JPH0853788A - Washing method of mechanical parts - Google Patents

Abstract

PURPOSE:To provide a washing method of mechanical parts which decreases frequencies of renewing or regenerating a washing liquid and features excellent washing efficiency. CONSTITUTION:The oil-components sticking to the surfaces of the mechanical parts dissolve into the first washing liquid when the mechanical parts are first washed by the first washing liquid consisting of a hydrocarbon based org. solvent and, therefore, the mechanical parts are washed. The first washing liquid in which the oil- components sticking to the mechanical parts are dissolved is completely separated and floated from the mechanical parts by the washing with the second washing liquid when the mechanical parts are washed with the second washing liquid consisting of a high-boiling nitrogen-contg. compd. based org. solvent or high-boiling sulfur-contg. compd. based org. solvent and, therefore, the oil-components in the first washing liquid are easily removed. The washing efficiency of the mechanical parts is, therefore, improved and since the sepn. of the first washing liquid sticking to the mechanical parts is good, there is no carryover to the ensuing stage and the first washing liquid is usable fully up to its performance even if the stains of the washing liquid are accumulated by the dissolution of the oil-components in the first washing liquid. The mechanical parts are washed with hot water or cold water and then dried after washing with the second washing liquid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cleaning oil adhering to the surface of machine parts after machining.

[0002]

2. Description of the Related Art Since oil adheres to the surfaces of machine parts after machining, it is necessary to wash these machine parts in order to remove the oil. Conventionally, in order to wash this mechanical part, after the oil is washed and removed with a washing liquid using an organic solvent or an alkaline liquid, it is dried after draining, or washed by washing with water or hot water. Examples of the organic solvent used as the cleaning liquid include hydrocarbons such as industrial gasoline, benzene, and kerosene, as well as dimethylformaldehyde.
High-boiling nitrogen-containing compounds such as dimethylacetamide, hexamethylphosphoramide, and N-methylpyrrolidone have been used.

[0003]

Among the methods for cleaning mechanical parts described above, in the cleaning method using a hydrocarbon-based organic solvent, since the removed oil is dissolved in the organic solvent in the cleaning solution, the cleaning solution There is a problem that oil is gradually accumulated inside. Therefore, when a certain amount or more of oil is accumulated in the cleaning liquid, the oil content of the cleaning liquid itself that has adhered to the machine parts after cleaning adheres to the product again in the drying process after draining, and the desired quality of cleaning can be achieved. Disappear.

Therefore, in the cleaning method using a hydrocarbon-based organic solvent, the cleaning step is divided into two steps, that is, preliminary cleaning and finish cleaning, and drying is performed after draining. And since the oil content dissolves in any cleaning solution, it is necessary to recycle or recycle it, but especially the finishing cleaning solution does not improve the cleaning effect unless it is kept clean. Requires processing.

On the other hand, in the method for cleaning mechanical parts using an alkaline cleaning solution, the cleaning solution is emulsified by oil, so that the cleaning solution needs to be renewed frequently, and in the subsequent washing step, fresh water is constantly used. It is necessary to put it in and release it continuously. Needless to say, wastewater from any process needs to be treated. In the cleaning method using the alkaline cleaning solution, since the cleaning solution is alkaline, the surface is corroded or discolored, and cleaning of aluminum or copper alloy parts is inappropriate.

Among the cleaning methods using an organic solvent, the high boiling point nitrogen-containing compound type or high boiling point sulfur containing compound type cleaning method does not dissolve the washed oil component in the cleaning liquid, and the oil component after cleaning is the cleaning liquid. Since it floats up, the oil can be easily separated and removed, and the life of the cleaning liquid is very long. Moreover, since it is water-soluble, it has a good draining property, so that the washing effect is good, and the washing water can be recycled and reused.

However, the high boiling point nitrogen-containing compound organic solvent or the high boiling point sulfur-containing compound organic solvent is
Since it cannot dissolve lower aliphatic hydrocarbons, the cleaning method using this type of organic solvent has an oil component that cannot be cleaned, and the cleaning effect is largely different from that of the hydrocarbon type organic solvent. There is a problem that it does not exist.

