JP3108937B2 - Work cleaning method and cleaning device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for cleaning a work, and more particularly to a technique for preventing rust on a metal surface of the work.

[0002]

2. Description of the Related Art A halogen-based cleaning agent represented by trichloroethane has a high cleaning ability for a work, and is capable of drying and removing the cleaning agent from a cleaned work as it is. It is not widely used for cleaning works such as circuit boards and metal parts. However, since the halogen-based cleaning agent has a problem for the human body and a problem of environmental destruction, it is being replaced with a cleaning solution mixed with a work cleaning agent such as a surfactant. In the cleaning method using a cleaning liquid containing a surfactant and the like, the work cleaning agent adhering to the cleaned work cannot be removed from the work only by drying. Therefore, the cleaned work is rinsed in pure water and the cleaning liquid is removed. After being washed off, pure water adhering to the work is dried and removed.

[0003]

When such a cleaning method is adopted for cleaning a metal part or a work having a metal part,
Heat is supplied to the workpiece with pure water attached to it, and the pure water is dried and removed, so that the metal surface reacts with pure water or dissolved oxygen in pure water to generate rust on the metal surface. Have a problem. Further, rust may be generated on the metal part of the work during rinsing with pure water, which is not preferable as a method for cleaning a metal part or a work having a metal part.

Therefore, a method of rinsing with alcohol or the like instead of pure water is also conceivable. However, when this method is adopted, the problem of rust generation is solved, but running cost becomes extremely high due to consumption of alcohol or the like, so that it cannot be a practical measure.

In view of the above problems, an object of the present invention is to provide a rinsing-preventive treatment for pure water so that rust does not occur on a metal portion of the work even in a drying step and a rinsing step. It is to realize a method and a cleaning device.

[0006]

In order to solve the above-mentioned problems, in a work cleaning method according to the present invention, after performing a cleaning step of washing off deposits and the like from a work using a cleaning liquid, rust prevention on the work is performed. A rinsing step of washing off the cleaning liquid adhering to the work using pure water containing an agent is performed, and then a drying step of drying and removing the pure water adhering to the work after the rinsing step is performed.

Here, in order to prevent the rust inhibitor from remaining on the work after drying, it is preferable to use a vaporizable rust inhibitor as the rust inhibitor.

In addition, prior to the rinsing step, in the case of performing a pure water rinsing step of washing off the cleaning liquid adhering to the work using pure water, a deaeration treatment is performed using a gas-water separation membrane or the like. Pure water, especially its dissolved oxygen content is about 3ppm
It is preferable to use the following pure water. In order to realize such a cleaning method, the cleaning apparatus according to the present invention includes a work cleaning unit including a cleaning liquid tank storing a cleaning liquid, and a pure water tank storing pure water, and is attached to the cleaned work. Equipped with a pure water rinsing part for washing off the cleaning liquid and a pure water tank storing pure water containing a rust inhibitor for the work, and the cleaning liquid and pure water adhering to the work passed through the pure water rinsing part are purified water containing a rust inhibitor. And a drying unit provided with a drying unit for drying and removing pure water adhering to the rinsed work.The pure water rinsing unit is provided after pure water is drawn out of the pure water tank. A pure water circulating means for returning to the pure water tank, and a deaeration means for removing dissolved oxygen contained in the circulating pure water, interposed in a pure water circulating path formed by this means, for example,
It is characterized by having a device utilizing a steam-water separation membrane or the like.

Further, in order to prevent rust from being generated on the metal surface of the workpiece during the cleaning step, it is preferable that the cleaning liquid also contains a rust inhibitor for the workpiece.

[0010]

In the work cleaning method according to the present invention, the cleaned work is rinsed with pure water mixed with a rust preventive agent for the work to remove the cleaning liquid adhering to the work, and then the drying step is performed. In the rinsing step and in the drying step, the work surface is protected by a rust inhibitor, for example, in a state in which a protective film is formed, and is in contact with pure water or in a state where pure water is attached. Even when exposed to high temperatures, the metal surface of the work does not react with pure water or dissolved oxygen in pure water, so no rust is generated on the metal surface of the work.

When a pure water rinsing step using pure water is performed as a rinsing step, pure water degassed by using a water / water separation membrane or the like, particularly, the dissolved oxygen amount is about 3%.
Even when pure water of ppm or less is used, the reaction between the metal and the dissolved oxygen or the reaction between the metal and the water is suppressed, so that rust does not occur on the metal surface of the workpiece during rinsing.

[0012]

【Example】

Embodiment 1 Hereinafter, Embodiment 1 of the present invention will be described with reference to the drawings.
Will be described.

