JPH062181A - Method of washing ferrous sliding parts - Google Patents

Abstract

(57) [Summary] [Purpose] Maintains the anticorrosive effect of parts during and after the cleaning process, and also stabilizes the cycle of the sliding system incorporating iron-based sintered sliding parts, especially the generation of sludge. To prevent. [Structure] The first iron-based sliding part cleaning method includes a step of performing degreasing cleaning with a volatile organic solvent, and a step of forming an adhesion layer of an iron complex compound after the step of performing degreasing cleaning. The second method for cleaning iron-based sliding parts consists of a step of cleaning the iron-based sliding parts with a water-soluble cleaning agent, and a cleaning agent containing alcohol, water and a vaporizable rust preventive agent after this cleaning step. And the step of washing with.

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 iron-based sliding parts, and more particularly, to maintain the anticorrosion effect of iron-based sliding parts during and after the cleaning process and to incorporate iron-based sliding parts. The present invention relates to an improved cleaning method capable of achieving stability of a refrigeration cycle in a compressed compression mechanism unit.

[0002]

2. Description of the Related Art For use in refrigeration cycle, the use of Freon 113, 1,1,1-trichloroethane and other Freon-based and chlorine-based organic solvents is regulated due to the problem that they destroy the environment. There is also a need to improve the method of cleaning iron-based sliding parts of compressors.

From the viewpoint of mechanical characteristics, sliding characteristics, dimensional accuracy, workability, etc., the compression mechanism parts typified by refrigeration cycle compressors are ferrous metal materials such as sintered materials, cast iron, and cemented carbide tool steel. Are used as iron-based sliding parts. Since these iron-based sliding parts have processing oil residues and cutting debris remaining on the surface of the parts after they have been machined to the specified shape, they must be cleaned before assembly to include degreasing. Is done. Conventionally, this cleaning has excellent degreasing cleaning power and permeability, and since it does not easily remain on parts,
Freon-based and chlorine-based organic solvents such as 113, 1,1,1-trichloroethane and methacrene were often used as cleaning agents.
However, these CFC-based and chlorine-based organic solvents have a problem that they destroy the ozone layer in the stratosphere, and their use is regulated. For this reason, water-soluble alkaline detergents and organic solvents other than the above, such as kerosene and alcohol, are being investigated as alternatives to the fluorocarbon and chlorine detergents.

[0004]

However, when an iron-based sliding part is washed with an organic solvent, the degreasing and detergency is excellent, but since the object is an iron-based material and is particularly prone to corrosion, on the contrary, Due to excessive cleaning, the rust preventive power of the component surface is insufficient, and special treatment such as oil impregnation is required to compensate for it. Especially cast iron is prone to rust,
There was a problem that the dimensional accuracy during fitting was likely to be impaired.

On the other hand, when only a water-soluble alkaline cleaner is used, when cleaning sintered material parts, water tends to remain in the pores of the sintered material, and when used in a closed system such as a refrigeration cycle. There was a problem that the residual water decomposes the organic materials and refrigerant in the compressor. Also, when using only a water-soluble alkaline cleaning agent, a rust preventive film is formed on the parts at the same time as the cleaning, but especially if the parts have a complicated shape, the rust preventive agent may not spread evenly or may be locally excessive. There is a problem that stains are likely to remain with the remaining cleaning liquid or the aging of the cleaning liquid. In particular, an excessive amount of the cleaning agent left inside the refrigeration cycle has an adverse effect such as corrosion, leading to a reduction in refrigerating capacity.

The present invention has been made to solve the above problems, and in a method of cleaning iron-based sliding parts, the rust-preventive effect of the parts is maintained during and after the cleaning process and the iron-based sliding parts are maintained. An object of the present invention is to provide a cleaning method for improving the cycle stability of a sliding system in which moving parts are incorporated, particularly the chemical stability such as prevention of sludge generation.

[0007]

A first method for cleaning iron-based sliding parts according to the present invention comprises a step of degreasing and cleaning iron-based sliding parts with a volatile organic solvent, and this degreasing and cleaning. And a step of forming an adhesion layer of an iron complex compound after the step.

