Roof panel and vehicle roof structure

Abstract

To reduce the weight of a vehicular roof panel and secure rigidity at low costs.SOLUTION: A roof panel 3 made of a thermoplastic resin is joined to a roof reinforcement 24 extending in a vehicle width direction at a vehicle upper part and has: a panel body 31; and multiple thick ribs 32 integrally molded with a lower surface of the panel body 31 and extending in a vehicle fore and aft direction spaced apart from each other in the vehicle width direction. The thick rib 32 has: a first thick area 32a having a maximum thickness and joined to the roof reinforcement 24; and a second thick area 32b located adjacent to the first thick area 32a and having a thickness which reduces in a direction away from the first thick area 32a.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a roof panel and a vehicle roof structure. [Background technology]

[0002] Conventionally, vehicles have been known in which the majority of the roof is constructed from a resin roof panel in order to further reduce the weight of the vehicle body. As the resin for such roof panels, the use of thermosetting fiber-reinforced resin has been considered from the viewpoint of mechanical strength such as rigidity and impact resistance (see, for example, Patent Document 1), and its practical application is also being promoted. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-023263 Summary of the Invention [Problem to be solved by the invention]

[0004] However, roof panels made of thermosetting resins are expensive because they require a long molding cycle time and post-processing after molding, and are therefore currently only suitable for use in some luxury vehicles.In order to expand the use of resin roof panels to a variety of vehicle types, it is possible to use inexpensive thermoplastic resins instead of thermosetting resins, but this requires measures to ensure the necessary rigidity while maintaining light weight.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to achieve both weight reduction and rigidity of a roof panel at low cost. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the roof panel of the present invention is a thermoplastic resin roof panel joined to a roof reinforcement extending in the vehicle width direction at an upper part of a vehicle, and has a panel body and a plurality of thick ribs integrally molded on the underside of the panel body and extending in the vehicle front-rear direction at intervals in the vehicle width direction, and the thick ribs are: A plurality of such sensors are provided along the front-rear direction of the vehicle. a first thick region having a maximum thickness and joined to the roof reinforcement; and a second thick region adjacent to the first thick region and having a thickness that decreases with increasing distance from the first thick region. and third thick-walled regions that are arranged alternately with the first thick-walled regions along the vehicle longitudinal direction and are thinner than the first thick-walled regions. have The first thick region and the third thick region are disposed in the center of the thick rib in the vehicle width direction, and the second thick region has a thickness that decreases from the first thick region toward the third thick region along the vehicle front-rear direction, and decreases in thickness as it moves away from the first thick region and the third thick region along the vehicle width direction. .

[0007] In addition, the vehicle roof structure of the present invention has the above-mentioned roof panel and a roof reinforcement extending in the vehicle width direction at the upper part of the vehicle and supporting the roof panel, and the roof panel is joined to the roof reinforcement at the first thick region of the thick rib by mastic adhesive. [Effects of the Invention]

[0008] As described above, according to the present invention, it is possible to achieve both weight reduction and rigidity of a vehicle roof panel at low cost. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view of a vehicle roof structure according to an embodiment of the present invention; [Figure 2] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Figure 3] 1A and 1B are a plan view and a cross-sectional view of a roof panel of the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] Fig. 1 is a perspective view of a vehicle roof structure according to one embodiment of the present invention, and Fig. 2 is a cross-sectional view taken along line AA in Fig. 1.

[0012] The vehicle roof structure (hereinafter also simply referred to as "roof structure") 1 has a roof frame member 2 that forms the frame of the upper part (roof) of the vehicle. The roof frame member 2 has a pair of roof side rails 21, a front header panel 22, a rear roof rail 23, and a plurality of roof reinforcements 24.

[0013] The roof side rails 21 are disposed at both ends in the vehicle width direction and extend in the vehicle front-to-rear direction. The front header panel 22 and the rear roof rail 23 are respectively bridged between the pair of roof side rails 21 at the vehicle front and rear ends along the vehicle width direction. The roof reinforcements 24 are disposed in the roof opening 25 thus formed at intervals in the vehicle front-to-rear direction and bridge the pair of roof side rails 21 along the vehicle width direction. The roof side rail 21 is composed of a side outer 21a, a side inner 21b disposed on the passenger compartment inside of the side outer 21a, and a roof side rail reinforcement 21c disposed between the side outer 21a and the side inner 21b. These components are joined together to form the roof side rail 21 with a closed cross-sectional structure. Although not shown, the rear roof rail 23 also has a similar closed cross-sectional structure.

