JPH0435773A - Painting method on automobile production line - Google Patents

Abstract

PURPOSE:To increase work efficiency by detaching doors from an automobile body after final coating with paint and coating parts of the doors with paint different from the paint for final coating in color. CONSTITUTION:An automobile body X with covers such as doors Z conveyed through an automobile body conveying line 6 is finally coated with paint, this paint is baked and the doors Z are detached from the body X and conveyed through a door conveying line 9. Parts of the doors Z are coated with paint different from the paint for final coating in color, the upper paint is baked and the doors Z are fitted to the automobile body Y with no doors conveyed through the line 6. Work efficiency is increased and the flow of a producing line can be made efficient.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a coating method in an automobile production line.

(Prior Art) Conventionally, in the painting method used on automobile production lines, in order to prevent paint color differences, painting is performed with the door attached to the car body, and then the car body and the door are separated and painted separately. There is a known method of assembling the door and then assembling the door to the vehicle body.

In this type of painting method, as shown in FIG. 4, first, the car body X, with the door Z attached to the car body Y, is transported through the first car body transport line 50 and a top coat is applied. A top coating step 51 is performed in which the top coat is baked.

Next, in the inspection process 5, it is determined whether or not correction is necessary for the painting of the car body Y and the door Z of the car body X after the top coat has been applied.
2.

Then, the automobile bodies X are divided into automobile bodies X that require correction of the top coat and automobile bodies X2 that do not require correction according to the results of the inspection in the inspection step 52.

Here, the automobile body X, which requires correction, is transferred to the second vehicle body transfer line 5 while the door Z is attached to the vehicle body Y.
3, and the correction location of the automobile body X is corrected in a correction step 54.

After the correction has been completed, the automobile body X undergoes inspection step 5 again.
2, the inspection is performed.

As a result of the inspection step 52, the automobile body X for which correction is not required and the automobile body X1 for which correction has been made are coated separately from the above-mentioned top coat on the hulk head portion, side sill portion, etc. of the vehicle body body Y, and the sash portion of the door Z. A different color painting step 55 is performed in which a colored paint is applied and baked.

Next, the door Z of the automobile body X2 is removed from the vehicle body Y in a door removal step 56.

The vehicle main body Y separated in the door removal process 56 is transported by the first vehicle body transport line 50, and the door Z is transported by the door transport line 57, and the doors are transported by the respective transport lines 50.
The vehicle body Y and the door Z are assembled by a vehicle body assembly process 58 and a door assembly process 59 provided along the line 57.

After the assembly of the vehicle body Y and the door Z is completed, the door Z is assembled to the vehicle body Y in an assembly step 60.

When using the above-described painting method, normally, in the correction step 54 and the different color painting step 55, the car body
Masking is performed to expose the corrected areas or areas painted in a different color and cover the other areas with a sheet material or the like.

However, when the correction step 54 is performed in the painting method, the car body X1 is in a state where the door Z is attached to the car body Y, so for example, there may be a paint defect on a part of the fender of the car body Y. If there is, mask the parts of the car body Y other than the fender part, and
Masking work is required over a wide area, including masking the door Z, which is disadvantageous in that the efficiency of the manufacturing line flow is reduced.

Also, when the different color painting step 55 is performed, the car body X2 is in a state where the door Z is attached to the car body Y, so for example, the top coat is applied to the sash part of the door Z. When applying a different color of paint, masking work is required over a wide range of areas, such as masking parts other than the door Z sash part and also masking the vehicle body Y, which reduces the efficiency of the production line flow. There is an inconvenience that the value decreases.

(Problems to be Solved by the Invention) In order to solve such inconveniences, the present invention eliminates the work of masking the automobile body when partially correcting the top coat and partially applying a paint of a different color from the top coat. It is an object of the present invention to provide a method for painting an automobile body, which can reduce the amount of work and improve work efficiency, and can make the flow of a production line more efficient.