The second iron-based sliding part cleaning method is as follows:
The method is characterized by including a step of cleaning the iron-based sliding parts with a water-soluble cleaning agent, and a step of cleaning with a cleaning agent containing alcohol, water and a vaporizable rust preventive agent after the cleaning step.

Volatile organic solvents related to the first iron-based sliding part cleaning method are hydrocarbon-based, alcohol-based, fluorine-based, and fluorocarbon-based solvents other than those regulated due to ozone depleting substances. And the like can be preferably used. For example,
Examples include gasoline, kerosene, solvent naphtha, petroleum-based solvents containing aromatics such as benzene, methanol, ethanol, 1-propanol, 2-propanol, HCFC123 and HCFC225. Among these organic solvents, volatile ones having a boiling point of from room temperature to about 85 ° C. can be preferably used. Further, these organic solvents can be used alone or in combination.

The step of forming the adhesion layer of the iron complex compound according to the first cleaning method is performed by passing the volatile rust preventive agent through a gas phase atmosphere after the step of performing degreasing cleaning. Volatile rust inhibitors include amine nitrates, carboxylates,
As represented by carbonates, it shows a rust preventive effect on iron,
Volatile substances can be used. As long as it is volatile, it can be used as a solid or liquid at room temperature. Examples thereof include dicyclohexylammonium nitrite, diisopropylammonium nitrite, dicyclohexylammonium caprylate, cyclohexylammonium carbamate, and cyclohexylamine carbonate.

The cleaning method according to the first aspect of the present invention is carried out by first dipping, ultrasonic cleaning, or steam cleaning in which the iron-based sliding parts are immersed in the volatile organic solvent for cleaning. Degreasing cleaning is performed in combination. Next, in the drying step after this degreasing cleaning, the method of making the drying furnace a volatile rust preventive atmosphere, the method of containing steam of these substances in the hot air blow, or the cleaning agent vapor volatile in the steam cleaning at the time of cleaning An adhesion layer of an iron complex compound is formed on the surface of the iron-based sliding part by a method of containing vapor of a rust preventive agent.

The water-soluble cleaning agent relating to the second method for cleaning iron-based sliding parts is, for example, a known one consisting of an inorganic alkali such as sodium hydroxide, an aliphatic amine, an anionic surfactant, and an organic rust preventive agent. Water-soluble degreasing detergents can be used.

The cleaning agent containing alcohol, water and a vaporizable rust preventive agent, which is related to the second method for cleaning iron-based sliding parts, comprises the following components. The alcohol component is preferably at least one selected from methanol, ethanol, 1-propanol, and 2-propanol. This is because these alcohols have a high evaporation rate and are preferable for draining and drying. As the vaporizable rust preventive component, amine carbonate is particularly preferably used. This is because, if washing is performed using an amine carbonate, contaminants such as sludge do not occur in the closed cycle system even after washing.

The cleaning agent contains an alcohol component of 10 to 6
It is preferable that the content of 0 vol% and the amine carbonate component is 0.1 to 10 vol%. This is because when the alcohol content is 10 vol% or more, the draining and drying speed is practically preferable, and when it is 60 vol% or less, the concentration of the detergent solution can be easily controlled. Furthermore, if the carbonate component of the amine is 0.1 vol% or more, the rust preventive power is improved, and if it is 10 vol% or less, the rinse effect is not lowered.

In the cleaning method of the second invention, first, the above-mentioned water-soluble cleaning agent is used for the primary alkali cleaning, and then the cleaning agent containing alcohol, water and a vaporizable rust preventive agent is used for the final cleaning. It is done by rinsing selectively.

[0016]

In the cleaning method of the first invention, the iron-based sliding part has a step of passing through the gas phase atmosphere of the volatile rust preventive, so that the steam of the rust preventive is uniformly filled on the part surface. Then, an iron complex compound layer coating having a strong rust-preventing effect is produced by an interfacial reaction with the surface of the component. Since the iron complex compound film is formed to have the minimum required thickness, the final amount of the rust preventive agent remaining on the surface of the iron-based sliding component is small. Further, since this process is performed in the gas phase, the mass production line of the cleaning process can be easily automated.

