JP2009167496A - Washing apparatus for pretreatment of electrodeposition coating - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a washing apparatus before electrodeposition coating in which the inside and small gaps of a bag-shaped product before electrodeposition coating is efficiently washed. <P>SOLUTION: In the pretreatment water washing apparatus 1 before electrodeposition coating is provided with dipping cleaning tanks 41, 61 and shower cleaning tanks 31, 51, 71 to wash a product W before electrodeposition coating alternately through the dipping cleaning tanks 41, 61 and the shower cleaning tanks 31, 51, 71, a bubble generating means 4 for generating micro-nanobubbles is provided in the bottom side of the dipping cleaning tanks 41, 61 and further a water jet riser is provided to jet a cleaning solution containing micro-nanobubble in the dipping cleaning tanks 41, 61 and the products in the dipping cleaning tanks 41, 61 are cleaned by being naturally abutted with the generated and floated micro-nanobubbles and being butted by the water jet riser. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a pretreatment water-washing apparatus for electrodeposition coating that is performed when impurities including a degreasing liquid are removed from a product that has been degreased before electrodeposition coating.

  Products that are subjected to electrodeposition coating should be free of oils and fats and dust / dust attached to the product before electrodeposition coating in order to perform electrodeposition coating well before the electrodeposition coating process. For the purpose, a degreasing treatment with a degreasing liquid and a water washing process for removing the degreasing liquid and dust and dust are performed. That is, the pre-treatment of electrodeposition coating is basically the degreasing treatment of the product W with the degreasing liquid, the water washing treatment of the degreasing liquid, the surface adjustment of the product W, the chemical conversion treatment on the surface of the product W, the surface treatment and the rust preventive film. It is divided roughly into five steps of water washing treatment in which the chemical conversion liquid is washed away, and in the final water washing treatment, washing with pure water is generally performed.

FIG. 6 shows a conventional pretreatment process before electrodeposition coating.
In the pretreatment apparatus 100 that performs the conventional pretreatment shown in FIG. 6, the product W is suspended and moved by a suspended conveying means 110 that sequentially conveys and moves the product W.
The suspended conveying means 110 is a conveying means for conveying the product W in an automobile factory or the like. In this conventional example, the product W to which the electrodeposition coating is applied is an automobile body, and the suspended conveying means 110 is a suspended conveying device used in a general automobile manufacturing factory. Control is performed by a controller (not shown) throughout the work process.

  In the pretreatment apparatus 100, first, the product W is first cleaned to perform preliminary cleaning to wash away dust and the like. Reference numeral 101 denotes the preliminary cleaning unit. The preliminary cleaning section 101 is provided with a preliminary cleaning tank 101a, and the preliminary cleaning tank 101a is filled with cleaning water. In the preliminary cleaning unit 101, the product W is immersed in the preliminary cleaning tank 101a to perform cleaning. This cleaning is performed for the purpose of infiltrating water into the hemming processed portion applied to the automobile body as the product W before the degreasing treatment. The penetration of water into the portion subjected to the hemming process before the degreasing process is an operation performed to prevent the degreasing liquid from entering the gap between the portions subjected to the hemming process. If the degreasing liquid enters the gap between the parts subjected to hemming, it becomes difficult to remove the degreasing liquid in the water washing process after the degreasing process, and the alkaline degreasing liquid enters the gap between the parts subjected to the hemming process. When the acidic electrodeposition paint is electrodeposited, paint aggregation occurs due to the difference in pH between the degreasing liquid and the electrodeposition paint. Therefore, water is allowed to enter the portion that has been subjected to hemming in advance in the pre-cleaning tank 101a to prevent degreasing liquid from entering the portion in the degreasing step.

  Reference numeral 102 denotes a degreasing portion. The degreasing unit 102 is provided as a process of processing the product W after the preliminary cleaning tank 101a, and is provided with a degreasing tank 102a. The degreasing tank 102a is filled with a degreasing solution, and a degreasing unit 101 is provided to degrease the product W by dipping and moving in the degreasing solution. At this time, the product W is immersed in the degreasing tank 102a only by being transported and moved because the product W in which the rails of the suspended conveying means 110 are suspended in advance is disposed in the degreasing tank 102a. .

  A water washing process is performed as a process performed subsequent to the degreasing unit 102. Reference numeral 103 denotes a first water washing section. The 1st water washing part 103 wash | cleans the product W which passed through the degreasing part 102 with the shower spray apparatus. Therefore, the shower spray device is installed so that cleaning water can be shower sprayed on the product W that has been transported and passed through the shower spray device, and cleans the product W.

The product W that has passed through the first water washing unit 103 is continuously moved to the second water washing unit 104.
The second water washing section 104 is provided with a second washing tank 104a, and the second washing tank 104a is filled with washing water. Then, the product W transported out of the first water washing section 103 by the suspended conveyance means 110 reaches the second water washing section 104 and is immersed in the second washing tank 104a. At this time, the product W is washed with water. The immersion movement of the product W may be controlled by a control unit (not shown) in the same manner as the immersion movement in the preliminary cleaning tank 101a.