FIG. 1 schematically shows the entire configuration of the work cleaning apparatus of the present embodiment. The apparatus of this example is for cleaning a metal part (work), and is configured to collectively clean the work using a cleaning basket. As shown in FIG. 1, the apparatus 1 of this embodiment includes a pre-cleaning unit 2, a cleaning unit 3, a first rinsing unit 4, and a second rinsing unit 5 (final rinsing unit 5) in this order from the upstream side of the work transfer path. ), And the drying section 6 is arranged. When using the work cleaning apparatus 1 of the present embodiment, as shown in FIG.
A cylindrical mesh basket 102 with 01 is used as a carrier of the work W. The transport mechanism 103 of the net basket 101 includes a hook portion 104 for suspending the handle 101 of the net basket 102.
, An arm 105 supporting the hook 104, and a moving unit 106 for moving the arm 105 in the horizontal and vertical directions, whereby the workpiece is cleaned by the pre-cleaning unit 2, the cleaning unit 3, the first A rinsing section 4, a second rinsing section 5,
The work can be conveyed to the drying unit 6 and the work can be vertically swung in the second rinsing unit 5.

Next, the configuration of each unit will be described with reference to FIG.

First, in the pre-cleaning section 2, a cleaning liquid tank 202 storing a cleaning liquid 201 containing a workpiece cleaning agent is provided.
In this example, the workpiece is preliminarily cleaned by spraying the aqueous cleaning liquid 201 mixed with a surfactant as a workpiece cleaning agent on the workpiece in the liquid. Here, the cleaning liquid tank 202 has a substantially cubic shape whose upper part is open,
Inside the four walls, four full-cone type nozzles 203 having a jet angle of 60 degrees are arranged. These nozzles 203
The cleaning liquid is sprayed obliquely from above onto the cleaning basket 12 carried into the cleaning liquid tank 202. Further, these nozzle groups communicate with the bottom surface of the cleaning liquid tank 202 via a cleaning liquid circulation path 204, and a pump 205 and a strainer 206 are interposed in the circulation path 204.

Next, in the cleaning unit 3, the work which has been preliminarily cleaned is immersed in a cleaning liquid tank 302 in which an aqueous cleaning liquid 301 having the same composition as the cleaning liquid 201 is stored.
Perform ultrasonic cleaning in 1. Here, the cleaning liquid tank 302
Also has a substantially cubic shape with an open top, and the cleaning liquid tank 3
The cleaning liquid 301 stored in the cleaning liquid 02
An ultrasonic wave having a frequency of 28 kHz can be propagated by an ultrasonic wave generator 303 arranged on the bottom side of 02.

Next, in the first rinsing section 4, dicyclohexylamine nitrite (rust inhibitor), which has a rust-preventing action on the work, is mixed with water containing no impurities such as a cleaning agent, ie, pure water. The work is carried into the rinsing liquid tank 402 storing the rinse liquid 401, and the cleaning liquid is washed from the work by spraying the rinsing liquid onto the work in the liquid. The nitrite of dicyclohexylamine is adsorbed on the metal surface and forms a thin protective film, thereby having an effect of preventing rust from being generated on the metal surface. Also, nitrite of dicyclohexylamine is
Its vapor pressure is high and it has vaporizability. Here, the rinsing liquid tank 402 also has a substantially cubic shape whose upper part is open, and four filled-cone type nozzles 403 having a spray angle of 60 degrees are arranged inside the four-sided walls. These nozzles 4
03 injects the rinsing liquid from obliquely above the cleaning basket 12 carried into the rinsing liquid tank 402. Also,
These nozzle groups communicate with the bottom surface of the rinsing liquid tank 402 via a rinsing liquid circulation path 404, and the circulation path 404 includes a pump 405 and a strainer 406.
Is inserted. In the first rinsing section 4,
The rinsing liquid 401 is constantly added to the rinsing liquid tank 402, while overflowing from the overflow section 402 a of the rinsing liquid tank 402, and is kept at a certain level of cleanliness.

Next, in the second rinsing section 5, the work is carried into a rinsing liquid tank 502 in which a rinsing liquid 501 is stored, and the work is swung up and down while the work is immersed in the rinsing liquid 501. By moving, the cleaning liquid adhering to the work is completely washed away. Here, the rinsing liquid 501 of the second rinsing unit 5 is similar to the rinsing liquid 401,
It is obtained by mixing dicyclohexylamine nitrite (rust inhibitor) having a rust-preventing action on a workpiece in pure water.
The rinsing liquid tank 502 also has a substantially cubic shape whose upper part is open.

