PREFORMED LINER STRUCTURE, PARTICULARLY FOR PASSENGER CAR ROOFS

Abstract: The liner structure (R), being of the moulded self-­ supporting type, is made of a material selected from a group which includes mats and bats mixed with heat setting resins, foamed polyurethane, wood fibers mixed with heat setting resins, cell polypropylene, and mouldable cardboard, and incorporates - embedded in the material of the liner (R) itself by a co-moulding process - a load bearing portion (CE) adapted to provide sufficient support for the car body roof sheet (C) to prevent the latter from appreciably deforming; the load-bearing portion (C) being independently and remov­ ably fastened to the car body.

Description: This invention relates to a structural preformed liner, particularly for passenger car roof panels and roof panels of motorvehicles in general. It is known that current passenger cars utilize reinforcing carlines mounted on the interior of the car body at the passenger compartment roof area. Such carlines are only intended to prevent the so-called "panting" of the car body roof sheet, that is the deformation of the sheet as resulting from vibration and/or aerodynamic pressure stresses and enhanced by the panel flexibility deriving from its large area and small thickness; the panting of the car body roof being especially noticeable in modern design cars which are characterized by the presence of large relatively flat surfaces. The utilization of inner carlines made integral with the car body structure is, however, complicated by the fact that the carlines cannot be anchored to the roof sheet -- such as by spot welding - if continuity breaks and a wavy surface, clearly visible from the outside, is to be avoided. The problem is obviated by interposing between a carline -- generally of channel configuration and the roof sheet a filler of expanded polymeric material. This material is introduced into the carline cavity in a precured state, and is then cured and expanded to provide perfect adhesion to the roof sheet. The operation involves an accurate proportioning and correct distribution of the material, in order to avoid the creation of tensions which would deform the sheet when overapplied, or of an insufficient layer, with attendant generation of noise at the carline-sheet interface, when underapplied. Moreover, the provision of the intervening expanded layer and the insertion procedures therefor interfere with the prior electrophoresis treatment, leaving the inner portions of the carlines unprotected by said treatment. Another drawback connected with the utilization of carlines as indicated, is that the manufacture and installation of roof self-supporting liners, where provided, is further complicated, or that of worsening the aesthetic appearance of the car roof interior surface where said liners are omitted. Thus, the task of the present invention is to eliminate the cited drawbacks. This task is achieved, according to the invention, by providing a preformed liner structure, particularly for passenger car roofs, characterized in that it incorporates, embedded in and/or moulded with the material of said liner structure, a load-bearing portion effective in use to provide support for the sheet member of the car body roof such as to prevent said roof sheet from deforming significantly, the load-bearing portion being, in use, independently and removably fastened to the car body. According to one embodiment of the invention, the load-bearing structure or portion is constructed by incorporating at least one carline or rib formation of metal or a rigid material, such as plastics or wood, in the material of the preformed liner; the carline being provided with salient ends formed with holes wherethrough fastening screws are passed to engage in corresponding threaded seats or sockets provided in the car body rib frame surrounding the roof. According to a modified embodiment of this invention, which is specially suitable for large size roofs, the load-bearing structure comprises a small rigid grid frame also embedded in the material of the preformed liner and having end or terminating elements which can be removably secured as by means of screws or the like fasteners to said car body rib. The preformed liner, of a self-supporting type known per se, is molded from a material selected from a group which includes mixtures of mats and bats with heat setting resins, heat formable or injectable foamed cell polyurethane, wood fiber admixed with heat setting resins, cell polypropylene, mouldable cardboard, and combinations thereof. The load-bearing structure, carlines or small frame, is embedded in the liner material by a co-moulding process. Further features and advantages of the invention will be apparent from the following detailed description, with reference to the accompanying drawings, given herein by way of example only and where: Figure 1 is a cutaway perspective view of the body of a passenger car incorporating the preformed structural liner of this invention; Figure 2 is a perspective bottom view of this structural liner; Figure 3 is an enlarged scale sectional view taken along the line III-III of Figure 2; Figure 4 is a perspective bottom view of a modified embodiment of this liner; and Figure 5 is a perspective view showing in detail the load-bearing structure included in the liner of Figure 4. With initial reference to Figures 1 to 3, the reference character C designates the roof panel of the car body S of a generical passenger car, and R designates the self-supporting structural liner, located on the inside of the car body roof panel and juxtaposed to the roof sheet C. In accordance with this invention, the liner R incorporates, embedded therein, a carline CE of a rigid material selected from the group comprising metals, rigid plastics, wood, and fibrous materials admixed with heat setting resins. In the example illustrated in Figure 3, the carline CE is formed from sheet steel and has a closed channel profile characterized by a high moment of inertia to bending as well as light weight. As clearly shown in Figure 3, the material of the liner R matches the profile of the carline to form, on the side facing the roof sheet, a bearing flange or sole SA intended to contact the roof sheet in order to prevent it from "panting". The carline CE has salient ends CE 2 which are suitably arched and provided with holes, wherethrough fastening screws V can be inserted to engage in corresponding threaded holes provided in the rib N overlying the frame for the car side doors. The screws V provide an independent and removable connection of the carline to the car body, which allows the assembling and disassembling of the liner R while ensuring the required indeformability and rigid mounting of the carline. The liner, of a type known per se, is formed from any material or combination of materials selected from a group which comprises: mats and bats mixed with heat setting resins, expanded polyurethane with a heat#formable or injectable cell structure, wood fibers or vegetal fibers admixed with heat setting resins, cell polypropylene, and mouldable cardboard. The liner is hot moulded and the carline is incorporated by a co-moulding process. The cited materials, while having such characteristics as to ensure the self-supporting feature of the liner, are highly soft and have in general marked sound deadening properties, thereby they will afford, at the contact area between the flange SA of the carline and roof sheet C, a continuous and moderately elastic support capable of ensuring a complete suppression of the generated noise. In Figure 4, there is shown a modified embodiment wherein the liner R incorporates a loadbearing structure comprising a small grid metal frame TZ, of double "H" configuration, which includes longitudinal girders II and cross-beams T; this structure being advantageous with large size roof sheet C. The longitudinal girders L have salient ends L1-L2 provided with holes allowing fastening screws therethrough removably, and the structure is advantageously formed from sheet steel by pressing. Said small frame is also fully incorporated by co-moulding in the material of the liner R, which has on its exposed side a surface pattern characterized by the presence of ribs corresponding to the frame members. The cavities of the carlines, longitudinal girders and cross-beams may be advantageously utilized to route electric cables therethrough and/or to circulate ventilation and conditioning air, while said carlines and frame provide adequate support for mounting lighting and/or conditioned air outlet elements. Of course, based upon the principle of this invention, the implementation details and embodiments thereof may be widely modified relatively to what has been herein described and illustrated by way of example without departing from the invention scope.

