JP2017070874A - Coating method of vehicle wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a vehicle wheel which can coat a front side and a rear side of a light alloy wheel on one coating stage while preventing adhesion of coating material to a coating gun without prolonging a cycle time of a coating process as compared with a conventional one.SOLUTION: A coating method of a vehicle wheel having a disc part with an opening part, and a rim part includes a front side coating process including a first front side coating process of coating a disc part front surface by jetting coating material from a first gun and a second front side coating process of coating a rim part front surface, and a rear side coating process including a first rear side coating process of coating a disc part rear surface by jetting the coating material from a second gun and a second rear side coating process of coating a rim part rear surface. The first front side coating process and the first rear side coating process are not carried out simultaneously. The first front side coating process and the second rear side coating process are carried out simultaneously. The first rear side coating process and the second front side coating process are carried out simultaneously. The front side coating process and the rear side coating process are carried out while holding the vehicle wheel on one stage.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for painting a vehicle wheel.

  In general, a vehicle wheel, which is an automobile (for example, passenger car) part formed by casting a light alloy such as aluminum, usually has a multilayer structure on its surface in order to have a high-quality appearance. Paint is applied. As this multi-layer coating, in general, for example, a primer layer made of powdered polyester, acrylic, epoxy, urethane, epoxy polyester-based resin, etc., which is applied with a thickness of about 50 to 100 μm in order to hide the unevenness of the casting surface, There are three-layer coatings consisting of polyester for producing the color of the appearance, a color base layer mainly composed of an acrylic resin, and a clear layer for enhancing the weather resistance and corrosion resistance as well as the color of the color base layer. In addition, in order to further enhance the texture, a metal-like silver layer (plating-like paint) reminiscent of a polished surface of metal is added, and a four-layer paint consisting of a primer layer, color base layer, metal-like silver layer, clear layer, etc. There is also a multilayer coating.

  Patent Document 1 discloses a vehicle wheel having a design surface including a window part and a spoke part that forms the window part, the spoke part having an edge part, and the edge part facing the window part. A vehicle wheel coating method comprising a side surface and a back surface with respect to the design surface, wherein the side surface and the back surface form an acute angle, wherein primer paint is applied to the front side and the back side of the design surface. The color base paint is sprayed on the primer layer from the back side of the design surface to coat the back side surface and the edge portion, and then the color base paint is sprayed from the front side of the design surface to the side surface and the edge. The method for painting a vehicle wheel is characterized in that the color base paint is baked on the part. According to the invention described in Patent Document 1, in order to increase the rust prevention at the ridge line portion between the spoke portion and the processed surface on the back side of the design surface by spraying the paint on the vehicle wheel, the paint is blown from the front side and the back side of the design surface. When applying, since it was first sprayed from the back side and then sprayed from the front side, the resin sprayed from the back side on the front side of the design surface was not scattered, and a flat and good painted surface was obtained.

Japanese Patent No. 5316926

  In the invention described in Patent Document 1, in order to paint the front side and the back side of the vehicle wheel, the painting stage that holds the vehicle wheel is divided into a first stage and a second stage, and the light stage held on the first stage is divided. The front side of the alloy wheel is painted, and then the back side of the vehicle wheel is painted on the second stage where the light alloy wheel is held again from the first stage. The above-mentioned painting method has an advantage that the cycle time of the painting process can be shortened by dividing the painting stage between painting on the front side and painting on the back side of the vehicle wheel. However, compared with the case where the front side and the back side are painted on one painting stage, there is a problem that an extra cost and installation space are required for installing the equipment.

