JP2001300448A - Cleaning method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning method which can obtain a high cleaning capacity. SOLUTION: In the cleaning method, when a cleaning solution is brought into contact with a work, which is an object to be cleaned, to remove fouling adherent to the work, the pressure of the periphery of the cleaning solution is changed. Preferably, an operation to increase the pressure and an operation to decrease the pressure are periodically repeated several times.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning method for removing stains on a work.

[0002]

2. Description of the Related Art For example, in the manufacture of a wristwatch, it is necessary to manufacture various wristwatch parts before assembling the wristwatch. Some of such wristwatch components require a polishing step during manufacture. And, when polishing is performed on watch parts,
The abrasive will adhere. Of course, such abrasives
It is removed by washing.

[0003] For a long time, triethane was used as a cleaning liquid for such cleaning. However, triethane is no longer used due to concerns about destruction of the ozone layer.

[0004] Instead of triethane, trichloroethylene has come to be used as a cleaning solution. However, trichloroethylene is not an environmentally friendly cleaning solution, and it is preferable not to use it if possible.

However, the fact is that most of the alternative cleaning liquids for trichlorethylene cannot obtain a cleaning power as high as that of trichlorethylene. For this reason, it has been difficult for such an alternative cleaning liquid to sufficiently remove, for example, an abrasive that has entered a small hole provided in a wristwatch component.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a cleaning method capable of obtaining high cleaning performance.

[0007]

This and other objects are achieved by the present invention which is defined below as (1) to (17).

(1) A cleaning method in which a cleaning liquid is brought into contact with a work to be cleaned to remove dirt attached to the work, wherein a pressure around the cleaning liquid is changed during the cleaning of the work. A cleaning method characterized by performing an operation.

(2) A cleaning method in which a cleaning liquid is brought into contact with a work to be cleaned to remove dirt attached to the work, wherein a pressure around the cleaning liquid is increased during cleaning of the work. A cleaning method comprising performing an operation and a reducing operation.

(3) A cleaning method in which a cleaning liquid is brought into contact with a work to be cleaned to remove dirt attached to the work, wherein a pressure around the cleaning liquid is increased during cleaning of the work. A cleaning method, wherein an operation and a reduction operation are alternately performed a plurality of times.

(4) The cleaning method according to (3), wherein the operation of increasing and decreasing the pressure around the cleaning liquid is performed periodically.

(5) The cleaning method according to the above (4), wherein one cycle time for increasing and decreasing the pressure is 5 to 300 seconds.

(6) The cleaning method according to the above (4) or (5), wherein a time for keeping the pressure substantially uniform is provided within one cycle of increasing and decreasing the pressure, and the time is 150 seconds or less.

(7) The cleaning method according to any one of (2) to (6), wherein the pressure increasing operation and the pressure decreasing operation are performed at least three times.

(8) The cleaning method according to any one of (1) to (7), wherein a difference between a maximum value and a minimum value of the pressure around the cleaning liquid during the cleaning is 200 Torr or more.

(9) The absolute value of the average pressure change rate (Torr / sec) when changing the pressure around the cleaning liquid is | Δ
The cleaning method according to any one of the above (1) to (8), wherein, when P |, the pressure is changed at least once so as to satisfy the relationship of 20 ≦ | ΔP | ≦ 5000.

(10) The cleaning method according to any one of the above (1) to (9), wherein the contact time for bringing the cleaning liquid into contact with the work is 30 seconds to 60 minutes.

(11) The cleaning method according to any one of (1) to (10), wherein the temperature of the cleaning liquid when the cleaning liquid is brought into contact with the work is 20 to 80 ° C.

(12) The cleaning method according to any one of the above (1) to (11), wherein the cleaning liquid is a hydrocarbon-based cleaning liquid.

(13) The cleaning method according to any one of (1) to (12), wherein the work is cleaned while irradiating the cleaning liquid with an ultrasonic wave.

