JPS596966A - Top-coating of automobile body - Google Patents

Abstract

PURPOSE:To contrive to make the work of top-coating full automatic, by coating the inner plate of a door and the limited part of the outer plate of a body with robots and then the remainder of the outer plate of the body with an automatic coater. CONSTITUTION:After the inner plate of a door and the limited part 26 of the outer plate of a body are coated using a coating robot holding a spraying gun excellent in straightforwarding and another coating robot holding a rotary atomizing electrostatic coater, respectively, the remainder 27 of the outer plate of the body is coated using an automatic coater movable on vertical and horizontal planes. Thus, the work of top-coating can be made full automatic, and parts to be coated with the coating robots are reduced to save paint.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for topcoating an automobile body.

Automobile bodies that are welded and assembled at body shops undergo pretreatment such as degreasing and phosphate coating.
An undercoat is applied by electrodeposition, then an intermediate coat of the outer panel and a top coat are applied to the engine room and the inner panel of the trunk room at the same time, followed by a top coat of the outer panel and the inner panel of the door.

In recent years, rotary atomizing electrostatic atomizers with high coating efficiency have been adopted in the topcoating process in order to automate and save resources. It is difficult to apply sufficient coating with an electric coating machine. In addition, for areas that are narrow and locally curved, such as parts of the pillars of exterior panels and the front of the body, conventional fixed or short reciprocating rotary atomizing electrostatic coating machines for vertical and horizontal surfaces are sufficient. It is difficult to apply a suitable coating. Therefore, in areas that cannot be sufficiently coated with a fixed or short reciprocating rotary atomizing electrostatic sprayer using conventional painting methods, the operator can later use an air atomizing spray gun or an air atomizing electrostatic spray gun to apply paint to the door. The actual situation is that complete automation of topcoating is desired since it is undesirable for interior panels and also hinders resource conservation of paint.

In recent years, attempts have been made to have painting robots holding air atomizing spray guns or air atomizing electrostatic spray guns perform the above-mentioned correction painting instead of workers, but due to the limits of the control ability of painting robots, It is not possible to perform fine-grained correction painting from a close position like that of a person, and when correcting solid paint or clear paint, the solvent often evaporates and dry paint particles, that is, paint dust, cause surface roughness. To prevent this skin roughness, it is necessary to bring the robot closer to the body, and it is necessary to move the painting robot over a wide range.

In addition, in the case of two-coat one-base painting consisting of metallic base painting and clear painting, color differences and metal unevenness are likely to occur at the interface between the local correction painting area and the entire surface painting area during the former correction painting, so local correction painting is performed by a robot. Afterwards, the entire surface needs to be corrected by a painting robot, resulting in a large amount of paint being wasted.

Furthermore, in order to perform wide-area correction painting or full-surface correction painting using a painting robot as described above, it is necessary to increase the movement range of the painting robot, making the topcoating booth unnecessarily long and large, making it difficult to use the limited factory space. This makes implementation difficult.

SUMMARY OF THE INVENTION An object of the present invention is to provide a topcoating method that achieves full automation of topcoating and reduces the number of parts to be painted by a coating robot, thereby saving paint usage.

In the perspective view of the automobile body shown in Fig. 2, the parts indicated by twill lines or diagonal lines are the door inner panel coating area (twill line part) 25 and the outer panel local coating area, which is difficult to coat with the above-mentioned rotary atomizing electrostatic coating machine. (Shaded area) 26 is shown. The present inventors believe that phenomena such as color difference, metal unevenness, or rough skin that occur in the boundary area between the entire surface painting area and the correction painting area are caused by an uneven coating film due to the difference in surface tension or fluidity due to the difference in dryness of both coating films. We realized that this was caused by the formation of paint, so we painted the inner and outer panels of the door, which had previously been done by corrective painting, first, and then painted the remaining outer panels with a large amount of paint. By painting the entire surface, both coatings were made homogeneous, and the robot painting was limited to a narrow area.

Zunawara The top coating method of the present invention uses a painting robot holding a blow TJ gun to paint the inner panel of the door, and a painting robot holding a rotary atomizing electrostatic coating machine to paint the external part of the body. After these parts have been painted, the remaining parts of the body skin are painted using an automatic vertical and horizontal painting machine.

In the method of the present invention, the gun used for painting the inner panel of the door is an air atomizing spray gun with high straightness, an air atomizing electrostatic spray gun, an air atomizing electrostatic spray gun, an airless atomizing gun, or a spray gun. Some i1 are used. These have low coating efficiency and require a large amount of paint, so they are used to paint the inner panel of the door, which has a recessed, curved shape. The rotary atomizing electrostatic coating machine used for painting the local parts of the exterior panels is, for example, the Müller model 20-40, which is small enough to be held by a robot and has a narrow application vacuum.

No robot was used to paint the remaining body exterior panels, but a rotary atomizing electrostatic coating device, described in JP-A-56-115652, attached to an automatic vertical surface coating machine and an automatic horizontal surface coating machine was used.

Hereinafter, the top coating method of the present invention will be explained with reference to the drawings.

