JP2010163673A - Metal workpiece and method for working the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metal workpiece which has a predetermined metal surface and a bent surface that has been bent with a predetermined angle from the predetermined metal surface, and shows an enhanced anti-rust effect at an edge part formed by a metal surface that has been shaving-worked and a bent surface, and to provide a method for working the metal workpiece. <P>SOLUTION: This metal workpiece has: the worked surface 131 of which the metal surface has been shaved off; the bent surface 132 which has been bent with the predetermined angle from the worked surface 131; and a transparent electrodeposition coating film 1303 formed on the worked surface 131 including the edge part 133 formed by the worked surface 131 and the bent surface 132. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a metal workpiece having a predetermined metal surface and a bent surface bent from the predetermined metal surface at a predetermined angle, and a method for processing the metal workpiece.

  There was a time when chemical conversion treatment using chromic acid was carried out on the metal surface in order to enhance the rust prevention effect of the metal workpiece. However, the environmental load of chromic acid has become a problem, and currently, a non-chromium type chemical conversion treatment not containing chromic acid is being carried out. In the non-chromium type chemical conversion treatment, the rust prevention effect cannot be increased as much as the chemical conversion treatment using chromic acid, and the rust prevention effect is further enhanced by a primer. However, in a metal workpiece having a predetermined metal surface and a bent surface that is bent at a predetermined angle from the predetermined metal surface, even if a primer that increases the rust prevention effect is applied from the bent surface to the metal surface, the predetermined metal surface At the edge portion between the surface and the bent surface, the primer is liable to sag, and the primer cannot be applied well on the edge portion, resulting in insufficient rust prevention effect at the edge portion.

  On the other hand, the metal workpiece can be subjected to electrodeposition coating, and the rust prevention effect can be enhanced by this electrodeposition coating (see, for example, Patent Document 1). In addition, if the metal workpiece having the edge portion is subjected to electrodeposition coating, the edge portion is sharp and thus an electrodeposition coating is easily attached, and the rust prevention effect can be enhanced even at the edge portion.

JP-A-2005-36287

  By the way, in the metal workpiece, the metal surface may be subjected to a process of scraping the metal surface, such as a cutting process or a polishing process, for the purpose of making it a brilliant specification or the like. In the metal workpiece having the edge portion, after applying a primer that enhances the rust prevention effect from the bent surface to the metal surface, the metal surface is bent to the predetermined metal surface and then bent. The electrodeposition coating is easily scraped off at the edge with the surface.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a metal workpiece that has enhanced the rust prevention effect of the edge portion between the processed surface and the bent surface that have been processed to scrape off the metal surface, and a method for processing the metal workpiece. It is what.

The metal workpiece of the present invention that solves the above-mentioned object is a machined surface that has been processed to scrape off the metal surface,
It has a bent electrode surface bent at a predetermined angle from the processed surface, and a transparent electrodeposition coating film formed on the processed surface including an edge portion between the processed surface and the bent surface.

  The process of scraping off the metal surface here may be a cutting process or a buffing process, and the processing method is not limited. In addition, the purpose of performing the processing may be the purpose of making the metal surface a desired shape in addition to the purpose of smoothing the metal surface for brilliant specifications, specular surface specifications, etc. There is no limitation. In addition, the bent surface may be formed of a coating film, or may be formed of a metal surface without forming a coating film. Even if it exists, the process may not be performed. The same applies to the following description.

  According to the metal workpiece of the present invention, since the edge portion is sharp, the electrodeposition coating film is easily attached, and the electrodeposition coating film is formed after the processing, so that it may be scraped off by the processing. Nor. Therefore, the metal workpiece of the present invention has an enhanced rust prevention effect at the edge portion between the processed surface and the bent surface.