(14) The cleaning method according to any one of the above (1) to (13), wherein at least a pressure around the cleaning liquid is changed, an ultrasonic wave is applied to the cleaning liquid.

(15) The cleaning method according to any one of (1) to (14), wherein an ultrasonic wave is applied to the cleaning liquid when at least a pressure around the cleaning liquid is constant.

(16) The cleaning method according to any one of the above (1) to (15), wherein the work is a watch part.

(17) The cleaning method according to any one of the above (1) to (16), wherein the work and the cleaning liquid are placed in a sealable tank and the work is cleaned.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on preferred embodiments. According to the cleaning method of the present invention, a cleaning liquid (cleaning agent) is brought into contact with a workpiece to be cleaned to remove stains on the workpiece (cleaning the workpiece).
In this case, an operation of changing the pressure around the cleaning liquid is performed. In this case, it is preferable to perform the operation of increasing the pressure and the operation of decreasing the pressure. It is considered that such an operation causes an instantaneous flow of the cleaning liquid.
This flow is considered to be one of the major driving forces for removing dirt attached to the work.

Further, when cleaning the work, it is preferable to alternately increase and decrease the pressure around the cleaning liquid a plurality of times.

By performing such an operation, a high cleaning effect can be obtained as described later, and dirt on the work can be suitably removed. In particular, according to the present invention, abrasives and the like that have entered small holes provided in a wristwatch component or the like can be suitably removed. In particular, when the operation of increasing the pressure and the operation of decreasing the pressure are performed alternately a plurality of times, the flow of the cleaning liquid also changes according to the increase and decrease of the pressure, and this change makes the removal of the stain on the work more effective. . In addition, the cleaning effect is improved according to the number of such operations.

When the operation of increasing the pressure around the cleaning liquid and the operation of decreasing the pressure are alternately performed a plurality of times, it is more preferable to periodically perform the operation. When the work is cleaned in this manner, the number of times the pressure is increased / decreased per unit time can be increased, and the work cleaning efficiency is further improved. Also, the operation to periodically increase and decrease the pressure is
Suitable for automatic cleaning by the cleaning device.

FIG. 1 shows a number of patterns (diagrams) when the operation of increasing and decreasing the pressure around the cleaning liquid (hereinafter simply referred to as “pressure”) is performed alternately a plurality of times. Here is an example.

The first pattern referred to in FIG. 1 is (1
-0) The pressure is increased from normal pressure (atmospheric pressure) to a high pressurized state (higher than normal pressure), and (1-1) the pressure is maintained at the high pressurized state for a certain period of time. The pressure is reduced from a high pressurized state to a low pressurized state (a pressure state lower than the high pressurized state and higher than the normal pressure). 4) The pressure is increased from a low pressurized state to a high pressurized state, and then (1-1) to (1)
-4).

The second pattern referred to in FIG. 1 is (2
-1) The pressure is increased from normal pressure to a pressurized state, and (2-2)
The pressure is maintained for a certain period of time in a pressurized state, (2-3) the pressure is reduced from the pressurized state to normal pressure, and (2-4) the pressure is maintained for a certain time at normal pressure.

The third pattern referred to in FIG. 1 is (3
-0) The pressure is increased from normal pressure to a pressurized state, and (3-1)
(3-2) Reduce the pressure from the pressurized state to the depressurized state, (3-3) Maintain the pressure for a certain time in the depressurized state, (3-4) Apply the pressure from the depressurized state. The pressure is increased to the pressure state, and thereafter, the cycle is repeated (3-1) to (3-4).

The fourth pattern referred to in FIG. 1 is (4
-1) Decrease pressure from normal pressure to reduced pressure, and (4-2)
The pressure is maintained for a certain period of time in a reduced pressure state, (4-3) the pressure is increased from the reduced pressure to normal pressure, and (4-4) the pressure is maintained for a certain time at normal pressure.