(Means for Solving the Problems) In order to achieve such an object, a first aspect of the present invention includes:
The door is separated from the painted car body with the door and other covers attached, and the car body and the door are assembled separately, and then the door is assembled to the car body in the car manufacturing line. A top coating step in which a top coat is applied and baked on a car body with a lid such as a door attached, which is transported by a transport line; and a door removal step in which at least the door is removed from the car body after the top coat process. Then, the door removed from the vehicle body in the door removal process is transported by a door transport line separate from the vehicle body transport line, and a part of the door is coated with a paint of a different color from the top coat. transporting the vehicle body from which the door has been removed through the door removal step, through the vehicle body transport line; The present invention is characterized by comprising a vehicle body assembly step of assembling the vehicle body.

Furthermore, in the first aspect of the present invention, the door color 2
When performing the mounting process, the door is held in an inverted position with the door sash facing downward by a door holding means, and only the sash of the door in the inverted state is dipped in a paint of a different color from the top coat. It is characterized by being applied.

Further, a second aspect of the present invention is to separate a door from a painted automobile body with a lid such as a door attached,
After assembling the vehicle body and the door separately, in an automobile manufacturing line where the door is assembled to the vehicle body, the automobile body with lids such as doors, etc., being attached is transported by a first vehicle body conveyance line. A top coating process in which a top coat is applied and baked; an inspection process in which it is inspected to see if correction is necessary for the painting of the automobile body in the top coating process; and after the inspection process, a door is removed from the car body The door removed from the car body in the removal process and the door removal process is transferred to a first car body conveyance line separate from the first car body conveyance line.
A separate door color painting process in which a part of the door is transported by a door transport line and coated with a paint of a different color from the top coat paint and baked, and after the door separate color painting process, the painting is corrected by the inspection process. A door painting correction step in which the door that requires the above is transported by a second door transport line that is different from the first door transport line, the correction portion of the door is corrected, and then returned to the first door transport line; a door assembly step of assembling a door that does not require correction and is transported by the first door transport line and a door that has been corrected by the door painting correction step;
Of the vehicle bodies from which the door has been removed in the door removal step, the vehicle body whose painting requires correction in the inspection step is transported by a second vehicle body transport line that is separate from the first vehicle body transport line. A car body painting correction step in which the corrected parts of the car body body are corrected and, after step 1, the car body paint correction step is returned to the inspection step, and a car body body that does not require correction and is transported by a first conveyance line, and a car body that has been corrected in the car body paint correction step. and a vehicle body assembly process for assembling the main body.

Furthermore, in the second aspect of the present invention, when performing the door-separate color painting step, the door is held in an inverted position with the door sash facing downward by the door holding means, and the door sash is held in an inverted position. It is characterized in that only the above-mentioned portion is coated by dipping it in a paint of a different color from the top coat paint.

(Function) First of the present invention! According to Mr. tE, first, a top coat is applied to the automobile body with the door attached in the top coat process.

Next, at least the door is removed from the vehicle body in the door removal step.

The door removed from the vehicle body is transported by the door transport line, and the vehicle body from which the door is removed is transported by the vehicle body transport line.

The door transported by the door transport line is coated with a paint of a different color from the top coat paint on a part of the door in the door-separate color painting step and baked. In the step of painting the door in a different color, when masking the door, the different color painted part of the door is exposed and the other parts are masked. In this way, in the door-specific color painting process, the painting work is carried out on the doors separately from the car body, and even if masking is required, it only needs to be done on the doors, so the scope of masking is greater than in the past. becomes small.

Thereafter, the door is assembled by the door assembly process.

On the other hand, the vehicle bodies transported by the vehicle body transport line are assembled in the vehicle body assembly process.

After the vehicle body and the door are assembled separately in this manner, the door is assembled to the vehicle body.

Furthermore, in the first aspect, when painting the sash portion of the door in a different color, the door is held in the door holding means and only the sash portion is held in an inverted position with the sash portion of the door facing downward. may be applied by dipping it in a paint of a different color from the top coat. By doing so, masking in the door-separate color painting process becomes unnecessary.