  Here, the metal workpiece of the present invention may be a casting. The metal workpiece of the present invention may be a vehicle wheel, or may be a light alloy vehicle wheel mainly composed of a light alloy such as aluminum, magnesium, or titanium. The vehicle wheel referred to here may be a wheel for a four-wheeled vehicle, a wheel for a two-wheeled vehicle, a wheel for a bicycle, or a wheel for a three-wheel buggy. May be. That is, the type of vehicle to which the wheel is attached does not matter. Further, the processed surface may be a metal surface in a disk portion of a vehicle wheel, a metal surface in a spoke portion, a metal surface in a hub portion, or a rim flange portion. The metal surface may be used, and the part is not limited.

  Moreover, the metal workpiece of this invention WHEREIN: It is preferable to have a clear layer which covers the said electrodeposition coating film and the said bending surface.

  By providing the clear layer, chemical resistance, scratch resistance and the like are improved. Moreover, since the rust prevention effect is enhanced by the electrodeposition coating film, it is not necessary to add a rust prevention material to the clear layer, the transparency of the clear layer is improved, and the processed surface can be shown.

Furthermore, in the metal workpiece of the present invention, the bent surface may have a colored layer under the clear layer,
The bent surface may have a primer layer under the colored layer.

  By carrying out like this, the rust prevention effect is heightened by the said primer layer, and the designability can be improved by the said colored layer.

The metal workpiece processing method of the present invention that solves the above-mentioned object is a metal workpiece processing method having a predetermined metal surface and a bent surface that is bent at a predetermined angle from the predetermined metal surface.
A processing step of performing processing to scrape the predetermined metal surface;
A transparent electrodeposition coating film forming step of forming a transparent electrodeposition coating film on the metal processing surface including an edge portion between the metal processing surface processed in the processing step and the bent surface; To do.

  According to the metal workpiece processing method of the present invention, the metal workpiece of the present invention can be obtained.

  The predetermined metal surface may be a metal surface that has been subjected to another processing before the processing step is performed.

  Moreover, in the processing method of the metal workpiece of this invention, after implementing the said transparent electrodeposition coating-film formation process, it has an overcoat clear coating process which forms the clear layer which covers the said electrodeposition coating film and the said bending surface. Is preferred.

  Furthermore, in the method for processing a metal workpiece according to the present invention, before performing the processing step, a primer layer is formed from the bent surface to the predetermined metal surface, and then a colored layer is formed on the primer layer. It may be a method having a coating process to be formed.

  ADVANTAGE OF THE INVENTION According to this invention, the metal workpiece which improved the rust prevention effect of the edge part of the process surface which gave the process which scrapes off a metal surface, and a bending surface, and the processing method of the metal workpiece can be provided.

It is a figure which shows the perspective view of the wheel for vehicles which is one Embodiment of the metal workpiece of this invention. It is a flowchart which shows the flow of the process process which is one of the manufacturing processes which manufacture the wheel for vehicles shown in FIG. It is a figure which shows typically the cross section of the spoke part of the workpiece | work which finished the primary coating process. It is a figure which shows typically the cross section of the spoke part of the workpiece | work which finished the cutting process for setting it to a brightness specification. It is a figure which shows typically the cross section of the spoke part of the workpiece | work which finished the baking process of the transparent electrodeposition coating film. It is a figure which shows typically the cross section of the spoke part of the workpiece | work which finished the secondary coating process. It is the photograph which expanded and image | photographed the cross section of the spoke part of the vehicle wheel shown in FIG. It is a figure which shows typically the cross section of the spoke part of the workpiece | work which finished the cutting process for making it a brilliant specification in a modification. It is a figure which shows typically the cross section of the spoke part of the workpiece | work which finished the secondary coating process in a modification.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a perspective view of a vehicle wheel that is an embodiment of a metal workpiece according to the present invention.

