WO2008050528A1

WO2008050528A1 - Vehicle body production line

Info

Publication number: WO2008050528A1
Application number: PCT/JP2007/066316
Authority: WO
Inventors: Koichi Odaka
Original assignee: Honda Motor Co., Ltd.
Priority date: 2006-10-26
Filing date: 2007-08-16
Publication date: 2008-05-02
Also published as: JP4546438B2; JP2008104979A

Abstract

A vehicle body production line including a protective material application stage for applying a protective material to a surface of a coat after a vehicle body has been coated. The protective material application stage (13) has a plurality of application sub lines (21, 22, 23) that branch off from the production line. A different protective material is applied to each vehicle body in the application sub- lines. The values for the total time obtained by adding the time for applying the protective material and the time required to transport the vehicle in the respective application sub -lines are set to be substantially equal.

Description

DESCRIPTION

VEHICLE BODY PRODUCTION LINE

TECHNICAL FIELD

The present invention relates to an improvement in a vehicle body production line including, after coating of a vehicle body, a protective material application stage for applying a protective material onto a coated surface of the vehicle body. BACKGROUND ART

A vehicle body production line comprising a coating stage for coating a vehicle body, and a protective material application stage for applying a protective material to the coated vehicle body is known from, for example, Japanese Patent No. 2793110. The known vehicle body production line will be described below with reference to FIG. 4 hereof.

A vehicle body production bine 100, as shown in FIG. 4, comprises a coating step 101 for coating a vehicle body, a protective material application step 103 for applying a coat-protecting material (also referred to as "protective material") to the coated vehicle body, and an assembly step 102 for mounting vehicle components to the vehicle body that has been coated with the protective material.

In certain circumstances, different types of protective material may be applied in the coat-protecting-material application step 103 provided to the vehicle body production bine 100. For example, a protective material may be applied to prevent the coated surface of the vehicle body from being marred or soiled, so as to provisionally form a protective film. Alternatively, fluorine coating is carried out in order to endow the film with superhydrophobic performance. In such cases, the operating time required to apply the film to the vehicle body varies according to the type of protective material used. Since the operating time fluctuates when many types of vehicle bodies are passing through the production process at the same time, the type of protective material may disturb flow cycle time on the production line.

Furthermore, when a plurality of types of protective materials is to be applied, certain types of coating materials may cause unproductive downtime, leading to the drawbacks that the flow of the entire main line 105 is adversely affected, and productivity is compromised.

A demand has accordingly existed for a vehicle body production line allowing a plurality of types of protective materials to be applied without compromising the productivity of the main bine.

DISCLOSURE OF THE INVENTION According to the present invention, there is provided a vehicle body production line comprising: a welding stage for producing a vehicle body by welding; a coating stage for coating the vehicle body; a protective material application stage for applying a protective material onto a coat after drying to form a protective film thereon; and an equipping stage for mounting vehicle components on the vehicle body on which the protective film has been formed, wherein the protective material application stage comprises a plurality of application sub-lines, which branch away from the production bine, for applying a predetermined protective material to the vehicle body; and is configured so that values for total time are substantially the same, the total time being obtained by adding operating time required to apply the protective material to the vehicle body to transport time during which the vehicle body moves between the production line and the application sub -lines.

According to the production line of the present invention, the values of the total time obtained by adding the protective material application time of the application sub-lines and the time required to transport the vehicle body transport are thus set so as to be substantially equal in the protective material application stage. Therefore, as long as the total time is harmonized with the cycle time of the main line, a different type of protective material can be applied to each vehicle body without compromising the productivity of the main line.

Preferably, the plurality of application sub lines comprise a first application sub-line having a long operating time required for a protective material to be applied, and a second application sub line having a shorter operating time required for a protective material to be applied than that of the first application sub-line. The first application sub-line is disposed in a main bine that is routed through the coating stage and the equipping stage. The second application sub-bine goes around the first application sub bine so that substantially equivalent values are obtained for the total time that is obtained by adding the operating time required to apply the protective material and the transport time during which the vehicle body moves between the main bine and the second application sub-line, and the total time that is obtained by adding the operating time required to apply the protective material in the first application sub-line and the transport time during which the vehicle body moves between the main bine and the first sub-line. Therefore, as long as the application sub-lines are diverted from and go around the main line so - A - that the values of the total time are substantially equal, the number of application sub-lines can be increased, and a greater variety of protective materials can be handled.