  Reference numeral 105 denotes a surface adjustment unit. In the surface adjustment unit 105, the product W that has been washed with water by the first water washing unit 103 and the second water washing unit 104 is suspended and moved by the suspended conveyance device 110 to be surface-adjusted. The surface adjustment unit C is provided with a surface adjustment tank 105a. In the surface adjustment part 105, it is performed as a surface adjustment process performed in order to make it easy to form a chemical conversion film on a product made of a steel plate during the chemical conversion treatment, and the surface of the product W is adjusted by the adjustment liquid filled in the surface adjustment tank 105a. Make adjustments.

  Reference numeral 106 denotes a chemical conversion processing unit. The chemical conversion treatment unit 106 is a step performed on the product W after the surface adjustment unit 105. The chemical conversion treatment unit 106 is provided with a chemical conversion treatment tank 106a and is filled with a chemical conversion treatment liquid. Then, the product W that has been transported out of the surface adjustment unit 105 by the suspended transport device 110 is dipped and transported into the chemical conversion treatment tank 106a, and the chemical conversion liquid in the chemical conversion treatment tank 106a forms a rust preventive film on the product W. To do.

Reference numeral 107 denotes a third water washing section. The 3rd water washing part 107 is installing the shower spray apparatus similarly to the 1st water washing part 103, and wash | cleans the surface of the product W processed by the surface adjustment part 105 and the chemical conversion treatment part 106 with washing water.
The third water washing unit 107 is the same as the first water washing unit 103.

  Reference numeral 108 denotes a fourth water washing section. In the fourth water washing section 108, the product W that has been washed with water by the third water washing section 107 is suspended and moved by the suspended conveying device 110 to perform water washing. The fourth water washing section 108 is provided with a fourth water washing tank 108a and filled with washing water. And the product W is immersed in the 4th washing tank 108a by conveyance of the suspending conveyance apparatus 110, and the washing water in the 4th washing tank 108a rinses and wash | cleans the product W.

  Reference numeral 109 denotes a fifth water washing section. The fifth water washing section 109 is the same as the first water washing section 103 and is provided with a shower spray device, and the product W moved from the fourth water washing tank 108a by the suspended conveyance device 110 is washed by the shower spray of the shower spray device. To do.

  And after completion | finish of the washing | cleaning by the 5th water-washing part 109, the product W was immersed in the electrodeposition coating tank A by the hanging conveyance apparatus 110, and the electrodeposition coating was given.

  In the above conventional example, the product W is an automobile body, and thus the electrodeposition coating process and the cleaning process are described as part of a line in an automobile manufacturing factory.

In the case where the product W is an automobile body having a seam or a bent portion formed by hemming the steel plate, etc., in order to prevent the occurrence of alkali agglomeration due to the remaining degreasing liquid, In addition, the product W is immersed in the pre-cleaning portion 101 so that the degreasing liquid does not enter the bent portion, so that water is infiltrated into the joint and the bent portion.
Although the occurrence rate of product defects due to alkali agglomeration butts, etc. has decreased in the preliminary cleaning by the preliminary cleaning unit 101 as described above, in order to further suppress this occurrence rate, the inventor has determined the state of penetration into seams and bent portions, An attempt was made to artificially reproduce the gap and reveal it through experiments.

That is, first, it was found that the result of measuring the gap between the seam and the bent portion by hemming was 0 [μm] to 300 [μm]. Further, when the gap between the alkali agglomerated flaws generated in the product W, which was a defective product, was measured, it was found that it was 100 [μm] to 300 [μm].
Therefore, the inventor artificially creates a gap of 100 [μm] to 300 [μm] with a glass plate, and performs the preliminary cleaning unit 101 using a test piece that is closed in three directions with a sealing material and opened in only one direction. The permeability of the washing water and the permeability of the degreasing liquid used in the degreasing unit 102 were confirmed. As a result, in the gap of 300 [μm] reproduced on the glass plate, it was confirmed that both the washing water and the degreasing liquid penetrated and entered the gap, but in the gap of 200 [μm] and 100 [μm]. Although the penetration of the degreasing liquid was confirmed, it was found that the washing water did not enter the gap and could not penetrate.

  The inventor inferred from this result that the difference in penetrating power into narrow gaps may be due to the difference in surface tension between the two liquids, and in addition to both liquids, each of the paint and chemical conversion treatment liquid used in electrodeposition coating. When the surface tension was measured, it was 65 [dyn / cm] for the washing water used in each washing unit, 36 [dyn / cm] for the degreasing liquid, and 70 [dyn / cm] for the chemical conversion treatment liquid. It was found that the electrodeposition paint was 35 [dyn / cm]. From this result, it is understood that the cleaning water that is usually used has a larger surface tension than the degreasing liquid, and the cleaning water cannot enter a gap smaller than a predetermined dimension that the degreasing liquid can finally enter.

  Furthermore, even if water has previously penetrated into the gap to the extent that the degreasing liquid can penetrate and the cleaning water cannot penetrate, when it is immersed in the degreasing liquid, it is replaced with the previously invaded water. It was also found that the liquid entered.

