Method for cleaning objects

Abstract

To provide a method for cleaning an object to be cleaned, which does not require a large amount of cleaning solvent even when removing a large amount of oil, is considerate of safety and the global environment, and can keep cleaning costs low. [Solution] The method includes a heating step in which the object to be cleaned (14) is heated to 100°C or higher by immersing the object in heated oil (4) at 100°C or higher; a peeling step in which the object to be cleaned (14) is brought into contact with heated water (6) to perform peeling and cleaning, which physically peels off dirt adhering to the object to be cleaned (14) by the pressure of the generated steam; a solvent liquid cleaning step in which the object to be cleaned (14) is brought into contact with a cleaning solvent (13) having a boiling point lower than the temperature of the object to be cleaned (14) after the peeling and cleaning, thereby removing any oil remaining on the object to be cleaned (14); and a drying step in which the temperature of the object to be cleaned (14) is maintained higher than the boiling point of the cleaning solvent (13), and the cleaning solvent (13) adhering to the object to be cleaned (14) is evaporated by the heat of the object to be cleaned (14).

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. [Background technology]

[0002] 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, the presence of processing oil causes dirt such as oil and cutting chips to adhere to the industrial products to be cleaned in this application, and these must be removed.

[0003] When cleaning such objects to be cleaned, it has been common practice to use a large amount of cleaning solvent in liquid cleaning and vapor cleaning 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 phased out worldwide in 1995, reducing 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 during cleaning. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. H05-004077 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in cleaning for removing grease, carbon, water-soluble cutting oil, etc., strong physical forces or a large amount of cleaning solvent may be required to remove a large amount of oil. Therefore, it is still necessary to use a large amount of cleaning solvent. In addition, as described in Reference 1, when performing vapor cleaning using a cleaning solvent, there are concerns about the diffusion of solvent vapor into the atmosphere and the consumption of the cleaning solvent, which can easily cause problems in terms of environmental load, safety, and even cleaning costs.

[0006] Therefore, the present application aims to solve the above-mentioned problems by providing a cleaning method for objects to be cleaned that does not require a large amount of cleaning solvent even when removing a large amount of oil, while being considerate of safety and the global environment and keeping cleaning costs low. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention includes a heating step in which the object to be cleaned is heated to 100°C or higher by immersing the object in heated oil heated to any temperature above 100°C, and a peeling step in which the object to be cleaned is brought into contact with heated water after the heating step, and the pressure of the steam generated when the object to be cleaned comes into contact with the heated water physically peels off dirt adhering to the object to be cleaned. The heated water can be set to any temperature below 100°C depending on the purpose of cleaning.

[0008] The temperature of the object to be cleaned after the heating step is 100°C or higher, and since the object to be cleaned at 100°C or higher is brought into contact with heated water during the subsequent peeling and cleaning, the temperature of the object to be cleaned during the peeling and cleaning is lower than the temperature of the heated oil and is the same as or higher than the temperature of the heated water. After the peeling step, the object to be cleaned is brought into contact with a liquid cleaning solvent having a boiling point lower than the temperature of the object to be cleaned after the peeling and cleaning, thereby performing a solvent liquid cleaning step to remove oil remaining on the object to be cleaned.

[0009] After the solvent liquid washing step, a drying step is performed in which the cleaning solvent adhering to the object is evaporated by the heat of the object while the temperature of the object is kept higher than the boiling point of the cleaning solvent. In order to keep the temperature of the object higher than the boiling point of the cleaning solvent as described above, it is preferable to move to a drying step of the object as soon as possible after the solvent liquid washing step.

[0010] The oil used in the method of the present invention is not particularly limited, but preferred are processing oil, rust-preventive oil, heat treatment oil, polishing liquid, etc., and the cleaning solvent used in the method of the present invention is not particularly limited, but preferred are chlorine-based solvents, fluorine-based solvents, alcohol-based solvents, etc.