  However, simply providing two painting guns for front and back painting on one painting stage and trying to paint the front and back sides of a vehicle wheel at the same time, the paint discharged from one painting gun is the other. There is a possibility that the problem of sticking to the paint gun may occur. That is, the front side of the vehicle wheel is used by using a coating apparatus having a stage on which the vehicle wheel is placed and held, a first gun provided on the front side of the held vehicle wheel, and a second gun provided on the back side. It is possible to paint the vehicle wheel on a single painting stage without extending the cycle time of the painting process compared to the conventional art. However, since the disk portion of the vehicle wheel usually has an opening (such as a window), a part of the paint discharged from the first gun when the coating film is formed on the surface of the disk portion. Scatters through the opening to the back of the vehicle wheel. The paint scattered to the back side adheres to the second gun when the second gun is present there. If paint continuously adheres to or near the discharge port of the second gun, there will be a decrease in the amount of paint discharged from the second gun or a change in the discharge direction, causing the backside coating to not be performed properly. May occur. There is a possibility that the same problem may occur in the front side coating for the same reason. Such a problem does not occur in a conventional painting method in which one painting gun is provided in one painting stage and either the front side or the back side of the vehicle wheel is painted independently.

  The object of the present invention is to apply the coating on the front and back sides of the vehicle wheel in one painting stage while maintaining the same cycle time of the painting process and preventing the adhesion of the paint to the painting gun. It is providing the manufacturing method of the vehicle wheel which can be performed.

  A method for manufacturing a vehicle wheel according to the present invention for solving the above-described problem is a method for coating a vehicle wheel having a disk portion and an rim portion in which an opening is formed, and sprays paint from a first gun. Then, a front side painting process including a first front side painting process for painting the surface of the disk part and a second front side painting process for painting the surface of the rim part, and a back surface of the disk part by ejecting paint from a second gun A first back side painting step for painting on the back side and a back side painting step including a second back side painting step for painting on the back surface of the rim part, and either the first front side painting step or the first back side painting step After the process is completed, the other process is started, and the first front-side coating process and the second back-side coating process are performed while the other process is performed, and the first back-side coating is performed. Process and The second front side painting step is carried out while carrying out one of the other steps, and the front side painting step and the back side painting step are carried out while holding the vehicle wheel on one stage. Features.

  In the present invention, it is preferable that the first front side painting process is started after the first back side painting process is completed.

  According to the vehicle wheel painting method of the present invention described above, while maintaining the cycle time of the painting process to the same level as in the prior art and preventing adhesion of the paint to the painting gun, The back side can be painted in one painting stage.

It is the top view which looked at the wheel for vehicles from the front side of the disc surface. It is a flowchart which shows the whole manufacturing process of the wheel for vehicles. (A) (b) is a figure which shows the embodiment of the coating method of this invention, (c) is a table | surface which shows the coating method of (a) (b) in time series. (A) (b) is a figure which shows another embodiment of the coating method of this invention, (c) is a table | surface which shows the coating method of (a) (b) in time series. (A) (b) is a figure which shows the coating method outside this invention, (c) is a table | surface which shows the coating method of (a) (b) in time series. It is a figure which shows the position of the circumferential direction with respect to the vehicle wheel of the 1st gun and 2nd gun in the embodiment of the coating method of this invention shown in FIG.

  As described above, the method for painting a vehicle wheel according to the present invention is a method for painting a vehicle wheel having a disk portion and a rim portion in which an opening is formed. A front side painting process including a first front side painting process for painting the disk part surface and a second front side painting process for painting the rim part surface, and paint is ejected from the second gun to paint the back side of the disk part. A first back side painting process and a back side painting process including a second back side painting process for painting on the back surface of the rim portion, and either of the first front side painting process and the first back side painting process includes: After the completion, the other process is started, and the first front-side coating process and the second back-side coating process are performed while the other process is performed while the first back-side coating process and the second back-side coating process are performed. Table 2 Coating process, carried out either process the other process while carrying out the front side painting process and back coating process, and performs while maintaining Wheel the vehicle in one stage.