Claims: CLAIMS 1. A preformed liner structure, particularly for passenger car roofs, characterized in that it incorporates, embedded in and/or moulded with the material of said liner structure (R), a load-bearing portion (CE) effective in use to provide support for the sheet member of the car body roof (C) such as to prevent said roof sheet (C) from deforming significantly, the load-bearing portion (CE) being, in use, independently and removably fastened to the car body. 2. A structure according to Claim 1, wherein the load-bearing portion is made by incorporating at least one rib formation (CE) of a rigid material in the liner material, the rib formation (CE) being provided with salient ends (CE - C having holes where through 1 E2) are passed, in use, fasteners (V) to engage corresponding threaded seats or sockets formed in the inner rib (N) of the car body around the roof panel. 3. A structure according to Claim 1, wherein said load-bearing portion comprises a small rigid grid frame (m) embedded in the liner (R) material and having salient end elements (L1 T2? adapted to be 1 2secured by means of screws to the inner rib (N) of the car body around the roof panel (C). 4. A structure according to the preceding claims, wherein the rigid material of the rib formation (CE) or small frame (TH) is selected from a group comprising metal, plastics, and wood materials. 5. A structure according to the preceding claims, wherein said rib formation (CE) or small frame (TH) are co-moulded with the material of said liner (R). 6. A structure according to the preceding claims, wherein, said liner (R) material is mouldable and selected from a group including: mats and bats mixed with heat setting resins, heat formable or injectable foamed cell polyurethane, wood fiber admixed with heat setting resins, cell polypropylene, mouldable cardboard, and combinations thereof. 7. A structure according to the preceding claims, wherein the liner (R) material matches the profile of the load-bearing portion (CE - TH) incorporated therein to form, on the side facing the roof panel sheet (C) of the car body, a bearing flange or sole (SA) adapted to contact said roof panel sheet (C). 8. A structure according to the preceding claims, wherein said rib formation (CE) or frame members (TH) are hollow to define passageways for electric cables and/or conditioning air ducts. 9. A preformed liner structure, particularly for passenger car roofs, substantially as herein described and illustrated.

Inventors: GAGGERO, ATTILIO
Applicants: FIAT AUTO S.P.A.
Application year: 1982
Main classification: B62D25
IPC codes: B60R13