[0011] The solvent liquid washing step may be a method of showering the object to be washed with the washing solvent, or a method of immersing the object to be washed in the washing solvent. Effect of the Invention

[0012] As described above, the present invention physically removes dirt adhering to the object to be cleaned in the peeling step, and then performs a solvent liquid cleaning step to remove oil remaining on the object to be cleaned after the peeling step. Therefore, even for stubborn dirt on the object to be cleaned that was difficult to remove in the past, the effect of removing dirt adhering to the object to be cleaned easily and reliably can be achieved by successively removing the physical dirt and the chemical dirt in the peeling step and the solvent liquid cleaning step, so that even if a large amount of oil is adhering to the object to be cleaned before cleaning, the oil can be removed quickly and effectively.

[0013] In addition, since the present invention does not use vapor cleaning with a cleaning solvent, it is not necessary to use a large amount of cleaning solvent and the consumption of the cleaning solvent can be kept low, which makes it possible to consider safety and the global environment and to reduce cleaning costs.

[0014] As described above, the drying process of the present invention is a process in which the temperature of the object to be cleaned is kept higher than the boiling point of the cleaning solvent after the solvent liquid cleaning process, and the cleaning solvent adhering to the object to be cleaned is evaporated by the heat of the object to be cleaned. Therefore, no special device or the like is required for drying, and the object to be cleaned can be dried quickly and reliably at low cost. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a conceptual diagram of a first embodiment of the present invention. Example 1

[0016] A first embodiment of the present invention will be described with reference to Fig. 1. (1) is an oil tank equipped with a first heater (2) and a first temperature sensor (3) on the bottom side. Oil (4) that can be heated to any temperature above 100°C is stored in the oil tank (1). A water tank (5) is provided adjacent to the oil tank (1) and water (6) is stored in the water tank (5). A second heater (7) and a second temperature sensor (8) are provided on the bottom side of the water tank (5), and the water (6) in the water tank (5) can be constantly heated and kept warm at a constant temperature by the second heater (7) and the second temperature sensor (8).

[0017] 1, a solvent tank (10) is disposed adjacent to the water tank (5), and a third heater (11) and a third temperature sensor (12) are provided on the bottom side of the solvent tank (10). A cleaning solvent (13) is stored inside the solvent tank (10), and the temperature of the cleaning solvent (13) can be heated by the third heater (11) and maintained at a constant temperature by the third temperature sensor (12).

[0018] A method for washing an object (14) using the washing device configured as described above will be described below. First, before starting washing, the oil (4) in the heating oil tank (1) is heated by the first heater (2) to a desired temperature that is 100°C or higher and lower than the boiling point of the oil (4), and the temperature is maintained by the first temperature sensor (3). The oil (4) can be heated to any temperature between 100°C or higher and lower than the boiling point of the oil depending on the purpose of washing. The water (6) stored in the water tank (5) is heated by the second heater (7) to a predetermined temperature of 100°C or lower, and the temperature is maintained by the second temperature sensor (8).

[0019] The cleaning solvent (13) contained in the solvent tank (10) is heated to a predetermined temperature, which will be described below, by the third heater (11), and the temperature is maintained by the third temperature sensor (12).

[0020] Next, the cleaning process of the object (14) in this embodiment will be described. First, the object (14) is immersed in an oil tank (1) containing oil (4) heated to 100°C or higher, thereby performing a heating process in which the object (14) is heated to 100°C or higher. After the object (14) is heated to a predetermined temperature of 100°C or higher in the heating process, the object (14) is removed from the oil tank (1) and a peeling process is performed.

[0021] In the peeling process, the object (14) to be cleaned, which has been heated to 100°C or higher as described above, is immersed in the heated water (6) in the water tank (5). By immersing the object (14) to be cleaned, which has been heated to 100°C or higher, in the heated water (6), the heated water (6) comes into contact with the object (14) to be cleaned, which has a temperature of 100°C or higher, and the heated water (6) evaporates instantaneously. Therefore, the pressure of the steam generated during the instantaneous evaporation of the heated water (6) can physically and instantaneously peel off dirt such as oil (4) and chips adhering to the object (14) to be cleaned.

