JPH1018087A - Hanger for electrodeposition coating equipment - Google Patents

Abstract

(57) [Summary] In a hanger 1 of an electrodeposition coating apparatus, even when the hanger 1 is reused without going through a heating and drying process, the electrodeposition coating film formed on the article 2 to be coated has defects. The object of the present invention is to make it possible to maintain a high coating film quality without causing defects and therefore even when repeatedly used. An FRP coating is performed on at least a part of an outer surface (4) of a hanger (1) which is lower than a height at which a liquid surface of an electrodeposition paint reaches during an immersion process in an electrodeposition tank, excluding an energized part (attachment). 3 is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrodeposition coating apparatus used for priming an automobile body, and more particularly to a hanger for suspending and transporting an object (automobile body) in the apparatus.

[0002]

2. Description of the Related Art Conventionally, undercoating of an automobile body has been performed by a series of processes of electrodeposition coating, washing with water, and heating and drying (baking). Electrodeposition coating is performed by immersing the car body in an electrodeposition tank and energizing it.Washing is performed by spraying water on the car body in a rinsing chamber, and heating and drying is performed by drying the car body in an oven. This is done by heating and baking the electrodeposition paint. Conventionally, as a device for transporting and moving an automobile body over each of the steps of undercoating, a hanger of a type for suspending and transporting an automobile body, that is, a so-called overhead hanger is used. In addition, a mechanism for intermittently transporting the automobile body is employed as the transport mechanism, and therefore, the automobile body is transported while swinging to some extent. In the conventional undercoating process, the hanger is made of metal, so that the electrodeposition paint is slightly electrodeposited on the surface during the electrodeposition coating process to form a coating film. The coating of the electrodeposition paint formed on it will be baked and firmly fixed, and will not peel off due to rocking during transportation, so the hanger that has gone through a series of undercoating processes will be electrodeposited again It could be used in the process, so the hanger could be used many times without any special treatment, and in fact was used tens of times a day.

[0003] However, the upper portion of the above-mentioned overhead hanger (such as a structural portion which engages with the transport rail) is located above the suspended workpiece (automobile body), and thus is deposited on the upper portion of the hanger. Dust, dust, etc. fall during the process of transporting the object to be coated, especially in the process after electrodeposition coating, and adhere to the surface of the object to be coated. This may cause poor coating quality. Despite the undercoating, it is desirable to avoid the adhesion of dust after electrodeposition coating in fields requiring extremely high quality coating such as automobiles. Therefore,
Recently, for the process of electrodeposition coating and washing, the automobile body is transported by a so-called overhead hanger,
Here, transfer the car body to a conveyor of the type that carries it on a trolley, and for the subsequent heating and drying process,
A method of transporting an automobile body by the conveyor has begun to be adopted.

[0004]

However, when the above-mentioned method is adopted, a problem which has not occurred before has newly arisen. That is, in this method, the hanger is returned to the start position of the electrodeposition coating process again for the next use after the washing process is completed. Therefore, the coating of the electrodeposition paint formed on the surface of the hanger in the course of the electrodeposition coating is different from the conventional one in that it is simply dried without baking, and then the starting step of the next undercoating process (that is, electrodeposition coating). Painting). Therefore, the electrodeposition coating film formed on the surface of the hanger is cracked, cracked, cracked, etc. due to rocking in the process of collecting the hanger, and some of the coating film pieces are peeled off. May fall into the electrodeposition tank, and at the stage where the hanger is immersed in the electrodeposition tank, the electrodeposition paint penetrates into the gaps of the cracked coating film, and A part of the electrodeposition paint may be peeled off and mixed into the bulk of the electrodeposition paint. The stripped pieces of the electrodeposition coating film thus generated are further vigorously stirred in an electrodeposition tank by a riser tube or the like, and become a very small coating piece. Therefore, the incorporation of such a coating film piece into the coating material causes a coating defect called lumps, resulting in poor quality of the undercoat coating film.

