Vehicle roof and method for manufacturing vehicle roof

Abstract

To provide a vehicle roof that is able to maintain the characteristics of the roof even when a mastic sealer of a commercial product is used for repair, and a manufacturing method for the vehicle roof.SOLUTION: A vehicle roof 10 includes: a roof panel 12 of a vehicle body; a roof member 11 extending in a vehicle width direction with respect to the roof panel 12 and reinforcing the roof panel 12 from an inner side of the vehicle body; a roof-side electrodeposition coating film 16a formed on a surface of the roof panel 12; a member-side electrodeposition coating film 16b formed on a surface of the roof member 11; and a normal-temperature curing mastic sealer 15 joining the roof-side electrodeposition coating film 16a and the member-side electrodeposition coating film 16b.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a roof for a vehicle such as an automobile, and a method for manufacturing the same. [Background technology]

[0002] Generally, a roof panel of a vehicle is reinforced by being supported from the inside by a long roof member. In order to improve the design of the roof panel, the roof panel and roof member are joined at the surface with mastic sealer, an elastic thermosetting adhesive, instead of welding. Mastic sealer is a loosely kneaded mixture or gel in its uncured state, and exhibits rubber-like adhesive strength upon curing. Mastic sealer is placed in areas of the roof panel that experience high vibrations, and also functions to prevent unpleasant metallic sounds from being generated by contact with the roof panel.

[0003] Conventionally, a mastic sealer is applied to either the roof panel or the roof member before the panels are bonded together. The uncured mastic sealer then goes through a pre-treatment process before being cured in a heating oven used to dry the electrodeposition coating. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 63-54590 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when repairing areas where mastic sealer has been applied during sheet metal repairs, the mastic sealer is generally replaced with a commercially available room-temperature curing mastic sealer. However, room-temperature curing mastic sealers have different properties, such as elasticity and heat resistance, from heat-curing mastic sealers, which poses a problem in that the condition of the roof, such as deformation, cannot be maintained before and after the repair. Furthermore, in the conventional technology described above, the mastic sealer undergoes various painting processes in an uncured state, which poses the problem that the mastic sealer can be deformed and even peeled off due to water flow or deformation of the roof panel.

[0006] The present invention has been made in consideration of the above circumstances, and aims to provide a vehicle roof and a method for manufacturing a vehicle roof that maintains the properties of the roof even when repairs are performed using commercially available mastic sealers. [Means for solving the problem]

[0007] The roof of the vehicle according to this embodiment includes a roof panel of a vehicle body, a roof member extending in the vehicle width direction relative to the roof panel and reinforcing the roof panel from the inside of the vehicle body, and The roof panel is provided with a roof-side electrodeposition coating film formed on the surface thereof, a member-side electrodeposition coating film formed on the surface thereof, and a room temperature curing mastic sealer that bonds the roof-side electrodeposition coating film and the member-side electrodeposition coating film.

[0008] In addition, the method for manufacturing a vehicle roof according to this embodiment includes a step of welding a roof member that reinforces a roof panel to a roof panel of a vehicle body from the inside of the vehicle body, an electrocoating step of electrocoating the welded roof panel and roof member to form an electrocoating film, a baking step of heating and hardening the electrocoating film in a heating furnace, and a step of applying a room temperature hardening mastic sealer after the baking step. [Effects of the Invention]

[0009] The present invention provides a vehicle roof and method for manufacturing a vehicle roof that maintains roof properties even when repaired using commercially available mastic sealers. [Brief explanation of the drawings]

[0010] [Figure 1]1A is a schematic diagram of the roof of a vehicle according to an embodiment, viewed from the inside of the vehicle, excluding the interior, and FIG. 1B is an enlarged perspective view of the roof member in the Ω range of FIG. 1A. [Figure 2] 1(A) is a cross-sectional view of the roof member and roof panel taken along line II in the Ω range of FIG. [Figure 3] 4 is a flowchart showing a manufacturing process for forming a roof of a vehicle according to an embodiment. [Figure 4] 1A is a perspective view of a roof member showing a recessed portion preferably used in an embodiment, and FIG. 1B is a perspective view of the roof member when the roof member of FIG. 1A is turned over and the recessed portion is viewed from the inside of the vehicle. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. In the embodiment, the reference for the "front-rear" direction and "vehicle width" direction of each member is the front-rear direction and vehicle width direction of the vehicle when the member is installed on the vehicle.

[0012] FIG. 1(A) is a schematic diagram of a roof 10 of a vehicle according to an embodiment, viewed from the inside of the vehicle, excluding the interior, and FIG. 1(B) is an enlarged perspective view of a roof member 11 in the Ω range of FIG. 1(A). As shown in FIG. 1(A), a roof 10 of a vehicle is configured by a roof panel 12 fixed to a body frame and reinforced by roof members 11 from the inside of the vehicle. The roof member 11 is fixed along the vehicle width direction at a position where the vertical vibration of the roof panel 12 becomes large. Most roof members 11 support the roof panel 12 with multiple members. To increase the strength of the roof member 11, the surface of the roof member 11 is provided with multiple ridges 14 generally along the longitudinal direction of the roof member 11, as shown in FIG. 1(B). The ridges 14 are formed with a top surface 14a having a predetermined width.