In the application sub-lines, production line managing means preferably manages the progress of the application sub-lines and the time of arrival at a terminal positioned downstream from the coating stage in the application sub -lines, so that the vehicle body is sent to the equipping stage according to the sequence in which the vehicle bodies are sent from the coating stage. Therefore, as long as the transport time of the vehicle bodies in the application sub-lines is controlled by controlling the speed of the conveyors, production can be carried out according to a schedule without any variation in the sequence of the vehicles transported from the equipping stage.

One of the application sub -lines preferably includes a step for applying a fluorine coating as one type of protective material. Including a fluorine coating step in the application sub-lines thus makes it possible to carry out a superhydrophobic treatment in the vehicle body production line, to perform treatments using other protective materials, and otherwise to increase the variety of protective materials that can be applied in the application sub-lines.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram illustrating a vehicle body production line according to the present invention;

FIG. 2 is a diagrammatical view showing the time structure of application sub-lines constituting the protective material application stage shown in FIG. l; FIG. 3 is a diagrammatical view in which the total time values obtained by adding the protective material application time to the transport time in the application sub-lines have been made equal; and

FIG. 4 is a block diagram showing a conventional vehicle body production line.

BEST MODE FOR CARRYING OUT THE INVENTION Referring now to FIG. 1, a vehicle body production line 10 comprises a welding stage 11 for producing a vehicle body by welding; a coating stage 12 connected with the welding stage 11 and performed for coating the vehicle body; a protective material application stage (coat-protecting-material application stage) 13 connected with the coating stage 12 and performed for applying a protective material to the coat after drying, so as to form a protective film; a terminal 14 connected with the protective material application stage 13 and for performing sequential assembly, according to production information from a production management computer (production line management unit) 25, of the vehicle body on which the protective film has been formed; an equipping stage 15 connected with the terminal 14 and disposed for mounting vehicle components on the vehicle body on which the protective film has been formed; and a final inspection stage 16 connected with the equipping stage 15 and disposed for inspecting the completed vehicle.

The protective material application stage 13 has a plurality of application sub lines diverted from a main line 24 of the production line by a branching part 31. A predetermined protective material is applied to the vehicle body in the application sub-lines. Specifically, the protective material application stage 13 comprises first through third application sub lines 21 to 23 provided in parallel, and a different type of coat-protecting material is applied to the vehicle body in each application sub-line.

The first application sub-line 21, which has the longest protective material application time (also referred to as "operating time"), is disposed in direct connection with the main line 24. The second application sub-line 22, which has a shorter protective material application time than that of the first application subline 21, is disposed so as to go around the first application sub-line 21. The third application sub-line 23, which has the shortest protective material application time, shorter even than that of the second application sub-line 22, is disposed furthest from the main line 24 so as to go around the first and second application sub-lines 21, 22.

The coated vehicle body is transported to a predetermined application subline according to the vehicle body production information, and coated with a predetermined coat-protecting material. In other words, the desired coat- protecting material is applied in each application sub line 21 to 23.

The production management computer 25 manages the production of the main line 24.

The protective material application stage 13 comprises a branching conveyor controller 32 and return conveyor controller 33. These conveyor controllers 32, 33 collect vehicle body production information IBP outputted from the production management computer 25. The vehicle body is guided to a predetermined application sub-line by the branching conveyor controller 32, and coated with a protective material. The vehicle body coated with the protective material is returned to the main line (terminal) by the return conveyor controller 33.

Specifically, in the application sub-lines, the rate of the application sub-lines is managed by the production management computer 25 so that the vehicle body is transported to the equipping stage 15 according to the sequence of vehicle bodies transported from the coating stage. The time at which the vehicle body arrives at the terminal 14 is also managed by the production management computer.

If the speed of the conveyors is controlled, production can be carried out according to the production schedule in terms of the transport time for sending the vehicle body from the main Line to the application sub-lines and the transport time for transporting the vehicle body coated with a protective material from the application sub-lines to the terminal (main line). This can be achieved without any variation in the sequence of the vehicles transported from the equipping stage.