According to the second aspect of the present invention, first, the top coating process is performed on the automobile body with the door attached, as in the first aspect.

Subsequently, the automobile body is inspected in the above-mentioned inspection step to determine whether correction is necessary or not in the painting performed in the top coating step.

Next, in the door removal step, the door is removed from the automobile body that has undergone the inspection step.

The door removed from the vehicle body is transported by the first door transport line. The door transported by the first door transport line is coated with a paint of a different color from the top coat paint on a part of the door and baked in the door-separate color painting process, similarly to the first aspect. In the step of painting the door in a different color, when masking the door, the different color painted part of the door is exposed and the other parts are masked. In this way, in the door color painting process,
Separately from the car body, only the doors were painted separately.
Even if masking is to be performed, it only needs to be done on the door, so the range of masking is smaller than in the past.

Subsequently, as a result of the inspection process, doors whose coating requires correction are transported by the second door transport line separately from doors for which correction is not required.

The door transported by the second door transport line is subjected to topcoat correction work in the door paint correction process. In the door painting correction step, the correction portion of the door is exposed, and the other portions except the correction portion are masked, and then the painting is corrected. In this way, in the door paint correction process, the correction work is carried out on the door separately from the car body itself, and at that time, masking only needs to be done on the door, so the masking is much easier than in the past. The range is small.

Then, doors that do not require correction and doors that have been corrected in the door painting correction process are assembled in the door assembly process.

On the other hand, among the vehicle bodies from which the door has been removed in the door removal step, the vehicle body whose painting requires correction in the inspection step is transported to the second vehicle body separately from the vehicle body whose painting does not require correction. Conveyed by line. The vehicle body conveyed by the second vehicle body conveyance line undergoes topcoat correction work in the vehicle body paint correction process. In the car body paint correction process, the correction part of the car body body is exposed, the parts other than the correction part are masked, and then the paint is corrected. In this way, in the car body painting correction process, the correction work is carried out on the car body separately from the door, and masking at that time only needs to be done on the car body, so the masking is much easier than in the past. The range of is small. Then, the vehicle body body that has been corrected in the vehicle body paint correction process is inspected again in the inspection process to determine whether or not correction is necessary in the painting process in the top coating process.

Thereafter, both the vehicle body whose door has already been removed in the door removal step and which has been corrected in the vehicle body painting correction step and the vehicle body whose door has been removed in the door removal step and which does not require correction, The vehicle body is transported by the first vehicle body transport line. The vehicle bodies transported by the first vehicle body transport line are assembled in the vehicle body assembly process in the same manner as in the first TI.

After the vehicle body and the door are assembled separately in this manner, the door is assembled to the vehicle body.

Further, in the second aspect as well, similarly to the first aspect, the door is held by the door holding means, and only the sash portion of the door is coated with the top coat in an inverted position with the sash portion of the door facing downward. It may be applied by dipping into a paint of a different color from the paint. By doing so, masking in the step of painting the doors in different colors becomes unnecessary.

(Example) An embodiment of the present invention will be described based on the drawings.

FIG. 1 is a schematic diagram showing the steps of this embodiment, and FIG. 2 is an explanatory diagram of the door holding means of this embodiment.

In this example, a door is separated from a painted car body with an ornament such as a door attached, and the car body and door are assembled separately, and then the door is assembled to the car body. This is a coating method used on the production line.

In Fig. 1, 1 is a top-coating process in which a top coat is applied and baked on the automobile body X to which ornaments such as the door 2 are attached;
3 is a car body separate color painting in which a paint different from the top coat is applied and baked on a part of the car body Y from which the door Z has been removed in the door removal process 2. Step 4 is a vehicle body assembly step in which the vehicle main body Y is assembled after the vehicle body-specific color painting step 3; 5 is a door installation step in which the door is reattached to the vehicle body Y from which the door Z has been removed in the door removal step 2. It is. These steps 1.2, 3, and 4.5 are arranged along a vehicle body conveyance line 6 that conveys the automobile body X.