  Therefore, as in the conventional example, even if the product W is first immersed in water and water enters the gap, the degreasing liquid can be replaced with the degreasing liquid in the gap where the degreasing liquid cannot enter and the cleaning water cannot enter. It has been difficult to effectively prevent alkali aggregation.

  Therefore, in view of the above problems, the present invention provides a cleaning apparatus capable of physically pre-processing and cleaning a product having a seam of a steel plate or a bent or curved interior having a bag shape. The task is to do.

  In this invention, in order to completely clean the degreasing liquid adhering to the degreasing treatment performed before the electrodeposition coating, an immersion cleaning tank and a shower cleaning tank are provided before the electrodeposition coating and before the electrodeposition coating. This is a pre-treatment water washing device for electrodeposition coating that passes through the immersion cleaning bath and shower cleaning bath alternately before the electrodeposition coating, and is capable of generating micro-nano bubbles on the bottom side of the immersion cleaning bath Provided is a pretreatment water-washing apparatus for electrodeposition coating, characterized in that a generating means is provided and the generated micro-nano bubbles are applied to a product in an immersion cleaning tank for cleaning.

Furthermore, in order to make the generated micro / nano bubbles act efficiently, an immersion washing tank and a shower washing tank are provided after the electrodeposition coating pretreatment and before the electrodeposition coating, and the product is prepared after the electrodeposition coating pretreatment. This is a water-washing apparatus for electrodeposition coating that alternately passes through an immersion cleaning tank and a shower cleaning tank, and is provided with bubble generating means capable of generating micro-nano bubbles on the bottom side of the immersion cleaning tank, and further includes micro-nano bubbles A water jet riser that can spray the cleaning liquid in the immersion cleaning tank is installed.
Pre-treatment water washing for electrodeposition coating, wherein the generated micro-nano bubbles float on the product in the immersion washing tank and naturally come into contact with the product and are forcedly brought into contact with a water jet riser to wash the product. Providing equipment.

In these electrodeposition coating pretreatment washing apparatuses, the micro / nano bubbles generated by the micro / nano bubble generating means are mixed with the cleaning liquid and can float for a long time. The bubble liquefied cleaning liquid penetrates into a small gap where normal cleaning water in the product before electrodeposition coating cannot enter in the immersion cleaning tank and already enters the gap, and the characteristics of the micro-nano bubbles contained in the cleaning liquid To remove the degreasing liquid that has entered and adhered to the fine gaps on the surface of the product.
In addition, a water jet riser is provided in the immersion cleaning tank to forcibly inject the cleaning liquid in the form of bubbles into the product. In particular, in the case of a product having a bag shape, the injection direction of the water jet riser is adjusted so as to inject toward the inside of the bag shape. As a result, the cleaning liquid containing the micro / nano bubbles efficiently penetrates into the bag-like interior, and the cleaning is performed more efficiently.

  Therefore, according to the present invention, the micro / nano bubbles generated by the micro / nano bubble generating means stay in suspension in the cleaning liquid in the immersion cleaning tank for a long time and come into contact with the product immersed in the immersion cleaning tank. Thus, it is possible to wash and remove the degreasing liquid that has entered the very small gap in the degreasing treatment performed as a pretreatment for electrodeposition coating. In particular, cleaning in a gap of 200 μm or less, which cannot be cleaned by ordinary immersion cleaning or cleaning by a shower spray device, can be performed by using bubble liquefied cleaning water containing micro-nano bubbles.

  In addition, the water jet riser forced the RO water by liquefying the bubble toward the inside of the bag shape where the washing water cannot be sufficiently flowed by simply passing it through the immersion washing tank and the washing becomes insufficient. , The bubble-like cleaning liquid is sufficiently supplied to the inside of the bag shape, and the inside of the bag shape, which has been likely to cause frequent cleaning defects, can be sufficiently cleaned. This makes it possible to perform the cleaning with more efficient.

  And by performing these washings properly, the degreasing liquid remaining on the product before the electrodeposition coating can be removed almost completely as compared with the conventional case. Can be eliminated, and it can contribute to the improvement of production efficiency and the reduction of the total manufacturing cost.

The 4th water washing part 6 is a water washing part which performs immersion washing. In the fourth water washing section 6, the product W is immersed and moved by the suspended conveying device 8 in the washing water filled in the washing tank 61 to perform immersion washing.
The cleaning water filled in the cleaning tank 61 may be sequentially supplied with new cleaning water, while an amount corresponding to the supply amount may be discharged, and the cleaning tank 61 is always filled with the cleaning water. Although the state can be maintained, the supply and drainage of the washing water are the same as in the prior art, so illustration is omitted and detailed explanation is omitted.