In the example shown in the drawings, the first application sub-line 21 has a fluorine coating step 34, the second application sub-line 22 has a high-gloss clear coat step, and the third application sub -line 23 has a primary protective material application step.

An example of the three application sub -lines 21 to 23 is shown in the drawings, but the present invention is not limited thereto. Four or more application sub-lines may be present, as shown by dotted lines.

As shown in FIG. 2, til is the transport time during which the vehicle body moves from the position of the coating stage 12 to the position of the first application sub-line 21, tl is the time for applying the protective material and includes idle time and the like, and tl2 is the transport time during which the vehicle body moves from the position of the first application sub-line 21 to the position of the terminal 14. The total time Tl is therefore (til + tl + tl2). t21 is the transport time during which the vehicle body moves from the position of the coating stage 12 to the second application sub-line 22, t2 is the protective material application time including idle time and the like, and t22 is the transport time during which the vehicle body from the position of the second application line 22 to the position of the terminal 14. The total time T2 is therefore (t21 + t2 + t22).

Similarly, t31 is the transport time during which the vehicle body moves from position of the coating stage 12 to the position of the third application sub-line 23, t3 is the protective material application time including idle time and the like, and t32 is the transport time during which the vehicle body moves from the position of the third application sub -line 23 to the position of the terminal 14. The total time T3 is therefore (t31 + t3 + 132). As shown in FIG. 3, a first protective material is applied in the first application sub-line 21, a second protective material is applied in the second application sub line 22, and a third protective material is applied in the third application sub line 23. The first protective material, second protective material, and third protective material are each different materials, and the protective material application times differ accordingly. The relation t3<t2<tl applies in the present example.

The protective material application stage 13 shown in FIG. 1 comprises 3 application sub-lines 21 to 23 disposed parallel to each other. Specifically, the protective material application stage 13 comprises the first application sub-line 21, which has the longest operating time (tl) required to apply the protective material, as shown in FIG. 3; the second application sub-line 22, wherein the operating time (t2) required to apply the protective material is shorter than the operating time (tl) of the first application sub-line 21; and the third application sub-line 23, which has a shorter operating time (t3) required to apply the protective material than the operating time (t2) of the second application subline 22.

The following description is presented with reference to FIGS. 1 and 3. The first application sub-line 21 is disposed on the main line 24, which is routed through the coating stage 12 and the equipping stage 15. The second application sub line 22 is provided apart from the main line 24, so that total time (T2), which is obtained by adding the transport time (t21 + t22), during which the vehicle body moves between the main line 24 and the second application sub-line 22, to the operating time (t2) required to apply the protective material, is substantially equal to the total time (Tl) required to apply the protective material in the first application sub-line 21.

Finally, the third application sub-line 23 is provided apart from the main line 24 so that the total time (T3), which is obtained by adding the transport time (t31 + t32), during which the vehicle body moves between the main line 24 and the third application sub-line 23, to the operating time (t3) required to apply the protective material, is substantially equal to the time (Tl) required to apply the protective material in the first application sub-line 21. Specifically, the total time values have a relationship of Tl ^T2 ^T3. The transport time is adjusted by the length of the protective material application time, and the application sub-lines 21 to 23 are disposed with respect to the main line 24 so that the total time values (Tl, T2, T3) of the application sub-lines are substantially equal.

As long as the application sub-lines are made to branch off from the main line, so that the values of the total time of the respective application sub-lines are substantially equal, four or more application sub-lines can be provided, and a greater variety of protective materials can be handled. Specifically, the application sub -lines include a step for applying a fluorine coating as one type of a protective material. Including a fluorine coating step in the application sub-lines thus makes it possible to carry out a superhydrophobic treatment in the vehicle body production line, to perform treatments using other protective materials, and otherwise to increase the variety of protective materials that can be applied in the application sub-lines.

The following is a description of the operation of the vehicle body production line comprising the protective material application stage described above.