  According to such a vehicle wheel coating method, (1) the first front side painting step and the first back side painting step start the other step after either step is completed. The first gun used in the first front side painting process for performing the coating and the second gun used in the first back side painting process for coating the back surface of the disk portion are in a state of discharging the paint relative to the same period. In this case, the discharged paint can be prevented from adhering to the first gun and the second gun through the opening formed in the disk portion. In addition, in the coating method according to the present invention, (2) the first front side coating step (disk portion surface coating) and the second back side coating step (rim portion back surface coating) are performed while one of the steps is performed. The process is performed, and (3) the first back side coating process (disk part back surface coating) and the second front side coating process (rim part surface coating) are performed while performing one of the other processes. That is, as described above, the coating time (cycle time) of the entire coating of the vehicle wheel is the same as the conventional one, while assuming the component (1) for preventing the paint from adhering to the first gun and the second gun. Therefore, by applying the above components (2) and (3), a pair of the disk portion surface and the rim portion back surface, a pair of the disk portion back surface and the rim portion surface, and two surfaces in each pair It is configured to paint in parallel. And, in the coating method according to the present invention, the front side painting step comprising the first front side painting step and the second front side painting step, and the back side painting step comprising the first back side painting step and the second back side painting step are: Since the vehicle wheel is held by one stage, the cycle time of the painting process can be maintained at the same level as the conventional one while suppressing the installation space and cost of the painting equipment.

  The present invention will be described based on specific embodiments with reference to the drawings. In addition, this invention is not limited to the Example demonstrated below, In addition, as long as there exists an effect of this invention, it can deform | transform suitably within the range of identity.

  First, an example of the structure of a vehicle wheel and its manufacturing process will be described with reference to FIGS.

  FIG. 1 is a plan view of a vehicle wheel (hereinafter sometimes simply referred to as a wheel) as viewed from the front side of the disk portion. The wheel 1 has an annular rim portion 2 on which a tire (not shown) is mounted, and a disc portion 6 provided inside the rim portion 2. The disk portion 6 has a hub portion 3 at the center for fixing the wheel to the axle, and a spoke portion 4 that extends radially from the hub portion 3 toward the rim portion 2 and connects the two. A relatively large window-shaped space surrounded by the rim part 2, the hub part 3, and the spoke part 4 is an opening part (so-called window part) 5. The wheel shown in FIG. 1 is a spoke type wheel, and the spoke part 4 is designed to extend radially from the hub part 3 toward the rim part 2, but the design of the disk part of the wheel is the spoke type. Not exclusively. For example, in the case of a wheel in which the disk portion 6 has a mesh type design, a portion corresponding to the spoke portion 4 in FIG. 1 has a mesh shape, and the opening portion 5 is an opening portion that is a relatively small space having a hole shape. In the following description, the surface facing the vehicle when the wheel is attached to the axle of the vehicle is referred to as the “back surface” of the wheel, and the surface opposite to the back surface and facing the outside of the vehicle is referred to as the “surface” of the wheel. I will do it.

  The whole manufacturing process of the vehicle wheel of the present invention will be described with reference to FIG. 2 by taking the case where the wheel forming process is based on a casting method as an example. In the wheel forming step, molten metal is poured into the mold, and after cooling, the cast is taken out of the mold to obtain a wheel having an opening on the design surface. Next, a wheel heat treatment step is performed as necessary. Next, a processing step for performing processing such as chamfering and deburring of portions other than the opening is performed as necessary. Next, a pre-painting treatment step for performing degreasing / chemical conversion treatment on the wheel surface as necessary is performed. Finally, the vehicle wheel is completed by painting the wheel in the painting process for carrying out the painting process according to the present invention.

  Hereinafter, the coating method according to the present invention will be described based on Examples 1 and 2.

Example 1
In a specific example 1 of the coating method according to the present invention, a primer coating for forming a primer layer on the wheel back surface and the wheel surface, a color base coating for forming a color base layer on the wheel surface, and then on the color base layer. Apply clear coating to form a clear layer. In Example 1, the primer method, the color base coating, the clear coating, and the three types of coating are applied to the coating method according to the present invention described in detail below (the same applies to Example 2 described later).