In the cleaning method of the second invention, by using a cleaning agent containing alcohol, water and a vaporizable rust preventive as a rinse agent in the final rinsing step, the draining and drying action by the alcohol can be improved and the vaporizable rust preventive agent can be used. Adsorption of the agent components on the surface of iron-based sliding parts causes rust prevention. further,
By using alcohol and water as a base, the range in which the volatile rust preventive component dissolves in the rinse liquid expands, and the concentration of the volatile rust preventive component can be made higher than that of a simple water-based system, so iron-based sliding with a complicated shape is possible. A strong anti-corrosion effect can be obtained even for parts. Further, the amine carbonate used as the volatile anticorrosive component does not generate sludge or other contaminants even when the iron-based sliding parts are applied to the closed cycle.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. Example 1 FIG. 1 shows a cleaning process of iron-based sliding parts as Example 1. Using cast iron (FC-25) as the material, make sliding parts (cylinder, blade, roller, etc.) of the rotary compressor, wipe and wash with acetone once, and after drying, measure the initial weight and use the mineral oil-based cutting fluid. The test piece was a fixed amount.

After ultrasonic cleaning in 2-propanol for 5 minutes, it was left in the vapor atmosphere of dicyclohexylammonium nitrite (80 ° C.) for 10 minutes, and then the weight was measured again. The effect of the rust preventive agent was evaluated as the residual amount on the surface and as a percentage with respect to the initial weight. Further, it was left in an atmosphere of 90RH% and 40 ° C, and the time until rusting was measured. The number of test pieces was measured at n = 5. The results are shown in FIG. 5 as the relationship between the standing time until rusting and the amount of residue on the surface of the component. No rusting occurred for 5 to 6 hours, and there was little variation between test pieces.

Embodiment 2 FIG. 2 shows a cleaning process for iron-based sliding parts as Embodiment 2. The same test piece as in Example 1 was subjected to ultrasonic cleaning in 2-propanol for 5 minutes, and then steam cleaning in 2-propanol containing 2% dicyclohexylammonium nitrite for 5 minutes. Then, the same evaluation as in Example 1 was performed. Results are shown in FIG. Results similar to those in Example 1 were obtained.

COMPARATIVE EXAMPLE 1 FIG. 3 shows a cleaning process for iron-based sliding parts as Comparative Example 1. The same test piece as in Example 1 was subjected to ultrasonic cleaning in 2-propanol for 5 minutes and dried at 80 ° C. for 10 minutes, and the same evaluation as in Example 1 was performed. The results are shown in Figure 5.
Shown in. It can be said that rust prevention is inferior only by solvent cleaning.

Comparative Example 2 FIG. 4 shows a cleaning process for iron-based sliding parts as Comparative Example 2. For the same test piece as in Example 1, first, an inorganic alkaline aqueous solution (containing 1% sodium hydroxide) was used, and the liquid temperature was 60.
Ultrasonic cleaning was performed at 5 ° C for 5 minutes, and then, as a second cleaning, an organic alkaline aqueous solution (containing 0.5% of aliphatic amine) was used for ultrasonic cleaning at a liquid temperature of 60 ° C for 5 minutes. Furthermore, Freon 1
Cleaning with 13 (ultrasonic cleaning, vapor cleaning) was performed.
Then, the same evaluation as in Example 1 was performed. Results are shown in FIG. The rust preventive power does not change much on average on average, but there are many variations, suggesting the non-uniformity of the rust preventive coating.

From the above results, Examples 1 and 2 are located in the upper left region of FIG. 5, which is highly evaluated as a rust preventive force, and there is little variation in measured values, so that the rust preventive film is thin. It can be seen that rust is unlikely to occur. Furthermore, even when a refrigeration cycle is actually set up, the amount of surface residue is small, which means that there is little possibility of adversely affecting the inside of the cycle.

Example 3 FIG. 6 shows a cleaning process for iron-based sliding parts as Example 3. Using cast iron (FC-25) as the material, make sliding parts (cylinder, blade, roller, etc.) of the rotary compressor, wipe and wash with acetone once, and after drying, measure the initial weight and use the mineral oil-based cutting fluid. The test piece was a fixed amount.

