe 40 ... Pressure pump 41 ... Shower nozzle 42 ... Liquid level adjuster 43 ... Moisture separator 43a ... Solvent outlet 44 ... Pressure pump 45 ... Solvent heating tank 46・ ・ ・ Pressure gauge 47 ・ ・ ・ Pressure switch 48 ・ ・ ・ Temperature adjustment heating tube 49 ・ ・ ・ Open / close valve 50 ・ ・ ・ Shower / circulation switching valve 51 ・ ・ ・ Flow rate adjustment valve 52 ・ ・ ・ Check valve 53 ... Chlorine remover

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[Procedure amendment]

[Submission date] February 6, 1995

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Fig. 2]

[Figure 3]

[Figure 4]

[Figure 6]

[Figure 7]

[Figure 5]

[Figure 8]

[Figure 9]

[Figure 10]

FIG. 11

[Fig. 12]

[Fig. 13]

Claims (18)

[Claims] 1. A cleaning step of removing an object to be cleaned adhered to a work in a combustible solvent such as a petroleum solvent; pulling up the work from the combustible solvent to remove the combustible solvent adhered to the work. A vacuum cleaning / drying method comprising a drying step and a solvent regeneration step of regenerating the flammable solvent mixed with the object to be cleaned by distillation, and performing each of the steps in a vacuum. 2. The drying step is performed at a vacuum degree higher than a vacuum degree in a lower chamber in an upper compartment formed by vertically partitioning an internal space of a vacuum container storing the combustible solvent. The vacuum cleaning / drying method according to claim 1, wherein 3. The cleaning step comprises cleaning the work in the boiling combustible solvent by heating the combustible solvent and reducing the pressure to a vapor pressure of the combustible solvent or less. The vacuum / drying method according to claim 1. 4. The first cleaning step of immersing in the flammable solvent in the cleaning step, and the second cleaning step in which the combustible solvent distilled and regenerated in the solvent regenerating step is sprayed by a shower. The vacuum cleaning / drying method according to claim 1, further comprising a cleaning step. 5. The vacuum cleaning / drying method according to claim 1, wherein the flammable solvent is heated and the internal space of the vacuum container is decompressed by a vacuum pump, whereby the flammable solvent vaporized with the air in the vacuum container. A vacuum cleaning / drying method characterized in that the partial pressure of oxygen in the container is reduced by substituting the organic solvent gas. 6. The vacuum cleaning / drying method according to claim 5, wherein the vaporized combustible solvent is liquefied by a condenser provided between the vacuum pump and the vacuum container, and is refluxed in the vacuum container. A vacuum cleaning / drying method characterized by: 7. The vacuum cleaning / drying method according to claim 1, wherein the work is mounted on a holding table, and hot water is circulated inside the holding table. 8. A cleaning step of immersing the work in the flammable solvent at a first vacuum degree, and a drying step of rapidly reducing the pressure to a second vacuum degree higher than the first vacuum degree. The vacuum cleaning / drying method according to claim 2, which is characterized in that. 9. A cleaning step for removing an object to be cleaned containing a chlorine-based extreme pressure agent adhering to a work in a flammable solvent such as a petroleum solvent; the work is pulled up from the flammable solvent and adhered to the work. In a vacuum / drying method in which the drying step for removing the flammable solvent is performed while vacuuming with a vacuum pump, the gas exhausted by the vacuum pump is introduced into the water through a pipe so that it is included in the exhausted gas. A vacuum cleaning / drying method characterized in that chlorine derived from the chlorine-based extreme pressure agent is dissolved in water. 10. A cleaning / drying device for cleaning and drying a work by using a flammable solvent such as a petroleum solvent as a cleaning agent, and a vacuum container for vacuum cleaning and drying the work, and the inside of the vacuum container. Vacuum cleaning means for vacuuming the workpiece in the vacuum container that stores the heated cleaning agent, and has a distillation regenerating means for regenerating the cleaning solution by distillation and a heating means for heating the cleaning agent. And a vacuum cleaning / drying device which is adapted to perform vacuum drying. 11. The exhaust valve according to claim 10, further comprising a gate valve for partitioning the inside of the vacuum container into upper and lower parts, and an upper portion of the inside of the vacuum container partitioned by the gate valve is connected to an exhaust pipe by the vacuuming means. The vacuum cleaning / drying device is characterized in that the end of the exhaust pipe is immersed in the water stored outside the vacuum container. 12. The work elevating means capable of holding a work in a lower part, an intermediate part and an upper part in the vacuum container, and a partition in the vacuum container between the upper part and the intermediate part. And a distillation regeneration means for regenerating the cleaning agent by vacuum distillation, and an exhaust pipe by the vacuum evacuation means is connected to an upper part in the vacuum container partitioned by the gate valve. In the lower part of the vacuum container, an immersion cleaning chamber in which a flammable solvent is stored is formed, and in the intermediate part, a nozzle for spraying the cleaning agent distilled by the distillation regeneration means onto the workpiece is provided. A shower chamber is formed, and a vacuum drying chamber is formed in the upper portion by closing a gate valve. Vacuum cleaning / drying device. 13. The vacuum cleaning according to claim 12, further comprising: a holding table for holding the work attached to the work lifting means, and a means for heating the inside of the holding table with warm water. -Drying device. 14. The vacuum cleaning / drying apparatus according to claim 10, further comprising pressure adjusting means for connecting the vacuum vessels having different degrees of vacuum and the vacuum distillation means. 15. The exhaust pipe according to claim 10, which is connected to a side surface of the vacuum container at a portion higher than a liquid level of the cleaning agent stored in the vacuum container,
A reflux pipe connected to the exhaust pipe and having a diameter smaller than that of the connection pipe connected to the side surface of the vacuum container at a portion higher than the liquid level of the cleaning agent, and a connecting portion between the vacuum container and the reflux pipe. A vacuum cleaning / drying device having a cooling means provided between the two. 16. The vacuum cleaning / drying apparatus according to claim 10, wherein chlorine removing means is provided in a pipe between the vacuum container and the distillation regenerating means. 17. The vacuum cleaning / drying apparatus according to claim 12, wherein a lower portion of the vacuum container serving as a cleaning chamber is not exposed to the atmosphere during the cleaning / drying process. 18. The means according to claim 12, which detects a decrease in the degree of vacuum in the lower portion of the vacuum container serving as the cleaning chamber, and before the degree of vacuum becomes equal to the atmospheric pressure in accordance with the decrease in the degree of vacuum. A vacuum cleaning / drying device, characterized in that it has an alarm means for notifying an abnormality to.