[0005] Therefore, under the present circumstances, at the stage when the washing process is completed, an operation of removing the coating film of the electrodeposition paint formed on the surface of the hanger has been performed. The coating film of the electrodeposition paint cannot be easily peeled off, and in order to completely remove the coating film, careful work and carefulness are required. Further, since the work of peeling the coating film has to rely on manual work, it takes a lot of labor and time. further,
The stripped electrodeposition coating film was discarded as it was, which was not economical in this respect, contrary to the saving (small amount) of paint used.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to reuse a hanger in an electrodeposition coating apparatus without going through a heating and drying (baking) process. Even when the coating is performed, the electrodeposition coating film formed on the article to be coated does not cause defects or defects, and therefore, it is possible to maintain high coating film quality even when repeatedly used. . Also, the present invention
Another object of the present invention is to provide an electrodeposition coating apparatus provided with the hanger, in addition to the hanger that solves the problem, and to provide a method of fabricating the hanger.

[0007]

SUMMARY OF THE INVENTION According to the present invention, a desired portion of the hanger surface is insulated by forming an FRP coating, so that the electrodeposition paint is deposited on the hanger surface during the electrodeposition coating process. It is something that was not done. More specifically, the present invention relates to a hanger for suspending and transporting an object to be coated in an electrodeposition coating apparatus so as to be immersed in an electrodeposition tank, at least of the outer surface of the hanger,
The present invention relates to a hanger characterized in that an FRP coating is formed on a portion lower than a height at which a liquid surface of the electrodeposition paint reaches during the immersion process, except for a portion to be energized (for example, an attachment). The present invention also relates to an electrodeposition coating apparatus provided with the above hanger. The electrodeposition coating apparatus according to the present invention is not limited to a set of apparatuses for performing an electrodeposition coating process including an electrodeposition tank, an electrode, a riser tube, and the like, and an apparatus for performing a subsequent washing process. It also includes a set (eg, a washing chamber, a full dip washing tank).

Although the above-mentioned FRP coating can be formed according to a method conventionally used for other products, the present invention also relates to a more preferable FRP coating method for a hanger of an electrodeposition coating apparatus.
That is, in the present invention, a primer is applied to the outer surface of a hanger of an electrodeposition coating apparatus, and then a mat, cloth or tape of resin-impregnated glass fiber is wound around the hanger, followed by air bubbles remaining in the wound object. And after solidification of the wrap, the surface is polished if necessary, and further coated with a top coat containing a thermoplastic resin powder, and then dried to form an FRP coating. The present invention also relates to a method for producing the above hanger, which is formed on the outer surface of the hanger.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS F formed on the outer surface of a hanger
The RP coating is a coating made of a composite material composed of a resin, for example, a thermosetting resin such as an unsaturated polyester resin, an epoxy resin, a phenol resin, and a bisphenol resin as a matrix, and fibers (mainly, glass fibers) as a reinforcing material. It is characterized by its light weight and excellent mechanical strength, particularly excellent specific strength (strength / density). The thickness of the FRP coating is usually 1 to 5 mm, more preferably 1.5 to 3 mm. Further, a more preferable resin is a bisphenol-based vinyl ester resin or a novolak-based vinyl ester resin which is excellent in each property of acid resistance, alkali resistance and solvent resistance. The fibers are also generally used in the form of a mat, cloth or tape. For example, a glass chopped strand mat, a glass surface mat, a glass roving cloth, and a glass tape. However, the FRP coating in the present invention may be of any type as long as it can insulate the hanger surface so that the electrodeposition coating does not electrodeposit in the process of electrodeposition coating, and its type, composition and structure are basically Does not matter.

[0010] In the present invention, due to the insulation by the FRP coating, in the process of electrodeposition coating, the electrodeposition paint in the electrodeposition tank does not electrodeposit on the outer surface of the dipping portion of the hanger,
In the next washing step, the electrodeposition paint adhered to the hanger surface is washed away with water. Therefore, the hanger is returned to the start stage of the electrodeposition coating without the electrodeposition paint being electrodeposited or adhered on its outer surface, and is reused in the next priming process.

