JP2002035692A - Method for surface-treating vehicle part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a uniform coating film at a low cost by uniformly electrifying a powder coating, making the atmosphere concentration constant on the surface of a product, hence easily depositing the coating even on the recess which is likely to be shaded and depositing the coating on the whole product at the same time. SOLUTION: The electrified powder coating is suspended in a high-voltage electric field, the powder coating is deposited on the surface of the vehicle part, the part coated with the powder coating is baked and cured, and a coating film is formed on the surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for surface treatment of vehicle parts.

[0002]

2. Description of the Related Art Conventionally, a method for surface treatment of a bar roof rail disposed on a roof of a vehicle part or a division bar of a side window frame of a vehicle has been subjected to solvent spray coating for decorative purposes.

In addition, surface treatment methods for disk brakes for vehicles employ Zn plating, cationic electrodeposition coating, and solvent spray coating for the purpose of preventing rust.

[0004] The problem of the surface treatment method for vehicle parts according to the above method is that the surface treatment uses an environmentally regulated substance such as a solvent, which is a surface treatment method having a bad influence on the global environment.
In addition, cost was increased by spraying work by robots and humans.

[0005] As a method for solving this problem, there is a powder coating method as a surface treatment method that does not use environmentally regulated substances and does not require wastewater treatment equipment.

[0006]

However, the fluid immersion method, the electrostatic fluid immersion method and the electrostatic spray method of the powder coating method described above have a small application area due to the construction method, and the processing time is long when the entire product is coated. In addition, a thick film (80 μm or more) was required in order to ensure decorativeness and corrosion resistance because bubbles were involved and pinholes were formed due to application at a high concentration.

In addition, the above-mentioned method has a problem that the film thickness varies greatly with respect to the product length and irregularities, making it difficult to perform uniform coating and increasing the material cost. Further, there is a problem that the size of the coating equipment increases and the equipment cost increases.

The present invention has been made in view of the above situation, and is a surface treatment method for uniformly and thinly applying a powder coating treatment to a vehicle component. The bar roof rail, which is a long product, and a side window of a vehicle. It is an object of the present invention to provide a surface treatment method for uniformly applying a thin-film powder coating process to a vehicle part such as a frame division bar or a vehicle part such as a disk brake having a complicated product shape.

[0009]

Means for Solving the Problems To solve the above technical problems, the invention of claim 1 comprises a step of floating a charged powder paint in a high voltage electric field, and a step of floating the powder paint on a surface of a vehicle component. A method for treating a surface of a vehicle part, comprising: a step of applying the powder coating; and a step of baking and curing the vehicle part to which the powder coating is applied to form a coating film on a surface.

According to the first aspect of the present invention, the powder coating is uniformly charged, and the atmosphere concentration on the surface of the product is uniform. At the same time, it is possible to apply a uniform thin film at low cost.

According to a second aspect of the present invention, which has been made to solve the above-mentioned technical problem, in the first aspect, the step of floating the powder coating material comprises the step of applying the powder coating material placed on a porous plate to an air nozzle. A surface treatment method for a vehicle component, comprising:

According to the second aspect of the present invention, in addition to the effect of the first aspect, the more uniformly charged paint can be applied with a high density without entrainment of air, and the paint is thickened to ensure corrosion resistance due to pinholes. There is no need to make a film.

According to a second aspect of the present invention, there is provided a method for treating a surface of a vehicle component, wherein the particle size of the powder coating is 5 to 50 μm. It is.

According to the third aspect of the present invention, when the particle diameter of the powder coating is 5 to 50 μm, the powder coating adheres more uniformly to the vehicle parts, and the appearance level and the corrosion resistance of the coating are sufficient. . If the average particle size of the powder coating is less than 5 μm, the surface area increases and a phenomenon called blocking, in which the coating adheres to the coating, occurs. On the other hand, if it is larger than 50 μm, the appearance level of the coating film becomes insufficient.

According to a fourth aspect of the present invention, which has been made to solve the above technical problem, in the first aspect, the step of floating the powder coating material comprises blowing air pressure: 0.1 to 2 0.0 kg / cm2G, ejector air pressure: 0.1-0.5 kg / cm2G, cloud air pressure: 0.2-2.0 kg / cm2G, coating air pressure:
0.1-0.5kg / cm2G, applied voltage of painted electrode:
A surface treatment method for a vehicle component, which is performed at -20 to -100 KV.

According to the fourth aspect of the invention, in addition to the effect of the first aspect, when all of the above conditions are satisfied, it is optimal for forming a cloud.

According to a fifth aspect of the present invention, there is provided a method for treating a surface of a vehicle part, wherein the vehicle part is a long exterior product. is there.

According to the fifth aspect of the present invention, in addition to the effect of the first aspect, the appearance of coating with the same film thickness is greatly improved, and the film thickness variation and the coating processing time can be shortened.

According to a sixth aspect of the present invention, there is provided a method for treating a surface of a vehicle part, wherein the vehicle part is a disk brake.