[0014] The roof structure 1 also has a roof panel 3 that covers the roof opening 25 in the roof frame member 2. The roof panel 3 is made of a conductive thermoplastic resin, preferably polyphenylene ether resin (PPE / PPO). The roof panel 3 is fixed around its entire periphery to the roof side rails 21, front header panel 22, and rear roof rails 23 with a structural adhesive 4. A sealant 5 is provided on the outer periphery of the structural adhesive 4 to seal the gaps between the roof panel 3 and the roof frame member 2, i.e., the gaps between the roof side rails 21, front header panel 22, and rear roof rails 23, thereby ensuring watertightness between them.

[0015] The roof panel 3 has a panel main body 31 and a plurality of thick ribs 32 that are integrally molded on the underside of the panel main body 31 and that increase the rigidity of the roof panel 3. As will be described in detail later, the thick ribs 32 extend in the fore-and-aft direction of the vehicle so as to intersect with the roof reinforcement 24, and are joined to the roof reinforcement 24 by mastic adhesive 6 applied to the intersections. The mastic adhesive 6 is an elastic adhesive that secures the roof panel 3 and the roof reinforcement 24 together to ensure the tensile rigidity of the roof panel 3, and also has the function of suppressing vibration and noise from the roof panel 3.

[0016] Here, the detailed shape of the thick ribs of this embodiment will be described with reference to Fig. 3. Fig. 3(a) is an enlarged plan view showing a portion of the underside of the roof panel of this embodiment. Fig. 3(b) is a cross-sectional view taken along line BB in Fig. 3(a), and Fig. 3(c) is a cross-sectional view taken along line CC in Fig. 3(a). Note that the arrangement of the thick ribs in Fig. 3(a) is merely an example and does not limit the present invention.

[0017] The thick ribs 32 are integrally molded on the underside of the panel main body 31 so as to extend in the vehicle longitudinal direction at intervals in the vehicle width direction. The thick rib 32 has a first thick region 32a, which has the greatest thickness, and a second thick region 32b adjacent to the first thick region 32a, whose thickness decreases with increasing distance from the first thick region 32a. The first thick region 32a is positioned opposite the roof reinforcement 24 and is a region to which a mastic adhesive 6 is applied and bonded to the roof reinforcement 24. The first thick region 32a is positioned in the center of the thick rib 32 in the vehicle width direction, and multiple first thick regions 32a are provided along the vehicle longitudinal direction. Therefore, the thickness of the second thick regions 32b decreases with increasing distance from the first thick region 32a in both the vehicle longitudinal direction and the vehicle width direction.

[0018] The thick rib 32 also has third thick regions 32c that are thinner than the first thick regions 32a and are arranged alternately with the first thick regions 32a along the vehicle longitudinal direction. Like the first thick regions 32a, the third thick regions 32c are arranged in the center of the thick rib 32 in the vehicle width direction. Therefore, the thickness of the second thick regions 32b decreases from the first thick regions 32a toward the third thick regions 32c along the vehicle longitudinal direction, and also decreases with increasing distance from the third thick regions 32c along the vehicle width direction. The area of ​​the first thick regions 32a in a plan view is larger than the area of ​​the third thick regions 32c in a plan view. Accordingly, the width of the thick rib 32 is maximum near the first thick regions 32a, gradually decreases from there toward the third thick regions 32c along the vehicle longitudinal direction, and is minimum near the third thick regions 32c.

[0019] As described above, in this embodiment, the roof panel 3 is provided with thick ribs 32 extending in the vehicle longitudinal direction, and the roof panel 3 is supported by the roof reinforcement 24 that intersects with the thick ribs 32. This allows the roof panel 3 to withstand loads in both the vehicle longitudinal direction and the vehicle width direction, ensuring sufficient rigidity. Furthermore, the mastic adhesive 6 that bonds the roof panel 3 to the roof reinforcement 24 is applied to the first thick region 32a of the thick rib 32, which has the greatest thickness. Mastic adhesive contains a foaming agent for vibration-proofing and cushioning properties, and shrinkage (hardening) during the cooling process after heat treatment can cause sink marks in the bonded portion, particularly in the case of thin plate members. However, in this embodiment, the thickness of such region 32a is relatively thick, thereby suppressing the occurrence of such sink marks.