In order to enhance the adhesion between the FRP coating and the underlying metal hanger, it is more preferable to apply a primer to the outer surface of the hanger before winding the resin-impregnated mat, cloth or tape. Preferred primers include modified urethane primers. In addition, in order to further improve the adhesiveness, it is more preferable to grind the outer surface of the hanger, particularly both ends of the portion around which the mat or the like is wound, using a grinder, a file or the like before applying the primer. preferable.

In addition, the FRP coating of the present invention not only preferably has a smooth surface but also requires a high smoothness on the coating surface in terms of practical quality. If the surface of the FRP coating is not smooth and has irregularities, the electrodeposition paint that has adhered to the surface, particularly to the concave portion, remains in the concave portion without being washed away even in the water washing process. The electrodeposition paint gradually accumulates in the recesses on the coating surface, and the solidified paint pieces eventually fall off from the recesses into the electrodeposition tank and mix into the bulk of the electrodeposition paint, reducing the quality of the coating film. This is because it is presumed that aggravation may occur. From this point, it is more preferable that the FRP coating has a structure having a smooth top coat as a surface layer. From the viewpoint of forming a smooth surface and selecting a material having good anti-adhesion performance, a more preferable top coat is a thermoplastic resin powder, for example, having a particle size of 10
Examples include powders of polyethylene, polypropylene or fluororesin having a particle size of μm or less mixed in the main resin of the coating.

When winding a mat or the like of resin-impregnated glass fiber, typically, first, the mat, cloth, or tape is cut into an appropriate size and shape according to the external shape of each hanger to be wound ( Cuts and the like are also made if necessary), and then the resin, for example, unsaturated polyester is impregnated into the mat, cloth or tape using a roller or the like, and then wound around each part of the hanger to which the primer has been previously applied. Then, for example, pressing the wound with a roller, etc., to expel bubbles remaining in the wound to the outside,
After the solidified product is wound, if necessary, the surface is polished by sanding or the like.
Thereafter, the top coat is coated and dried to form an FRP coating. That is, a top coat containing a thermoplastic resin powder is coated on a wound product of the resin-impregnated glass fiber with a suitable FRP roller or the like, and then, preferably, a release film is wound around the application surface. After that, the FRP coating is formed on the outer surface of the hanger by air drying usually for about one day.

[0014]

EXAMPLES Examples of the present invention will be described below, but these are merely examples, and do not limit the scope of the present invention in any way.

FIGS. 1 and 2 show a hanger of this embodiment used in an electrodeposition coating apparatus. The hanger 1 is a hanger of a type in which an object to be coated (automobile body) 2 is suspended and immersed in an electrodeposition bath in an electrodeposition coating apparatus and is conveyed, and is called an overhead hanger or a C-type hanger. In this embodiment, characteristically, the hanger 1 has a thickness of at least about a part of the outer surface below the height at which the liquid level of the electrodeposition paint reaches in the immersion process. An FRP coating 3 of 5 to 3 mm is formed. Other configurations of the hanger 1 are basically the same as those of the conventional hanger. For example, a transport mechanism 10 that transports the vehicle body 2 while supporting it in a swingable state to some extent, and a hanger 1 At the lower part, there are provided an attachment 11 for preventing a displacement of the vehicle body 2 and enabling power supply to the vehicle body 2, and a current collector 29 receiving power from a power supply bar 31. In the figure, reference numeral 12 denotes a transport rail on which the hanger 1 is hung.