[0013] For example, cylindrical or rectangular parallelepiped mastic sealer 15 is applied to multiple locations on top surface 14a. Mastic sealer 15 is a room temperature curing adhesive that hardens by mixing two components, a base agent and a hardener, such as a two-component curing urethane resin, a two-component curing epoxy resin, or a two-component curing acrylic resin. However, the mastic sealer 15 does not have to be a two-component curing type as long as it is a room temperature curing type. For example, the mastic sealer 15 may be a type that reacts with trace amounts of moisture in the air and cures at room temperature. After curing, the mastic sealer 15 bonds the roof panel 12 and the roof member 11 together with its own adhesive strength.

[0014] 2 is a cross-sectional view of the roof member 11 and the roof panel 12 taken along line II in the Ω range in FIG. 1(A). Also, FIG. 3 is a flowchart showing the manufacturing process for forming the roof 10 of the vehicle according to the embodiment. The vehicle roof according to the embodiment will be described below along with its manufacturing process using the cross-sectional view of Fig. 2 and the flowchart of Fig. 3. In Fig. 3 and the following description, each step in the manufacturing process will be represented by an "S", such as "S11".

[0015] As shown in FIG. 3, the roof panel 12 according to the embodiment is integrated with the roof member 11 by welding the ends of the roof panel 12 to the roof member 11 (S11). Next, the roof panel 12 and the roof member 11 integrated by welding are subjected to electrodeposition coating in the electrodeposition coating step (S12) as shown in FIG. 2, so that the entire surface is covered with electrodeposition coating films 16a, 16b. The formed electrodeposition coatings 16a, 16b are then cured and fixed to the surface in the baking step (S13). Hereinafter, the electrodeposition coating 16a formed on the roof panel 12 will be referred to as the roof-side electrodeposition coating 16a, and the electrodeposition coating 16b formed on the roof member 11 will be referred to as the member-side electrodeposition coating 16b.

[0016] Next, the roof panel 12 and roof member 11 covered with the electrodeposition coating films 16a, 16b are painted with an intermediate coat and a top coat (S14). These intermediate coat and top coat paints are applied to the visible design surfaces, so no paint layer is formed on the opposing surfaces of the roof member 11 and the roof panel 12. In other words, even after the intermediate coat and top coat are applied, the opposing surfaces of the roof member 11 and the roof panel 12 remain exposed with the electrodeposition coating films 16a, 16b. Note that the intermediate coat layer and top coat layer formed by the intermediate coat and top coat are not shown in Figure 2. Then, the intermediate coat layer and the top coat layer are also cured by baking and fixed onto the electrodeposition coating films 16a, 16b (S15).

[0017] Then, a room-temperature-setting mastic sealer 15 is applied by injection between the roof panel 12 and the roof member 11, both of which are covered with the electrodeposition coatings 16a and 16b (S16). The mastic sealer 15 is injected, for example, from an injection hole 17 provided in the roof member 11 using a tube bottle 18. The tube bottle 18 is held, for example, by a robot arm disposed along the production line. The mastic sealer 15 adheres to the surfaces of both the roof panel 12 and the roof member 11 and gradually hardens (END). At this time, because the surfaces of the roof panel 12 and the roof member 11 are covered with the electrodeposition coatings 16a and 16b, the mastic sealer 15 bonds the roof-side electrodeposition coating 16a and the member-side electrodeposition coating 16b. Because the mastic sealer 15 adheres to the electrodeposition coatings 16a and 16b in this way, there is less adhesion of dirt compared to when adhering to unpainted bonding surfaces, and therefore a decrease in adhesive strength can be suppressed.

[0018] In this manufacturing method for the roof 10, the step S16 of applying the mastic sealer 15 occurs after the baking steps S13 and S15. Therefore, in these baking steps S13 and S15, the baking environment, such as the heating temperature, can be set without taking into account the curing characteristics of the mastic sealer 15. In particular, from the perspective of reducing carbon dioxide emissions, there is a demand for lower coating temperatures. This demand can be easily met because the baking environment can be adjusted independently of the curing characteristics of the mastic sealer 15. Conversely, in the manufacturing method according to the embodiment, the properties of the mastic sealer 15, such as adhesion, elasticity, and durability, can be exhibited regardless of the coating baking environment.

[0019] Next, with reference to FIG. 4 and subsequently FIG. 2, the shape of the roof member 11 that is preferably used to form the roof 10 of the vehicle according to the embodiment will be described. Fig. 4(A) is a perspective view of the roof member 11 showing the recessed portion 19 preferably used in the embodiment, and Fig. 4(B) is a perspective view of the roof member 11 when the roof member 11 is turned over and the recessed portion 19 is viewed from the inside of the vehicle. Figs. 4(A) and (B) each show two types of recessed portion 19, one long and one short.

