JPH04326971A - Method for washing article having recessed part - Google Patents

Abstract

PURPOSE:To effectively wash an article having a recessed part up to the deepest part of the recess. CONSTITUTION:After an article 2 having a recessed part 1 is heated to first temp., the article 2 is immersed in the washing solution stored in a washing tank 3 in such a state that the recessed part 1 is opened upwardly. The temp. of the washing solution 4 is set to second temp. lower than the temp. of the article 2. Next, the pressure in the washing tank 3 is lowered to a pressure range from the vapor pressure of the washing solution at temp. slightly lower than the first temp. to the vapor pressure of the washing solution at the second temp.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] A method for cleaning articles having recesses according to the present invention uses a cleaning liquid such as an organic solvent or distilled water to remove dirt such as oil adhering to the surface of various articles such as molds. It is used when dropping.

0002

BACKGROUND OF THE INVENTION It is common practice to clean dirt adhering to the surfaces of various articles using a cleaning liquid such as an organic solvent or pure water. When cleaning, various items to be cleaned are placed in a sealed cleaning tank, and the cleaning liquid is heated and ultrasonic vibrations are applied.
Removes dirt adhering to the surface of the object to be cleaned.

However, in the conventional cleaning method, when cleaning an article 2 having a deep recess 1 as shown in FIG. 6, it is not possible to effectively clean the depth of the recess 1.

That is, when cleaning the article 2 having the recess 1, conventionally the article 2 is stored in the cleaning tank 3 with the opening of the recess 1 facing downward, as shown in FIG. death,
The pressure inside the cleaning tank 3 is lowered to expand the air inside the recess 1, and as shown in FIG. 8, the air inside the recess 1 is discharged. The process of contracting the air in the recess 1 and allowing the cleaning liquid 4 to enter the depth of the recess 8 as shown in FIG. 9 is repeated.

However, since the pressure inside the cleaning tank 3 does not become zero even when the pressure is reduced, the air inside the recess 1 cannot be completely exhausted, and when the pressure inside the cleaning tank 3 is increased, However, the cleaning liquid 4 does not reach the innermost part of the recess 1, and the innermost part of the recess 1 cannot be cleaned.

[0006] The method of cleaning an article having a concave portion according to the present invention includes:
This solves the above-mentioned inconveniences.

[0007]

[Means for Solving the Problems] A method of cleaning an article having a recessed portion according to the present invention involves heating the article having a recessed portion to a first temperature, and then cleaning the article by opening the recessed portion upwardly or horizontally. In this state, the article is immersed in a cleaning liquid stored in a closed container at a second temperature lower than the temperature of the article, and then the pressure inside the closed container is lowered to a temperature slightly lower than the first temperature. The pressure is lowered to less than the vapor pressure of the cleaning liquid at the temperature and higher than the vapor pressure of the cleaning liquid at the second temperature.

[0008]

[Operation] When an article having a concave portion is cleaned by the method for cleaning an article having a concave portion of the present invention configured as described above, the cleaning liquid bumps on the surface of the article, and the resulting air bubbles are transferred to the surface of the article. rise along.

[0009] Air bubbles are also generated inside the recess and rise within the recess, so the air lift effect accompanying the rise of the air bubbles replaces the cleaning liquid within the recess, effectively cleaning the interior of the recess to the deepest part. is washed.

0010

EXAMPLE An article having a concave portion to be cleaned is immersed in heated water 5 to raise the temperature sufficiently to the inside, as shown in FIG. For example, in this step, the temperature of the article 2 is raised to a first temperature of about 60°C.

The article 2 whose temperature has been sufficiently raised is then soaked in the cleaning liquid 4 stored in the cleaning tank 3, as shown in FIG.
Immersion is performed with the recess 1 open upward. The cleaning liquid 4 has a second temperature lower than the temperature of the article 2 (60°C), for example, about 30°C. By immersing the article 2 in the cleaning liquid 4, the surface temperature of the article 2 will be slightly lower than the first temperature, but if the article 2 has a large heat capacity such as a mold, the surface temperature will be lower than the first temperature. The temperature does not drop immediately, but is maintained at, for example, about 50° C. for a relatively long time.