FIG. 3 shows a typical internal structure of the FRP coating 3, but it is needless to say that the present invention is not limited to this laminated structure. The FRP coating 3 includes a primer layer 5 formed on the outer surface 4 of the hanger, a resin-impregnated glass fiber mat 6 laminated thereon, and a top coat 9 covering the surface. The primer layer 5 is composed of a modified urethane-based primer. Examples of the primer include Polytac # 2000 (trade name).
(POLYTAC # 2000, manufactured by Fuji Resin Industry Co., Ltd.) is preferably used. The composition of Polytack # 2000 is as follows. Alkanol amine Epoxy resin 35.5% by weight Xylene 45.0% by weight Ethyl glycol acetate 19.5% by weight The resin-impregnated glass fiber mat 6 is the lower two layers of resin-impregnated glass chopped strand mats 7, 7 (basis weight). Three
00 to 450 g / m ² , in one layer) and one upper layer of resin-impregnated glass surface mat 8 (basis weight 30 to 100 g / m ² ). The glass surface mat used here is a glass fiber mat with finer eyes than the glass chopped strand mat. In addition, a glass fiber roving cloth or tape can be used instead of the glass fiber mat. As a resin to be impregnated in these mats and the like, bisphenol-based vinyl ester resins (for example, trade name: Fujichemeq # 6R clear (Fujichemeq Line, manufactured by Fuji Resin Industry Co., Ltd.))
And novolak-based vinyl ester resins (for example, Fujichemeq # 6H Clear (trade name, Fujichemeq Line, manufactured by Fuji Resin Industry Co., Ltd.)) are more preferably used. The top coat 7 is made of a composite material in which, for example, a thermoplastic resin powder is mixed at a ratio of 3 to 50% by weight in a resin similar to the resin used for the resin-impregnated glass fiber mat 6. Preferably, a composite product in which 10 to 20% by weight of a fluororesin powder having a particle size of 10 μm or less is blended in a bisphenol-based vinyl ester resin or a novolak-based vinyl ester resin, for example, non-scale coat #
6R (base resin: bisphenol-based vinyl ester resin, manufactured by Fuji Resin Industries Co., Ltd.) and non-scale coat # 6H (base material resin: novolak-based vinyl ester resin, manufactured by Fuji Resin Industry Co., Ltd.) You.

FIG. 4 shows an electrodeposition coating apparatus provided with the above-mentioned hanger. The apparatus is provided with a long, large paint tank 13 for the electrodeposition coating process and an overflow tank 14 next to it, and subsequently several washing chambers 15 to 15 for the washing process. 19 are arranged. In the drawings, p indicates a pump. Paint tank 13
The inside is filled with the electrodeposition paint supplied from the paint tank 22, for example, an acrylic cationic electrodeposition paint, and the paint overflowing from this flows into the overflow tank 14 and is stored therein. ing. Further, a circulation pipe extends from a lower portion of the overflow tank 14 through a pump and a filter, for example, an ultrafiltration membrane device 23,
The electrodeposition paint is connected to a riser pipe 24 disposed at the bottom of the paint tank 13, and during operation, the electrodeposition paint circulates in this pipe, and at the same time, impurities are removed by filtration.
Further, another circulation pipe is also provided via the heat exchanger 25 so that the electrodeposition paint can always be maintained at a predetermined temperature. In addition, although not shown, a pH controller and a viscometer for adjusting the pH and viscosity of the paint are provided. A sprayer 26 is provided in each of the washing chambers 15 to 19, and a water storage tank 27 is provided.
The supplied water can be sprayed on the object at a water pressure of about 3 kg / cm ² , or a full dip tank 28 is provided so that the object can be immersed.

The paint tank 13 and the overflow tank 1
A mechanism for continuously transporting the automobile body 2 together with the above-mentioned hanger 1 is provided above the washing machine 4 and inside the washing chambers 15 to 19. In the figure, reference numeral 12 indicates the transport route (rail). Therefore, the vehicle body 2 suspended and supported by the hanger 1 is moved from the entry area to the paint tank 1.
3, where the power is supplied from the power supply bar 31 shown in FIG. 1 through the current collector 29 and the attachment 11, thereby performing electrodeposition coating. Thereafter, the wafers are carried into washing chambers 15 to 19, and the electrodeposition coating film is washed with water in each chamber. Then, in this embodiment, after the completion of the washing, the car body 2 is lowered from the hanger 1 and transferred to the conveyor trolley 20, and then placed in an oven (not shown) for the next heating and drying process. It is being sent. The car body 2 sent to the oven is heated and dried, and the electrodeposition coating film is baked, thereby completing the undercoating process. On the other hand, the hanger 1 is collected and returned to a position just before the entering area of the paint tank 13, and is reused in the undercoating process, that is, the electrodeposition coating.