  In the 4th water washing part 6, the micro nano bubble generator 9 is provided. In this embodiment, four micro / nano bubble generators 9 are provided and can generate micro / nano bubbles, respectively. That is, the washing water is taken out from the washing tank 61 by the pump 91, and the washing water is supplied to the generator main body 93 through the filter 92. The generator main body 93 takes in the outside air and generates a large amount of micro / nano bubbles in the washing water. Wash water containing micro-nano bubbles is supplied from 94 to the wash tank 61. Further, a valve 96 for adjusting the amount of micro-nano bubbles generated is provided in front of the generator main body 93. The cleaning tank 61, the pump 91, the filter 92, the valve 96, the generator main body 93, and the jet outlet 94 are provided. Are connected by a pipe line 95, and the jet port 94 is installed at the bottom of the cleaning tank 61.

  The micro / nano bubbles generated by the micro / nano bubble generating device 9 are bubbles having a diameter of about 0.2 μm to 10 μm, and the micro / nano bubble generating device 9 generates and supplies bubbles containing a large amount of micro / nano bubbles of this size in the washing water. To do. Therefore, it is desirable that the bubbles generated by the micro / nano bubble generating device 9 are only micro / nano bubbles, but there is no micro / nano bubble generating device 9 that generates only micro / nano bubbles. Bubbles are also generated at the same time, as long as they contain many micro / nano bubbles.

The fourth water washing unit 6 is provided with a water jet riser 10. The water jet riser 10 is a device that jets cleaning water vigorously toward the product W transported and moved in the cleaning tank 61. The water jet riser 10 includes a riser body 10b having a plurality of discharge ports 10a that are fixedly installed so as to sandwich the product W from both sides of the product W transported and moved into the cleaning tank 61 and that can discharge cleaning water in the product W direction. A discharge pump 10c is provided for supplying cleaning water containing micro / nano bubbles in the cleaning tank 61 to the riser body 10b. Then, the discharge pump 10c and the cleaning tank 61 are connected to supply cleaning water in the cleaning tank 61 to the discharge pump 10c, and the discharge pump 10c and the riser main body 10b are connected to the riser main body 10b to the discharge pump 10c. A pipe 10d for supplying cleaning water is provided. Further, a valve 10e is provided in the pipe 10d between the discharge pump 10c and the riser body 10b.
The water jet riser 10 configured as described above can efficiently clean the product W by directing the discharge port 10a so that the cleaning water discharged into the steel plate formed in the bag shape of the product W enters. Adjust to.
The 5th water washing part 7 is provided so that the shower spray washing | cleaning is possible following the washing | cleaning by the 4th water washing part 6. FIG. The 5th water washing part 7 is a washing | cleaning part which performs spray washing, and is provided with the shower spray apparatus as shown in FIG.

  Embodiments of the present invention will be described below with reference to the drawings. 1 is an overall explanatory view showing an embodiment of the present invention, FIG. 2 is a partial explanatory view of FIG. 1, FIG. 3 is a partial explanatory view of FIG. 1, and FIG. 4 is an explanatory view of micro-nano bubbles. FIG. 5 is an explanatory diagram comparing the permeability of micro-nano bubbles.

  1 is a pretreatment water washing apparatus for electrodeposition coating according to the present invention. In this embodiment, the water washing apparatus 1 is provided in a water washing process before electrodeposition coating performed after a pretreatment process provided in a production line of an automobile manufacturing factory. An example of processing a steel plate having a bag-shaped portion such as a center pillar will be described. In this embodiment, the production line in the automobile manufacturing factory is taken as an example. However, the production line is not limited to the automobile manufacturing factory, and it may be a home appliance manufacturing factory, other machine manufacturing factory, etc. It is not limited as long as the electrodeposition coating is performed after the steel plate is processed, and washing is performed in the pretreatment step before the electrodeposition coating.

In the pre-process of the water rinsing apparatus 1, a degreasing process is performed in which the product W is immersed in the degreasing tank B and the oil adhering to the product W is washed away by the degreasing liquid. In the apparatus 1, the degreasing solution after the degreasing treatment is washed away.
Further, since electrodeposition coating is performed in the subsequent process of the water washing apparatus 1, the electrodeposition tank A is provided after the transport path of the water washing apparatus 1, and the work W is immersed and passed through the electrodeposition tank A. Paint is applied.
And the workpiece | work W is suspended and conveyed by the suspension conveyance apparatus 8 in the movement to a degreasing process, a water washing process, and an electrodeposition coating process. Since the suspended conveying device 8 may be one conventionally used in a production line of an automobile manufacturing factory, it will not be described in detail.

  Reference numeral 2 denotes a preliminary cleaning unit. The preliminary cleaning unit 2 is a cleaning unit that immerses and cleans the product W transported by the suspended transport device 8. Accordingly, the preliminary cleaning section 2 is provided with the preliminary cleaning tank 21 filled with the cleaning water, and cleaning is performed by immersing and moving the product W into the preliminary cleaning tank 21 while the suspended transport device 8 is transporting. The cleaning water in the preliminary cleaning tank 21 will not be described in detail, but necessary devices such as piping and filtration regenerators are attached so that they can be appropriately replaced or re-used for filtration. Filter reused. The preliminary cleaning unit 2 is performed as the first step of the process before electrodeposition coating.