The fifth pattern referred to in FIG. 1 is (5
-0) Decrease pressure from normal pressure to low pressure reduction state (pressure lower than normal pressure), (5-1) maintain pressure in low pressure reduction state for a certain time, (5-2) high pressure reduction from low pressure reduction state The pressure is increased to a state (a pressure state higher than the low pressure reduction state and lower than the normal pressure), (5-3) the pressure is maintained at the high pressure reduction state for a certain time, and (5-4) the high pressure reduction state to the low pressure reduction state. Decrease the pressure and then (5-1) to (5-4)
Is repeated.

When the present invention is carried out as described above, the absolute value of the average pressure change rate (Torr / sec) when changing the pressure is |
When ΔP |, | ΔP | is 20 ≦ | ΔP | ≦ 5
000, preferably 70 ≦ | Δ
It is more preferable to satisfy the relationship of P | ≦ 2000. When | ΔP | is low, a case where a sufficient flow or the like does not occur in the cleaning liquid may occur, and a sufficient cleaning effect may not be obtained. On the other hand, from the viewpoint of device performance, safety, etc., | ΔP
It may not be desirable to make | too high. For example, in each example shown in FIG. 1, the slope of the line indicating the change in pressure in the diagram corresponds to the average pressure change speed. Note that not all operations for changing the pressure need to be performed so as to satisfy the above expression. Further, the pressure may be changed so as not to satisfy the above expression.

When the present invention is carried out, the difference between the maximum value and the minimum value of the pressure is preferably 200 Torr or more, more preferably 500 Torr or more. This makes it easy for the cleaning liquid to flow sufficiently to remove the stain on the work, and the stain on the work can be more appropriately removed. In consideration of the performance and safety of the apparatus, the difference between the maximum value and the minimum value of the pressure may be better to be less than 5000 Torr in some cases.

In particular, when the pressure is reduced to less than normal pressure,
The minimum pressure for carrying out the present invention is preferably about 50 to 400 Torr. The present inventor has discovered that when the minimum pressure is within this range, the work can be optimally cleaned. When the pressure is increased beyond the normal pressure, the maximum pressure is set to 1500 to 5 from the viewpoint of the load on the apparatus and safety.
Preferably, the pressure is about 000 Torr.

When the operation of increasing the pressure and the operation of decreasing the pressure are performed alternately and periodically, a plurality of times, as shown in each pattern shown in FIG. Is preferably provided. This makes it less likely that a large load will be placed on the cleaning device and the like. In addition, when a large number of works are placed in the cleaning tank at a high density, the works move due to the flow of the cleaning liquid, and it is difficult for the works to contact each other. In addition, for example,
In each example shown in FIG. 1, in the diagram, the total of the time during which the slope of the line indicating the change in pressure is 0 per cycle is the time during which the pressure is kept substantially uniform.

As described above, when providing a time for keeping the pressure substantially uniform within one cycle, the time is preferably 150 seconds or less, and more preferably 50 seconds or less. If the time for keeping the pressure substantially uniform is too long, the cleaning efficiency per unit time tends to decrease.
It is not necessary to provide a time for keeping the pressure substantially uniform within one cycle of increasing and decreasing the pressure.

When the operation of increasing the pressure and the operation of decreasing the pressure are alternately and periodically performed a plurality of times, one cycle time (time of one cycle) is preferably about 5 to 300 seconds, and 10 to 50 seconds. More preferably, it is set to about seconds.
If one cycle time is too short, a load may be imposed on the cleaning device and the like. Also, if one cycle time is too long, the cleaning efficiency per unit time tends to decrease.

The operation of increasing or decreasing the pressure is preferably performed at least three times (three cycles), more preferably six times (six cycles). In general, a higher cleaning effect can be expected by increasing the number of times the pressure is increased or decreased. In particular, when the pressure is increased or decreased the number of times or more, a high cleaning effect can be obtained. The operation of increasing or decreasing the pressure can be performed, for example, within 100 times.

In carrying out the present invention, the time for bringing the cleaning liquid into contact with the work is preferably about 30 seconds to 60 minutes, and more preferably about 30 seconds to 20 minutes. If the contact time is too short, the work may not be sufficiently cleaned. On the other hand, even if the contact time is too long, there is a case where a cleaning effect corresponding to the contact time cannot be expected.

