Method for cleaning objects by performing peeling cleaning followed by vapor cleaning with a cleaning solvent, and cleaning device used in said method

Abstract

To enable peeling and cleaning without using a cleaning solvent, and to improve the cleaning effect of vapor cleaning of an object to be cleaned after the peeling and cleaning. [Solution] The object to be cleaned 17 is heated to 100°C or higher by immersing the object to be cleaned 17 in heated oil 1 heated to 100°C or higher, and then the object to be cleaned 17 is brought into contact with heated water 8, whereby peeling and cleaning is performed in which dirt adhering to the object to be cleaned 17 is physically peeled off by the pressure of steam generated when the object to be cleaned 17 comes into contact with the heated water 8, and after the peeling and cleaning, the object to be cleaned 17 is cooled and dried at room temperature, and then steam cleaning is performed on the object to be cleaned 17.

Description

[Technical field]

[0001] The present invention relates to a cleaning method for removing dirt adhering to objects to be cleaned, such as machine parts, electronic parts, medical equipment, etc., and to a cleaning device for the objects to be cleaned, which is used in this cleaning method. [Background technology]

[0002] [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. H05-004077 [Patent Document 2] Patent No. 6306257 DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0004] When manufacturing industrial products made of metals, ceramics, resins, etc., heat is generated during processing such as pressing and cutting, so it is common to cool the materials using processing oil during the process. Therefore, when such processing is performed, oil, cutting waste, and other contaminants adhere to the industrial products to be cleaned in this application, and these must be removed.

[0005] Conventionally, as a method for cleaning the above-mentioned objects to be cleaned, it has been common to use a large amount of cleaning solvent as shown in Patent Document 1. However, the use of such a large amount of cleaning solvent has caused photochemical smog, ozone layer destruction, soil contamination, and public hazards. In addition, since the use of fluorocarbon 113,1.1.1-trichloroethane was completely abolished worldwide in 1995, the reduction of carbon dioxide emissions has become a global issue in recent years. In order to solve such problems, it is necessary to significantly reduce the amount of cleaning solvent used when cleaning the objects to be cleaned.

[0006] However, in the currently commonly used cleaning methods, dirt such as oil, cutting chips, and cutting waste adhering to the object is simultaneously removed from the object by simultaneously using chemical and physical methods, so it is still necessary to use a large amount of cleaning solvent. Therefore, in order to avoid using such a large amount of cleaning solvent, a method is already known in which a heated object is brought into contact with boiling water or heated water to be rapidly cooled, as shown in Patent Document 2, and dirt adhering to the object is removed by the physical force of the steam generated by this rapid cooling.

[0007] However, as described in Patent Document 2, even if the object is quenched by contacting it with boiling water or heated water, the temperature of the object at the end of the liquid cleaning is often maintained at nearly 100°C. Therefore, when the object is subjected to steam cleaning after the liquid cleaning as described above, the surface temperature of the object is high, so that even if the cleaning vapor of the cleaning solvent comes into contact with the object, a sufficient condensation ratio cannot be obtained and it is difficult to condense and liquefy the cleaning vapor. In particular, the boiling point of a general cleaning solvent is often 100°C or less, and in such a case, it is necessary to cool the object after the liquid cleaning to near room temperature in order to obtain a sufficient condensation ratio, and it is difficult to condense and liquefy the cleaning vapor, making it extremely difficult to obtain a sufficient cleaning effect of the steam cleaning.

[0008] The first and second inventions of the present application are intended to solve the problems described above, by enabling peeling and cleaning, which is liquid cleaning that does not use a cleaning solvent, and by improving the cleaning effect of steam cleaning of the object to be cleaned after the peeling and cleaning. [Means for solving the problem]

[0009] In order to solve the above problems, the first invention of the present application involves immersing an object to be cleaned in heated oil heated to 100°C or higher, heating the object to 100°C or higher, and then contacting the object with heated water to physically peel off dirt adhering to the object by the pressure of steam generated when the object comes into contact with the heated water, and after the peeling and cleaning, cooling and drying the object in an environment at room temperature, and then steam cleaning the object with cleaning steam from a cleaning solvent. Specific examples of the heating oil that can be used in the first invention of the present application and the second invention described below include processing oil, rust-preventive oil, heat treatment oil, and polishing liquid.