Example: After four degreasing and chemical conversion treatments, an automatic body produced at an auto body factory was subjected to an undercoat electrodeposition coating with an epoxy resin cationic paint, followed by a sealer application, rust prevention treatment, and soundproofing treatment, followed by polyester resin coating. Spray the intermediate coat on the outer panel surface, then spray the gray polyester resin top coat inside the engine room, the rank room and the fuel inlet, and after an appropriate setting time, bake it to dry. Next, the body is covered with ≠600 paper and cleaned with tack rag varnish gauze at the entrance of the top coating booth to complete the pre-painting treatment.

Next 18 In the top coating process according to the method of the present invention, Figure 1 shows the planar layout of the first top coating zone B with the metallic base paint during the process of applying one top coat of the pretreated automatic tank body with the metallic cream paint and the clear paint. Only a few illustrations are shown.

Reference numeral 1 denotes a tunnel-type top coat coating booth 1, and a conveyor 3 continuing from the above-mentioned intermediate coat coating process A is arranged on the floor 2 of the coating booth 1. The conveyor 3 passes through the second top coating zone C to the next drying station 8 (not shown) in order to transport the trolley (not shown) on which the own filJ car body W is placed.
It follows. After the pretreatment of the automobile body, the doors on both the front and rear sides of the body are opened by the door opening device 10 and 11, and the car body is advanced to a multi-arm type or multi-joint type general-purpose or dedicated painting robot 4, 5, and then the painting robot 4,5
Spray guns 8, 9 attached to the tip of arm 6.7
The door inner plate coating portion 25 is painted with an acrylic resin metallic base paint. When the painting is completed, the door of the body is closed by the door closing device 12-13. A general-purpose or dedicated painting robot 14-15, such as a multi-arm type or multi-joint type, is arranged behind the door closing device 12, 13 for painting the outer panel local painting section 26. At the tip of the 150 arm 16, 1.7 is a rotary exposure electrostatic coating machine 18.19 (model 2) made by Mueller.
〇-40) is installed, and the door inner panel painted part 2
At the same time as the painting in step 5, the local coating parts 26 of the outer panels such as pillars and the front part of the body can be painted.

As mentioned above, the door inner panel painting part 25 and the outer panel local painting part 2
After painting 6, it is white! The vII tun body W advances to the next vertical surface automatic coating machine 20, 21, 22, and 23. These are fixed or wheel part elevating type, JP-A-56-1.156
The rotary atomizing electrostatic coating device described in No. 52 is installed. Furthermore, a horizontal surface automatic coating machine 24 of a fixed or short reciprocating type that moves up and down along the body shape is disposed behind it, and a rotary electrostatic coating machine described in Japanese Patent Application Laid-Open No. 115652/1984 is also attached. The automobile body W is coated with the remaining exterior coating portion 27 by the above-mentioned vertical and horizontal automatic coating machine, and then transferred to the next baking and drying process.

Behind the sugar l topcoat zone B, there is a second topcoat zone C using a heating device similar to the core first topcoat zone B. It is coated with an acrylic resin-based clear paint and is baked to dry to complete the painting. Do T. In addition, when painting with solid paint, first top coat coating zone B or second top coat coating zone C
Painted on both or either side.

As described above, in the painting method of the present invention, the spray paper with excellent straightness is used to paint the inner panel of the door with a gun, and after painting the local part of the outer panel with a small rotary atomizing electrostatic coating machine, the remaining part of the outer panel is coated. By painting this area, there will be a slight difference in the color of the paint film in the area.

In addition to being able to prevent metal unevenness, etc., spraying with low first-coat efficiency can slightly reduce the paint area of the gun and reduce the paint application rate.1. By setting fl to 1(]q for painting the inner and outer parts of the door, the movement range of the painting robot could be changed from the furnace to the furnace, thereby reducing the space required.Furthermore, it was possible to reduce the space required for painting the painting robot and rotating parts. We were able to achieve complete automation of the topcoating process through an effective combination of atomizing electrostatic coating machines.

[Brief explanation of drawings]

FIG. 1 shows a side view of one embodiment of the present invention.
The figure shows the painted parts of the car body (Figure 1). In the diagram: ■・・・Painting booth 2・・・Floor 3
...... Conveyor 4.5.../%
440 bots 6.7... 7-m 8
, 9...Blow I: 1 ke gun to, J, i・
... Door opening purchase 12.13 ... Door 1
4 equipment 14.15...Painting robot 16.
17...Arm 18.19...Rotating atomizing electrostatic coating machine 20.21
, 22.23... Vertical surface automatic coating machine 24...
...Horizontal surface automatic coating machine 25...Door inner panel painting section 26...Outer panel local coating section 27...Outer panel residual painting section

Claims (1)

[Claims] A painting robot holding a spray gun was used to paint the inside panels of the doors, and a robot holding a rotary atomizing electrostatic sprayer was used to paint the outside panels of the body. After that, the remaining parts of the body outer panel are coated using an automatic coating machine on both vertical and horizontal surfaces.