JPH11147064A - Removal of lightweight foreign matter and cleaning apparatus for coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lightweight foreign matter removing method capable of efficiently removing waste refuse such as a metal powder or the like and a cleaning apparatus for coating. SOLUTION: A cleaning soln. I to which a surfactant is added is sprayed on a body B to wash off waste refuse and collected in a tank 11 along with the washed-off waste refuse and bubbles S are generated on the surface of the cleaning soln. in the tank 11 to collect the waste refuse and these bubbles S are removed from a discharge port 111. A process for generating bubbles on the surface of the washing soln. includes as aeration process. The collected cleaning soln. is aerated to easily generate bubbles and, since the generated bubbles are floated toward the surface of the cleaning soln. from the bottom surface thereof, the foreign matter mixing into the cleaning soln. can be efficiently collected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing light foreign matter and a cleaning device for painting for removing dust such as iron powder adhering to an automobile body and parts, and for example, a preliminary cleaning device and a cleaning device for a pretreatment process. The present invention relates to a method for removing lightweight foreign matter and a cleaning apparatus for painting which are preferably applied to an apparatus.

[0002]

2. Description of the Related Art In a production line of an automobile body, a white body after a welding process is subjected to various cleaning and degreasing processes such as pre-cleaning, washing, hot water washing, preliminary degreasing, and degreasing, and then a zinc phosphate film is formed on the body surface. Is sent to a chemical conversion treatment step for forming a chemical conversion film consisting of, and thereafter, an electrodeposition coating as an undercoat is applied.

In such a pretreatment / electrodeposition process, the white body is subjected to various surface treatments while being continuously and constantly conveyed by an overhead conveyor while being mounted on a hanger.

[0004]

In the welding process, which is a process prior to the painting process, since the body panels are assembled by spot welding or arc welding, etc., iron powder such as spatter during spot welding is generated in the automobile body. It is brought to the painting process while adhering to the surface. As described above, a multi-step cleaning step is provided in a step before the chemical conversion step in order to clean such foreign substances. In particular, as a method of removing metallic foreign matter such as iron powder, a method using a magnet, a method using a rotary separator, and the like have been proposed in addition to providing a filter in a circulation system.

[0005] However, even with such a conventional method, fine and lightweight iron powder could not be completely washed away. If iron powder that could not be removed in the cleaning process is carried into the chemical conversion treatment tank while adhering to the body, the iron powder adhering to the steel sheet surface is buried in the chemical conversion film, and an electrodeposition coating film is formed on this. Then, a coating film defect such as dust is caused.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to provide a method for removing lightweight foreign matter and a cleaning apparatus for painting which can efficiently remove dust such as metal powder. Aim.

[0007]

(1) To achieve the above object, according to a first aspect of the present invention, as described in claim 1, a step of spraying a cleaning liquid onto an object to be cleaned to wash away foreign matter. And a step of collecting the cleaning liquid together with the washed foreign substances, a step of generating bubbles on the collected cleaning liquid surfaces, and a step of removing bubbles generated on the cleaning liquid surfaces. A method for removing lightweight foreign matter is provided.

According to the first aspect of the present invention, the cleaning liquid is sprayed onto the cleaning object to wash away the foreign substances attached to the cleaning object, and the cleaning liquid mixed with the foreign substances is collected. At this time, since bubbles are generated on the collected cleaning liquid surfaces, the light foreign matter floats on the cleaning liquid surfaces while being captured by the bubbles.

Therefore, foreign matter can be discharged out of the system by removing the bubbles floating on the surfaces of the cleaning liquid. As described above, the foreign matter removing method of the present invention can remove foreign matters with a significantly simpler structure than the removing method using a magnet or a rotary separator.

In the first aspect of the present invention, the means for generating bubbles on each surface of the cleaning liquid is not particularly limited.
In the described invention, the step of generating bubbles on each surface of the cleaning liquid includes a step of adding a foaming agent to the collected cleaning liquid.

In this case, the foaming agent is not particularly limited, but the invention according to claim 3 is characterized in that the foaming agent is a surfactant.

If a foaming agent made of a surfactant is used as a means for generating bubbles on the surfaces of the cleaning liquid, the cleaning effect is exhibited in addition to the large foaming effect. It will be preferable.