  A vehicle wheel 1 shown in FIG. 1 is a light alloy vehicle wheel in which a metal mainly composed of aluminum is formed by die casting. The vehicle wheel 1 is a spoke-type one-piece wheel for a four-wheel vehicle, and a rim portion 11 on which a tire (not shown) is mounted and holding the tire, and a hub attached to the vehicle body of a four-wheel vehicle (not shown). Part 12 and five spoke parts 13 connecting rim part 11 and hub part 12. Hereinafter, in the wheel width direction W, the side on which the hub portion 12 and the spoke portion 13 are provided (the front side on the paper surface) is referred to as the outer side, and the opposite side (the back side on the paper surface) is referred to as the inner side. Rim flange portions 111 and 112 are formed at the outer end portion and the inner end portion of the rim portion 11, respectively.

  The vehicle wheel 1 shown in FIG. 1 is a brilliant wheel. The surface (design surface) facing the outer side of each of the five spoke portions 13 is subjected to cutting for the purpose of achieving a brilliant specification. The spoke portion 13 shown in the upper right of FIG. Hereinafter, the surface subjected to the cutting process is referred to as a cutting surface 131. The surface roughness of the machined surface 131 is 12.5 s or less (12.5 μm or less) in terms of the average interval between local peaks. The spoke portion 13 is provided with a bent surface 132 that is bent at an angle θ of about 120 degrees from the cutting surface 131 toward the inner side (see FIG. 3). The angle θ may be 90 degrees or more and less than 180 degrees, and is preferably larger than 90 degrees in consideration of a draft gradient during casting. The bent surface 132 is not cut. The boundary between the cut surface 131 and the bent surface 132 is an edge portion 133.

  FIG. 2 is a flowchart showing the flow of a processing step that is one of the manufacturing steps for manufacturing the vehicle wheel shown in FIG.

  The intermediate product (workpiece) of the vehicle wheel molded by die casting is subjected to heat treatment. The oxide film generated on the workpiece surface by the heat treatment is removed by shot blasting. Subsequently, when it is necessary to drill a bolt hole or make the design surface flat in the machining process, the design surface is cut, and the primary coating process is performed first.

  In this primary coating process, pre-processing is first performed (step S11). In this pretreatment, degreasing and acid cleaning are performed to remove oil components such as cutting oil adhered in the machining process and residual oxide components that could not be removed by shot blasting. Further, in the pretreatment, in consideration of the environmental load of chromic acid, a non-chromium type chemical conversion treatment (for example, chemical conversion treatment using titanium, zirconium, or cobalt) that does not contain chromic acid is performed. In this chemical conversion treatment, a film having a certain degree of rust prevention effect is chemically formed on the work surface.

  Next, base primer coating is performed (step S12). Here, an epoxy resin is applied to the workpiece surface, and a primer layer is formed on the workpiece surface. This primer layer also enhances the rust prevention effect. In addition, it may replace with the solvent coating which apply | coats an epoxy resin, and may form a primer layer by powder coating. In solvent coating, an acrylic melamine resin or a polyester resin may be used instead of the epoxy resin.

  Subsequently, color coating is performed using an acrylic melamine resin (step S13). The acrylic melamine resin used in this color coating is a clear paint in which a silver pigment is added. A silver colored layer is formed on the work surface. In addition, it may replace with the solvent coating which apply | coats an acrylic melamine type resin, and may form a colored layer by powder coating. In the solvent coating, an epoxy resin or a polyester resin may be used instead of the acrylic melamine resin.

  Thereafter, a baking process is performed under the conditions of 120 ° C. or higher and 170 ° C. or lower (preferably 140 ° C. or higher and 160 ° C. or lower) and 10 minutes or longer and 40 minutes or shorter (preferably 15 minutes or longer and 25 minutes or shorter) (step S14). In the primary coating process, two coats and one bake are applied to the workpiece. This primary coating process corresponds to an example of a coating process according to the present invention. In the primary coating step, 1 coat 1 bake or 3 coat 2 bake may be applied.

