GB2227188A

GB2227188A - Painting exterior vehicle body panels

Info

Publication number: GB2227188A
Application number: GB9001277A
Authority: GB
Inventors: Hiroshi Segawa; Koji Chiba; Uchida Kensuke; Toshifumi Inoue
Original assignee: Nissan Motor Co Ltd
Current assignee: Nissan Motor Co Ltd
Priority date: 1989-01-20
Filing date: 1990-01-19
Publication date: 1990-07-25
Anticipated expiration: 2010-01-19
Also published as: JPH02193784A; GB2227188B; GB9001277D0

Abstract

Exterior panels W are provided separately from a vehicle body main assembly (constituted by chassis members and interior panels). The panels W are provided with a finish coat while being held in such a manner that their exterior surfaces 28 are substantially horizontal and directed upwards. The panels W are then dried while being held in such a manner that their exterior surfaces 28 are substantially horizontal and directed downwards. After the finish coating and drying, the exterior panels are secured to the main assembly to constitute the vehicle body. <IMAGE>

Description

PAINTING EXTERIOR VEHICLE-BODY PANELS The present invention relates in general to a method of producing a vehicle and particularly to painting of a vehicle body. More particularly. the present invention relates to painting of exterior panels of a vehicle body.

Figs. 14A and 14B show a prior art method of painting exterior panels of a vehicle body. In the figures, a vehicle body 1 is assembled to include exterior panels as an engine hood 2, front fender panel 3, front door outer panel 4, rear door outer panel 5, rear fender panel 6, trunk lid 7, roof panel, etc. The vehicle body equipped with such exterior panels is installed on a truck 8 and, as showin Fig.

15, provided with undercoat 12 and intermediate coat 13 on the exterior surfaces of each exterior panels 11 made of metal. The exterior panels are then provided with finish coat 14 by means of spray guns 9 with downwardly directed nozzles and spray guns 10 with sideways or horizontally directed nozzles. Thereafter, the exterior panels are dried in an oven including an infrared ray drier.

By the prior art method, the exterior panels are provided with finish coat and dried after installation on the vehicle body main assembly constituted by chassis members and interior panels. For this reason, in case of some exterior panels which are disposed nearly vertically as the front door outer panel 4 and rear door outer panel 5, the paint thereof may flow downward by the effect of gravity to cause defective coating as runs, orange peel, etc.

In order to solve this problem, it has been proposed by Japanese Patent Provisional Publication No. 63-107782 assigned to the same assignee as this application, to provide the exterior panels independently or separately from the vehicle body main assembly, apply intermediate coat and finish coat to the exterior panels while holding the exterior panels in such a manner that the exterior surfaces thereof are substantially horitontal, apply intermediate coat and finish coat to the vehicle body main assembly independetly from the paint coating of the exterior panels, and install the exterior panel. having been applied with the intermediate coat and finish coat to the vehicle body main assembly to constitute a vehicle body.

However, since the exterior panels are held in such a manner that the exterior urfaces thereof are substantially hoziontal, it is easy for floating dust to fall on the finish coat and stick or adhere to same, thus deteriorating the surface quality of the paint coated exterior panels.

In accordance with the present invention, there is provided a method of producing a vehicle body comprising the steps oft providing a vehicle body main assembly constituted by chassis members end interior panels of a vehicle body; providing exterior panels of the vehicle body separately from said vehicle body main assembly; applying finish coat to the exterior surfaces of said exterior panels while holding said exterior panels in such a manner that exterior surfaces thereof are substantially horizontal and directed upwards; drying said exterior panels while holding said exterior panels in such a manner that the exterior surfaces thereof are substantially horizontal and directed downwards; and connecting said exterior panels to said vehicle body main assembly to constitute the vehicle body.

The above method is effective for overcoming the above noted shortcoming inherent in the prior method of painting the exterior panels of the vehicle body.

It is accordingly an object of the present invention to provide a method of producing a vehicle which can improve the surface quality of paint coated exterior panels of a vehicle body.

It is another object of the present invention to provide a method of producing a vehicle, of the above described character,which can assuredly prevent floating dust from deteriorating the surface quality of the paint coated exterior panels.

It is a further object of the present invention to provided a method of producing a vehicle, of the above described character which can assuredly prevent the paint on the exterior panels from causing, due to gravity, a defective surface as runs, orange peel, etc.

It is a further object of the present invention to provide a method of producing a vehicle, of the above described character which can reduce the number of painting processes of the vehicle body for thereby reducing the manufacturing expense.

It is a further object of the present invention to provide a method of producing a vehicle, of the above described character which makes it possible to install operating parts and interior parts, as an engine and seats on the vehicle body with ease and efficiency for thereby reducing the assembly expense.