[0013] In the invention described in claim 4, the step of generating bubbles on each surface of the cleaning liquid includes an explosive step. By detonating the collected cleaning liquid,
Since the foam easily foams and the generated foam floats from the bottom surface of the cleaning liquid toward the surface, foreign substances mixed in the cleaning liquid can be efficiently captured. Further, since the explosive means can be constituted by a very simple device, the capital investment cost and the running cost can be suppressed.

According to a fifth aspect of the present invention, the step of generating bubbles on each surface of the cleaning liquid includes a step of dropping the cleaning liquid together with the washed foreign substances from a high place. By dropping the cleaning liquid from a high place, bubbles can be generated on the surfaces of the cleaning liquid, and foreign substances contained in the dropped cleaning liquid can be immediately captured.

Although the method for removing lightweight foreign matter provided by the first aspect of the present invention is not particularly limited, it may be used in a cleaning step in a pretreatment step of an automobile coating line as described in claim 6. preferable.

(2) In order to achieve the above object, according to a second aspect of the present invention, as described in claim 7, cleaning means for spraying a cleaning liquid onto an object to be cleaned to wash away foreign matter,
It has a tank for collecting the cleaning liquid together with the washed foreign substances, a foaming unit for generating bubbles on the collected cleaning liquid surfaces, and a removing unit for removing bubbles generated on the cleaning liquid surfaces. A cleaning device for painting is provided.

In the invention according to the seventh aspect, the cleaning means sprays the cleaning liquid on the object to be cleaned to wash away foreign substances adhering to the object to be cleaned, and collects the cleaning liquid containing the foreign substances into the tank. At this time, since bubbles are generated on the surfaces of the cleaning liquid gathered by the foaming means, the light foreign matter floats on the surfaces of the cleaning liquid while being captured by the bubbles.

Therefore, foreign matter can be discharged out of the system by removing the bubbles floating on the surfaces of the cleaning liquid by the removing means. As described above, the coating cleaning apparatus of the present invention can remove foreign matters with a significantly simpler configuration than a cleaning apparatus using a magnet, a rotary separator, or the like.

In the invention according to the seventh aspect, the means for generating bubbles on each surface of the cleaning liquid is not particularly limited.
In the invention described, a foaming agent is added to the tank.

In this case, the foaming agent is not particularly limited, but the invention according to claim 9 is characterized in that the foaming agent is a surfactant.

If a foaming agent comprising a surfactant is added to the tank as a foaming means for generating bubbles on the surfaces of the cleaning liquid, the cleaning effect is exhibited in addition to the large foaming effect. This is preferable when applied to a pretreatment cleaning step of an automobile coating line.

Further, the invention according to claim 10 is characterized by further comprising explosive means for exploding the cleaning liquid in the tank. By exploding the collected cleaning liquid, it easily foams, and the generated bubbles float from the bottom surface of the cleaning liquid toward the surface, so that foreign substances mixed in the cleaning liquid can be efficiently captured. Further, since the explosive means can be constituted by a very simple device, the capital investment cost and the running cost can be suppressed.

According to an eleventh aspect of the present invention, the cleaning liquid sprayed on the object to be cleaned is dropped on the tank from a high place. By dropping the cleaning liquid from a high place, bubbles can be generated on the surfaces of the cleaning liquid, and foreign substances contained in the dropped cleaning liquid can be immediately captured.

In the inventions of claims 7 to 11, the removing means is not particularly limited, but in the invention of claim 12, the removing means has a discharge port provided on one side of the tank via a weir. It is characterized by having. By constructing the removing means in a so-called overflow manner, the bubbles floating on the water surface of the tank can be efficiently discharged out of the system.

[0025]

According to the present invention, bubbles are generated on the collected cleaning liquid surfaces, and light foreign substances can be captured by the bubbles. Therefore, if the bubbles floating on the cleaning liquid surfaces are removed, the foreign substances are discharged out of the system. can do. As described above, the foreign matter can be removed with a significantly simpler configuration as compared with the removal method using a magnet or a rotary separator.

According to the third and ninth aspects of the present invention, since a foaming agent comprising a surfactant is employed as a means for generating foam on each surface of the cleaning liquid, the cleaning effect is exhibited in addition to the large foaming effect. This is particularly preferable when applied to a washing step.