  As the primer paint, resins such as polyester, acrylic, epoxy, and urethane can be used. The thickness of the primer layer is preferably about 40 to 200 μm when it is necessary to hide the unevenness of the cast surface of the wheel. An electrostatic coating apparatus can be used for the coating film apparatus. As the color base paint, for example, a paint made of acrylic, polyester, epoxy resin or the like and containing a solvent can be used. Spray the wheels with air spray or electrostatic paint. The film thickness is preferably 10 to 40 μm. The clear layer desirably has durability and translucency. For example, a solvent-based clear paint or a powder-based clear paint in which a polymer or an oligomer is dissolved in an organic solvent can be used. The clear paint is sprayed by air spray or electrostatic coating, and the film thickness is preferably 10 to 40 μm.

  The coating method of Example 1 is demonstrated in detail using FIG. FIGS. 3A and 3B are diagrams illustrating a coating method according to the first embodiment, and the wheel 1 is shown in a cross-sectional view taken along the line AA of the wheel illustrated in FIG. 1. As shown in FIGS. 3 (a) and 3 (b), a coating apparatus that embodies the coating method of the first embodiment includes a coating stage (not shown) that mounts and holds the wheel 1, and a wheel 1 that is held. A rotation driving mechanism (not shown) of the painting stage that can be rotated around the central axis, a first gun 10 provided on the front side of the wheel 1, and a second gun 20 provided on the back side of the wheel 1. It has.

  The coating method of Example 1 using the coating apparatus proceeds in the following procedure. That is, first, the wheel 1 is placed on and held on the painting stage (one stage). The holding of the wheel 1 by this painting stage is maintained during the front side painting process and the back side painting process described below, and is released after all the painting of the wheel 1 is completed. That is, the front side painting process and the back side painting process described below are performed while holding the wheel 1 on one stage. As described above, the wheel 1 is held on the painting stage, and before the start of painting, the first gun 10 is disposed at a position facing the front side of the disk portion 6, and the second gun 20 is a rim. It is arranged at a position facing the back side of the part 2.

  FIG. 6 is a plan view of the wheel 1 of FIG. 3 as viewed from above, and shows the positional relationship between the first gun 10 and the second gun 20 with respect to the wheel 1. From the viewpoint of preventing adhesion of the paint to the first gun 10 and the second gun 20, the first gun 10 and the second gun 20 do not overlap in a plan view and are in different positions during painting. It is preferable to paint while controlling each position. Specifically, the second gun 20 does not enter the paint discharge range 10 a discharged from the first gun 10, and the first paint is within the paint discharge range 20 a discharged from the second gun 20. For example, if the first gun 10 and the second gun 20 are arranged with an angle θ at an angle around the central axis of the wheel in a plan view, the first gun 10 may be prevented from entering. This is desirable because adhesion of the paint to the second gun 20 can be further suppressed. Here, the angle θ between the first gun 10 and the second gun 20 is a half line 10 b connecting the first gun 10 and the center of the wheel 1 and the center of the second gun 20 and the wheel 1. Is defined as an angle (angle on the narrow angle side) at which the half straight line 20b is connected. This angle θ is more preferably 90 ° or more and 180 ° or less. In Examples 1 and 2 and Comparative Example 1, the angle θ between the first gun 10 and the second gun 20 was set to 135 °. In addition, it is more preferable that the first gun 10 and the second gun 20 are periodically cleaned before use or even during use.

  Next, after the wheel mounted on the coating stage started to rotate and the rotation speed was stabilized, the wheel was painted as shown in FIG. 3C, which is a table showing the coating method of Example 1 in time series. To do.