The vehicle body production line 10 in FIG. 1 is configured so that the protective material application stage 13 is provided between the coating stage 12 and the equipping stage 15, and a protective material is applied onto the coat. It is therefore possible to achieve a dramatically higher efficiency in terms of applying the protective material than when a coat-protecting film is applied to individual vehicle bodies outside of the vehicle body production line 10. The increase in efficiency with which the protective material is applied allows the costs associated therewith to be reduced. Moreover, since the work takes place on the vehicle body production line 10, the quality with which the coat-protecting material is applied can be readily assured.

In addition, the surface of the coat will have been covered with the protective material when vehicle components are mounted in the equipping stage 15. The coat will tend not to get scratched when a part of a worker's body or a tool comes in to contact therewith. The fact that the coat is covered with the protective material makes it possible to avoid the use of a damage-preventing cover, which is temporarily attached to the vehicle when the vehicle components are to be mounted.

The performance required of the coat-protecting material varies according to the environment in which the vehicle resides, the residence time, and other factors. A plurality of types of coat-protecting materials is used in order to obtain the requisite performance. Specifically, the vehicle body is coated with a coat- protecting material selected in advance according to the environment in which the vehicle is to be stored.

Conventionally, in cases where a single coat-protecting material selected from a plurality of types of coat-protecting materials is applied in the vehicle body production line 10, the productivity is normally severely compromised when a different type of coat-protecting material is applied in the main Line 24, due to differences in the protective material application time.

In the production line of the present invention, the first application sub line 21 is directly connected to the main line 24, the second application sub-line 22 is placed somewhat apart from the main line 24, and the third application sub-line 23 is placed further apart from the main line 24 so that the values of the total time (T) obtained by adding the protective material application time to the transport time of the application sub-lines 21 to 23 are thereby made substantially equal in the protective material application stage 13. Not only may different protective material treatment steps be performed in separate application sub-lines, but the total time (T) obtained by adding the protective material application time and the transport time may be equal to that of the other sub lines. Moreover, in cases where a specific protective material takes less time to apply than in other sub-lines, the idle time may be taken up by applying another protective material.

In the protective material application stage 13, if the total time (T) obtained by adding the protective material application time and the time required to transport the vehicle body is harmonized with the cycle time of the main line 24, a plurality of types of protective materials can be applied without compromising the productivity of the main bine 24.

An example was described in the present embodiment of an application involving a four-wheeled vehicle production line, but applications involving three- wheeled production lines are also possible. The present embodiment may be used in a standard vehicle production line. INDUSTRIAL APPLICABILITY

The production line of the present invention is suitable for use in a vehicle body production line for applying a protective material used to protect a coat.

Claims

1. A vehicle body production line comprising: a welding stage for producing a vehicle body by welding; a coating stage for coating the vehicle body; a protective material application stage for applying a protective material onto a coat after drying to form a protective film thereon; and an equipping stage for mounting vehicle components on the vehicle body on which the protective film has been formed, wherein the protective material application stage comprises a plurality of application sub-lines, which branch away from the production Line, for applying a predetermined protective material to the vehicle body, and is configured such that values for total time are substantially the same, the total time being obtained by adding operating time required to apply the protective material to the vehicle body to transport time during which the vehicle body moves between the production line and the application sub-lines.

2. The production line of claim 1, wherein the plurality of application sub-lines comprise a first application sub-line having a long operating time required for a protective material to be applied, and a second application sub-line having a shorter operating time required for a protective material to be applied than that of the first application sub-line; the first application sub line is disposed in a main line that is routed through the coating stage and the equipping stage; and the second application sub -line goes around the first application sub -line so that substantially equivalent values are obtained for the total time that is obtained by adding the operating time required to apply the protective material and the transport time during which the vehicle body moves between the main line and the second application sub-line, and for the total time that is obtained by adding the operating time required to apply the protective material in the first application sub^¬ line and the transport time during which the vehicle body moves between the main line and the first sub-line.

3. The production line of claim 1, wherein production line managing means manages the progress of the application sub-lines and the time of arrival at a terminal positioned downstream from the coating stage in the application sub lines, so that the vehicle body is sent to the equipping stage according to the sequence in which the vehicle bodies are sent from the coating stage.

4. The production line of claim 1, wherein one of the application sub-lines includes a step for applying a fluorine coating as one type of protective.