Further, 7 in FIG. 1 is a door-separate color painting step in which a paint of a different color than the top coat is applied and baked on a part of the door Z removed from the automobile body X in the door removal step 2; is a door assembly process in which the door Z is assembled after the door color painting process 7.

Each of these processes 7 and 8 is arranged along a door conveyance line 9 that conveys the door Z removed from the automobile body X in the door removal process 2.

In the painting method of this embodiment having the above configuration, the car body X is painted by the following procedure.

First, the automobile body X, which has been subjected to electrodeposition coating, intermediate coating, drying, etc., is transported by the vehicle body transport line 6, and the top coating process 1 is performed.

The top coating process 1 is performed with the door Z etc. assembled on the car body X in order to prevent color differences between ornaments such as the door Z and the car body Y when the top coat paint is applied. .

Next, the door Z is removed from the vehicle body X in the door removal step 2. Vehicle body Y from which door Z has been removed
is transported by the vehicle body transport line 6. The vehicle main body Y transported by the vehicle body transport line 6 is subjected to the vehicle body specific color painting step 3, in which a paint of a different color from the top coat is applied to the bulk hend portion, side sill portion, etc. of the vehicle body main body Y and baked.

Note that the vehicle body color painting process 3 may be performed in the top coating process 1. That is, after applying the top coat paint, a different color paint may be applied, and both paints may be dried at the same time.
In the car body color painting process 3, painting can be performed without masking by performing the painting work using a device that uses a painting nozzle or the like that can limit the painting area.

Thereafter, the vehicle body Y is transported through the vehicle body transport line 6, and the interior of the vehicle body Y is assembled in the vehicle body assembly process 4.

On the other hand, the vehicle body X is removed by the door removal process 2.
The door Z removed from the door Z is conveyed by a door conveyance line 9 separate from the vehicle body conveyance line 6 in synchronization with the conveyance speed of the vehicle body Y conveyed by the vehicle body conveyance line 6.

The door Z is coated with a paint of a different color from the top coat paint on the sash portion of the door Z by the door color painting process 7 provided along the door conveyance line 9 and baked. In the door different color painting process 7, as shown in FIG. 2, the door Z is painted in a different color and painted by a door holding means 10 that holds the door in an inverted position with the sash part ZI of the door Z facing downward. Burning is performed. The door holding means 1O is movable up and down by a lifting device (not shown), and includes a door holding part 11 that holds the door Z at its lower end, and an overhead conveyor that moves the door holding part 11 in the transport direction of the door transport line 9. It consists of 12.

As shown in FIG. 2, in the door color painting step 7,
The door Z is first moved by the door holding part 1 of the door holding means 10.
1 descends and is immersed in a different color paint 14 in a paint liquid tank 13. At this time, by dipping only the sash part Z+ of the door Z, the different color paint 14 is applied only to the sash part Zl. Next, the door holding part 11 is raised, and the door Z is
Door conveyor line 9 by overhead conveyor 12
conveyed in the downstream direction. Thereafter, the door Z is carried into the oven 15 and baked, and the door-specific color painting step 7 is completed.

In this way, since only the door Z is dipped in the different color paint 14 in the inverted position with the door Z facing downward, masking in the door different color painting step 7 is not necessary. .

Furthermore, in the door-specific color painting step 7, the door Z may be masked. In this case, the sash part Z1, which is the part painted in a different color of the door Z, is exposed, and the other part Z2 is masked.

At this time, the door Z is painted separately from the vehicle main body Y in the door removal process 2, and even if masking is to be performed, it is only necessary to apply it to the door Z. Thereby, there is no need to mask the vehicle body Y, so the range of masking can be made smaller than in the past. In this way, after masking, a paint of a different color from the top coat is applied, and the paint is baked to complete the door separate color painting step 3.

Thereafter, the door Z is assembled by the door assembly process 8, in which a door opening/closing handle, window glass, etc. are attached.