THE DRAWINGS Fig. 1 is a schematic perspective view of exterior panels of a vehicle body arranged with respect to the advancing direction of a conveyor according to an embodiment of the present invention; Fig. 2 is an exploded view, in a reduced scale, of a vehicle body main assembly on which the exterior panels of Fig. 1 are to be installed; Figs. 3A and 3B are elevational, partly sectioned views of a conveyor and its double-head carrier for use in the embodiment of this invention: Figs. 4A to 4C are elevational, partly sectioned views of the above described conveyor and its siglehead carrier for use in the embodimet of this invention:: Fig. 5 is an enlarged perspective view of a holding mechanism for holding a work (exterior panel), for use in the embodiment of this invention; Fig. 6 is a fragmentary sectional view of the holding mechanism of Fig. 5 and in a state of holding the work Fig. 7 is a block diagram of painting processes of exterior panels according to the embodiment of this invention; Fig. 8 is a block diagram of painting processes of a vehicle body main assembly according to the embodiment of the present invention; Fig. 9A is a schematic elevational view of o finish coating process according to the embodiment of this invention; Fig, 9B is a schematic side view of the finish coating process of Fig. 9A;; Fig. 10 is a sectional view taken along the line a - a of Fig. 2 Fig. 11 is is a sectional view taken along the line b - b of Fig. 2: Fig. 12 is a sectional view taken along the line c - c of Fig. 2 Fig. 13 is a sectional view taken along the line d - d of Fig. 2; Figs. 14A and 14B are schematic views of a prior art painting process of a vehicle body; and Fig. 1S is an enlarged, schematic sectional view of a paint coated exterior panel of a vehicle body according to the prior art painting process of Pigs.

14A and 14B.

Referring first to Figs. 1 and 2, a vehicle body 1 consists of a main assembly 15, constituted by chassis members and interior panels, and exterior panels provided indepedently or separately from the main assembly 15. The exterior panels are an engine hood 2, front fender panel 3, front door outer panel 4, rear door outer panel 5, roof panel 24, rear fender panel 6,and trunk lid 7. The interior panels are a rear pillar inner panel 30 shown in Fig. 12, a wheel house outer panel 35 shown in Fig. 13, etc.

In the painting line, the exterior panels are carried by a conveyor 16 shown in Flg; 1, 3A-3B,and 4A-4C. The conveyor 16 is provided with a plurality of double-head carriers 19 shown in Figs. 3A-3B and a plurality of single-head carriers 21 shown in Figs.

4A-4C.

Each double-head carrier 19 has support arms 17 and 17 projecting in the opposite directions. Each support arm 17 has at a free end a small-sized finger unit 18 which is rotatable 1800 about a horizontal axis. On the other hand, each single-head carrier 21 has a large-sized finger unit 20 which is rotatable 1800 about a horizontal axis.

Each of the small-sized finger unit 18 and large-sized finger unit 20, as shown in Figs. 5 and 6, has a holding mechanism constituted by a rotatable shaft 22 including a concentric clamp base portion 25, a location pin portion 23 concentric with the clamp base portion 25 for insertion into an elongated hole 27 formed in an exterior member or work W, and a clamp tip portion 26 eccentric with the clamp base portion 25.

Each of the exterior members or works W is formed with the elongated hole 27. The location pin portion 23 and clamp tip portion 26 are movably received in the elongated hole 27, and then the shaft 22 is rotated so that the portion of the work W around the hole 27 is placed between the clamp bese portion 25 and the clamp tip portion 26. By this, the work W is fixed to the carrier 18 or 20. Each of the carriers 18 and 20 is provided with two holding mechanisms described above, and each exterior panel or work W is formed with two elongated holes 27 described above so that each work W is fixed to the corresponding carrier 18 or 20 in two places.

As shown in Fig. 1, the exterior panels are arranged on the conveyor 16 in the order of installation on the main assembly 15, i.e., the earlier the exterior panels are to be installed on the main assembly 15, the more forward places (indicated by 16a in Fig. 1 is the forward part of the conveyor 16 and by 16b is the rearward part) they are installed on the conveyor 16 to take with respect to the advancing direction of the conveyor 16.

The exterior panels arranged in the above order on the conveyor 16 are, as shown in Fig. 7, pretreated (a) and oven-dried (b). Then, they are provided with electrodeposition coat (c) and oven-dried (d).

Further, the exterior panels are provided with intermediate coat (e) and oven-dried (f). Thereafter, they are provided with finish coat (g).

in the above painting processes, the work W is held in such a manner that its exterior surface 28 is substantially horizontal and directed upwards while its interior surface 29 is directed downwards. The work W held in the above manner is provided with intermediate coat and finish coat by means of spray guns 9 with downwardly directed nozzles. By this, it becomes possible to assuredly prevent the paint on the exterior surface 28 of the work W from causing, due to gravity, a defective surface as runs, orange peel, etc.