According to the invention of claim 6, in addition to the effect of claim 1, the corrosion resistance at the same film thickness is greatly improved.
It is also possible to reduce the thickness variation and the coating processing time.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 shows a vehicle part as a long object used as an exterior part of a vehicle (automobile). A long object as an automobile exterior part includes a bar roof rail 501 arranged on a roof 50 of a vehicle, a window glass 60 that moves up and down, and a body 70.
There is a division bar 502 or the like dividing the window glass 80 fixed to the side. Since these vehicle parts are exterior parts, they are required to have a painted appearance and a weather resistance function.

FIG. 2 shows a bar roof rail 501.
FIG. 2 is a partially cutaway perspective view taken along line AA of FIG. 1. The surface of the bar roof rail 501 is subjected to a surface treatment according to the present invention.

Next, FIG. 3 shows a schematic view of the electric field cloud type powder coating apparatus 100. The apparatus 100 is constituted by a floating device using an air nozzle that first floats a paint at a high concentration and then floats the entire booth in a low-concentration cloud shape (cloud shape).

FIG. 4 is a schematic diagram viewed from the B direction of FIG. 2 (the upper part is omitted). As shown in FIG. 1, a vehicle component 10 as a product to be coated is hung on a hanging bracket 102 fixed to a ceiling 103 of an electric field cloud type powder coating apparatus 100. Further, the vehicle parts are arranged at positions facing the electrodes 1 and 2 as shown in FIG. The opposing positions may be arranged at positions where the electrodes 1 and 2 alternately sandwich the vehicle parts as shown in FIG.

As shown in FIG. 3, the electrodes 1 and 2 are arranged on upper and lower electrode arrangement members 12, 12, 22, and 22, respectively.
Have two. When the vehicle component 10 is passed between the electrodes 1 and 2 by a conveyor or the like from right to left in FIG. 4, powder coating is continuously performed.

The electrodes 1 and 2 are made to be negative electrodes, and the vehicle component 10 is grounded (positive side). The applied voltage of this coating electrode is -20 to -100K
V.

In the lower part of the coating apparatus 100, an air pressure G is applied to the powder coating material 4 placed on the porous plate 3 from the air box to float the porous coating 3 at a high concentration. The paint is fluidized by blowing more air. The air pressure to blow up is 0.1 ~ 2.0
kg / cm2G.

The porous plate 3 is made of a resin material such as polyester or polyethylene, and has a hole diameter of 50 μm. The pitch of these holes is not uniform due to the porous plate, but the aperture ratio is 43%.

The powder coating material 4 is placed on the porous plate 3 and projects upward from the surface of the powder coating material 4 (having a diameter of 20 m).
m), a plurality of ejectors 6 are provided.

In the above embodiment, the powder coating material 4 is blown up from the first air nozzle 6 and further blown up by the second air nozzle 5 so that the powder coating material 4 is uniformly clouded at low temperature (cloud shape). Floated on.

In the booth 101, the electrodes 1 and 2 having corona pins 11 and 21 connected to the high voltage generator are uniformly installed, so that the entire booth 101 is in a uniform electric field state, and the floating paint in the electric field is uniform. Charge.

A coating air hole 1 is provided between the corona pins 11 and 11 of the electrode 1 and between the coronas 12 and 12 of the electrode 2.
A and 1B are respectively provided in plurality, and powder paint is sprayed toward vehicle parts from the paint air holes.

According to the above-described structure, the vehicle component 10 which is a long object put into the booth in which the paint is floating in the cloud state has the powder paint uniformly adhered thereto, and then is baked and hardened to thereby form the powder coating. Can be.

The conditions for forming the cloud are as follows: the air pressure blown up by the air nozzle 7: 0.1 to 2.0 kg / cm 2
G, ejector air pressure of the ejector 6: 0.1 ~
0.5 kg / cm2G, cloud air pressure of air nozzle 5: 0.2 to 2.0 kg / cm2G, corona pin 11
The coating air pressure blown from the coating air holes between the intervals 12 and 12 is 0.1 to 0.5 kg / cm2G, and the applied voltage to the electrodes 1 and 2 is -20 to -100 KV. Here, as a condition for forming a cloud, when all of the above conditions are satisfied, it is optimal to form a cloud. The unit: kg / cm2G is an air pressure (kg) applied per 1 cm2.

Regarding the particle size of the powder coating, not only those having a generally used average particle size of 30 to 50 μm, but also fine particles having a particle size of 5 to 20 μm can be suspended. It is also possible to use fine powder particles, and it is also possible to perform thin film coating.

If the average particle size of the powder coating is less than 5 μm, the surface particles become large and a phenomenon called blocking, in which the coating adheres to the coating, occurs. On the other hand, if it is larger than 50 μm, the appearance level of the coating film becomes insufficient.

The floating powder coating is uniformly charged because a high-voltage electric field atmosphere composed of a large number of corona pins is exposed to a uniform electric field. In addition, even in a method in which a paint that has been charged in advance by an electrostatic spray gun or the like is floated in a cloud shape, the powder paint is uniformly attached to a long object in a thin film. In addition, the long object is previously subjected to degreasing or chemical conversion treatment according to the required quality. Further, the use of finely divided powder coating particles can further reduce the thin film limit.