The present invention has been made in order to solve the above-mentioned problems of the method for cleaning the oil content of machine parts, and the frequency of the cleaning solution regeneration treatment is reduced to wash the armpit until the cleaning solution is completely contaminated. It is an object of the present invention to provide a method for cleaning a mechanical component which can be used and which has a higher cleaning efficiency than ever before.

[0009]

Means for Solving the Problems Under the idea that the above problems can be solved by combining cleaning methods, the inventor has conducted intensive studies on the combination of cleaning methods and the order thereof. As a result, first cleaning with a hydrocarbon-based organic solvent, followed by cleaning with a high-boiling nitrogen-containing compound-based organic solvent, a hydrocarbon-based cleaning liquid in which oil adhering to the cleaned parts is dissolved, The cleaning liquid containing the high boiling point organic solvent of
The present invention has been completed by newly finding that a cleaning liquid composed of a hydrocarbon-based organic solvent can be used up to the limit of contamination by oil, and the cleaning efficiency is remarkably improved.

The method for cleaning a mechanical part of the present invention comprises cleaning the mechanical part with a first cleaning liquid composed of a hydrocarbon-based organic solvent,
Then, the main point is to wash with a second washing liquid consisting of a high-boiling point nitrogen-containing compound organic solvent or a high-boiling point sulfur-containing compound organic solvent, wash with hot water or water, and then dry.

The hydrocarbon-based organic solvent used in the present invention is, for example, a water-insoluble organic solvent such as benzine, kerosene, toluene or xylene. Further, as the high-boiling nitrogen-containing compound organic solvent, dimethylformaldehyde, dimethylacetamide, hexamethylphosphoramide,
N-methylpyrrolidone or the like is used, and all of these are water-soluble solvents having a boiling point range of 150 ° C. or higher.

[0012]

When the mechanical part is washed with the first cleaning liquid composed of a hydrocarbon-based organic solvent, the oil component adhering to the surface of the mechanical part is dissolved in the first cleaning liquid, so that the mechanical part is cleaned. Machine parts that have been cleaned with the first cleaning liquid are transferred to a second cleaning liquid composed of a high-boiling point nitrogen-containing compound organic solvent or a high-boiling point sulfur-containing compound organic solvent. The dissolved first cleaning liquid adheres. The oil component in the first cleaning liquid that has adhered to this machine component is completely separated from the mechanical component and floats by the cleaning with the second cleaning liquid, so that the oil component in the first cleaning liquid can be easily removed. . Therefore, the cleaning efficiency of the mechanical parts is improved, the adhered first cleaning liquid is well separated, and is not brought into the next process. Even if dirt of the cleaning liquid is accumulated due to the dissolution of oil in the first cleaning liquid, The cleaning liquid of No. 1 can be used up to its full performance. Further, since the second cleaning liquid is water-soluble, it drains well, and if the floating oil is removed, the cleaning water can be circulated and reused, and no waste water is produced.

[0013]

EXAMPLES Examples of the present invention will be described in comparison with conventional examples,
The effect of the present invention will be clarified. As the mechanical part samples, steel balls A, B, and C having a diameter of 10 mm before cleaning were used, and the respective adhered oil components were first measured. The oil content was measured using a non-dispersive infrared analyzer manufactured by Horiba Ltd. to measure the oil content attached to each steel ball. The oil content of each steel ball measured before cleaning is shown in Table 1.

Subsequently, the steel ball A was washed by a washing method using a hydrocarbon organic solvent (manufactured by Nippon Oil Co., Ltd., trade name Isol) as Conventional Example 1. That is, the steel ball A was immersed in a cleaning liquid composed of a hydrocarbon-based organic solvent, rocked at room temperature for 5 minutes for cleaning, then drained, and then dried at a temperature of 80 ° C. for 5 minutes. As the hydrocarbon-based organic solvent used as the cleaning liquid, a new liquid in which oil was not dissolved was used.