[0020] On the other hand, locally thickening the roof panel 3 can also raise concerns about the occurrence of sink marks. However, the thickness of the thick rib 32 gradually decreases with increasing distance from the first thick region 32a, thereby not only suppressing the occurrence of sink marks but also making them less noticeable, even if they do occur. Furthermore, the width of the thick rib 32 is wide in the region 32a, where sufficient thickness is required, and narrow in the region 32c, where such thickness is not required. This allows the roof panel 3 to be lightweight while maintaining the aforementioned sufficient rigidity. Furthermore, using a conductive thermoplastic resin for the roof panel 3 not only significantly reduces material costs, but also has the advantage of significantly reducing painting costs, since painting of the roof panel 3 can be performed simultaneously or sequentially during the vehicle body electrodeposition painting process.

[0021] To effectively prevent sink marks, it is preferable that the thickness of the second thick region 32b of the thick rib 32 change as smoothly as possible. Specifically, in a cross section passing through the first thick region 32a and parallel to the vehicle width direction (see FIG. 3(b)), the inclination α of the second thick region 32b relative to the panel main body 31 is preferably 10° or less. In a cross section passing through the third thick region 32c and parallel to the vehicle width direction (see FIG. 3(b)), the inclination β of the second thick region 32b relative to the panel main body 31 is preferably 10° or less. In a cross section passing through the third thick region 32c and parallel to the vehicle front-rear direction (see FIG. 3(c)), the inclination γ of the second thick region 32b relative to the third thick region 32c is preferably 10° or less.

[0022] The number, arrangement, and size of the thick ribs 32 are not particularly limited and can be set appropriately depending on the mechanical strength required for the roof panel 3. The first thick regions 32a of the thick rib 32 are formed at least in positions facing the roof reinforcements 24, but the number does not necessarily have to be the same as the number of the roof reinforcements 24, and may be less than that. Therefore, the arrangement of the first thick regions 32a across the entire roof panel 3 is not limited to a lattice pattern and may be, for example, a staggered pattern. In other words, in thick ribs 32 adjacent to each other in the vehicle width direction, the first thick regions 32a may be located in the same position in the vehicle front-rear direction, or the first thick regions 32a and the third thick regions 32c may be located in the same position. The number of roof reinforcements 24 is not limited to three as shown in the figure and may be two or less, or four or more. [Explanation of symbols]

[0023] 1. Vehicle roof structure 2 Roof frame members 21 Roof side rail 21a Side Outer 21b Side Inner 21c Roof side rail reinforcement 22 Front Header Panel 23 Rear roof rails 24 Roof reinforcement 25 Roof opening 3 roof panels 31 Panel body 32 Thick Rib 32a First thick region 32b Second thick region 32c Third thick region 4. Structural adhesives 5 Sealing material 6. Mastic adhesive

Claims

1. A roof panel made of thermoplastic resin that is joined to a roof reinforcement extending in the vehicle width direction at the upper part of the vehicle, a panel body; and a plurality of thick ribs integrally formed on a lower surface of the panel body and extending in a vehicle front-rear direction at intervals in a vehicle width direction, The thick rib is provided in plurality along the vehicle longitudinal direction, and has a first thick region that has a maximum thickness and is joined to the roof reinforcement, a second thick region that is adjacent to the first thick region and whose thickness decreases with increasing distance from the first thick region, and a third thick region that is arranged alternately with the first thick region along the vehicle longitudinal direction and has a thickness thinner than that of the first thick region, a roof panel in which the first thick-walled region and the third thick-walled region are arranged in a central portion of the thick-walled rib in the vehicle width direction, and the second thick-walled region decreases in thickness from the first thick-walled region toward the third thick-walled region along the vehicle front-rear direction, and decreases in thickness as it moves away from the first thick-walled region and the third thick-walled region along the vehicle width direction.

2. 2. The roof panel according to claim 1, wherein in a cross section passing through the first thick region and parallel to the vehicle width direction, the inclination of the second thick region with respect to the panel body is 10 degrees or less.

3. 3. The roof panel according to claim 1, wherein in a cross section passing through the third thick-walled region and parallel to the vehicle width direction, the inclination of the second thick-walled region relative to the panel body is 10° or less, and in a cross section passing through the third thick-walled region and parallel to the vehicle fore-and-aft direction, the inclination of the second thick-walled region relative to the third thick-walled region is 10° or less.

4. 4. The roof panel according to claim 1, wherein the width of the front thick rib decreases from the first thick region toward the third thick region along the vehicle longitudinal direction.

5. The roof panel according to claim 1 , wherein an area of ​​the first thick region in a plan view is larger than an area of ​​the third thick region in a plan view.

6. A roof panel according to any one of claims 1 to 5; a roof reinforcement extending in the vehicle width direction at an upper portion of the vehicle and supporting the roof panel; A vehicle roof structure, wherein the roof panel is joined to the roof reinforcement at the first thick region of the thick rib by a mastic adhesive.

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