[0010] The second invention of the present application is a cleaning device used in the cleaning method of the first invention, which includes a heated oil tank for storing heated oil of 100 degrees or more and for immersing the object to be cleaned in the heated oil, a heated water tank for storing heated water therein and for immersing the object to be cleaned treated in the heated oil tank in the heated water to perform stripping cleaning to strip off dirt adhering to the object to be cleaned, a cooling mechanism for placing the object to be cleaned treated in the heated water tank and for cooling and drying the object to be cleaned, and a steam cleaning tank for placing the object to be cleaned that has been cooled and dried in the cooling mechanism and for performing steam cleaning of the object to be cleaned using cleaning steam of a cleaning solvent. Effect of the Invention

[0011] As described above, the first and second inventions of the present application use only oil and water without using a cleaning solvent during the peeling and cleaning of the object to be cleaned, which is a liquid cleaning of the object to be cleaned, so there is no need to use a large amount of cleaning solvents that have a large environmental impact, making it possible to reduce the burden on the global environment. In addition, this peeling and cleaning involves contacting the object to be cleaned, which has been heated to 100°C or more in advance, with heated water, so that the pressure of the steam generated when the object to be cleaned comes into contact with the heated water makes it possible to physically peel off the dirt attached to the object to be cleaned.

[0012] In addition, because the method of the present invention can effectively remove oil and solids adhering to the object to be cleaned, even when precision cleaning is required in the next step of steam cleaning using a cleaning solvent, the amount of oil, dirt, etc. adhering to the object to be cleaned is significantly reduced. Therefore, in the steam cleaning performed after the peeling cleaning, it is possible to reduce the amount of cleaning solvent used compared to the conventional method, thereby reducing the burden on the environment.

[0013] Furthermore, since cooling and drying are performed after the peeling and cleaning, even if the object is close to 100°C after the peeling and cleaning is completed, the cooling and drying can significantly lower the temperature of the object to close to room temperature when the next step is performed for steam cleaning with cleaning vapor of the cleaning solvent, compared to the temperature at the end of the peeling and cleaning. This makes it possible to obtain a sufficient condensation ratio between the surface of the object and the cleaning vapor, and promotes the condensation and liquefaction of the cleaning vapor on the surface of the object, thereby improving the cleaning effect of the steam cleaning.

[0014] In addition, the first invention of the present application can reduce the cleaning cost because it can perform everything from peeling and cleaning to cooling and drying with only the thermal energy cost of producing boiling water and heated oil. Also, as described above, the oil and solid matter attached to the object to be cleaned can be physically removed from the object to be cleaned instantly as the water evaporates, so the time required for cleaning can be much shorter than that of conventional methods.

[0015] In addition, since the second invention of the present application can implement the first invention of the present application with a simple configuration as described above, it is possible to obtain a cleaning device that is easy to manufacture and low cost without requiring complex machines, etc. Furthermore, by performing peeling cleaning with heated water as described above in the heated water tank of the second invention, solid matter such as cutting chips and shavings attached to the object to be cleaned will settle in the heated water tank.

[0016] In conventional liquid cleaning, solids such as chips and shavings that have settled in the cleaning tank are dissolved before being collected and reused, but if a large amount of oil is attached to the solids, problems such as carbonization can occur. However, in the first and second inventions of this application, the solids removed from the object to be cleaned settle in the heated water tank, but the oil is peeled off at the same time as the object to be cleaned during peeling and cleaning with heated water. Therefore, since there is less oil attached to the solids that have settled in the heated water tank, problems such as carbonization are less likely to occur when the solids are reused, and it becomes possible to reuse the solids easily and efficiently at low cost. [Brief description of the drawings]

[0017] [Figure 1] 1 is a conceptual diagram of a cleaning device showing a first embodiment of the first and second inventions of the present application. Example 1

[0018] 1, a first embodiment of the first and second aspects of the present application will be described. (1) is a heating oil tank, and heating oil (2) having a boiling point exceeding 100° C. is stored inside the heating oil tank (1). A first heater (3) and a first temperature sensor (4) are disposed in the heating oil tank (1), and the heating oil (2) is constantly maintained at a temperature of 100° C. or higher and lower than the boiling point of the heating oil (2) by the first heater (3) and the first temperature sensor (4).