The steel ball B was washed by the conventional method 2 using only the high boiling point nitrogen-containing compound organic solvent.
It was washed. That is, the steel ball B is immersed in a cleaning liquid consisting of a high boiling point nitrogen-containing compound organic solvent at a temperature of 70 ° C., shaken for 5 minutes to be washed, and then shaken for 1 minute in washing water consisting of water at room temperature to wash with water. And subsequently dried at a temperature of 80 ° C. for 5 minutes. As the cleaning liquid composed of the high boiling point nitrogen-containing compound organic solvent (trade name: Kasei Cleaner, manufactured by Mitsubishi Kasei Co., Ltd.) used as the cleaning liquid, a new liquid not yet used as the cleaning liquid was used.

As for the steel balls C, as an example of the present invention, the steel ball C is first washed with a first cleaning liquid containing a hydrocarbon organic solvent, and then with a second cleaning liquid containing a high boiling point nitrogen-containing compound organic solvent. Was washed with. That is,
The steel balls C are immersed in a cleaning liquid composed of a hydrocarbon organic solvent, rocked at room temperature for 3 minutes to clean, and then immersed in a cleaning liquid composed of a high boiling point nitrogen-containing compound organic solvent at a temperature of 70 ° C. It was shaken for a minute to wash, and then shaken in a wash water consisting of water at room temperature for 1 minute to wash with water, and finally dried at a temperature of 80 ° C for 5 minutes. The hydrocarbon-based organic solvent used as the first cleaning liquid was a new liquid in which oil was not dissolved, and the cleaning liquid composed of the high-boiling nitrogen-containing compound organic solvent used as the second cleaning liquid was not A new solution not used as a cleaning solution was used.

Subsequently, with respect to the steel balls A, B, and C cleaned by each cleaning method, the adhered oil content was measured for each steel ball using the above-mentioned non-dispersive infrared analyzer manufactured by Horiba Ltd. The measurement results are as shown in Table 1.

[0018]

[Table 1]

As shown in Table 1, steel balls A and B before cleaning
The oil content of C and C is 4.79 mg and 5.02, respectively.
It was mg and 4.98 mg. By the subsequent washing, the adhered oil content of the steel balls A and B washed by the conventional method after washing was 0.307 mg and 0.321 mg. On the other hand, the oil content after washing of the steel balls C washed by the method of the present invention is 0.157 mg, which means that the washing effect of the method of the present invention is improved about twice as compared with the conventional method. It became clear and the effect of the present invention was confirmed.

[0020]

As described above, the method for cleaning mechanical parts of the present invention comprises cleaning the mechanical parts with the first cleaning liquid consisting of a hydrocarbon organic solvent, and then using a high boiling nitrogen-containing compound organic solvent or a high boiling point compound. Second consisting of sulfur-containing compound organic solvent
Is washed with hot water or water, and then dried. When the machine part is washed with the first cleaning liquid consisting of a hydrocarbon-based organic solvent, the oil content adhered to the surface of the machine part is Dissolves in the first wash solution,
Machine parts are washed, but when they are transferred to a second cleaning liquid composed of a high boiling point nitrogen-containing compound organic solvent, the first cleaning liquid in which the oil content adhering to the mechanical parts is dissolved is washed by the second cleaning liquid. As a result, the oil component in the first cleaning liquid can be easily removed because it is completely separated from the mechanical component and floats. Therefore, the cleaning efficiency of the mechanical parts is improved, the adhered first cleaning liquid is well separated, and is not brought into the next process. Even if dirt of the cleaning liquid is accumulated due to the dissolution of oil in the first cleaning liquid, The cleaning liquid of No. 1 can be used up to its full performance. Further, since the second cleaning liquid is water-soluble, it drains well, and if the floating oil is removed, the cleaning water can be circulated and reused, and no waste water is produced.

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Claims (2)

[Claims] 1. A machine part is washed with a first cleaning liquid containing a hydrocarbon organic solvent, and then with a second cleaning liquid containing a high boiling point nitrogen-containing compound organic solvent or a high boiling point sulfur-containing compound organic solvent. A method for cleaning machine parts, which comprises washing with hot water or water, and then drying. 2. The high-boiling nitrogen-containing compound-based organic solvent is one or more selected from dimethylformaldehyde and dimethylacetamide, hexamethylphosphoramide, and N-methylpyrrolidone. The method for cleaning mechanical parts according to claim 1, wherein the sulfur compound-based organic solvent is dimethyl sulfoxide.