In this way, the vehicle body Y and the door Z are transported by the vehicle body transport line 6, the door transport line 9, and the guard respectively, and assembled separately. Then, the door installation is step 5.
As a result, the door Z transported to the door transport line 9 is attached to the vehicle body Y transported by the vehicle body transport line 6.

Next, other embodiments of the present invention will be described.

FIG. 3 is a schematic diagram showing the steps of another embodiment.

In FIG. 3, the steps similar to those in the embodiment described above are given the same reference numerals as in FIG. 1, and their explanation will be omitted.

As shown in FIG. 3, between the top coating process 1 and the door removal process 2, there is an inspection process 1 for inspecting whether correction is necessary or not in the painting of the automobile body X in the top coating process 1.
6 is provided.

The automobile body X is transported by a first vehicle body transport line 17, and after the top coating step 1 is completed, the inspection step 16 is performed. Subsequently, the vehicle body X is subjected to the door removal step 2, and the vehicle body Y is conveyed to the first vehicle body conveyance line 17 and the door Z is conveyed by the first door conveyance line 18.

Then, among the vehicle bodies Y from which the door Z has been removed in the door removal step 2, the vehicle body Y whose painting does not require correction in the inspection step 16 is transferred to the vehicle body-specific color by the first vehicle body conveyance line 17. It is transported to painting process 3. Further, the vehicle body Y whose painting required correction in the inspection process 16 is transferred to a second vehicle body transport line separate from the first vehicle body conveyance line 17.
It is transported by the vehicle body transport line 19. The vehicle body Y transported by the second vehicle body transport line 19 is transferred to a vehicle body painting correction process 2 provided along the second vehicle body transport line 19.
The correction location is corrected by 0.

In the vehicle body paint correction step 20, the correction portion of the vehicle body Y is exposed and other portions are masked. At this time, in the door removal process 2, the car body Y of the car body X is painted independently, separately from the door Z, and masking only needs to be done on the car body Y at that time. Thereby, there is no need to mask the door Z, so the range of masking can be made smaller than in the past. In this way, after masking, the paint is repainted and dried, and the vehicle body paint correction process 20 is completed.

After being corrected in the vehicle body painting correction step 20, the vehicle body Y is transferred to the inspection step 1 by the second vehicle body conveyance line 19.
It will be returned to 6.

After the vehicle body paint correction step 20 is completed, the vehicle body Y returned to the inspection step I6 is again inspected for paint.

In this way, the vehicle body Y that does not require correction is
It is transported by the vehicle body transport line 17. Subsequently, the vehicle body main body Y is subjected to a vehicle body-specific color painting process 3 while being transported by the first vehicle body transport line 17, and then a vehicle body assembly process 4 is performed. Note that the car body color painting process 3 is the same as the top coating process 1! What may be done here is as described above.

On the other hand, after the door color painting process 2, the door Z transported by the first door transport line 18 is subjected to a door color painting process 7.

In the door-separate color painting step 7, the second
The illustrated door holding means 1O holds the door in an inverted position with the sash part Z of the door Z facing downward, and painting and baking in a different color is performed.

In this way, since only the sash part Z1 of the door Z is dipped in the different color paint 14 in the inverted position with the sash part Z facing downward, masking in the door different color painting step 7 is not necessary.

Furthermore, in the door-specific color painting step 7, the door Z may be masked in the same manner as in the embodiment described above. As a result, the door Z is painted separately from the vehicle body Y in the door removal process 2, and even if masking is to be performed, it only needs to be applied to the door Z, so that There is no need to mask Y, and the range of masking can be made smaller than in the past.

Thereafter, among the doors Z for which the door-specific color painting process 7 has been completed, the doors Z for which correction in the painting is not required in the inspection process 16 are transported to the door assembly process 8 by the first door transport line I8. . Further, the door Z whose coating requires correction in the inspection step J6 is transported by a second door transport line 21 that is separate from the first door transport line 18. The door Z transported by the second door transport line 21 has its corrected portion corrected by a door painting correction process 22 provided along the second door transport line 21 .

