JP2537380B2 - Automotive body painting method and painting equipment - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating method and a coating apparatus for an automobile body that requires a high degree of coating quality, and particularly to a surface of a vehicle body that has been undercoated or intermediate coated. The present invention relates to a coating method and a coating device for an automobile body, which are subjected to intermediate spray coating or top spray coating.

Prior art and its problems As a coating method for automobile bodies, undercoating (electrodeposition),
Method of performing double coating finish of top coat (spray) (truck, light vehicle, etc.) and method of performing triple coat finish of undercoat (electrodeposition), intermediate coat (spray), top coat (spray) (passenger car) However, in the case of a luxury car, the top coat may be applied twice (eg, JP-A-61-138570).

In the conventional double overcoating method, the flash time is set between the first overcoating and the second overcoating, so even if spray coating is performed wet-on-wet, The surface of the first top-coating film has already been dried and cured when the second top-coating is performed (first
See figure. In the figure, 01 is an object to be coated, 02 is an undercoat and an intermediate coating film, 03 is a first top coating film, 04 is a second top coating film, and FT is a flash time). In the conventional two-time overcoating method, on the undercoat coating film 02 formed by undercoating the object 01 to be coated, the first intermediate coating or top spray coating (hereinafter referred to as the first coating and The second time is referred to as the second time of coating.) After the completion, 2 to 2 necessary for the solvent in the surface of the coating film 03 by the first time to evaporate
Since the flash time FT of about 4 minutes is set, even if the second coating is performed on the surface of the first coating film 03, the second coating is performed, even if the spray coating is wet-on-wet. Has already dried and hardened (FIG. 1 (b)) on the surface of the coating film 03 of the first coating. The speed at which the solvent in the paint from the second coating penetrates into the coating film 03 is small, and the influence of the surface unevenness of the coating film 03 extends to the coating film 04 of the second coating where the drying and curing progresses, and the coating film 04. However, there was a problem that the image clarity, smoothness, and gloss of the coating film were not good.

Means for Solving Problems and Effects The present invention relates to an improvement in a method for coating an automobile body which overcomes such problems, and an intermediate coating spray is applied to a surface of an automobile body which is undercoated or intermediate coated. Applying the method of painting or topcoat spraying, apply the first intermediate coat or topcoat spray coat to the vehicle body surface, and wet the second intermediate coat or topcoat spray at a time interval of 2 to 30 seconds. It is characterized by being applied on-wet.

As described above, the present invention provides a very short time interval of 2 to 30 seconds without the flash time of about 2 to 4 minutes required for the solvent on the surface of the coating film by the first coating to evaporate. Since the second coating was performed, the coating film and the coating film formed by the second coating are well blended into the first coating and quickly integrated, and the surface shape of the coating film formed by the first coating depends on the second coating. It is possible to obtain a coated surface which does not adversely affect the surface shape of the coating film, has good smoothness, and has good image clarity and gloss and excellent appearance.

In addition, 2 to 4 minutes without flash time,
As a result of the second coating with a short time interval of 30 seconds, the coating time required for each car body is shortened and the coating line length is also shortened, improving productivity and reducing costs. Become.

Further, in the present invention, a coating device for coating an automobile body is provided, which is a conveying device for conveying the automobile body along the direction of the automobile body, and 2 to 30 seconds on both left and right sides of the conveying device in the conveying direction of the conveying device. A plurality of pairs of side surface coating apparatus arranged at an interval that the previous coating portion can reach at a time interval of, and in the conveying direction of the conveying apparatus on the upper side of the conveying apparatus, 2 to 30 seconds. It is characterized by comprising a plurality of pairs of top coaters arranged at intervals so that the previously painted portion can reach at a time interval. By using such a coater, a coater is provided. By using, the above-mentioned coating method can be reliably and easily performed.

Examples The contents of the present invention will be described below with reference to specific examples (Figs. 2 to 6).