Since the degreasing step is performed following the precleaning step by the precleaning unit 2, the degreasing processing unit B is provided at the next transfer position by the suspended transfer device 8. In the degreasing part B, the product W is washed with a degreasing liquid. In this embodiment, a degreasing liquid shower spray device B1 and a degreasing liquid tank B2 are provided so that washing by shower spraying and washing by immersion can be performed. Accordingly, in the degreasing treatment unit B, the product W conveyed from the preliminary cleaning unit 2 by the suspended conveying device 8 is subjected to shower spray cleaning by the degreasing liquid shower spray device B1, and the product W is put in the degreasing liquid tank B2 after shower spray cleaning. It is immersed and washed by the suspended conveying device 8.
The degreasing liquid shower spray device B1 is a device that showers and sprays the degreasing liquid on the product W to wash away the oil and fat components adhering to the surface of the product W. The degreasing liquid shower spray device B1 sprays the degreasing liquid pumped from the degreasing liquid tank B2 by a pump (not shown) from the side of the product W to be transported and moved to wash away the oil and fat adhering to the product W. The washing water containing the washed-off oil and fat is again collected in the degreasing liquid tank B2 by a drain receiver (not shown) provided below. As with the cleaning liquid in the preliminary cleaning unit 2, the degreasing liquid is also reused by filtering and washing off the oil and fat components that have been washed and attached to the degreasing liquid shower spray device B1 and the degreasing liquid tank B2. Alternatively, it may be formed so that all are replaced after being used for cleaning a predetermined number of times.

  In addition, in each cleaning unit described below, necessary equipment such as pipes and filtration regenerators are attached so that the cleaning liquid used for cleaning can be reused and replaced in the same manner as the pre-cleaning unit 2 and the degreasing unit B unless otherwise specified. It is assumed that

Subsequent to the degreasing treatment part B, water washing is performed by the post-degreasing water washing part 1a for washing away the degreasing liquid adhering to the degreased product W.
In the post-degreasing water washing part 1a, before performing the surface adjustment part C and the rust preventive film chemical conversion part D performed after the post-degreasing water washing part 1a, cleaning by shower spray cleaning with a cleaning liquid and immersion in a cleaning liquid is performed. Accordingly, in the post-degreasing water washing section 1a, the first water washing section 3 is responsible for shower spray washing, and the second water washing section 4 is responsible for washing by immersion.
The first water washing unit 3 is a step of washing the product W by shower spray. As shown in FIG. 2, the filtered washing water is sprayed on the product W by a shower spray device to adhere to the surface of the product W. It is a device to wash off the attached degreasing liquid. The shower spray device sprays cleaning water (hereinafter simply referred to as cleaning water) from the side, upper, and lower sides of the product W to be transported and moves the attached degreasing liquid attached to the product W to flow down. The wash water containing the attached degreasing liquid that has flowed down is collected in a water receiving tank 31 provided below, and from the water receiving tank 31, necessary devices such as piping and a filtering device are installed in the same manner as the preliminary cleaning unit 2. Then, it is refreshed and supplied again to the shower spray device. However, it may be possible to always supply fresh washing water and perform shower spraying. In addition, since supply of the washing water to the shower spray device and the shower spray device is not different from the conventional device configuration, the description is omitted.

It is the 2nd water-washing part 4 installed so that a washing process is possible following the 1st water-washing part 3. FIG.
The 2nd water washing part 4 is located as a next process of the 1st water washing part 3, and is a water washing part which performs immersion washing after washing | cleaning by the shower spray apparatus of the 1st water washing part 3. FIG.
The second water washing section 4 is provided with a washing tank 41 having a size capable of immersing at least the product W, and the washing tank 41 is filled with washing water. Then, when the suspended transport device 8 transports the product W to the second water washing section 4 position, the product W moves so as to be transported while being immersed in the cleaning tank 41 to the cleaning tank 41 of the second water washing section 4. Then, due to the movement, the cleaning liquid in the cleaning tank 41 adheres to the product W, and the attached degreasing liquid that has not been removed by the first water washing unit 3 is washed. Although the 2nd water washing part 4 is provided with required members, such as a pipe line and a pump for supplying or discharging washing water like the 1st water washing part 3, it is the device similar to the former, and is not explained in full detail.

It is the surface adjustment unit C that continuously conveys after the conveyance device 8 finishes the immersion cleaning by the second water washing unit 4.
In the surface adjustment unit C, the product W that has been washed with water by the first water washing unit 3 and the second water washing unit 4 is suspended and moved by the suspended conveying device 8 to be surface-adjusted. The surface adjustment unit C is provided with a surface adjustment tank C1. In the surface adjustment part C, it is performed as a surface adjustment process to facilitate the formation of a chemical conversion film on a product made of a steel sheet during the chemical conversion treatment, and the surface adjustment of the product W is performed by the adjustment liquid filled in the surface adjustment tank C1. To do.