As shown in FIG.3 (c), the coating method which concerns on this invention has a front side coating process and a back side coating process. The front side painting process includes a first front side painting process P _O1 for spraying paint from the first gun 10 and painting the surface of the disk portion 6, and a second front side painting process P for painting the surface of the rim part 2. _O2 is included. The back side painting process includes a first back side painting process _Pr 1 for painting the back surface of the disk portion 6 by spraying paint from the second gun 20 and a second back side painting for painting the back surface of the rim portion 2. The process _Pr2 is included.

Then, as shown in FIG. 3 (c), in the coating method of Example 1, a second back coating step P _r2 while performing a first front coating step P _O1 during the time after the start of the painting T ₁ performed with (FIG. 3 (a)), and then performing a first backside coating step _{P r1} while performing a second front coating step _{P O2} during the time _{T 2} following the _{T 1} (Figure 3 (b)). Thus, since the coating of the front surface and the back surface of the wheel 1 is performed in parallel, it is possible to paint the front side and the back side on one painting stage without making the cycle time of the painting process longer than in the past. Furthermore, in the coating method of Example 1, the first front side coating process P _O1 is started first, and after the first front side coating process P _O1 is completed, the first back side coating process P _r1 is started. After the first front side painting process _PO1 is completed in this way, the first backside painting process _Pr1 is performed, so that the paint discharged from the first gun 10 is discharged from the second gun 20 to the second gun 20. The applied paint is prevented from passing through the opening 5 and adhering to the first gun 10.

  Here, the coating method of the first embodiment is an example in which after the disk portion surface is coated with the first gun 10, the disk portion back surface is coated with the second gun 20. As described above, when the back surface of the disk part is applied after the coating on the surface of the disk part, the paint discharged from the second gun 20 passes through the opening 5 when the back surface of the disk part is applied. The part adheres to the surface of the disk part or the rim part, and for example, a coating defect such as satin or cocoon skin may occur on the surface. However, the quality of the coating film on the surface of the wheel prepared in this example was at a level with no practical problem. The coating quality was evaluated with the 20th wheel manufactured after cleaning the first gun and the second gun, and evaluated with ○ to × on the basis of the evaluation by the conventional coating method (Table 1).

(Example 2)
The coating method of Example 2 is demonstrated in detail using FIG. 4 (a) and 4 (b) are diagrams showing a coating method of Example 2. FIG. As shown in FIGS. 4A and 4B, the coating apparatus that embodies the coating method of the second embodiment has the same configuration as that of the first embodiment.

  The coating method of Example 2 using the said coating apparatus is demonstrated. First, the wheel 1 is held on the painting stage. Before the start of painting after the wheel 1 is held on the painting stage, the first gun 10 is in a position facing the front side of the rim part 2, and the second gun 20 is opposed to the back side of the disk part 6. Placed in position.

  Next, after the rotation of the wheel placed on the coating stage started and the rotation speed was stabilized, the coating of the wheel was performed as shown in FIG. 4C, which is a table showing the coating method of Example 2 in time series. carry out.

Figure 4 (c), the the method of coating in Example 2 containing front painting process and back painting process as in Example 1, the first back coating step P during the time after the start of the painting T ₁ while implementing _r1 performed second front coating step _{P O2} (FIG. 4 (a)), then the second back coating step while carrying out the first front coating step _{P O1} during the subsequent time _{T 2} to _{T 1} P _r2 is performed (FIG. 4B). Thus, since the coating of the front surface and the back surface of the wheel 1 is performed in parallel, it is possible to paint the front side and the back side on one painting stage without making the cycle time of the painting process longer than in the past. Furthermore, in the coating method of Example 2, the first back side coating process P _r1 is started first, and after the first back side coating process P _r1 is completed, the first front side coating process P _O1 is started. Since the first front side painting process _PO1 is performed after the first back side painting process _Pr1 is completed in this way, the paint discharged from the first gun 10 is discharged from the second gun 20 to the second gun 20. The applied paint is prevented from passing through the opening 5 and adhering to the first gun 10.