In the present embodiment, since the required portion of the outer surface of the hanger 1 is insulated by the FRP coating 3, the electrodeposition paint in the electrodeposition tank 13 is removed from the hanger 1 during the electrodeposition coating process. The electrodeposition paint adhered to the hanger surface is washed away with water in the next washing process without electrodeposition on the outer surface of the immersed portion. Therefore, the hanger 1 is returned in a state where the electrodeposition paint is neither electrodeposited nor adhered to its outer surface, and is reused in the next undercoating process. Therefore, the electrodeposition coating film formed on the painted product (automobile body) does not cause defects or defects due to the coating film on the hanger or the peeled pieces thereof. The film quality could be maintained.

Next, a method of fabricating the hanger 1 will be described in the order of steps. First, of the hanger 1, both end portions of the outer surface on which the FRP coating 3 is to be formed (width 50 to 300 m)
m) is polished using a grinder or a file. Next, a glass fiber mat, cloth, or tape is cut into an appropriate size and shape according to the outer shape of each part of the hanger 1 to be wound, and cuts, cutouts, and the like are made as necessary. Subsequently, the mat, cloth or tape is impregnated with a bisphenol-based or novolak-based vinyl ester resin using a roller or the like. Thus, a resin-impregnated glass chopped strand mat 7 is produced. Next, the primer 5 is applied to the outer surface 4 of the hanger 1
Apply to required areas. Then, a glass chopped strand mat 7 impregnated with resin is wound around a required portion (on which the primer 5 is applied) of the outer surface 4 of the hanger, and a plurality of mats 7 are laminated as necessary. In this case, the winding is preferably performed in order from both ends of the outer surface of the hanger 1 where the FRP coating 3 is to be formed, toward the center. FIGS. 5 to 8 specifically illustrate the process of winding the resin-impregnated glass fiber mat 6 around the branch portion, the tip portion, the attachment attachment portion, and the joint portion of the hanger 1 at this stage. Is what you do. As shown in FIG. 5, two mats 6, 6 are used for winding around the branch portion, and are wound around the entire circumference of the hanger branch, and are wound until both ends overlap to some extent. In the drawing, reference numeral 30 indicates the overlapping portion.
As shown in FIG. 6, the winding around the distal end portion is performed by folding the mat 6 on the outer surface 4 of the hanger so that the distal end surface of the hanger 1 is covered. Also, as shown in FIG. 7, the attachment 11 is wound around the attachment portion so that the attachment 11, especially the current-carrying surface at the tip thereof, can be energized to the vehicle body 2 without being covered. This is done by winding the mat 6 around the outer surface 4 of the hanger, using a small cut piece of mat as necessary. Further, as shown in FIG. 8, the winding around the joint portion is similar to the winding around the branch portion,
Wrap two mats 6, 6 around the entire outer surface 4 of the hanger,
And wind until both ends overlap to some extent. In the drawing, reference numeral 30 indicates the overlapping portion. Subsequently, the wound material on the outer surface 4 of the hanger is pressed with, for example, a roller to expel air bubbles remaining in the wound material, and after solidification of the wound material, sanding is performed as necessary. Polish its surface. Next, the production of the resin-impregnated glass surface mat 8 and the winding around the hanger 1 are performed in the same manner as in the case of the resin-impregnated glass chopped strand mat 7. That is, the glass fiber surface mat is cut into an appropriate size and shape according to the outer shape of each part of the hanger 1 to be wound, and if necessary, cuts and cutouts are formed. The surface mat is impregnated with a bisphenol-based or novolak-based vinyl ester resin. The resin-impregnated glass surface mat 8 thus produced is wound on the wound resin-impregnated glass chopped strand mat 7. The winding method is the same as that for the mat 7. Thereafter, the wound material is pressed with, for example, a roller to expel bubbles remaining therein, and after the wound material is solidified, its surface is polished by sanding or the like as necessary. Then, finally, a layer of the resin-impregnated glass fiber mat 6 having a smooth surface is formed on the surface of the hanger 1. At this stage, it is checked whether the layer of the resin-impregnated glass fiber mat 6 thus produced is electrically insulated from the hanger outer surface 4 underneath. If the insulation is insufficient, further winding of the resin-impregnated glass fiber mat 6 is performed at a necessary place. Thereafter, the surface of the resin-impregnated glass fiber mat 6 around which the top coat 9 is wound is coated using an FRP roller or the like. After the coating is completed, a release film is wrapped around the coated surface and then air dried, usually for about one day.