As a primary cleaning of this test piece, ultrasonic cleaning was carried out for 5 minutes using a cleaning agent (PH 9.2) consisting of sodium hydroxide, an aliphatic amine, an anionic surfactant and an organic rust preventive agent, and then dibutylamine. At room temperature with a rinse solution consisting of 3 vol% carbonate, 50 vol% 2-propanol and 47 vol% water.
Ultrasonic cleaning was performed for 5 minutes. After that, air blowing was performed to dry the test piece. The weight of the obtained test piece was measured and the difference from the initial value was shown as the amount of residue on the surface of the component. The test piece was left in an atmosphere of room temperature and 80 RH%, and the time until rusting was measured. The number of test pieces was measured at n = 6. The results are shown in FIG. 8 as the relationship between the time left until rusting and the amount of residual material on the surface of the component.

Comparative Example 3 FIG. 7 shows a cleaning process for iron-based sliding parts as Comparative Example 3. The same test piece as in Example 3 was subjected to the same primary cleaning as in Example 3, and then triethanolamine 10 vol was added.
%, Alkyl amide carboxylic sun salt 25vol%, water 65vol% ultrasonic cleaning for 5 minutes at room temperature. After that, air blowing was performed to dry the test piece. The obtained test piece was evaluated in the same manner as in Example 3. The results are shown in Fig. 8.

From the above results, it can be seen that Example 3 is located in the upper left region of FIG. 5, which is highly evaluated as a rust preventive force, and that the measured values have little variation, and thus the rust preventive property is excellent. Recognize. Furthermore, even when a refrigeration cycle is actually set up, the amount of surface residue is small, which means that there is little possibility of adversely affecting the inside of the cycle.

[0028]

The method for cleaning iron-based sliding parts according to the present invention comprises:
As the invention of 1, since it has a step of degreasing and cleaning with a volatile organic solvent, and then a step of passing it through the gas phase atmosphere of the volatile rust preventive agent, a thin film having a strong rust preventive power can be obtained. It is possible to obtain the iron-based sliding parts you have. Further, since the generation of sludge is small, it is possible to obtain an iron-based sliding component that can reduce adverse effects on the refrigeration cycle. Furthermore, since the final step of this method is performed in the gas phase, the mass production line of the cleaning step can be easily automated and the number of steps can be reduced.

The cleaning method for iron-based sliding parts according to the present invention is the second method.
Of the invention, since it has a step of washing with a water-soluble detergent, and then a step of washing with a detergent containing alcohol, water and a vaporizable rust preventive agent, It is possible to obtain an iron-based sliding part having a strong anticorrosive coating. Furthermore, since the amount of sludge generated is small, it is possible to obtain an iron-based sliding component that can reduce adverse effects on the refrigeration cycle. Further, the drainage property after washing becomes easy and the constraint condition for drying can be reduced, and at the same time, the rust preventive process such as oil impregnation, which is required when drying with chlorofluorocarbon, etc., is not necessary, so that the number of processes can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a process used in Example 1.

FIG. 2 is a diagram showing a process used in a second embodiment.

FIG. 3 is a diagram showing a process used in Comparative Example 1.

FIG. 4 is a diagram showing a process used in Comparative Example 2.

FIG. 5 is a diagram showing a relationship between a leaving time until rusting and a residual amount on a surface of a component when a cleaned test piece is left in an atmosphere of 40 ° C. and 90 RH%.

FIG. 6 is a diagram showing a process used in a third embodiment.

FIG. 7 is a diagram showing a process used in Comparative Example 3.

FIG. 8 is a diagram showing a relationship between a leaving time until rusting and a residual amount on a surface of a component when a cleaned test piece is left in an atmosphere of room temperature and 80 RH%.

[Explanation of symbols]

1 ……… solvent cleaning, 2 ……… drying, 3 ……… primary cleaning,
4 ……… Secondary cleaning, 5 ……… CFC cleaning, 6 ……… Aqueous solution rinse.

Claims (2)

[Claims] 1. A step of degreasing and cleaning an iron-based sliding part with a volatile organic solvent, and a step of performing the degreasing and cleaning,
And a step of forming an adhesion layer of an iron complex compound. 2. A method of cleaning an iron-based sliding part with a water-soluble cleaning agent, and a step of cleaning with a cleaning agent containing alcohol, water and a vaporizable rust preventive after the cleaning step. A characteristic method of cleaning iron-based sliding parts.