When cleaning the work, it is preferable to clean the work while irradiating the cleaning liquid with ultrasonic waves. Irradiation with ultrasonic waves further increases the cleaning effect due to the increase and decrease in pressure.

In particular, when the cleaning liquid is irradiated with ultrasonic waves when the pressure is changed, the size of bubbles generated by the ultrasonic waves changes according to the pressure, and this change further increases the cleaning effect of the work. Thereby, even if the dirt attached to the work is a dirt that is relatively difficult to remove such as an abrasive, the dirt can be suitably removed.

When the pressure is constant, the ultrasonic oscillator that oscillates ultrasonic waves tends to be in an optimal state for oscillating ultrasonic waves. For this reason, when the ultrasonic wave is applied when the pressure is constant, the ultrasonic wave having a relatively strong output with respect to the cleaning liquid is oscillated. Therefore, even when the pressure is substantially uniform, the cleaning liquid can maintain a constant level of cleaning power.

When irradiating the cleaning solution with ultrasonic waves, the frequency of the ultrasonic waves is preferably about 20 to 100 kHz. The output of the ultrasonic wave is preferably about 600 to 1800 W. Thereby, the above-mentioned effect can be obtained more effectively.

The temperature of the cleaning liquid when the cleaning liquid is brought into contact with the work is preferably about 20 to 80 ° C. When the temperature of the cleaning liquid is within this range, it is possible to suitably remove stains on the work. Further, the temperature of the cleaning liquid when bringing the cleaning liquid into contact with the workpiece is more preferably about 25 to 60 ° C. Accordingly, even when the cleaning liquid is easily flammable, such as a hydrocarbon cleaning liquid, it is possible to remove stains on the work while maintaining high safety. In addition, it is preferable that the work is rocked during the cleaning. Thereby, the above-described cleaning effect is further improved.

The cleaning liquid used in the present invention includes hydrocarbon-based (eg, naphtha-based, isoparaffin-based, pyrrolidone-based, terpene-based, etc.), chlorine-based, alternative Freon-based, alcohol-based, terpene-based, and silicone-based cleaning liquids. Any of a solvent-based cleaning liquid, a higher alcohol-based cleaning liquid, a quasi-aqueous cleaning liquid such as a hydrocarbon + surfactant + ether, and an aqueous cleaning liquid such as pure water, an alkaline aqueous solution, and a surfactant aqueous solution may be used.

In particular, according to the present invention, dirt can be suitably removed even with a hydrocarbon-based cleaning liquid having a slightly lower cleaning ability. When a hydrocarbon-based cleaning liquid is used, unlike a water-based cleaning liquid, there is no need to provide a wastewater treatment facility.
Therefore, the equipment of the cleaning device can be simplified. Further, the hydrocarbon-based cleaning liquid can be easily recycled by distillation regeneration or the like. For this reason, the cleaning liquid can be used repeatedly, and the cleaning liquid can be effectively used. In addition, hydrocarbon-based cleaning liquids are less likely to have a negative effect on the natural environment than chlorine-based cleaning liquids and the like. Since the hydrocarbon-based cleaning liquid has such properties, if a hydrocarbon-based cleaning liquid is used as the cleaning liquid used in the present invention, while preventing pollution of the natural environment due to waste liquid,
The dirt on the work can be suitably removed.

In addition, according to the present invention, parts of a watch, etc.
Even a work having a small hole or hole can suitably remove dirt that has entered the hole or hole. Therefore, for example, as described later, for example, the holes or holes 11a, 1a, 1b of the watch components 10A, 10B, 10C as shown in FIG.
Abrasives and the like that have entered 1b, 11c and the like can also be suitably removed. Since the present invention has such excellent effects, according to the present invention, various stains such as abrasives, inks, and adhesives can be suitably removed.