  FIG. 3 is a diagram schematically showing a cross section of the spoke portion of the workpiece after the primary coating process. FIG. 3 is a cross-sectional view, but hatching is omitted (the same applies to the cross-sectional views of FIG. 3 and subsequent figures).

  In the workpiece 2 shown in FIG. 3, a primer layer 1301 having a thickness of 10 μm or more and 30 μm or less is formed from the metal surface 130 which is the design surface of the spoke portion 13 to the bent surface 132, and the metal surface 130 and the bent surface are formed. At the edge portion 133 with 132, the primer hangs down and the thickness of the primer layer 1301 is extremely thin. Further, a colored layer 1302 is formed on the surface of the primer layer 1301 of the work 2 shown in FIG. Also at the edge portion 133 of the colored layer 1302, the thickness of the colored layer 1302 is thin.

  In addition, when powder coating is performed by base primer coating in step S12 or color coating in step S13, the thickness of the formed coating film is 80 μm or more and 120 μm or less.

  When the baking process of step S14 shown in FIG. 2 is completed, in order to make the metal surface 130, which is a design surface, a brilliant specification, a cutting process for scraping the metal surface 130 is performed (step S15). The cutting process here is performed using a lathe, and the metal surface 130 which is the design surface is formed into a cutting surface 131 having a surface roughness of 12.5 s or less (12.5 μm or less) in terms of the average interval between the local peaks. Become. The step of cutting in step S15 corresponds to an example of the processing step referred to in the present invention, and the metal surface thus subjected to the cutting processing corresponds to an example of the processed surface referred to in the present invention.

  Here, although the cutting process is performed, other processing methods for scraping the metal surface 130 such as a buffing process may be used. In addition to the glitter specification, the metal surface 130 is also cut in the case of a specular specification or a cutting round coating specification. Both specular and specular specs are specs that give a glossy surface of the metal base, and clear coating is applied in the top coat. The specular specification gives a higher gloss than the specular specification, so the surface roughness is smaller in the specular specification than in the specular specification. In the specular specification, the surface roughness of the cut surface 131 is preferably 12.0 s or less (12.0 μm or less). In the present invention, the value of the surface roughness of the metal surface 130 after the metal surface 130 is scraped is not limited at all. Further, the purpose of performing the processing here may be the purpose of making the metal surface 130 a desired shape in addition to the purpose of smoothing the metal surface 130 for the glitter specification or the specular specification.

  FIG. 4 is a diagram schematically showing a cross section of the spoke portion of the workpiece after the cutting process for making it glitter.

  In the workpiece 2 shown in FIG. 4, the metal surface 130 as a design surface is cut, so that the primer layer 1301 and the colored layer 1302 formed on the metal surface 130 are removed together with the aluminum base material. In addition, the edge portion 133 of the primer layer 1301 and the colored layer 1302 is also scraped away to form an inclined surface 1300 that gradually inclines downward as the distance from the edge portion 133 increases. The inclination angle of the inclined surface 1300 is further increased by deburring the edge portion 133 after the cutting process. In FIG. 4, the cutting surface 131 including the edge portion 133 is exposed, and the rust prevention effect is lost in the cutting surface 131 including the edge portion 133. On the other hand, the primer layer 1301 and the colored layer 1302 remain on the bent surface 132, and the rust prevention effect of the bent surface 132 is maintained.

  When the cutting process in step S15 shown in FIG. 2 is completed, the cutting surface 131 is preprocessed (step S16). In this pretreatment, degreasing and acid cleaning are performed on the cut surface 131 in the same manner as in the pretreatment in step S11, and oil components such as cutting oil attached in the cutting are removed. In this pretreatment, a non-chrome type chemical conversion treatment may be applied to chemically form a coating film having a certain degree of rust prevention effect on the cut surface 131.