  It is the chemical conversion treatment part D that carries the product W following the surface adjustment part C. The chemical conversion treatment part D is a process applied to the product W after the surface adjustment part C. The chemical conversion treatment unit D is provided with a chemical conversion treatment tank D1 and is filled with a chemical conversion treatment liquid. Then, the product W that has been transported out of the surface adjustment unit C by the suspended conveyance device 8 is dipped and conveyed in the chemical conversion treatment tank D1, and the chemical conversion treatment liquid in the chemical conversion treatment tank D1 forms a rust preventive film on the product W. To do.

Subsequent to the chemical conversion treatment unit D, the final water washing unit 1b performs an operation of washing away the treatment liquid adhering to the product W by the processing of the surface adjustment unit C and the chemical conversion treatment unit D.
First, after the chemical conversion treatment section D, cleaning is performed by the third water washing section 5 that performs shower spray cleaning.
The 3rd water washing part 5 is provided as a washing | cleaning process after the chemical conversion process part D, and wash | cleans the product W with a shower spray apparatus similarly to the 1st water washing part 3. FIG. The 3rd water washing part 5 is the same as the 1st water washing part 3, The washing water which was sprayed to the product W with the shower spray apparatus and washed off the adhesion degreasing liquid from the product W is collect | recovered by the water receiving tank 51, and the collect | recovered washing water Is treated in the same manner as the first water washing section 3. In addition, for the supply and discharge of washing water, as with the first water washing unit 3 and the second water washing unit 4, supply / discharge distribution pipes necessary for supply and discharge of washing water, such as pipes and pumps, pumps necessary for water supply / drainage, etc. It is assumed that these devices are also included.

6 is the 4th water washing part which performs immersion washing similarly to the 2nd water washing part 4. FIG. In the fourth water washing section 6, the product W is immersed and moved by the suspended conveying device 8 in the washing water filled in the washing tank 61 to perform immersion washing.
The cleaning water, which is the cleaning water filled in the cleaning tank 61, is sequentially supplied with new cleaning water. On the other hand, an amount corresponding to the supply amount is discharged, and the cleaning tank 61 is always filled with the cleaning water. Although the state can be maintained, the supply and distribution of the cleaning water are the same as in the prior art, and are not shown and will not be described in detail.

  Further, the fourth water washing unit 6 is provided with a micro / nano bubble generator 9. In this embodiment, four micro / nano bubble generators 9 are provided and can generate micro / nano bubbles, respectively. That is, the washing water is taken out from the washing tank 61 by the pump 91, and the washing water is supplied to the generator main body 93 through the filter 92. The generator main body 93 takes in the outside air and generates a large amount of micro / nano bubbles in the washing water. Wash water containing micro-nano bubbles is supplied from 94 to the wash tank 61. Further, a valve 96 that adjusts the supply amount of cleaning water containing micro-nano bubbles and the like is provided in front of the generator main body 93, and includes a cleaning tank 61, a pump 91, a filter 92, a valve 96, a generator main body 93, Each of the spouts 94 is connected by a pipe 95, and the spout 94 is installed at the bottom of the cleaning tank 61. The spout 94 is provided at the bottom of the cleaning tank 61, but may be provided slightly above the bottom of the cleaning tank 61, or may be provided on the bottom side of the side surface of the cleaning tank 61 as necessary.

The micro / nano bubbles generated by the micro / nano bubble generating device 9 are bubbles having a diameter of about 0.2 μm to 10 μm. The micro / nano bubble generating device 9 generates and supplies bubbles containing a large amount of micro / nano bubbles of this size in the washing water. To do. Therefore, it is desirable that the bubbles generated by the micro / nano bubble generation device 9 are only micro / nano bubbles, but there is no micro / nano bubble generation device 9 that generates only micro / nano bubbles. Although it is generated, it suffices if it contains many micro / nano bubbles.
Below, the magnitude | size of the bubble produced | generated and its effect | action are demonstrated based on FIG. FIG. 4A is an explanatory diagram showing the generation from the generation to the disappearance of a normal bubble Bu having a diameter of 50 μm or more, and FIG. 4B shows the process from the generation to the disappearance of a micro-nano bubble having a diameter of about 0.2 μm to 10 μm. FIG. A normal bubble Bu having a diameter of 50 μm or more shown in FIG. 4A has a large levitation force in water, and is generated in the washing water, then expands while floating, and when it reaches the water surface L, it bursts and disappears. On the other hand, as shown in FIG. 5B, micro-nano bubbles are generated in washing water, then float in the washing water for a relatively long time while shrinking, and dissolve and disappear in the washing water. Have. When the dissolution of the micro-nano bubbles MNB changes, the flow of the liquid around the micro-nano bubbles MNB changes, so that the flow field is changed. This change in the flow field causes cleaning such as peeling of dirt to be cleaned. It is estimated that it contributes to the effect. Also, some micronanobubble MNBs (including those that are larger than micronanobubble MNB) will not be able to withstand the rise of their own internal pressure before dissolution and rupture so that they will erupt into multiple pieces. It is presumed that the transfer energy also contributes to a cleaning effect such as peeling of dirt to be cleaned. Furthermore, since the micro-nanobubble MNB has a very small radius and a large specific surface area (surface area ratio relative to the bubble volume), the bubble surface area that is supposed to contribute to the cleaning effect is much larger than that of the normally generated bubble. It is speculated that this also contributes to a cleaning effect such as peeling of dirt to be cleaned. Furthermore, the presence of gas in the liquid changes the arrangement of the hydrophilic groups and hydrophobic groups of the surfactant component in the degreasing liquid. However, the presence of a large amount of micro-nano bubbles MNB in the liquid may cause a change in the arrangement state. Since many changes can be given, it is presumed that this also contributes to a cleaning effect such as peeling of dirt to be cleaned. Furthermore, since the micro / nano bubble MNB can float in the liquid for a long time, it is estimated that impurities such as a degreasing liquid in the RO water can be adsorbed well. Such micro-nano bubbles MNB are used in other fields such as wastewater treatment by utilizing the characteristics thereof, and are used for oil and fat separation in contaminated water, removal of impurities, and the like.