  Here, in the coating method of Example 2, after the coating film formation on the back surface of the disk part 6 (first back side coating process) is completed, the coating film formation on the surface of the disk part 6 (first front side coating process) is performed. This is different from the first embodiment in that As described above, after the coating of the back surface of the disk portion is completed, when the coating is performed in the order of coating on the surface of the disk portion, the surface of the wheel 1, particularly the surface of the disk portion 6 where design is required, is excellent with few coating defects. It is preferable because a coating film having a high quality can be formed.

  In the first embodiment and the second embodiment, two steps that are paired on the front side and the back side of the wheel that are performed in parallel, that is, the first front side coating step (disk portion surface coating) and the second back side coating step are performed. (Rim part back surface coating), first back side coating process (disk part back surface coating) and second front side coating process (rim part surface coating) are all performed at the same time at the same time. However, the two steps to be paired may be performed in parallel, and the order is not limited. That is, the first front side coating step and the second back side coating step are performed while either one step is being performed, and the first back side coating step and the second front side coating step are also performed by either step. It is only necessary that the other process is performed while performing.

(Comparative example)
The coating method of the comparative example which is outside the scope of the present invention will be described in detail with reference to FIG. FIGS. 5A and 5B are diagrams showing a coating method of a comparative example. As shown in FIGS. 5A and 5B, the coating apparatus that embodies the coating method of the comparative example has the same configuration as that of the first embodiment.

  The coating method of the comparative example using the coating apparatus includes a front side coating process and a back side coating process with respect to the above-described Examples 1 and 2, and the front side coating process and the back side coating process are performed in one stage of the wheel 1. However, the following points are different.

That is, as shown in FIG. 5 (c), in the coating method of the comparative example, the second back coating step P _r2 while performing a second front coating step P _O2 during the time after the start of the painting T ₁ embodiment and (FIG. 5 (a)), and then performing a first backside coating step _{P r1} while performing a first front coating step _{P O1} during the time _{T 2} following the _{T 1} (Figure 5 (b)).

In other words, the method of coating the comparative example, unlike Example 1 and Example 2, the time the first front coating step (disk portion surface coating) between the T ₂ P _O1 and the first back coating step (disk portion back surface coating ) P _r1 is performed simultaneously. Therefore, the paint discharged from the first gun 10 adheres to the second gun 20 and the paint discharged from the second gun 20 passes through the opening 5 and adheres to the first gun 10. The coating quality on the surface of the disk until the 10 wheels were painted was at a level that had no problem in practice, but the 11th and subsequent coatings were affected by the adhesion of the paint to the first gun 10 and the second gun 20. Gradually, the 20th wheel coating was not only thinner than the intended thickness, but also had a non-uniform thickness.

  Table 1 shows the evaluation of the above examples and comparative examples.

1 Vehicle wheel (wheel)
2 Rims 3 Hubs 4 Spokes 5 Openings 6 Discs 10 First Gun 20 Second Gun

Claims (2)

A method of painting a vehicle wheel having a disk portion and a rim portion in which an opening is formed,
A front side painting step including a first front side painting step of spraying paint from the first gun and painting the surface of the disk portion and a second front side painting step of painting the surface of the rim portion;
A backside coating process including a first backside painting process for spraying paint from the second gun and painting on the backside of the disk part and a second backside painting process for painting on the backside of the rim part,
The first front side painting step and the first back side painting step start the other step after either step is completed,
The first front side coating step and the second back side coating step are performed while performing one of the other steps,
The first back side painting step and the second front side painting step are performed while performing one of the other steps,
The front side painting process and the back side painting process are performed while holding the vehicle wheel on one stage.
A method for painting a vehicle wheel, characterized in that: The method for painting a vehicle wheel according to claim 1, wherein the first front side painting step is started after the first back side painting step is completed.

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