[0020] As described above, in the manufacturing method according to the embodiment, the mastic sealer 15 is applied after the roof member 11 is welded together (S11) and the various painting steps (S12 to S15). Therefore, as shown in Figures 2 and 4(A) and (B), it is desirable to provide a recess 19 that protrudes from the roof panel 12 toward the interior of the vehicle and opens toward the roof panel 12, and an injection hole 17 in this recess 19. The nozzle of a tube bottle 18 is brought into contact with this injection hole 17, and the mastic sealer 15 is gradually filled and applied into the recess 19.

[0021] It is desirable that injection hole 17 be provided on the side wall surface of recess 19. As mentioned above, in many cases, a robot arm holding tube bottle 18 is inserted through a body opening, such as a side window frame, of a vehicle traveling on a production line to apply mastic sealer 15. Therefore, from the perspective of shortening takt time, it is necessary to minimize and simplify the operation by eliminating as much of the robot arm's movement as possible, such as direction changes. By injecting mastic sealer 15 from the side wall surface of recess 19 parallel to application surface 19a of recess 19, mastic sealer 15 can be applied to the interior of recess 19 without having to insert a nozzle deep inside recess 19.

[0022] In addition to the robot arm, many repair personnel during sheet metal repairs also access the roof member 11 inside the vehicle through the vehicle's side window frame. Therefore, it is desirable that the injection hole 17 be provided with its opening facing the nearest side window frame. In other words, it is desirable that the injection hole 17 be provided so that it opens in the opposite direction from the direction facing the center C of the roof member 11 along the short side of the roof member 11 (i.e., the vehicle's front-to-rear direction), i.e., toward the edge. By opening it in such a position, the roof panel 12 and the tube bottle 18 do not come into contact with each other and are not damaged during application, making it easy to perform the application work.

[0023] As shown in Figures 2 and 4(A) and (B), recess 19 is formed so that the distance α between application surface 19a of recess 19 in roof member 11 and roof panel 12 is approximately 5 to 10 mm. Furthermore, since the diameter of the nozzle tip of tube bottle 18 is approximately 0.8 mm, the diameter β of injection hole 17 is preferably approximately 5 to 8 mm. Furthermore, the depth γ of application surface 19a of recess 19 from injection hole 17 is preferably approximately 10 to 40 mm. The slit width δ of injection hole 17 and the width of recess 19 in the slit direction of injection hole 17 are determined arbitrarily depending on the optimum amount of mastic sealer 15 to be applied.

[0024] As described above, with the vehicle roof 10 according to the embodiment, by using the room-temperature curing mastic sealer 15 after the baking process (S13, 15), the characteristics of the roof 10 can be largely maintained even when a commercially available mastic sealer 15 is used for repairs. Furthermore, by providing the repair industry with the room-temperature curing mastic sealer 15 used in the vehicle roof 10 according to the embodiment, the characteristics of the roof 10 can be maintained even after repairs. Furthermore, since the mastic sealer 15 is applied after all the steps related to painting (S12 to S15), deformation or peeling of the mastic sealer 15 due to disturbances such as vibration or running water can be prevented.

[0025] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, modifications, and combinations can be made without departing from the spirit of the invention. These embodiments and their variations are intended to be included in the scope of the invention and its equivalents as described in the claims, as well as in the scope and spirit of the invention.

[0026] For example, the vehicle roof and manufacturing method of the present invention can also be applied to hoods and doors that vibrate in a similar manner. Furthermore, in areas where room-temperature-setting mastic sealer can be applied through existing gaps, it is not necessary to form separate recesses and injection holes. For example, recesses can be replaced with appropriate ridges. [Explanation of symbols]

[0027] 10...roof, 11...roof member, 12...roof panel, 14 (14a)...ridge portion (top surface), 15...mastic sealer, 16 (16a, 16b)...electrodeposition coating (roof-side electrodeposition coating, member-side electrodeposition coating), 17...injection hole, 18...tube bottle, 19 (19a)...recessed portion (coated surface), α...distance, γ...depth, δ...slit width, O...center of roof panel.

Claims

1. The roof panel of the vehicle body, a roof member extending in a vehicle width direction relative to the roof panel and reinforcing the roof panel from the inside of the vehicle body; a roof-side electrodeposition coating film formed on the surface of the roof panel; a member-side electrodeposition coating formed on the surface of the roof member; a room-temperature-curing mastic sealer that bonds the roof-side electrodeposition coating film and the member-side electrodeposition coating film.

2. 2. The vehicle roof according to claim 1, wherein the mastic sealer is a two-component adhesive that hardens at room temperature.

3. a recess formed in the roof member; 3. The vehicle roof according to claim 1, further comprising an injection hole provided in a side wall surface of the recessed portion.

4. 4. The vehicle roof according to claim 3, wherein the injection hole is provided outward in the short direction of the roof member.

5. a step of welding a roof member that reinforces the roof panel to a roof panel of a vehicle body from an inside side of the vehicle body; an electrodeposition coating process for forming an electrodeposition coating film on the welded roof panel and the roof member; a baking step in which the electrodeposition coating film is heated and cured in a heating furnace; a step of applying a room temperature curing mastic sealer after the baking step.

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