Hereinafter, the present invention will be described more specifically with reference to the drawings. FIG. 2 is a diagram showing a configuration example of an apparatus for performing the cleaning method of the present invention.

A cleaning apparatus 1A shown in FIG. 2A includes a cleaning tank 2A having a tank body 3 and an ultrasonic oscillator 4, a heating means 5, a cleaning liquid supply line 61, and a cleaning liquid discharge line 65.
And an air supply line 7A and a deaeration line 8A.

The washing tank 2A comprises a tank body 3 and the tank body 3
It has an ultrasonic oscillator 4 installed on the bottom 32, a lid (not shown), and a rocking means (not shown) for rocking the work 10. The cleaning liquid 100 and the work 10 are put into the tank body 3, and the work 10 is cleaned. An openable / closable lid (not shown) is provided on the upper part 31 of the tank body 3.
The work 10 can be taken in and out of the tank body 3. Further, the lid is closed, and the valves (the valves 62, 66, 71, and 8 described later) of each line connected to the cleaning tank 2A are closed.
When 1) is closed, the inside of the tank body 3 is kept airtight. That is, the inside of the tank main body 3 is sealed.

The temperature of the cleaning liquid contained (stored) in the tank body 3 is appropriately adjusted by a heating means (liquid temperature adjusting means) 5. The heating means 5 includes a heating medium 54 covering the periphery of the tank body 3, a jacket 53 for storing the heating medium, a heating medium supply line 51 for supplying the heating medium to the jacket 53, and a heating medium in the jacket 53. And a heat medium discharge line 52 that discharges heat.

A cleaning liquid supply line 61 is connected to the upper portion 31 of the tank body 3. This cleaning liquid supply line 61
Is a line for supplying a cleaning liquid into the cleaning tank 2A. In the middle of the cleaning liquid supply line 61, a valve 62 for turning on / off the supply of the cleaning liquid, adjusting the supply amount of the cleaning liquid, and the like is provided.

A cleaning liquid discharge line 65 is connected to the bottom 32 of the tank body 3. The cleaning liquid discharge line 65 is a line for discharging the cleaning liquid in the cleaning tank 2A. A valve 6 for turning on / off the discharge of the cleaning liquid, adjusting the discharge amount of the cleaning liquid, etc. is provided in the middle of the cleaning liquid discharge line 65.
6 are provided.

Further, an air supply line 7A is connected to the upper portion 31 side of the tank body 3. The air supply line 7A is a line that sends air into the cleaning tank 2A. In the middle of the air supply line 7A, the flow of air into the cleaning tank 2A is turned on.
A valve 71 for turning off, adjusting the amount of inflow, and the like is provided.

Further, a deaeration line 8A is connected to the upper portion 31 of the tank body 3. Degassing line 8A
Is a line for discharging air from the cleaning tank 2A. The deaeration line 8A has a pump 82 and a valve 8 for turning on / off the discharge of air in the cleaning tank 2A, adjusting the outflow amount, and the like.
1 is provided. If such a cleaning device 1A is used, the air in the cleaning tank 2A can be discharged from the deaeration line 8A by operating the pump 82 and opening the valve 81. Therefore, valves 62, 66,
By closing 71 and discharging the air in washing tank 2A, the inside of washing tank 2A can be brought into a reduced pressure (pressure less than atmospheric pressure) state. Further, by opening the valve 71 (or 81), the pressure in the cleaning device 2A can be returned to normal pressure.
That is, if the cleaning apparatus 1A is used, the pressure in the cleaning tank 2A (the pressure around the cleaning liquid 100) between the normal pressure and the reduced pressure state.
Can be suitably changed. Therefore, if the cleaning device 1A is used, the pressure in the cleaning tank 2A can be changed, for example, as in patterns 4 and 5 shown in FIG.