[0019] In this embodiment, as shown in Fig. 1, a heated water tank (5) is disposed adjacent to the heated oil tank (1). A second heater (6) and a second temperature sensor (7) are disposed inside the heated water tank (5). Water is stored inside the heated water tank (5), and the temperature of the water is maintained at less than 100°C by the second heater (6) and the second temperature sensor (7).

[0020] As shown in Fig. 1, a cooling mechanism (10) is disposed adjacent to the heated water tank (5). No special devices are disposed inside the cooling mechanism (10), and the object (17) to be cleaned that has been peeled and cleaned in the heated water tank (5) can be placed in the cooling mechanism (10) to be cooled and dried at room temperature. Note that, although the cooling mechanism (10) in this embodiment uses a cleaning tank as shown in Fig. 1, in other different embodiments, this is not limited to this, and the object (17) to be cleaned can be placed in any location at room temperature to be cooled and dried.

[0021] 1, a steam cleaning tank (11) is disposed adjacent to the cooling mechanism (10). A third heater (13) and a third temperature sensor (12) are disposed on the bottom side of the steam cleaning tank (11), and a cooling coil (15) is wound around the inner circumferential surface of the steam cleaning tank (11) on the opening (14) side.

[0022] A method for washing an object (17) using the washing device configured as described above will be described below. First, before starting washing, the heated oil (2) is heated in the heated oil tank (1) to a temperature of 100°C or higher and below the boiling point of the heated oil (2). The water stored in the heated water tank (5) is heated to an appropriate temperature below the boiling point. The heated oil (2) in the heated oil tank (1) and the heated water (8) in the heated water tank (5) are both managed by the first temperature sensor (4) and the second temperature sensor (7) to maintain their respective set temperatures.

[0023] A cleaning solvent (18) is stored in the steam cleaning tank (11), and the cleaning solvent (18) is heated to a temperature equal to or higher than the boiling point of the cleaning solvent (18) by operating the third heater (13) in the steam cleaning tank (11), thereby generating cleaning steam (16) in the steam cleaning tank (11). Since the cooling coil (15) is wound around the opening (14) side of the steam cleaning tank (11) as described above, the cleaning steam (16) generated in the steam cleaning tank (11) comes into contact with the cooling coil (15) and is condensed and liquefied in the cooling coil (15), and is then dropped again into the cleaning solvent (18) in the steam cleaning tank (11) and recovered.

[0024] First, the object (17) is subjected to peeling cleaning, which is liquid cleaning. That is, as shown in Fig. 1, the object (17) is immersed in heated oil (2) heated in the heated oil tank (1). This makes it possible to remove some of the oil and solid matter such as cutting chips adhering to the object (17), and the object (17) is heated to 100°C or higher. After the object (17) is sufficiently heated, the object (17) is removed from the heated oil tank (1) and immersed in heated water (8) in a heated water tank (5) as shown by the second chain line in Fig. 1.

[0025] By immersing the object (17) in the heated water (8) in this manner, the heated water (8) that comes into contact with the surface of the object (17) evaporates instantaneously. Therefore, dirt adhering to the object (17) is physically peeled off by the pressure of the water vapor generated during the instantaneous evaporation of the heated water (8).

[0026] In this embodiment, pure water or nearly pure water is used as the heated water (8). When the object (17) is removed from the heated water tank (5), the heated water (8) adhering to the surface of the object (17) evaporates into the air. If tap water or the like is used, the evaporation of the heated water (8) can easily cause stains on the surface of the object (17). However, in this embodiment, pure water or nearly pure water is used as described above, so the occurrence of such stains after evaporation of the water can be minimized.

[0027] In addition, by performing peeling and cleaning in the heated oil tank (1) and heated water tank (5) as described above, it is possible to remove oil and solid matter adhering to the object (17) to be cleaned to a certain extent. Therefore, in the steam cleaning performed after the peeling and cleaning, it is possible to easily and quickly remove the remaining dirt adhering to the object (17) to be cleaned, and it is possible to reduce the amount of cleaning solvent (18) used in the steam cleaning.