Finally, in the drying section 6, the work is exposed to a high-temperature atmosphere to remove pure water (rinse liquid) adhering to the work. Here, the top cover 602 of the dryer 601 can be opened and closed in accordance with the timing of loading and unloading the work.

In the work cleaning apparatus 1 having this configuration, the work is first subjected to the jet of the cleaning liquid 201 from the nozzle 203 in the pre-cleaning section 2 to remove deposits and the like by the chemical cleaning power and physical power of the cleaning liquid 201. After that,
In the cleaning section 3, ultrasonic cleaning is performed, and the cleaning is performed completely. Next, the cleaned work is rinsed in the first rinsing section 4 by receiving a jet of the rinsing liquid 401 from the nozzle 403, and the cleaning liquid attached to the work is washed away. Further, in the second rinsing section 5, the workpiece is swung up and down in the rinsing liquid 501, and the cleaning liquid attached to the workpiece is completely washed away. As a result, the work is carried into the dryer 601 with the rinse liquid attached thereto and dried.

Here, the work being immersed in the rinsing liquids 401 and 501 and the work being dried are protected by the nitrite of dicyclohexylamine mixed in the rinsing liquid, so that they are immersed in the rinsing liquid. Further, even when the inside of the dryer 601 is exposed to a high-temperature atmosphere, it does not react with pure water and dissolved oxygen in the pure water, so that no rust is generated on the metal surface of the work. In addition, since the nitrite of dicyclohexylamine has a vaporizing property, it does not remain on the work surface after drying.

Embodiment 2 Hereinafter, Embodiment 2 of the present invention will be described with reference to FIG.

FIG. 3 schematically shows the entire configuration of the work cleaning apparatus of the present embodiment. The apparatus of this example is for cleaning a metal part (work), similarly to the work cleaning apparatus according to the first embodiment, and collectively collects works using the cleaning basket 102 and the transport mechanism 103 of FIG. It is configured to be cleaned. As shown in FIG. 3, the apparatus 11 of the present example includes a pre-cleaning unit 12, a cleaning unit 13, a first rinsing unit 14 (pure water rinsing unit), and a second rinsing unit in this order from the upstream side of the work transfer path. 15, a third rinsing section 16 (final rinsing section), and a drying section 17 are arranged.

Next, the configuration of each unit will be described with reference to FIG.

First, in the pre-cleaning section 12, an aqueous cleaning liquid 121 mixed with a surfactant as a workpiece cleaning agent is used.
Is sprayed onto the work in the liquid to perform pre-cleaning of the work. In the cleaning unit 13, ultrasonic cleaning is performed inside an aqueous cleaning liquid 131 having the same composition as the cleaning liquid 121. Here, both the cleaning liquid 121 and the cleaning liquid 131 are mixed with nitrite of cyclohexylamine having a rust-preventing effect on the work. The other configurations of the pre-cleaning unit 12 and the cleaning unit 13 are the same as the configurations of the pre-cleaning unit 2 and the cleaning unit 3 of the workpiece cleaning device 1 according to the first embodiment illustrated in FIG. I do.

Next, in the first rinsing section 14, ultrasonic cleaning is performed inside the pure water tank 142 in which the pure water 141 is stored, and the cleaning liquid is washed from the work. here,
The pure water tank 142 has a substantially cubic shape with an open top, and an ultrasonic wave generator 143 disposed on the bottom side thereof allows ultrasonic waves having a frequency of 28 kHz to propagate to the pure water 141. On the bottom side of the pure water tank 142, a pure water circulation path 144 that draws pure water out of the tank and returns the pure water to the pure water tank 142 is disposed. A unit 146 and a steam-water separation unit 147 (a degassing device) are inserted.

Here, the pure water regeneration unit 146 includes an activated carbon filtration unit 146a, a cation ion exchange unit 146b, and an anion ion exchange unit 164c, removes impurities from the circulating pure water, and regenerates the pure water for use. It is supposed to.