Such micro-nano bubbles can easily penetrate into the gaps of the product W, that is, the extremely small gaps formed in the joints or joints of the steel sheets, due to the floating characteristics and the size thereof. In addition, the adhering degreasing liquid remaining is adsorbed, or the adhering degreasing liquid is peeled off by the energy at the time of disappearance. In addition, since the floating characteristics are small and the floating time is long, it enters the bag-like product W with the washing water without opposing the washing water flow, and adsorbs the attached degreasing liquid remaining on the surface of the micro / nano bubbles. Or the adhering degreasing solution is peeled off by the change in energy or flow field during splitting. The cleaning action by the micro / nano bubbles is as shown in FIG.
That is, FIG. 5 shows the result of examining whether or not the cleaning water containing micro-nano bubbles and the normal cleaning water enter the gap in the product W and can be cleaned, and “TP gap” in the table is provided in the test piece. It is a gap and represents the width of the gap intentionally provided in the same material as the product W, and the column with “water” penetrates into the gap when normal washing water not containing micro-nano bubbles is used. The column “MNB water” indicates the presence or absence of permeation into each gap when the cleaning water in which micro-nano bubbles are generated is used. As can be seen from this result, in the case of “MNB water” containing micro-nano bubbles, it can enter a gap of 100 μm and exert a cleaning effect, whereas in the case of “water” which is normal cleaning water, 200 μm The result is that cleaning in the gap is not possible. Note that “water” is a conventionally used wash water, and “MNB water” is a conventionally used wash water in which micro-nano bubbles are included.

  As described above, the fourth water washing section 6 performs immersion cleaning with the cleaning water containing the micro / nano bubbles generated by the micro / nano bubble generator 9.

Furthermore, a water jet riser 10 is installed in the fourth water washing section 6. The water jet riser 10 is a device that jets cleaning water vigorously toward the product W transported and moved in the cleaning tank 61. The water jet riser 10 includes a riser body 10b having a plurality of discharge ports 10a that are fixedly installed so as to sandwich the product W from both sides of the product W transported and moved into the cleaning tank 61 and that can discharge cleaning water in the product W direction. A discharge pump 10c is provided for supplying cleaning water containing micro / nano bubbles in the cleaning tank 61 to the riser body 10b. Then, the discharge pump 10c and the cleaning tank 61 are connected to supply cleaning water in the cleaning tank 61 to the discharge pump 10c, and the discharge pump 10c and the riser main body 10b are connected to the riser main body 10b to the discharge pump 10c. A pipe 10d for supplying cleaning water is provided. Further, a valve 10e is provided in the pipe 10d between the discharge pump 10c and the riser body 10b.
The water jet riser 10 configured as described above can efficiently clean the product W by directing the discharge port 10a so that the cleaning water discharged into the steel plate formed in the bag shape of the product W enters. Adjust to. In addition, you may enable it to change the direction of the discharge outlet 10a for every shape of the product W conveyed by remote operation.

  Therefore, in the 4th water washing part 6, since the washing water containing the micro nano bubble generated in large quantities in washing water by the micro nano bubble generating device 9 constituted as mentioned above is filled up in washing tank 61, washing water In addition to being able to efficiently remove attached degreasing liquid, surface conditioning liquid and rust preventive film chemical treatment liquid that have passed through the product W passing through the micro-nano bubbles and have not been removed even by the cleaning by the UF recovery water washing section 11, the water jet Since the cleaning water containing a large amount of micro / nano bubbles can be brought into contact with the product W more efficiently by the riser 10, it becomes possible to perform cleaning more effectively.

  In addition, an outlet tank spray riser 11 for performing shower spraying is installed on the outlet side of the cleaning tank 61 of the fourth water washing section 6 for the product W coming out of the washing tank 61 of the fourth water washing section 6. The outlet tank spray riser 11 is a device that sprays cleaning water intensively on the product W from both sides of the product W that has come out of the cleaning tank 61 at the head in the conveyance direction of the product W, and has a plurality of shower spray nozzles. The spray unit 11a is arranged on both sides of the product W to be conveyed, and the spray unit 11a is connected to the discharge pump 10c of the water jet riser 10 and the valve 11c by the pipe 11b to include the micro / nano bubbles in the cleaning tank 61. The washing water can be supplied and sprayed on the product W.