By performing the above procedure, the FRP coating 3 having a very smooth surface is coated on the outer surface 4 of the hanger.
Could be formed. In addition, since this method is based on winding of a resin impregnated glass fiber mat or the like, there is no need for a large-scale facility for FRP coating, and there is an advantage that the FRP coating can be easily formed on site in a factory. Also have. When the hanger 1 of this embodiment made by such a method is used for the undercoating process, the electrodeposition coating does not adhere to and solidify on the surface of the FRP coating 3 even when the undercoating process is repeated. No deterioration of the coating quality due to the pieces occurred.

[0022]

As described above, according to the present invention,
In the electrodeposition coating process, even if the hanger of the electrodeposition coating equipment is reused without going through the heating and drying (baking) process, it does not cause defects or defects in the electrodeposition coating film formed on the workpiece. Therefore, the effect that high coating film quality can be maintained even when reused repeatedly is obtained.
Furthermore, according to the present invention, the insulation of the hanger by the FRP coating enables more uniform energization to each part of the object to be coated in the electrodeposition coating process, and thus more uniformity to each part of the coated article. An electrodeposition coating film can be formed, and furthermore, there is no need to carry out excessive current, which has been conventionally performed, and the effect that the life of the electrode can be further extended can be obtained. Further, according to the method of the present invention, an FRP coating having good adhesion and high surface smoothness can be formed on the outer surface of a required portion of the hanger, and therefore, the FRP-coated hanger can be reliably formed. The effect that it can be made is obtained.

[Brief description of the drawings]

FIG. 1 is a front view showing a hanger according to an embodiment of the present invention.

FIG. 2 is a side view showing the hanger of the embodiment.

FIG. 3 is a sectional view schematically showing the inside of an FRP coating formed on the outer surface of a hanger.

FIG. 4 is a schematic view showing a process of electrodeposition coating and washing with the hanger of the above embodiment.

FIG. 5 is a diagram illustrating a process of winding a resin-impregnated glass fiber mat around a branch of a hanger in the FRP coating.

FIG. 6 is a diagram illustrating a process of winding a resin-impregnated glass fiber mat around the tip of a hanger in the FRP coating.

FIG. 7 is a diagram illustrating a process of winding a resin-impregnated glass fiber mat around an attachment attachment portion of a hanger in the above-described FRP coating.

FIG. 8 is a diagram illustrating a process of winding a resin-impregnated glass fiber mat around a joint of a hanger in the FRP coating.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 hanger 2 object to be coated (automobile body) 3 FRP coating 4 hanger outer surface 5 primer layer 6 resin impregnated glass fiber mat (wrapped) 9 top coat 11 energized part (attachment) 12 transport rail (path) 13 paint tank 14 Overflow tank 15-19 Rinse chamber 20 Conveyor truck

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Norihiro Tanaka 3-8 Nihonbashi Kobunacho, Chuo-ku, Tokyo Inside Ohara Kako Co., Ltd. (72) Inventor Masaru Matsubara 1-3-2 Nihonbashi Honcho, Chuo-ku, Tokyo Fuji Resin Industry Co., Ltd.

Claims (3)

[Claims] 1. A hanger for suspending and transporting an object to be coated in an electrodeposition bath in an electrodeposition coating apparatus, wherein at least the outer surface of the hanger reaches a liquid level of the electrodeposition coating during the immersion process. A hanger characterized in that an FRP coating is formed on a portion lower than the height, excluding an energized portion. 2. An electrodeposition coating apparatus provided with the hanger according to claim 1. 3. A primer is applied to the outer surface of the hanger of the electrodeposition apparatus, and then a mat, cloth or tape of resin impregnated glass fiber is wrapped around the hanger,
Air bubbles remaining in the wrap are expelled out, and after solidification of the wrap, the surface is polished if necessary, and a top coat containing a thermoplastic resin powder is coated thereon, and thereafter, The method for making a hanger according to claim 1, wherein the FRP coating is formed by drying.