On the other hand, as shown in FIG. 4, the steam / water separation unit 147 has a cylindrical deoxygenation module 147a inserted in the circulation path 144, and water connected to a side surface of the module 147a via a valve 147b. It has a sealed vacuum pump 147c. As shown in FIG. 5, the deoxygenating module 147a has joints 147e and 147f connected to both sides of a cylindrical case main body 147d.
A large number of hollow fibers 147 are provided inside the cylindrical case body 147d.
It has a structure filled with g. In addition, the hollow fiber 147
g at both ends are fixed by an adhesive portion 147h that makes the inside of the cylindrical case body 147d watertight, and the pure water pumped to the cylindrical case body 147d passes only through the inside of the hollow fiber 147g. While the hollow fiber 147
The outer periphery of g is a decompression chamber 147i. The decompression chamber 147i is connected to a water-sealed vacuum pump 147c via a deaeration port 147j. When the inside is evacuated, the pressure of the hollow fiber 147g is reduced from pure water passing through the inside of the hollow fiber 147g. Oxygen is drawn in through the side wall, and oxygen and pure water can be separated. Therefore, pure water before treatment is
The amount of dissolved oxygen is about 6 to 8 ppm, and the metal and pure water are in a state where they easily react with each other.
Oxygen is removed from the pure water that has passed through 7a, and the dissolved oxygen amount is about 0.5 ppm or less, so that the reaction between the pure water and the metal is suppressed. Here, a smaller amount of dissolved oxygen tends to suppress the reaction between pure water and the metal,
In the case of general cleaning, the generation of rust can be prevented if the dissolved oxygen amount is set to about 3 ppm or less.

Further, in the first rinsing section 4, the pure water can be always used while being regenerated by the steam / water separation unit 147 and the pure water regenerating unit 146, so that the amount of drainage therefrom can be reduced. Has become.

Next, in the second rinsing section 15, the workpiece is placed in a rinsing liquid tank 152 storing a rinsing liquid 151 in which pure nitrate of cyclohexylamine having a rust-preventing action is mixed with pure water. After being carried in, the work is swung up and down by the transfer mechanism 103 to wash away the cleaning liquid and the like. Here, the rinsing liquid tank 152 also has a substantially cubic shape whose upper part is open. The rust preventive used herein is not limited to those having vaporizability such as nitrite of cyclohexylamine, and other kinds of rust preventives can be used as long as they are water-soluble rust preventives. .

Next, in the third rinsing section 16 as well, the work is placed in a rinsing liquid tank 162 containing a rinsing liquid 161 in which pure nitric acid of cyclohexylamine having a rust-preventing action is mixed with pure water. The workpiece is carried in, and the work is vertically swung by the transport mechanism 103. Here, the rinsing liquid tank 162 also has a substantially cubic shape whose upper part is open.

Finally, in the drying section 7, the work is exposed to a high-temperature atmosphere to remove pure water adhering to the work. Here, the upper cover 172 of the dryer 171 can be opened and closed in accordance with the timing of loading and unloading the work.

In the work cleaning apparatus 11 having this configuration,
First, in the pre-cleaning section 12, the work is
After receiving the jet of the cleaning liquid 121 from 3 and removing the deposits and the like, the cleaning unit 13 again performs complete cleaning. Here, the cleaning liquid contains nitrite of cyclohexylamine as a rust preventive for the work, so that no rust is generated on the work during the cleaning. Next, the cleaned work is rinsed with pure water in the first rinsing section 14, and the cleaning liquid attached to the work is removed. Here, since the dissolved water amount of the pure water is reduced to about 0.5 ppm or less by the gas-water separation unit 147, the work does not react with the pure water and the dissolved oxygen in the pure water during the rinsing. Rust does not occur. Further, in the second and third rinsing sections 15 and 16, the cleaning liquid and the pure water adhering to the work are completely replaced by the rinsing liquids 151 and 161, and then the work is carried into the dryer 171. , Dried.

Therefore, even if the work is exposed to a high-temperature atmosphere inside the dryer 171, the work is not rusted because it is protected by the nitrite of cyclohexylamine. Moreover, since the nitrite of cyclohexylamine is vaporizable, it does not remain on the work surface after drying.

As described above, in any of the embodiments, the rust preventive agent or the solution which has been subjected to rust preventive measures by degassing is used, so that rust does not occur on the metal surface of the work. Therefore, the work can be cleaned using a water-based cleaning liquid and a rinse using pure water as the rinse liquid.

The rust preventive used in the final rinsing step preferably has vaporizability, but a rust preventive having low vaporizability may be used depending on the use of the work. In particular, in a rinsing step other than the final rinsing step, the attached rust preventive is washed off by the final rinse and does not remain on the work after the cleaning, so that a rust preventive having no vaporization may be used. The method of supplying the rinsing liquid mixed with the rust preventive agent to the workpiece may be oscillating immersion, air jet injection, liquid jet injection, or simple immersion. In addition, the cleaning liquid, the method of supplying pure water to the work for rinsing, air jet injection, liquid jet injection,
Any method such as rocking immersion and simple immersion may be used.