In the door painting correction step 22, the corrected portion of the door Z is exposed and other portions are masked.

At this time, the door Z is painted separately from the vehicle main body Y in the door removal process 2, and only the door Z needs to be masked at that time. Thereby, there is no need to mask the vehicle body Y, so the range of masking can be made smaller than in the past. In this way, after masking, the paint is repainted and dried to complete the door paint correction step 22.

After being corrected by the door painting correction process 22, the door Z
is returned to the first door conveyance line 18 by the second door conveyance line 21.

Then, the doors Z returned to the first door transport line 18 after the completion of the door painting correction step 22 are transported by the first door transport line 18 together with the doors Z that do not require correction. Subsequently, the door Z is subjected to a door assembly process 8.

Then, the door Z for which the door assembly process 8 has been completed is
The door installation is transported towards step 5 by the door transport line 18.

A door stop portion 23 for temporarily stopping the door Z is provided between the door assembly step 8 and the door installation step 5. The door stop portion 23 is used to match the door Z that was attached to the automobile body X in the top coating step 1 to the vehicle body Y at that time, and send the door attachment to step 5. That is, for example, the vehicle body Y that is transported and corrected by the second vehicle body transport line 19 is placed in a different transport order from the transport order in the top coating process 1 when it returns to the first vehicle body transport line 17 again. Become. On the other hand, since the door Z corresponding to the vehicle body Y is transported by the first door transport line and each process is advanced, the transport order of the door 2 and
The transport order of the vehicle body Y corresponding to the door Z may be different. Therefore, by temporarily stopping the door Z by the door stop portion 23, the transport order of the door Z is matched with the transport order of the vehicle body Y corresponding to the door Z.

In this way, the door Z joins the first vehicle body transport line 17 via the first door transport line 18, and the door is attached to the vehicle main body Y transported by the first vehicle body transport line 17 in step 5. Said first door conveyance line 1
The door Z transported by 8 is attached.

As described above, in this embodiment, the vehicle body Y and the door Z are transported separately by the first vehicle body transport line 17 and the first door transport line 18, and painted in different colors and assembled. In addition, even if there is a correction point in the painting, the vehicle body Y and the door Z are corrected separately. Thereby, only the vehicle body Y is corrected in the vehicle body paint correction step 20, and only the door Z is corrected in the door paint correction step 22, so that the masking work performed at the time of correction can be reduced.

(Effects of the Invention) As is clear from the above, according to the first aspect of the present invention, at least the door is removed from the vehicle body in the door removal step following the top coating step, and then, The door-specific color painting process is performed. This results in
In the door-separate color painting process, masking of the vehicle body is not required, so the masking range can be made smaller than in the past, and work efficiency can be improved.

Furthermore, in the door-specific color painting step of the first aspect,
When painting the sash part of the door in a different color, the door is held in an inverted position with the sash part facing downward by the door holding means, and only the sash part is dipped in a paint of a different color from the top coat. Masking the door is no longer necessary. Thereby, the work efficiency in the door-specific color painting process can be further improved.

According to the second aspect of the present invention, at least the door is removed from the vehicle body in the door removal step after the inspection step is performed following the top coating step.

Thereafter, the vehicle body whose correction is not required in the inspection process is transported by the vehicle body transport line, and the door is subjected to the door-specific color painting process by the door transport line. On the other hand, the vehicle body paint correction process and the door paint correction process are performed separately for the vehicle body and the doors that require correction in the inspection process. This eliminates the need for masking the door in the car body painting correction process, and
In the door painting correction step, since masking of the vehicle body is not required, the range of masking can be made smaller than in the past, and work efficiency can be improved.

Furthermore, in the door-specific color painting step of the second aspect,
When painting the sash portion of the door in a different color, the door is held in an inverted position with the sash portion facing downward by the door holding means, and only the sash portion is dipped in a paint of a different color from the top coat. Masking the door is no longer necessary. Thereby, the work efficiency in the door-specific color painting process can be further improved.