[0022] After the peeling step is completed, the solvent liquid cleaning step is performed. The solvent liquid cleaning step is described below. The object (14) to be cleaned, which has been immersed in the heated water (6) in the water tank (5) during the peeling step, is removed and immersed in the cleaning solvent (13) in the solvent tank (10). Here, the object (14) to be cleaned is heated to 100°C or higher in the heating step, as described above, and then immersed in heated water (6) containing boiling water and having a temperature of 100°C or lower in the peeling step. Therefore, the temperature of the object (14) to be cleaned after the peeling step is cooled by the heated water (6), and becomes the same as or higher than the heated water (6).

[0023] The cleaning solvent (13) in the solvent tank (10) has a boiling point lower than the temperature of the object (14) to be cleaned after the peeling step. The cleaning solvent (13) is heated to a temperature lower than the boiling point of the cleaning solvent (13) by the third heater (11) of the solvent tank (10), and the heated state is maintained by the third temperature sensor (12).

[0024] By passing through this solvent liquid cleaning step, dirt on the object to be cleaned (14) that could not be completely removed in the peeling step can be chemically removed by contacting the dirt with the cleaning solvent (13). Therefore, by successively carrying out the peeling cleaning and the solvent liquid cleaning as described above, it becomes possible to physically and chemically remove stubborn dirt on the object to be cleaned (14) that was difficult to remove in the past.

[0025] In the solvent liquid cleaning step, the object to be cleaned (14) is immersed in the cleaning solvent (13) for several to several tens of seconds, thereby allowing the dirt on the object to be cleaned (14) to be sufficiently removed. In this embodiment, the object to be cleaned (14) is immersed in the cleaning solvent (13) as described above, but in other different embodiments, the method is not limited to this, and the solvent liquid cleaning can also be performed by showering the cleaning solvent (13) onto the object to be cleaned (14).

[0026] After the solvent liquid cleaning process is completed, the object to be cleaned (14) is dried. The drying process will be described below. First, the object to be cleaned (14) immersed in the cleaning solvent (13) in the solvent tank (10) is removed and left at rest in an arbitrary location in the atmosphere. In the solvent liquid cleaning process, the object to be cleaned (14) is immersed in the cleaning solvent for several to several tens of seconds to complete the solvent liquid cleaning. Therefore, by moving to the drying process immediately after the solvent liquid cleaning process is completed as described above, the temperature of the object to be cleaned (14) can be maintained at a temperature higher than the boiling point of the cleaning solvent (13) in the drying process as well, similar to the solvent liquid cleaning.

[0027] Therefore, the cleaning solvent (13) adhering to the object (14) during the solvent liquid cleaning is instantly evaporated by the heat of the object (14) which is higher than the boiling point of the cleaning solvent (13). Therefore, the object (14) can be quickly dried without requiring a special device for drying. [Explanation of symbols]

[0028] 4 oil 6 water 13 Cleaning Solvents 14 Items to be washed

Claims

1. A method for cleaning an object to be cleaned, comprising the steps of: a heating step in which the object to be cleaned is heated to 100°C or higher by immersing the object in heated oil that has been heated to any temperature of 100°C or higher; a peeling step in which the object to be cleaned is brought into contact with heated water after the heating step, and 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; a solvent liquid cleaning step in which, after the peeling step, the object to be cleaned is brought into contact with a liquid cleaning solvent having a boiling point lower than the temperature of the object to be cleaned after the peeling step, thereby removing oil remaining on the object to be cleaned; and a drying step in which, after the solvent liquid cleaning step, the cleaning solvent adhering to the object to be cleaned is evaporated by the heat of the object to be cleaned while maintaining the temperature of the object to be cleaned higher than the boiling point of the cleaning solvent.

2. 2. The method for cleaning an object to be cleaned according to claim 1, wherein said solvent liquid cleaning step comprises a method of showering said cleaning solvent onto said object to be cleaned, or a method of immersing said object in said cleaning solvent.

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