Further, as shown in FIG. 3, the floating paint in the booth 101 is sucked above the electric field cloud type powder coating apparatus 100 and circulated again below the booth via the pipe 103.

By this circulation, the use efficiency of the conventional gun type paint is about 70% and 30% is disposed of. However, the present invention is based on the fact that the suspended paint is circulated and collected. Can be reused, the efficiency becomes 95% or more, and the amount of use can be greatly reduced.

Table 1 shows the conventional method of electrostatic spray coating and the results of coating quality according to the present invention. According to the results, the appearance of the coating at the same film thickness was greatly improved, and the film thickness variation and the coating processing time were shortened.

Table 1 shows the evaluation results.

[0043]

[Table 1] Since the present invention is a surface treatment method including such steps, it has become possible to form a thin and uniform powder coating on a long object. In addition, the present invention is not only charging the paint near the electrode seen in the conventional powder coating,
All paint is charged because it circulates while floating inside the booth.

As described above, in the conventional method using an electrostatic spray gun or the like, the amount of charge of the paint was not uniform. However, the suspended powder paint according to the present invention was uniformly charged, and the atmosphere on the product surface was further reduced. Since the concentration is uniform, the coating easily adheres to the recesses and the like which are liable to become shadows, and the coating adheres to the entire product at the same time, so that a low-cost and uniform thin-film coating can be performed. In addition, a uniformly charged paint can be applied at a high density without involving air, so that it is not necessary to form a thick film in order to ensure corrosion resistance due to pinholes.

Further, in the embodiment of the present invention, the description has been made with respect to the elongated vehicle parts. However, the present invention may be applied to a disc brake used for a braking part of an automobile or a motorcycle. Disc brakes are composed of cylinders, mountings, brake pads, etc., but are required to have a corrosion-resistant function because they are exterior parts of the undercarriage, and the sliding parts are not coated.

Table 2 shows a conventional system by electrostatic spray coating and a coating quality result according to the present invention using a disk brake as an example. According to the results, the corrosion resistance at the same film thickness was greatly improved, and the film thickness variation and the coating processing time could be shortened.

[0047]

[Table 2]

[0048]

According to the present invention, a step of floating a charged powder coating in a high-voltage electric field, a step of depositing the powder coating on the surface of a vehicle component, and baking the vehicle component to which the powder coating is deposited. Since it is a surface treatment method for vehicle parts characterized by comprising a step of curing and forming a coating film on the surface, the powder coating is uniformly charged, and furthermore, the atmosphere concentration on the product surface is uniform, The coating easily adheres to the recesses and the like which are likely to be shadows, and the coating adheres to the entire product at the same time, so that low-cost and uniform thin-film coating is possible.

[Brief description of the drawings]

FIG. 1 is a view showing the arrangement of long objects used for exterior parts of a vehicle according to the present invention.

FIG. 2 is a sectional perspective view taken along line AA of FIG.

FIG. 3 is a schematic front view of an electric field cloud type powder coating apparatus.

FIG. 4 is a schematic side view of the electric field cloud type powder coating apparatus as viewed from the direction B in FIG. 1;

[Explanation of symbols]

 501 ... Bar roof rail 502 ... Division bar 100 ... Electric cloud type powder coating device 10 ... Vehicle parts 2 ... Electrode 11,12 ... Corona pin 3 ... Porous plate 4 ... Powder coating 6 ... First air nozzle 5 ... Second air Nozzle 5 1A, 1B ... Coating air hole

Continued on front page F term (reference) 4D075 AA09 AA83 AA87 BB26Z CA48 DA08 DA10 DC13 EA02 EB57 4F034 AA01 CA11 CA22 DA07 4F042 AA09 AB03 EC01 EC05

Claims (6)

[Claims] A step of floating the charged powder coating in a high-voltage electric field; a step of depositing the powder coating on a surface of the vehicle component; and baking the vehicle component to which the powder coating is deposited. A method for treating a surface of a vehicle component, comprising a step of curing to form a coating film on a surface. 2. The surface of a vehicle component according to claim 1, wherein the step of floating the powder coating comprises blowing up the powder coating placed on the porous plate from below using an air nozzle. Processing method. 3. The method according to claim 1, wherein the particle size of the powder coating is 5 to 50 μm. 4. The method according to claim 1, wherein the step of floating the powder coating comprises blowing air pressure: 0.1 to 2.0 kg.
/ Cm2G, ejector air pressure: 0.1-0.5k
g / cm2G, cloud air pressure: 0.2-2.0kg
/ Cm2G, painting air pressure: 0.1-0.5kg / cm
2G, a surface treatment method for a vehicle component, wherein the method is performed at an applied voltage of a coating electrode of -20 to -100 KV. 5. The method of claim 1, wherein the vehicle component is a long exterior product. 6. The method according to claim 1, wherein the vehicle component is a disk brake.