Therefore, according to the present invention, work efficiency can be improved by reducing the work of masking the automobile body when partially correcting the top coat and partially applying paint of a different color from the top coat. At the same time, it is possible to provide a method of painting an automobile body that can improve the efficiency of the flow of a production line.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing the process of this embodiment, Fig. 2 is an explanatory diagram of the door holding means of this embodiment, Fig. 3 is a schematic diagram showing the process of another embodiment, and Fig. 4 is a diagram of the conventional door holding means. It is a schematic diagram showing the steps of the painting method. X...Car body Y...Car body Z...Door ZI...Sash section 1...Top coating process 2...Door removal process 4...Vehicle body assembly process 6...Car body transport Line 7... Door color painting process 8... Door assembly process 9... Door transport line 10... Door holding means 16... Inspection process 17... First vehicle body transport line 18... First door conveyance line 19...Second vehicle body conveyance line 20...Vehicle painting correction process 21...Second door conveyance line 22...Door painting correction process

Claims (1)

[Claims] 1. Separate the door from the painted automobile body with the door and other covers attached, and after assembling the vehicle body and door separately, attach the door to the vehicle body. In the automobile manufacturing line for assembly, a top coating process is performed in which a top coat is applied and baked on the car body with lids such as doors that are transported by the car body transport line, and after the top coating process, the car body is The door removed from the vehicle body in the door removal step is transported by a door transport line separate from the vehicle body transport line, and a part of the door is coated with the top coat paint. A door separate color painting process in which a different color paint is applied and baked, a door assembly process in which the door is assembled after the door separate color painting process, and the vehicle body from which the door has been removed in the door removal process, A method for painting in an automobile manufacturing line, comprising a vehicle body assembly step of transporting the vehicle body by the vehicle body transport line and assembling the vehicle body. 2. When carrying out the step of painting the door in a different color, the door is held in an inverted position with the sash section facing downward by a door holding means, and only the sash section of the door in the inverted state is painted in a different color from the top coat. 2. The method of painting on an automobile manufacturing line according to claim 1, wherein the coating is applied by dipping the paint into the paint. 3. In an automobile manufacturing line where the door is separated from the painted automobile body with the lid such as door attached, and the vehicle body and door are assembled separately, and then the door is assembled to the automobile body. , Is it necessary to correct the top coating process in which a top coat is applied and baked on the car body with lids such as doors attached, which are transported by the first car body transfer line, and the painting of the car body in the top coat process? The first vehicle body transport line includes an inspection step of inspecting whether the door is unnecessary, a door removal step of removing at least the door from the vehicle body after the inspection step, and a door removed from the vehicle body in the door removal step. A separate door color painting step in which the door is transported by another first door transport line and a paint of a different color than the top coat paint is applied and baked on a part of the door, and after the door separate color painting step, the inspection step is performed. A door whose painting requires correction is transported by a second door transport line different from the first door transport line, and the correction portion of the door is corrected,
Thereafter, a door painting correction step of returning the door to the first door transport line, a door assembly step of assembling the door that does not require correction and is transported by the first door transport line, and the door that has been corrected in the door painting correction step, and the door Of the car bodies from which the door has been removed in the removal process, the car bodies whose painting required correction in the inspection process are transported by a second car body transport line that is separate from the first car body transport line. A vehicle body painting correction step in which corrected parts of the main body are corrected and then returned to the inspection step, and a vehicle body conveyed by a first conveyance line that does not require correction, and a vehicle body corrected in the vehicle body painting correction step are assembled. 1. A painting method in an automobile manufacturing line, characterized by comprising an assembly process. 4. When performing the door different color painting step, hold the door in an inverted position with the door sash facing downward using a door holding means, and paint only the sash part of the inverted door in a different color from the top coat. 4. The method for coating in an automobile manufacturing line according to claim 3, wherein the coating is applied by dipping the coating material into a paint.