According to the fourth and tenth aspects of the present invention,
Since explosive gas is used as the foaming means, the foam can be easily foamed, and the generated bubbles float from the bottom surface of the cleaning liquid toward the surface, so that foreign substances mixed in the cleaning liquid can be efficiently captured. Further, since the explosive means can be constituted by a very simple device, the capital investment cost and the running cost can be suppressed.

[0028]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing an embodiment of the coating cleaning apparatus of the present invention, and FIG. 2 is a schematic view showing a pretreatment cleaning step of a coating line to which the coating cleaning apparatus of the present invention is applied.

First, the configuration of the pretreatment cleaning step of the coating line will be described with reference to FIG. 2. The white body B, which has completed the welding step, is continuously and fixedly mounted on the hanger H by the overhead conveyor C. While being transported at a high speed, the chamber 1 of the pretreatment cleaning device is
Sent inside.

FIG. 3 shows only the pre-cleaning step 10, the pre-degreasing step 20 and the degreasing step 30 in the pre-processing cleaning step, and a surface conditioning step and a chemical conversion step are provided continuously on the right side of FIG. ing.

In the pre-cleaning step 10 to which the present invention is applied, a tank 11 for storing a cleaning liquid, a cleaning circulation system 12 for sucking the cleaning liquid in the tank 11 and spraying the cleaning liquid onto the body B in a shower form, There is provided an explosive means 13 for performing an explosive, the details of which will be described later.

In the next preliminary degreasing step 20, a degreasing step 3
A pre-degreasing circulating system 22 that sucks the degreasing liquid from the sub tank 32 and sprays it on the body B in a shower form;
A tank 21 for collecting the sprayed degreasing liquid is provided.

The next degreasing step 30 includes a degreasing tank 31 for performing so-called full dip degreasing, a sub-tank 32 for collecting the degreasing liquid overflowing from the degreasing tank 31, and a degreasing liquid in the sub-tank 32. Aspirate,
At the inlet and outlet of the degreasing tank 31, a degreasing circulation system 33 for spraying the body B in a shower is provided.

The structure of the pretreatment cleaning step is as follows.
This is merely an example, and does not limit the application of the coating cleaning apparatus and the method for removing lightweight foreign matter of the present invention.

As shown in detail in FIG. 1, the pre-cleaning step 10 of this embodiment has a tank 11 for collecting a cleaning liquid, and a discharge port 111 is provided on one side of the tank 11 through a weir 112. Is formed. The cleaning liquid L sprayed on the body B in the chamber of the pre-cleaning step 10 is collected in the tank 11, and the weir 112 is
It is formed slightly higher than the water surface inside.

The floor surface 14 of the chamber is formed to be slightly inclined toward the center, and the cleaning liquid L sprayed on the body B from the nozzle 123 passes through a drip hole formed in the center of the floor surface through a duct. While being guided by 141, the liquid is dropped onto the tank 11.

The cleaning liquid L collected in the tank 11 is sprayed onto the body B by the cleaning circulation system 12, and the cleaning circulation system 12 is connected to a pipe 124 provided between the tank 11 and the chamber. A pump 121 for suctioning the cleaning liquid L in the filter 11, a filter 122 for filtering dust mixed in the suctioned cleaning liquid L, and a plurality of nozzles disposed along the side wall of the chamber and discharging the cleaning liquid L toward the body B 123.

In particular, in the present embodiment, a cleaning liquid L obtained by adding a surfactant to water such as industrial water is used, and further, explosive means 13 for generating bubbles S on the liquid surface of the tank 11 is provided. doing.

The explosive means 13 is provided at an air supply source such as a factory compressor, an air pipe 132 provided between the air supply source 131 and the inside of the tank 11, and a tip of the air pipe 132. Multiple nozzles 13
And 3. From the air supply source 131,
Although not particularly limited, air having a pressure of, for example, about 5 kgf / cm ² is supplied.

Although not particularly limited, the air piping 132
Is provided in the vicinity of the bottom surface of the tank 11. When air is supplied into the tank 11, bubbles rise from the bottom surface of the tank 11 toward the water surface and are affected by the surfactant. Bubbles S are generated on the water surface of the tank 11. In particular, since aeration is performed from the bottom surface of the tank 11 to the water surface, it is possible to preferably capture iron powder and the like mixed in the cleaning liquid L during the ascent.

