A motor vehicle door structure

Abstract: A carrying structure for the side door of a motorcar, in particular a door having a window, comprises a window frame and an outer covering. The structure is further composed of an upper (24) and a lower (26) shaped cross member rigidly fixed to an inner contoured frame (18) so as to form a box-like structure.

Description: The present invention refers to a motor vehicle door structure, particularly for a motorcar side door with a window. Security systems which have been recently installed on motorcars have increased their weight, also increasing fuel consumption. In particular, side-collision protection bars are mounted at mid-height on the side doors of the most recent cars. Such bars, besides contributing to reinforce the car overall, limit inward deformation of the side door in case of crashes which could injure the passengers. A door structure with such burs is disclosed in the patent application GB-A- 2 191 156. However, this structure has a very large window frame thereby increasing its total weight. Obviously, the above bars increase the overall vehicle weight considerably and constitute an obstacle in mounting rationally apparatuses within the door, such as window regulator electric devices, locks, etc. The object of the present invention is to provide a door structure which besides being very safe and rigid both vertically and horizontally, is of reduced weight and easy to assemble. The above object is attained according to the present invention by the provision of a carrying structure for the side door of a motorcar as claimed in claim 1. Further characteristics and advantages of the present invention will be apparent from the following detailed description of a not-limiting embodiment considered in combination with the accompanying drawings in which: FIG. 1 is an exploded view of a door structure in accordance with the present invention; and FIG. 2 is a partial section view of the door of FIG. 1. With reference initially to the drawings, numeral 10 designates a side door of a vehicle, particularly a car. Door 10 has an upper frame 12 defining the window and acting as a guide means for the movable glass 13 which closes the window. Further, door 10 has an outer covering 14 and an inner contoured frame 18 providing an aperture 20 for access to the internal devices of the door. A panel 22 seals aperture 20. In accordance with the present invention, the carrying structure of door 10 is constituted by upper and lower shaped cross members 24, 26, respectively, obtained through shaping or moulding processes. Cross members 24, 26 are then coupled by welding or gluing to contoured frame 18 as shown in the circle of FIG. 2. The front ends 28, 30 of cross members 24, 26 provide attachment to door hinges 32, 34, respectively. Of the rear ends 36, 38 of said cross members, only that of upper cross member 24 provides an attachment for the lock (not shown) or a lock engaging member mounted to the body centre pillar (not shown). This recent constructional technique provides for weight reduction of the door. Also the other ends 36, 38 are connected to the window frame 12 which, unlike the front part that ends at the level of the upper cross member 24, extends to the lower cross member 26, thereby contributing to reinforce the structure as a whole. According to the invention, this construction provides for a less heavy door whilst maintaining adequate safety characteristics that allow the side-collision protection bars to be dispensed with. In fact the lower cross member 26 itself acts as such a bar. In addition, this construction allows to make generally thinner doors while improving accessibility to the space within the door, owing to the fact that aperture 20 is not hindered by a side-collision protection bar. Finally, the whole front part of frame 12 conventionally used for fixing the hinges is now eliminated, with the result of rendering the door construction lighter and simpler overall.

Claims: A carrying structure for the side door (10) of a motorcar, in particular a door having a window, comprising a window frame (12) and an outer covering (14), and an upper (24) and a lower (26) cross member characterised in that the cross members are rigidly fixed to an inner closed frame (18). A structure as claimed in claim 1, characterized in that one end (36) of the upper cross member (24) carries the mechanism of a lock. A structure as claimed in claim 1, characterized in that the closed frame (18) has a central aperture (20) providing for access to the inside of the door. A structure as claimed in claim 3, characterized in that said central aperture (20) of the closed frame (18) is sealed by a panel (22). A structure as claimed in claim 1, characterized in that at the front part of the door (10) the window frame (12) ends at and is connected to the upper cross member (24). A structure as claimed in claim 1, characterized in that the window frame (12) at the rear part of the door (10) is connected to the upper cross member (24) and ends at and is connected to the lower cross member (26).

Inventors: BARBIERO ROBERTO, BARBIERO, ROBERTO
Applicants: FIAT AUTO SPA, FIAT AUTO S.P.A.
Application year: 1996
Main classification: B60J5
IPC codes: B60J5