After finish coating (g), the work W is treated by oven-drying (h). In this connection, prior to oven-drying (h) of the work W, each finger units 18 and 21 are rotated 180 about the horizontal axes into the positions shown in Figs. 3B and 4C (Fig. 4B shows the crier 20 in a halfly rotated position). By this, the work W is rotated into the position of having the interior surface 29 on the upper side and the exterior surface 28 on the lower side. Thus, even when floating dust falls on the work W, the finish coat 28 on the exterior surface 28 of the work W is assuredly prevented from being adhered or stuck by the floating dust1 thus making it possible to attain the finish coat of a high surface quality. The exterior panels described above are made of steel.In case of the exterior panels made of a synthetic resinous material, the exterior panels may dispense with undercoat and intermediate coat and be provided with finish coat directly on the exterior surface.

In the painting process of the main assembly 15 constituted by the chassis members and the interior panels, the main assembly 15 is, as shown in Fig. 8, pretreated (a), oven-dried tub), provided with electrodiposition coat (C)1 oven-dried (d), provided with intermediate coat (e), and oven-dried (f). In this connection, it will be understood by comparison with the painting process of the exterior panels that the main assembly 15 is not provided with finish coat, since it is concealed from view when the assembly of the vehicle is completed.

The vehicle body main assembly 15, as shown in Fig. 10, is provided with a trunk side member 31 which is secured to the upper part of a rear pillar inner panel 30 and further with, as shown in Fig. 11, a rear panel upper 32 secured to the rear end portion of the rear pillar inner panel 30.

The vehicle body main assembly 15, as shown in Fig. 12, is further provided with a rear outer panel 34 secured to the above described rear pillar inner panel 30 to constitute a box-like closed section. The rear pillar outer panel 34, as shown in Fig. 13, is connected to the above described wheel house outer panel 36 which is in turn connected to a wheel house inner panel 35.

The above described rear fender panel 6 is bonded at the upper end portion to the above described trunk side member 31 and at the rear end portion to the above described rear panel upper 32 while at the same time being secured to the abovo described rear pillar outer panel 34 with bolts 37 and nuts 38.

Further, the exterior panels other than the rear fender panel 6 are fixed to the vehicle body main assembly 15 with suitable securing means. Further, as shown in Fig. 2, a front window 43, rear window 44, sill cover 45, etc. are installed on the vehicle body main assembly 15 to complete the assembly of the vehicle body 1.

In the foregoing, it is to be noted that since the vehicle body main assembly 15, particularly the exterior panels thereof, are provided separately from the exterior panels, it becomes easy to dispense with finish coating of the interior panels, thus making it possible to reduce the manufacturing expense.

It is further to be noted that the operating parts and interior parts, as for example an engine 40 for disposition in an engine compartment 39 and seats 46 for disposition in a passenger compartment 41, are installed on the vehicle body main assembly 15 after the completion of painting of the vehicle body main assembly 15 and prior to installation of the exterior panels on the vehicle body main assembly 15. By this, the operating parts and interior parts can be installed in the engine compartment 39 and the passenger compartment 41 of the vehicle body main assembly 15 without being obstructed by the exterior panels, thus making it possible to install the operating parts and interior parts with ease and efficiency for thereby reducing the assembly expense.

Claims

Claims:

1. A method of painting exterior panels for a vehicle body, comprising: providing the exterior panels separately from the vehicle body; applying a finish coat to the exterior panels while holding them in such a manner that their exterior surfaces are substantially horizontal and directed upwards; and drying the exterior panels while holding them in such a manner that their exterior surfaces are substantially horizontal and directed downwards.

2. A method of producing a vehicle body, comprising: providing a vehicle body main assembly constituted by chassis members and interior panels; providing exterior panels separately from the main assembly; applying a finish coat to the exterior surfaces of the exterior panels while holding the exterior panels in such a manner that their exterior surfaces are substantially horizontal and directed upwards; drying the exterior panels while holding the exterior panels in such a manner that their exterior surfaces are substantially horizontal and directed downwards; and installing the exterior panels on the main assembly to constitute the vehicle body.

3. A method as claimed in claim 2, wherein the main assembly is provided with an intermediate coat and is connected with the exterior panels without having been provided with a finish coat.

4. A method as claimed in claim 2 or 3, wherein operating parts of a vehicle are installed on the vehicle body prior to installation of the exterior panels on the main assembly.

5. A method as claimed in any of claims 2 to 4, wherein, in the step of applying the finish coat, the exterior panels are arranged on a conveyor in the order of installation on the main assembly.

6. A method of producing a vehicle body, substantially as described with reference to Figures 1 to 13 of the accompanying drawings.