As the degassing treatment other than the gas-water separation membrane, although the degassing ability is inferior, the amount of dissolved oxygen is reduced by using bubbling with nitrogen gas, or the amount of dissolved oxygen is reduced by using ultrasonic waves. May be reduced.

Further, as a configuration of the cleaning apparatus, a pure water tank, a rinsing liquid tank and the like may be added as necessary. Depending on the shape of the workpiece and the nature of the deposit on the workpiece,
It is of a nature that should be set optimally.

Examples of the rust preventive include cyclohexylamine, dicyclohexylamine, morpholine, ethanolamine, benzotriazole, and urea.
Any rust preventive may be used as long as it has a rust preventive effect on the work and is soluble in pure water.

[0040]

As described above, the cleaning method of the present invention is characterized in that pure water containing a rust preventive for the work is used in the rinsing step of washing off the cleaning liquid adhering to the cleaned work. Therefore, according to the present invention, even if the work comes into contact with pure water and is exposed to high temperature with the pure water attached, the work is protected by the rust inhibitor, and the work and pure water Or the reaction with dissolved oxygen is suppressed,
No rust is generated on the metal surface of the work.

When a volatile rust preventive is used as the rust preventive, the rust preventive does not remain on the work surface after drying.

Further, in the pure water rinsing step using pure water, pure water degassed by using a water / water separation membrane or the like, particularly water having a dissolved oxygen content of about 3 ppm or less is used. In the pure water rinsing step, the reaction between the work and pure water or dissolved oxygen is suppressed, and rust does not occur on the metal surface of the work.

When the cleaning liquid also contains a rust inhibitor,
Since the reaction between the work and the water or dissolved oxygen in the cleaning liquid is suppressed, even when an aqueous cleaning liquid is used as the cleaning liquid, rust does not occur on the metal surface of the work during the cleaning.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram schematically illustrating an overall configuration of a workpiece cleaning apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram of a work carrier used in the work cleaning apparatus of FIG. 1 and a transfer device therefor.

FIG. 3 is a schematic configuration diagram schematically illustrating an overall configuration of a workpiece cleaning apparatus according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram of a steam-water separation unit used in the work cleaning device of FIG. 3;

5 is a perspective view of a deoxygenation module used in the steam separation unit shown in FIG. 4 with a part of the case cut away.

[Explanation of symbols]

 Reference numerals 1, 11: Work cleaning device 2, 12: Preliminary cleaning unit 3, 13: Cleaning unit 4, 14: First rinsing unit 5: Second rinsing unit (final rinsing unit) 15 ... second rinsing part 16 ... third rinsing part (final rinsing part) 6,17 ... drying part 147 ... water-water separation unit (degassing means) 147a ... dewatering Oxygen module

Claims (8)

(57) [Claims] A cleaning step of washing off extraneous matter from the work using a cleaning liquid; a rinsing step of washing off the cleaning liquid adhering to the work using pure water containing a rust inhibitor for the work; A drying step of drying and removing pure water. 2. The method according to claim 1, wherein the rust preventive is a vaporizable rust preventive having a vaporizing property. 3. The method according to claim 1, further comprising, prior to the rinsing step, a pure water rinsing step of washing off a cleaning liquid adhering to the workpiece by using degassed pure water. Characteristic work cleaning method. 4. The method for cleaning a workpiece according to claim 3, wherein the degassing process uses a water / water separation membrane. 5. The method for cleaning a workpiece according to claim 3, wherein pure water used in the pure water rinsing step has a dissolved oxygen amount of about 3 ppm or less due to the deaeration treatment. . 6. The method for cleaning a workpiece according to claim 1, wherein the cleaning liquid also contains a rust preventive for the workpiece. 7. A work cleaning section including a cleaning liquid tank storing a cleaning liquid, a pure water rinsing section including a pure water tank storing pure water, and washing off a cleaning liquid attached to the cleaned work.
A final rinsing unit comprising a pure water tank storing pure water containing a rust inhibitor for the work, and replacing the cleaning liquid and pure water adhering to the work having passed through the pure water rinsing unit with pure water containing the rust inhibitor. A drying unit provided with a drying unit for drying and removing pure water adhering to the rinsed work, wherein the pure water rinsing unit draws pure water to the outside from the pure water tank, and then moves the pure water tank to the pure water tank. Work washing characterized by comprising a pure water circulation means for returning, and a deaeration means interposed in a pure water circulation path formed by the means and removing dissolved oxygen contained in the circulating pure water. apparatus. 8. A work cleaning apparatus according to claim 7, wherein said degassing means uses a water / water separation membrane.