In the cleaning apparatus 1B shown in FIG. 2B, a pump 72 is provided in the middle of the air supply line 7B. By operating this pump 72 to open the valve 71, air can be sent from the air supply line 7A into the cleaning tank 2A. Therefore, by closing the valves 62, 66 and 81 and sending air into the cleaning tank 2A, the cleaning tank 2A
The inside can be pressurized (pressure exceeding atmospheric pressure). The other items of the cleaning device 1B are the same as those of the above-described cleaning device 1A. Such a cleaning device 1B
By using the pressure, the pressure in the cleaning tank 2B can be suitably changed between the pressurized state and the depressurized state. Therefore,
By using the cleaning apparatus 1B, for example, the pressure in the cleaning tank 2A can be changed as in patterns 1 to 5 referred to in FIG.

In the cleaning device 1C shown in FIG. 2C, a pump 72 is provided in the middle of the air supply line 7A. No pump is provided in the deaeration line 8C.
Other items of the cleaning device 1C are the same as those of the above-described cleaning devices 1A and 1B. By using such a cleaning device 1C, the pressure in the cleaning tank 2C can be suitably changed between the pressurized state and the normal pressure. Therefore, if the cleaning apparatus 1C is used, the pressure in the cleaning tank 2C can be changed, for example, as in patterns 1 and 2 shown in FIG.

The cleaning apparatus 1B has an advantage that the pressure in the cleaning tank 2B can be largely changed over a wide range. Further, in the cleaning apparatuses 1A and 1C, the configuration of the apparatuses can be simplified, and the installation space can be reduced and the manufacturing cost can be reduced.

The use (operation) of these cleaning apparatuses 1A, 1B, and 1C is almost the same, and therefore, the method of using these cleaning apparatuses will be described using the cleaning apparatus 1B as a representative.

First, the valve 62 is opened, the cleaning liquid 100 is supplied from the cleaning liquid supply line 61, and the cleaning liquid 100 is put into the cleaning tank 2B.

Next, when a certain amount of the cleaning liquid 100 has accumulated in the cleaning tank 2B, the valve 62 is closed.

Next, a heating medium at a predetermined temperature is supplied from the heating medium supply line 51 into the jacket 5 to adjust the cleaning liquid 100 to a predetermined temperature. Thus, in the cleaning device 1B, the preparation for cleaning the work 10 is completed.

When the preparation for cleaning is completed, the lid (lid) provided on the upper part 31 of the tank body 3 is opened, and the work 10 is put into the cleaning tank 2B.

Then, the lid is closed and the work 10 is washed. During this cleaning, the above-described cleaning method of the present invention is performed. That is, the pressure in the cleaning tank 2B is changed (the pressure around the cleaning liquid 100 is changed). For example, during cleaning, opening and closing valves 71 and 81, pumps 72 and 8
By appropriately operating and stopping 2, the pressure in the cleaning tank 2B can be changed in each pattern as shown in FIG. Further, during the cleaning of the work 10, an ultrasonic wave is appropriately applied to the cleaning liquid 100 from the ultrasonic oscillator 4.
Further, during the cleaning of the work 10, the work 10 may be swung by using the above-described swinging means (not shown).
Preferred washing conditions in this step are as described above.

When the cleaning of the work 10 is completed, the lid of the tank body 3 is opened, and the work 10 is taken out. Thereafter, a new work can be put in the tank body 3 to wash another work.

For example, when the cleaning of the work is completed, the cleaning liquid 1
When 00 becomes dirty, the valve 66 is opened and the cleaning liquid 100 can be discharged from the cleaning liquid discharge line 65.

[0070]

EXAMPLE A cleaning apparatus having a structure as shown in FIG. 2B (a cleaning tank having a capacity of about 70 L) was manufactured.

(Example 1) -1- 70 L of a solvent naphtha-based (hydrocarbon-based) cleaning solution ("SolfineTM" manufactured by Showa Denko KK) was placed in the cleaning tank of this cleaning apparatus. The temperature of the cleaning liquid is 30
Set to ° C.

-2- Next, FIG.
60 watch parts (work) as shown in (a), (b) and (c) were put in, and the watch parts were cleaned. In addition,
This wristwatch component was immediately after the polishing step, and the abrasive was stuck to various places (particularly in the holes and holes).