  Subsequently, a secondary coating process is performed. In this secondary coating process, first, a transparent electrodeposition coating film is formed on the cut surface 131 (step S17). Here, the work is immersed in a transparent electrodeposition paint having an epoxy-based antirust effect and energized. By doing so, a transparent electrodeposition coating film is uniformly formed on the metal surface. Moreover, in electrodeposition coating, an electrodeposition coating film tends to stick to a sharp point. As the transparent electrodeposition paint, an acrylic type can be used in addition to an epoxy type. Epoxy-based electrodeposition paints have excellent corrosion resistance including a rust prevention effect, and also have good adhesion to an aluminum base material. On the other hand, acrylic electrodeposition paints are excellent in weather resistance. In addition, a polyester-based transparent electrodeposition coating material, a urethane-based transparent electrodeposition coating material, or an acrylic / epoxy-based / polyester-based / urethane-based transparent electrodeposition coating material can also be used. Furthermore, a cationic electrodeposition paint or an anion electrodeposition paint may be encountered, but here a cationic electrodeposition paint is used. The process of forming the transparent electrodeposition coating film in step S17 corresponds to an example of the transparent electrodeposition coating film forming process referred to in the present invention.

  Thereafter, under the same conditions as in step S14, 120 ° C. or higher and 170 ° C. or lower (preferably 140 ° C. or higher and 160 ° C. or lower) and 10 minutes or longer and 40 minutes or shorter (preferably 15 minutes or longer and 25 minutes or shorter). A film baking process is performed (step S18).

  FIG. 5 is a diagram schematically showing a cross section of the spoke portion of the workpiece after the baking treatment of the transparent electrodeposition coating film is completed.

  In the workpiece 2 shown in FIG. 5, a transparent electrodeposition coating 1303 having a thickness of 5 μm or more and 10 μm or less is formed on a cutting surface 131 including an edge portion 133. Therefore, the edge part 133 is covered with the transparent electrodeposition coating film 1303 having a high antirust effect. Actually, as a result of conducting a continuity test using a tester in the state of the workpiece 2 shown in FIG. 5, continuity with the workpiece 2 was not confirmed at the edge portion 133.

  The transparent electrodeposition coating 1303 has sufficient transparency, and the thickness thereof is also thin, and the lustrous specification cutting surface 131 can be seen well through the transparent electrodeposition coating 1303. As a comparison, the transparency is the same as that of a coating film formed by a clear clear coating described later. In general, as the film thickness of the coating film increases, the color of the coating film becomes yellowish, but this transparent electrodeposition coating film 1303 is thin while covering the edge portion 133 firmly, The yellowness is not noticeable.

  In addition, the transparent electrodeposition coating film is not formed in the surface of the colored layer 1302 which is a nonmetallic surface of the bending surface 132. FIG.

  As shown in FIG. 2, when the transparent electrodeposition coating 1303 is baked in step S18, a clear clear coating is then performed using an acrylic resin to form a clear clear layer (step S19). ). The acrylic resin used in this clear clear coating is highly transparent and excellent in chemical resistance, gasoline resistance, scratch resistance and the like. An acrylic resin is excellent in smoothness and has an excellent ultraviolet absorption effect (weather resistance). In the present embodiment, by using an epoxy-based transparent electrodeposition paint as described above, the corrosion resistance including the rust prevention effect is ensured, and the adhesion with the aluminum base material is also secured, and the acrylic coating is used as the clear paint for top coating. The smoothness and the weather resistance are ensured by using the thing. As the acrylic resin, for example, an acrylic melamine resin can be used. Further, instead of solvent coating for applying an acrylic resin, an overcoat clear layer may be formed by powder coating. In the solvent coating, an epoxy resin, a polyester resin, a urethane resin, or a hybrid type of these resins may be used instead of the acrylic resin. The step of forming the overcoat clear layer in step S19 corresponds to an example of the clear coating step according to the present invention, and the overcoat clear layer corresponds to an example of the clear layer according to the present invention.