[0028] Furthermore, by performing peeling and cleaning with the heated water (8) as described above in the heated water tank (5), solid matter such as cutting chips and shavings that have adhered to the object (17) to be cleaned together with oil settles in the heated water tank (5). Then, the oil content of the solid matter that settles in the heated water tank (5) is peeled off from the solid matter in the same manner as the object (17) to be cleaned when the object (17) is peeled and cleaned. Therefore, when reusing the solid matter recovered from the heated water tank (5), problems such as carbonization due to the oil adhering to the solid matter do not occur, and the solid matter can be easily and efficiently reused at low cost.

[0029] Then, as the next step after the peeling and cleaning, the object (17) is cooled and dried. That is, the object (17) that has been peeled and cleaned with heated water (8) as described above is left to stand at room temperature in the cooling mechanism (10) as shown in Fig. 1. As a result, the object (17) that was heated to nearly 100°C during the peeling and cleaning is cooled to nearly room temperature.

[0030] After the object (17) is cooled and dried, the object (17) is subjected to steam cleaning. To explain the steam cleaning method, first, a cleaning solvent (18) is placed in the cleaning tank (11) in advance. The cleaning solvent (18) may be a chlorine-based solvent, a fluorine-based solvent, an alcohol-based solvent, a petroleum-based solvent, or the like, which are widely and generally used in conventional cleaning. When a petroleum-based solvent is used, steam cleaning is performed under reduced pressure.

[0031] The cleaning solvent (18) is heated to a temperature equal to or higher than the boiling point of the cleaning solvent (18) by the third heater (13) in the steam cleaning tank (11), thereby generating cleaning steam (16) in advance in the steam cleaning tank (11). Then, as shown in FIG. 1, an object to be cleaned (17) is placed in the cleaning steam (16) generated in the steam cleaning tank (11).

[0032] At this time, since the object (17) to be cleaned was placed at room temperature in the cooling and drying process as described above, the temperature of the object (17) to be cleaned has been cooled to a temperature close to room temperature. Therefore, by placing the object (17) to be cleaned in the steam cleaning tank (11), the cleaning steam (16) comes into contact with the object (17) to be cleaned, and the cleaning steam (16) condenses on the surface of the object (17). Therefore, the condensation of the cleaning steam (16) makes it possible to effectively remove dirt remaining on the object (17) to be cleaned.

[0033] With the above-mentioned simple configuration, this embodiment can perform everything from peeling and washing to cooling and drying with only the thermal energy cost of heating the water and oil, and can instantly physically remove the oil and solid matter adhering to the object (17) to be washed from the object (17) by the pressure caused by the generation of steam as described above. Therefore, it is possible to greatly shorten the time required for peeling and washing and cooling and drying compared to the conventional method. In addition, it is possible to reduce the burden on the environment without requiring a large amount of washing solvent, and to keep the washing cost low. [Explanation of symbols]

[0034] 1 Heating oil tank 2 heating oil 5. Heated water tank 8 Heated water 10 Cooling mechanism 11 Steam cleaning tank 17 Items to be washed

Claims

1. A cleaning method for an object to be cleaned, characterized in that the object to be cleaned is heated to 100°C or higher by immersing the object in heated oil that has been heated to 100°C or higher, and then the object is brought into contact with heated water to perform peeling cleaning in which dirt adhering to the object to be cleaned is physically peeled off by the pressure of steam generated when the object to be cleaned comes into contact with the heated water, and after the peeling cleaning, the object to be cleaned is cooled and dried at room temperature, and then steam cleaning of the object to be cleaned is performed using cleaning steam from a cleaning solvent.

2. A cleaning device for objects to be cleaned, comprising: a heated oil tank for storing heated oil of 100 degrees or higher and for immersing the objects to be cleaned in the heated oil; a heated water tank for storing heated water therein and for immersing the objects to be cleaned that have been treated in the heated oil tank in the heated water to perform stripping cleaning in which dirt adhering to the objects to be cleaned is peeled off; a cooling mechanism for placing the objects to be cleaned that have been treated in the heated water tank and for cooling and drying the objects; and a steam cleaning tank for placing the objects to be cleaned that have been cooled and dried in the cooling mechanism and for performing steam cleaning of the objects to be cleaned using cleaning steam of a cleaning solvent.

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