FRONT DOOR OF MOTOR VEHICLES WITH REINFORCED STRUCTURE FOR PROTECTION AGAINST SIDE IMPACT

Abstract

The invention relates to a front door of a motor vehicle comprising, in its upper part, a window frame (1) formed of a profile (R) and delimited by a substantially horizontal lower band (C) and, in its lower part (B), a lining provided with an added reinforcing element (R2), characterized in that said band comprises an internal cavity (10) the wall of which is formed in one piece with the frame profile (R) (1) and which ensures, by inertia, the control of deformation of at least the upper part of the door in the event of a side impact. (Fig. 3)

Description

Title of the invention: FRONT DOOR OF MOTOR VEHICLES WITH REINFORCED STRUCTURE FOR PROTECTION AGAINST SIDE IMPACT

[0001] The invention relates, in general, to the field of passive safety of motor vehicles and is concerned, more particularly, with a structural improvement of the front doors intended to improve the protection of the vehicle's occupants in the event of a side impact.

[0002] Generally, during a side impact against the vehicle, the doors that rest on the vehicle structure are subjected to stress. Therefore, in order to guarantee the safety of the occupants during such an impact, the door deflection must be controlled, particularly in the area between the door edge marking the lower part of the window frame and the bottom of the door.

[0003] Indeed, this control is mandatory from a regulatory point of view because it is necessary in order to avoid a break and penetration into the passenger compartment of the door trim elements which are located in this area and which, in the event of a side impact, would injure the occupants.

[0004] To this end, reinforcing elements are incorporated into the door lining in this critical area. These elements generally consist of a horizontal or longitudinal reinforcing profile that controls the deflection of the upper third of the door at the frame and a diagonal reinforcing profile that controls the deflection of its lower two-thirds. Thus, in the event of an impact, the door's intrusion into the passenger compartment is contained, thereby preserving the physical integrity of the vehicle's occupants.

[0005] However, the installation of the horizontal reinforcement element is problematic because it requires, firstly, the stamping of a profile of specific geometry and then long and laborious operations of welding this profile onto the door frame, which naturally generates additional delays and costs.

[0006] Patent FR3138630 describes a side door for a motor vehicle, the The structure offers good resistance to side impacts. To this end, the door includes a reinforced belt in the form of an added profile with a notch designed to weaken it locally and selectively. This notch, which in the event of an impact controls and slows the penetration of the reinforcement profile into the passenger compartment, may be supplemented by a lower notch.

[0007] However, this door still incorporates a belt reinforcement. Consequently, the door covered by this patent does not provide a solution to the technical problem addressed by the invention, which aims precisely to eliminate this reinforcement.

[0008] Patent EP2885143 describes an alternative door structure for motor vehicles that provides improved absorption of frontal impacts. This structure comprises an internal door housing to which a single reinforcing profile is attached, internally dividing the space between two hollow sections that absorb the impacts. In the event of an impact, this profile is designed to penetrate a front chassis element.

[0009] However, this door structure is also reinforced by an added profile, which is contrary to the objective of the invention. Furthermore, this structure is designed to better withstand frontal impacts, whereas the invention addresses lateral impacts. Consequently, the door covered by this patent also fails to solve the technical problem defined above.

[0010] In this context, the invention sought an alternative technical solution, simple to implement, and making it possible to do away with the door belt reinforcement element without degrading the level of safety of the passenger compartment.

[0011] This goal is achieved, according to the invention, by means of a front door of a motor vehicle comprising, in the upper part, a window frame formed of a profile and delimited by a substantially horizontal lower band and, in the lower part, a lining provided with an added reinforcement element, characterized in that said band includes an internal cavity whose wall is formed in one piece with the frame profile and which ensures, by inertia, the control of the deformation of at least the upper part of the door in the event of a side impact.

[0012] According to a preferred embodiment of the door of the invention, the cavity is open towards the inside of the door.

[0013] According to an advantageous feature of the door of the invention, the wall of the cavity is made up of a local fold outwards of the frame profile.

[0014] According to another feature of the door of the invention, the height of the frame corresponds to one third of the total height of the door.

[0015] Preferably, the internal cavity extends along the entire length of the belt.

[0016] Another object of the invention is a method for manufacturing a front door of a motor vehicle as defined above, characterized in that the window frame is made in one piece by stamping a profile, leaving, at the level of the belt, an internal cavity open towards the inside of the door.

[0017] Yet another object of the invention is a motor vehicle comprising at least one front door having the characteristics defined above.

[0018] In its most general principle, the invention consists of eliminating the added horizontal reinforcement element usually present in door frames and allows thus the direct integration of a shock absorption function into the door frame.