  Finally, under the same conditions as in the conventional baking process, 120 ° C to 170 ° C (preferably 140 ° C to 160 ° C), 10 minutes to 40 minutes (preferably 15 minutes to 25 minutes), The overcoating clear layer is baked (step S20), the secondary coating process is completed, the series of processing steps shown in FIG. 2 is also completed, and any other necessary processes are applied to the vehicle shown in FIG. Wheel 1 is completed.

  In addition, in forming the transparent electrodeposition coating film in step S17, by using a room temperature curing type transparent electrodeposition paint, or by using a transparent electrodeposition paint having a large difference in SP value from the resin applied by the top clear coating, It is sufficient to perform the preliminary drying by omitting the baking process of the transparent electrodeposition coating film in step S18. Even when the baking process for the transparent electrodeposition coating film is omitted and the preliminary drying is performed, the baking process for the overcoat clear layer in step S20 is executed, and in this step S20, the transparent electrodeposition coating film is further stabilized.

  FIG. 6 is a diagram schematically showing a cross section of the spoke portion of the work after the secondary coating process.

  In the workpiece 2 shown in FIG. 6, an overcoat clear layer 1304 is formed from the transparent electrodeposition coating film on the cut surface 131 to the colored layer 1302 on the bent surface 132. That is, the overcoat clear layer 1304 covers the transparent electrodeposition coating 1303 on the cut surface 131 and the colored layer 1302 on the bent surface 132.

  The topcoat clear layer 1304 has sufficient transparency, like the transparent electrodeposition coating 1303. The thickness of the overcoat clear layer 1304 is 10 μm or more and 30 μm or less, but is preferably as thin as possible. The thinner the overcoat clear layer 1304 is, the more the metal feeling and brightness of the machined surface 131 and the edge feeling of the edge portion 133 are enhanced, and the design of the vehicle wheel 1 is improved. Further, if the thickness of the overcoat clear layer 1304 is thin, the risk of the topcoat clear layer 1304 being broken is reduced. The top coat clear layer 1304 shown in FIG. 6 also drips at the edge portion 133 and the thickness of the top coat clear layer 1304 is reduced. Since it is covered tightly and the rust-preventing effect is sufficiently enhanced by this transparent electrodeposition coating 1303, there is no problem even if the thickness of the overcoat clear layer 1304 is reduced at the edge portion 133. It is particularly preferable.

  FIG. 7 is a photograph taken by enlarging the cross section of the spoke portion of the vehicle wheel shown in FIG.

  A dotted line shown in FIG. 7 indicates an inclined surface 1300 extending from the edge portion 133 shown in FIG. The edge portion 133 is firmly protected by the transparent electrodeposition coating 1303 at the portion surrounded by the one-dot chain line circle shown in FIG. It shows how it is formed.

  As described above, in the vehicle wheel 1 of the present embodiment, since the edge portion 133 of the spoke portion 13 is sharp, the transparent electrodeposition coating 1303 is easily attached, and the transparent electrodeposition coating 1303 is shown in FIG. Since it is formed after finishing the glittering process in step S15 shown, there is no fear of being scraped off by the cutting process. Therefore, the vehicle wheel 1 of the present embodiment has an enhanced rust prevention effect of the edge portion 133.

  Subsequently, a modification of the processing step shown in FIG. 2 will be described. In the following description, the same constituent elements as those described so far are denoted by the same reference numerals as those used so far, and redundant description will be omitted.

  In this modification, a transparent electrodeposition coating film is formed on the surface of the workpiece that has been subjected to the pretreatment in step S11 before the base primer coating in step S12 shown in FIG. 2 is performed. The formation of the transparent electrodeposition coating film here is performed in the same manner as the formation of the transparent electrodeposition coating film in step S17 in FIG. 2, and the baking process for the transparent electrodeposition coating film is performed in the same manner as in step S18. Thereafter, the same steps as those after step S12 shown in FIG. 2 are performed.