Next, the operation will be described. The body B carried in by the overhead conveyor C is cleaned by sucking the cleaning liquid L to which the surfactant is added from the tank 11 by the pump 121 and spraying the cleaning liquid L from the nozzle 123. At this time, dust such as iron powder attached to the body B is washed away by the cleaning liquid L, dropped on the floor surface 14 of the chamber, collected at the center, and further dropped into the tank 11 from the drip hole of the floor surface 14.

On the other hand, air is supplied from the air supply source 131 to explode the inside of the tank 11. Since a surfactant is added to the cleaning liquid L in the tank 11, the explosion causes bubbles S to be generated on each surface of the cleaning liquid.

Therefore, dust contained in the cleaning liquid L dropped from the floor surface 14 of the chamber and dust contained in the cleaning liquid L in the tank 11 float on the surfaces of the cleaning liquid while being trapped by the bubbles S. Becomes When the explosion in the tank 11 is continued, the volume of the bubbles S floating on the surfaces of the cleaning liquid gradually increases, so that the bubbles S are automatically discharged over the weir 112 to the discharge port 1.
From 11 is discharged out of the system.

As described above, according to the present embodiment, it is possible to remove lightweight dust such as iron powder with a remarkably simple configuration as compared with the removal method using a magnet or a rotary separator. In particular, it is suitable for removing dust of about 20 to 70 μm.

Further, in this embodiment, since the surfactant is added to the industrial water as the cleaning liquid L, not only the foaming effect in the tank 11 is large but also the cleaning effect on the body B is exhibited. Become.

The embodiments described above are described for facilitating the understanding of the present invention, but are not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a coating cleaning apparatus of the present invention.

FIG. 2 is a schematic diagram showing a pretreatment cleaning step of a coating line to which the coating cleaning apparatus of the present invention is applied.

[Explanation of symbols]

 A: Air B: Body C: Overhead conveyor H: Hanger W: Dropping cleaning liquid L: Cleaning liquid S: Foam 10: Preliminary cleaning step 11: Tank 111: Discharge port 112: Weir 12: Cleaning circulation system 121: Pump 122: Filter 123 ... Nozzle 124 ... Piping 13 ... Explosive means 131 ... Air supply source 132 ... Air pipe 133 ... Nozzle 14 ... Chamber floor

Claims (12)

[Claims] 1. A step of spraying a cleaning liquid onto an object to be cleaned to wash away foreign substances, a step of collecting the cleaning liquid together with the washed foreign substances, a step of generating bubbles on the surfaces of the collected cleaning liquids, Removing the bubbles generated on the surface. 2. The step of generating bubbles on each surface of the cleaning liquid,
2. The method according to claim 1, further comprising a step of adding a foaming agent to the collected cleaning liquid. 3. The method according to claim 2, wherein the foaming agent is a surfactant. 4. The step of generating bubbles on each surface of the cleaning liquid,
The method for removing lightweight foreign matter according to any one of claims 1 to 3, further comprising an explosive process. 5. The step of generating bubbles on each surface of the cleaning liquid,
The method for removing lightweight foreign matter according to any one of claims 1 to 4, further comprising a step of dropping a cleaning liquid together with the washed away foreign matter from a high place. 6. The method for removing lightweight foreign matter according to claim 1, wherein the method is used in a washing step in a pretreatment step of an automobile coating line. 7. A cleaning means for spraying a cleaning liquid onto an object to be washed to wash out foreign substances, a tank for collecting the cleaning liquid together with the washed foreign substances, a foaming means for generating bubbles on the surfaces of the collected cleaning liquid, A cleaning means for removing bubbles generated on the surfaces of the cleaning liquid. 8. A coating cleaning apparatus according to claim 7, wherein a foaming agent is added to said tank. 9. The cleaning apparatus according to claim 8, wherein said foaming agent is a surfactant. 10. The coating cleaning apparatus according to claim 7, further comprising an explosive means for exploding the cleaning liquid in the tank. 11. The coating cleaning apparatus according to claim 7, wherein the cleaning liquid sprayed on the object to be cleaned is dropped from a high place onto the tank. 12. The cleaning apparatus according to claim 7, wherein said removing means has a discharge port provided on one side of said tank via a weir.