[0019] In addition, the invention allows specific control of deformations and, in particular, of the deflection in the upper third of the door, between the belt and the bottom of the door.

[0020] The cavity made at the factory inside the door frame itself ensures the absorption of shocks in the upper part thanks to the inertia of the hollow body thus formed and without the need for any welding.

[0021] Other features and advantages of the invention will become apparent from the following description, with reference to the accompanying figures, for which:

[0022] [Fig. 1] is an interior and side view of a traditional front side door of a motor vehicle.

[0023] [Fig.2] is a cross-sectional view along AA of the door of [Fig. 1].

[0024] [Fig.3] is an interior and side view of a preferred embodiment of a front side door of a motor vehicle according to the invention.

[0025] [Fig.4] is a cross-sectional view along AA of the door of [Fig.3].

[0026] For clarity, identical or similar elements are identified by identical reference signs throughout the figures.

[0027] Naturally, the embodiments of the front door according to the invention, schematically illustrated in the figures above and described below, are given only by way of non-limiting examples. It is explicitly provided for within the scope of the invention that different embodiments can be proposed and combined to create others.

[0028] The invention relates to the general field of passive safety of motor vehicles and is more particularly concerned with the structure of the front side doors.

[0029] Generally, and as illustrated in Figures 1 to 4, these front doors comprise, in their upper part, a window frame 1 (not shown) formed by a profile R and delimited by a substantially horizontal lower band C. In their lower part B, the door comprises a lining (not shown). The height of the frame 1 corresponds to approximately one-third of the total height of the door.

[0030] During a side impact against the vehicle, the doors, which are supported by the vehicle's structure, are subjected to stress. In order to guarantee the physical integrity of the occupants during such an impact, the deformations of the door and, in particular, its deflection, must be controlled.

[0031] In this respect, the area between the band C delimiting the lower part of the window frame 1 and the bottom of the door B is particularly critical because it contains trim elements which, if broken by a side impact, can penetrate the passenger compartment and injure the vehicle's occupants.

[0032] For safety and regulatory purposes, reinforcement elements are added to the door lining in this critical area. These elements generally consist of a horizontal or longitudinal reinforcement profile RI, which is attached and which controls the deflection of the upper third of the door at the frame 1. A second reinforcement profile R2 is mounted along the diagonal of the door and controls the deflection of its lower two-thirds, as illustrated in [Fig. 1].

[0033] However, the installation of the horizontal reinforcement element RI proves problematic because it requires, firstly, the stamping of a specific additional profile and then long and laborious welding operations of this RI profile on the frame 1 of the door.

[0034] Therefore, the invention proposes to do away with this RI profile while preserving a satisfactory level of protection for vehicle occupants with regard to the regulations in force.

[0035] To this end, the invention consists of modifying the structure of the door's C-belt so that it contains an internal cavity 10 forming a hollow body and whose wall is formed in one piece with the frame profile R 1. In this way, the C-belt is able to ensure, thanks to the inertia of the hollow body, the control of the deformation of at least the upper part of the door in the event of a lateral impact.

[0036] This cavity 10 is open towards the inside of the door and its wall is formed by a local outward fold of the frame profile R 1, as illustrated by [Fig.4]. Preferably, the internal cavity 10 extends along the entire length of the belt C, as illustrated by [Fig.3] and is open towards the inside of the door ([Fig.4]).

[0037] The production of the window frame 1 according to the invention is carried out in a simple and quick manner by stamping a one-piece profile R and can therefore be easily automated.

Claims

Demands

1. Front door of a motor vehicle comprising, in the upper part, a window frame (1) formed of a profile (R) and delimited by a substantially horizontal lower band (C) and, in the lower part (B), a lining provided with an added reinforcing element (R2), characterized in that said band comprises an internal cavity (10) the wall of which is formed in one piece with the frame profile (R) (1) and which ensures, by inertia, the control of the deformation of at least the upper part of the door in the event of a side impact.

2. Front door according to claim 1, characterized in that said cavity (10) is open towards the inside of the door.

3. Front door according to any one of the preceding claims, characterized in that the wall of said cavity (10) is made up of a local outward fold of the profile (R) of the frame (1).

4. Front door according to any one of the preceding claims, characterized in that the height of said frame (1) corresponds to one third of the total height of the door.

5. Front door according to any one of the preceding claims, characterized in that said internal cavity (10) extends over the entire length of the belt (C).

6. Method of manufacturing a front door of a motor vehicle according to one of the preceding claims, characterized in that the window frame (1) is made in one piece by stamping a profile (R) providing, at the level of the belt (C), an internal cavity (10) open towards the inside of the door.

7. Motor vehicle comprising at least one front door according to any one of claims 1 to 5.

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