-3- Further, after the cleaning of these watch parts (after the completion of the batch), new watch parts were cleaned (a new batch was performed). These batches were performed 100 times in total. During the cleaning of the wristwatch parts, the cleaning liquid contains ultrasonic waves (frequency 28 kHz, output 120
0 W). In addition, wrist watch parts were rocked.

Such an operation is performed in pattern 1 shown in FIG.
To 5 were performed. That is, the above step-2
In (−) and (−3), each pattern 1 shown in FIG.
The watch parts were washed by changing the pressure in the washing tank as shown in FIGS. At this time, in each pattern, one cycle of the pressure change was set to about 20 seconds, and an operation of changing the pressure for a total of 9 cycles, about 3 minutes was performed.

(Comparative Example 1) Wristwatch parts were washed in the same manner as in (Example 1) except that in the above-mentioned Step-2-, washing was performed at normal pressure without changing the pressure in the washing tank.

(Evaluation 1) After the cleaning, the presence or absence of the abrasive remaining on the wristwatch parts was visually checked, and the cleaning effect was evaluated based on the following criteria. <About the surface of wristwatch parts> ☆: 99% or more of wristwatch parts where no abrasive remains on the surface ◎: 98% or more and less than 99% of wristwatch parts where no abrasive remains on the surface ○: Surface 97% or more and less than 98% of wristwatch parts where no remaining abrasive was confirmed Δ: 96% or more and less than 97% of wristwatch parts where no remaining abrasive was observed on the surface ×: Residual abrasive was observed on the surface Less than 96% of wristwatch components not confirmed <About holes and holes in wristwatch components> ☆: 99% or more of wristwatch components with no remaining abrasive in holes and holes ◎: Polished in holes and holes 97% or more and less than 99% of wristwatch components where no residual agent was confirmed ○: 95% or more and less than 97% of wristwatch components where no residual abrasive was confirmed in holes or holes △: Polished in holes or holes No residual agent was confirmed Watch components is less than 95% 93% ×: shows a wristwatch parts remaining abrasive was not confirmed such less than 93% The evaluation results in a hole or bore in the following Table 1.

[0077]

[Table 1]

As can be seen from the results shown in Table 1, it was confirmed that according to the cleaning method of the present invention, the abrasive attached to the wristwatch parts can be suitably removed.

(Example 2) (1) Further, the temperature of the cleaning solution was 30 ° C., 50 ° C., 70 ° C.
And in step 2-, the pattern of the pressure change is a pattern of “normal pressure → 100 Torr → normal pressure” (5 seconds to reduce pressure, 5 seconds to return from reduced pressure to normal pressure, 1 cycle 1 cycle).
(0 seconds, about 3 minutes, 18 cycles), and the watch parts were washed in the same manner as in Example 1.

(2) Wrist watch parts were prepared in the same manner as in (1) above, except that the cleaning liquid was changed to an isoparaffin-based cleaning liquid (“Actrel 3338L” manufactured by Exxon Chemical Co., Ltd.), which is a kind of hydrocarbon-based cleaning liquid. Was washed.

Comparative Example 2 Wristwatch parts were washed in the same manner as in Example 2 except that the pressure change pattern in step 2-2 was constant at normal pressure and constant at 100 Torr.

(Evaluation 2) Then, with respect to the wristwatch parts cleaned in Example 2 and Comparative Example 2, the cleaning effect was evaluated according to the same evaluation criteria as described above. The results are shown in Table 2 below.

[0083]

[Table 2]

From the results shown in Table 2, it was confirmed that according to the cleaning method of the present invention, the abrasive attached to the wristwatch parts can be suitably removed.

[0085]

As described above, according to the present invention, it is possible to provide a method for cleaning a work which can obtain a high cleaning effect. As a result, the range of selection of the cleaning liquid is expanded, and a cleaning liquid that is less likely to contaminate the natural environment, a cleaning liquid that has low toxicity to the human body, and the like can be easily selected. In addition, a sufficient cleaning effect can be expected. As described above, according to the present invention, it is possible to provide a cleaning technique that is friendly to the environment and that provides a high cleaning effect.