Therefore, after sealing the cleaning tank 3, the pressure inside the cleaning tank 3 is adjusted to the level of the cleaning liquid at the surface temperature of the article 2 (50° C.), which is slightly lower than the first temperature. The pressure is lowered to below the vapor pressure and above the vapor pressure of the cleaning liquid at the second temperature of 30°C. For example, if the cleaning liquid 4 is pure water, the vapor pressure at 30°C is 31.8
vapor pressure of 92.5 torr at 50°C
The pressure inside the cleaning tank 3 is lowered to a pressure below r.

As a result of reducing the pressure in the cleaning tank 3 in this way, the cleaning liquid 4 bumps on the surface of the article 2, and the resulting bubbles rise along the surface of the article 2. Bumping is concave part 1
As shown in FIG. 3, the resulting air bubbles rise within the recess 1. Due to the air lift effect accompanying the rise of the air bubbles, the cleaning liquid 4 within the recess 1 is replaced. The inside is effectively cleaned to the deepest part.

At the same time, ultrasonic vibrations are applied to the cleaning liquid 4 by ultrasonic vibrators 6, 6 provided at the bottom of the cleaning tank 3, so that the surface of the article 2 can be more effectively cleaned.

Incidentally, in order to replace the cleaning liquid 4 in the recess 1 by the air lift effect in this manner, the recess 1 may be opened laterally as shown in FIG.

[0016] Furthermore, in order to more reliably improve the cleaning efficiency by applying ultrasonic vibration to the cleaning liquid 4,
It is known that removing the oxygen contained in it is effective. Therefore, as shown in FIG. 5, a deaerator 8 is provided in the middle of the pipe 7 through which the cleaning liquid 4 in the cleaning tank 3 is refluxed by the pump 9, and the oxygen in the cleaning liquid 4 is removed by this deaerator 8. If so, cleaning efficiency can be further improved.

The degassing device 8 is comprised of a permeable membrane (not shown) through which the cleaning liquid 4 passes, and a vacuum pump 10 for removing gas from the space outside the permeable membrane.

Furthermore, in order to further improve the cleaning effect,
When the temperature of the article 1 immersed in the cleaning liquid 4 decreases and approaches the second temperature (30°C), the pressure in the cleaning tank 3 is changed to the vapor pressure at the second temperature (the cleaning liquid 4 In the case of pure water, the entire cleaning liquid 4 can be caused to bump by lowering the pressure to 31.8 torr or less as described above.

[0019]

The method for cleaning articles having recesses according to the present invention is structured and operates as described above, so that articles having recesses can be effectively cleaned even to the deepest part of the recesses.

[Brief explanation of drawings]

FIG. 1 is a schematic longitudinal sectional view showing the first step of the method of the present invention.

FIG. 2 is a schematic longitudinal sectional view showing the second stroke.

FIG. 3 is a schematic longitudinal sectional view showing the third step.

FIG. 4 is a diagram similar to FIG. 1 showing another example of the method of the invention.

FIG. 5 is a schematic circuit diagram showing an example of installing a deaerator.

FIG. 6 is a schematic cross-sectional view illustrating an article to be cleaned according to the invention.

FIG. 7 is a schematic vertical cross-sectional view showing the implementation state of a conventional cleaning method.

FIG. 8 is a schematic vertical cross-sectional view showing the first step of a conventional cleaning method.

FIG. 9 is a schematic vertical sectional view showing the second stroke.

[Explanation of symbols]

1 Recessed part 2. Goods 3　Cleaning tank 4. Cleaning liquid 5 Heated water 6 Ultrasonic transducer 7 Piping 8 Deaerator 9 Pump 10 Vacuum pump

Claims (1)

[Claims] Claim 1: After heating an article having a recessed portion to a first temperature, the article is stored in a closed container with the recessed portion opened upwardly or horizontally. immersed in a cleaning liquid at a second temperature lower than the first temperature, and then the pressure inside the sealed container is lowered to the vapor pressure of the cleaning liquid at a temperature slightly lower than the first temperature, and the pressure is lowered to the second temperature. A method for cleaning articles having recesses, in which the pressure is lowered to a level higher than the vapor pressure of the cleaning liquid used.