  FIG. 8 is a diagram schematically showing a cross section of the spoke portion of the work after the cutting for making the glitter specification in the modified example is completed.

  The transparent electrodeposition coating 1305 formed before the primer coating in step S12 is applied to the bent surface 132 from the metal surface 130, which is the design surface of the spoke portion 13, before the cutting process for the glitter specification. Although formed, when a cutting process is performed to obtain a brilliant specification, as shown in FIG. 8, the transparent electrodeposition coating 1305 formed on the metal surface 130 is removed together with the aluminum base material. ing. As a result, the cutting surface 131 including the edge portion 133 is exposed, and the rust prevention effect is lost in the cutting surface 131 including the edge portion 133. On the other hand, the transparent electrodeposition coating film 1305, the primer layer 1301, and the colored layer 1302 remain on the bent surface 132, and the rust prevention effect of the bent surface 132 is maintained.

  FIG. 9 is a diagram schematically showing a cross section of the spoke portion of the work after the secondary coating process in the modification.

  In the workpiece 2 shown in FIG. 9, a transparent electrodeposition coating 1303 is formed on the cut surface 131, and the overcoat clear layer extends from the transparent electrodeposition coating 1303 on the cut surface 131 to the colored layer 1302 on the bent surface 132. 1304 is formed. In this modification, the transparent electrodeposition coatings 1303 and 1305 are formed on both the cutting surface 131 and the bent surface 132, but the edge portion 133 is formed on the cutting surface 131. 1303.

  In the above description, the vehicle wheel has been described as an example, but the present invention is not limited to the vehicle wheel, but can be applied to a wide range of general metal workpieces such as home appliances. Moreover, even if it sees only for a vehicle wheel, it can be applied to a steel vehicle wheel and can also be applied to a vehicle wheel for a motorcycle. Further, not only the spoke portion 13 but also the surface (design surface) facing the outer side of the hub portion 12 shown in FIG. 1 is made to have a glitter specification or the like, or the rim flange portions 111 and 112 are made to have a glitter specification or the like. Also, the present invention can be applied. In addition, the present invention can be applied to a dish type or mesh type as well as a spoke type vehicle wheel.

DESCRIPTION OF SYMBOLS 1 Vehicle wheel 11 Rim part 12 Hub part 13 Spoke part 130 Metal surface 131 Cutting surface 132 Bending surface 133 Edge part 1301 Primer layer 1302 Colored layer 1303 Transparent electrodeposition coating 1304 Top clear layer 1305 Transparent electrodeposition coating

Claims (7)

A machined surface that has been machined to remove metal surfaces.
A metal workpiece comprising: a bent surface bent at a predetermined angle from the processed surface; and a transparent electrodeposition coating film formed on the processed surface including an edge portion between the processed surface and the bent surface. .   The metal workpiece according to claim 1, further comprising a clear layer covering the electrodeposition coating film and the bent surface.   The metal workpiece according to claim 2, wherein the bent surface has a colored layer under the clear layer.   The metal workpiece according to claim 3, wherein the bent surface has a primer layer under the colored layer. In a processing method of a metal workpiece having a predetermined metal surface and a bent surface bent at a predetermined angle from the predetermined metal surface,
A machining step for machining the predetermined metal surface;
A transparent electrodeposition coating film forming step of forming a transparent electrodeposition coating film on the metal processing surface including an edge portion between the metal processing surface processed in the processing step and the bent surface; How to process metal workpieces.   6. The metal workpiece according to claim 5, further comprising an overcoat clear coating step of forming a clear layer covering the electrodeposition coating film and the bent surface after performing the transparent electrodeposition coating film forming step. Processing method.   The method according to claim 1, further comprising: a coating step of forming a primer layer from the bent surface to the predetermined metal surface before the processing step, and further forming a colored layer on the primer layer. The processing method of the metal workpiece of 5 or 6.