[Brief description of the drawings]

FIG. 1 is a diagram (diagram) showing a pattern for increasing and decreasing the pressure around a cleaning liquid.

FIG. 2 is a diagram showing a configuration example of an apparatus for performing the cleaning method of the present invention.

FIG. 3 is a view showing a watch component used in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1A, 1B, 1C Cleaning apparatus 2A, 2B, 2C Cleaning tank 3 Tank main body 31 Top 32 Bottom 4 Ultrasonic oscillator 5 Heating means 51 Heat medium supply line 52 Heat medium discharge line 53 Jacket 54 Heat medium 61 Cleaning liquid supply line 62 Valve 65 Cleaning liquid discharge line 66 Valve 7A, 7B, 7C Air supply line 71 Valve 72 Pump 8A, 8B, 8C Deaeration line 81 Valve 82 Pump 10 Work 10A, 10B, 10C Watch parts 11a, 11b, 11c Hole or hole 100 Cleaning liquid

Claims (17)

[Claims] 1. A cleaning method for removing dirt attached to a work to be cleaned by bringing the cleaning liquid into contact with the work, wherein an operation of changing a pressure around the cleaning liquid during the cleaning of the work. Cleaning method. 2. A cleaning method for removing dirt attached to a work to be cleaned by bringing the cleaning liquid into contact with the work, wherein the pressure around the cleaning liquid is increased during the cleaning of the work. And a reducing operation. 3. A cleaning method for removing dirt attached to a work to be cleaned by bringing the cleaning liquid into contact with the work to be cleaned, wherein an operation of increasing a pressure around the cleaning liquid during the cleaning of the work. And a reducing operation are alternately performed a plurality of times. 4. The cleaning method according to claim 3, wherein the operation of increasing and decreasing the pressure around the cleaning liquid is performed periodically. 5. The cleaning method according to claim 4, wherein one cycle time for increasing and decreasing the pressure is 5 to 300 seconds. 6. Within one cycle of increasing or decreasing the pressure, a time is provided for keeping the pressure substantially uniform, and the time is set at 15 times.
The cleaning method according to claim 4, wherein the cleaning time is 0 second or less. 7. The cleaning method according to claim 2, wherein the operation of increasing the pressure and the operation of decreasing the pressure are performed at least three times. 8. The cleaning method according to claim 1, wherein a difference between a maximum value and a minimum value of the pressure around the cleaning liquid during the cleaning is 200 Torr or more. 9. When the absolute value of the average pressure change rate (Torr / sec) when changing the pressure around the cleaning liquid is | ΔP |, the relationship of 20 ≦ | ΔP | ≦ 5000 is satisfied. 9. The cleaning method according to claim 1, wherein the pressure change is performed at least once. 10. The cleaning method according to claim 1, wherein a contact time for bringing the cleaning liquid into contact with the workpiece is 30 seconds to 60 minutes. 11. The temperature of the cleaning liquid when the cleaning liquid is brought into contact with the work is 20 to 80 ° C.
11. The cleaning method according to any one of items 10 to 10. 12. The cleaning method according to claim 1, wherein the cleaning liquid is a hydrocarbon-based cleaning liquid. 13. The cleaning method according to claim 1, wherein the cleaning of the work is performed while irradiating the cleaning liquid with an ultrasonic wave. 14. The cleaning method according to claim 1, wherein ultrasonic waves are applied to the cleaning liquid when at least the pressure around the cleaning liquid is changed. 15. The cleaning method according to claim 1, wherein ultrasonic waves are applied to the cleaning liquid when at least a pressure around the cleaning liquid is constant. 16. The cleaning method according to claim 1, wherein the work is a watch part. 17. The cleaning method according to claim 1, wherein the work and the cleaning liquid are placed in a sealable tank to clean the work.