Fig. 2 shows the automatic coating machine and transfer device in the spray booth.
FIG. 9 is a front view showing an automobile body 30 which is conveyed by 28 and subjected to coating processing. Left and right pair of side coating machines 10 and pair of top coating machines 14 (first top coating machine 14A, second top coating machine 14
B) is arranged so that the front part of the vehicle body including the hood 32 of the vehicle body 30 transported at a constant speed in the spray booth, the roof 34, and the rear portion of the vehicle body including the trunk 36 are painted. The side coater 10 and the top coater 14 each have a plurality of spray guns 12 and 24 that are swingable. Particularly in the top coater 14, the arm 22 carrying the spray gun 24 moves up and down by the rotation of the screw 16 and swings by the rotation of the gear 18 and the shaft 20. According to the shape, the spray gun 24 is always positioned at a constant distance from the surface of the vehicle body 30, and the paint can be sprayed from the direction perpendicular to the surface of the vehicle body 30. Further, the first upper surface coating machine 14A and the second upper surface coating machine 14B are arranged on the guide rail 26 at intervals, and can be individually moved along the guide rail 26.

For the vehicle body 30 that has entered the spray booth, first left and right first side coating machines 10A start the first coating on both the left and right sides, and as the vehicle body 30 progresses, a selected fixed time ( (For example, about 13 seconds), then left and right second side coating machine 10
B starts the second coating on both left and right sides.
The time interval between the first coating and the second coating is determined by the relationship between the traveling speed of the vehicle body 30 and the stationary intervals of the first side coating machine 10A and the second side coating machine 10B.

Further, when the second side coating is started, the first front coating of the vehicle body front surface by the first top coating machine 14A is started (Fig. 3), and the same time as in the case of the side coating (about
After 13 seconds), the second top coater 14B starts the second coat of the front of the vehicle body. At this point the first top coater 14
A is painting near the roof 34 (Fig. 4).
During this time, the first upper surface coating machine 14A and the second upper surface coating machine 14B are moved along the guide rails 26 so that the coating of the vertical surface and the inclined surface is performed in the same manner as the coating of the horizontal surface.

By the time the first coating by the first top coater 14A is completed, the second top coater 14B is painting the roof 34 (Fig. 5), and then the second top coater 14B alone is used for painting. Be seen.

FIG. 6 shows a state of a coating film formed by such a coating method. FIG. 6 (a) is an undercoat coating film 40 and the coating film applied on a vehicle body outer plate 38 such as a bonnet and a roof.
Shown is a first topcoat coating 42 (according to the first coat) applied over 40. The second coating is performed without a flash time, and the state immediately after the second top coating film 44 is applied onto the first top coating film 42 is shown in FIG. 6 (b). At the time when the second top coating film 44 is applied, the first top coating film 42 is in an undried state, both coating films 42 and 44 are well adapted to each other, and the coating film boundary surface 46 soon disappears. ), The surface of the second top coat film 44 becomes a smooth surface with less waviness.

The time interval between the first coating and the second coating is 2
It is recommended to select it in the range of 30 seconds, and this time interval makes it possible to obtain a coating surface with good smoothness.

[Brief description of drawings]

FIG. 1 is a sectional view showing the state of a coating film in a known coating method in which a flash time is set between the first coating and the second coating, and FIG. 2 is a spray booth showing an embodiment of the apparatus of the present invention. 3 is a plan view showing a coating mode according to the present invention, and FIG. 6 is a view showing a state of a coating film formed by the method of the present invention. 10 ... Side coating machine, 12 ... Spray gun, 14 ... Top coating machine, 14A ... First top coating machine, 14B ... Second top coating machine,
16 …… screw, 18 …… gear, 20 …… axis, 22 …… arm,
24 ... Spray gun, 26 ... Guide rail, 28 ... Conveyor,
30 …… Body, 32 …… Bonnet, 34 …… Roof, 36 ……
Trunk, 38 …… Body outer panel, 40 …… Undercoat, 42 ……
First top coat, 44 …… Second top coat.

Claims (2)

(57) [Claims] 1. A first intermediate coating or topcoat spray coating on a vehicle body surface by a method of performing intermediate coating spray coating or topcoat spray coating on a surface of an automobile body which has been subjected to undercoat coating or intermediate coating. And a second intermediate coating or top coating is applied wet-on-wet at a time interval of 2 to 30 seconds. 2. A coating device for coating an automobile body, comprising: a conveyor device for conveying the automobile body along the direction of the automobile body; and left and right sides of the conveyor device in the conveying direction of the conveyor device.
A plurality of pairs of side surface coating apparatus arranged at intervals such that a previous coating portion can reach at a time interval of 2 to 30 seconds, and above the conveying apparatus in the conveying direction of the conveying apparatus, 2
A coating apparatus for an automobile body, comprising: a plurality of pairs of top coating machines arranged at intervals such that a previous coating portion can reach at a time interval of ~ 30 seconds.