  The 5th water washing part 7 is provided so that the shower spray washing | cleaning is possible following the washing | cleaning by the 4th water washing part 6. FIG. The 5th water washing part 7 is a washing | cleaning part which performs spray washing similarly to the 1st water washing part 3 and the 3rd water washing part 5, and provides a shower spray apparatus as shown in FIG. The fifth water washing unit 7 is the same as the first water washing unit 3 and the third water washing unit 5.

Then, the product W that has been cleaned by the fifth water washing section 7 is transported to the electrodeposition tank A by the suspended transport device 8.
The electrodeposition tank A is a conventional electrodeposition tank A for electrodeposition coating, and the method of electrodeposition coating is not particularly limited.

In the water washing apparatus 1 configured as described above, the product W that has been degreased is subjected to shower spray washing with the shower spray device in the first water washing part 3 provided in the water washing part 1a after degreasing, and the shower spray washing is completed. Later, it is immersed in the cleaning tank 41 of the second water washing section 4 for cleaning. Next, the surface adjustment treatment and the rust preventive film chemical conversion treatment are performed, and the product W after the surface adjustment treatment and the rust preventive film chemical conversion treatment are further washed by the third water washing portion 5 provided in the final water washing portion 1b. Do.
And in the last water washing part 1b, in the 4th water washing part 6 which performs immersion washing, the micro nano bubble generated by the micro nano bubble generator 9 is included in washing water, and is washed.
And the product W which passed the 4th water-washing part 6 is finally shower spray wash | cleaned by washing water by the 5th water-washing part 7 which is a washing | cleaning final stage, and complete | finishes washing | cleaning.
The products W that sequentially perform cleaning in each of these cleaning tanks are sequentially suspended and transported by the suspended transport device 8 and moved.
The product W that has been washed in the fifth water washing section 7 is further moved to the next electrodeposition tank A by the suspended conveying device 8.

The present invention can be used in a line production factory for performing electrodeposition coating, and is particularly effective when a product obtained by processing a steel plate such as an automobile body into a bag shape is used for cleaning before electrodeposition coating.
Moreover, although the example used for the automatic washing | cleaning process by a several washing tank and a shower spray apparatus was demonstrated in the said Example, it is effective even if it uses for the washing tank only by the case of only the water washing process only by a water washing tank, or a manual operation.

Whole explanatory drawing showing the Example of this invention Partial explanatory drawing of FIG. Partial explanatory drawing of FIG. Illustration of micro / nano bubbles Explanatory diagram comparing the permeability of micro-nano bubbles Whole explanatory drawing showing the conventional washing apparatus

Explanation of symbols

A Electrodeposition coating part B Degreasing treatment part C Surface adjustment part C1 Surface adjustment tank D Rust prevention film chemical conversion treatment part MNB Micro nano bubble Bu Normal bubble 1 Water washing apparatus 1a Washing part after degreasing treatment 3 First water washing part
31 Water receiving tank 4 Second flushing section
41 Washing tank 5 Third washing section
51 Receiving tank
SP Shower spray device 1b Final flushing section 6 Fourth flushing section
61 Washing tank 7 Fifth washing section
71 Receiving tank
SP shower spray device 2 Pre-cleaning section 21 Pre-cleaning tank 8 Suspended transfer device 9 Micro / nano bubble generating device 91 Pump 92 Filter 93 Generating device main body 94 Outlet 95 Pipe line 96 Valve 10 Water jet riser 10a Spray unit 10b Riser main body 10c Discharge Pump 10d Piping 10e Valve 11 Drain tank spray riser 11a Spraying section 11b Piping 11c Valve

Claims (2)

Electrodeposition coating is a pretreatment for electrodeposition coating, and an immersion cleaning bath and shower cleaning bath are provided before electrodeposition coating, and products are passed through the immersion cleaning bath and shower cleaning bath before electrodeposition coating, and washed alternately. A pre-treatment water washing device for painting,
A pre-treatment water-washing device for electrodeposition coating, characterized in that a bubble generating means capable of generating micro-nano bubbles is provided on the bottom side of the immersion cleaning tank, and the generated micro-nano bubbles are washed against the product in the immersion cleaning tank. . Electrodeposition coating is a pretreatment for electrodeposition coating, and an immersion cleaning bath and shower cleaning bath are provided before electrodeposition coating, and products are passed through the immersion cleaning bath and shower cleaning bath before electrodeposition coating, and washed alternately. A pre-treatment water washing device for painting,
Provided with a bubble generating means capable of generating micro-nano bubbles on the bottom side of the immersion cleaning tank, and further provided with a water jet riser capable of spraying the cleaning liquid in the immersion cleaning tank containing micro-nano bubbles,
Pretreatment of electrodeposition coating, characterized in that the generated micro / nano bubbles float and naturally come into contact with the product in the immersion cleaning tank and are forcedly contacted by a water jet riser to clean the product. Flushing device.

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