Structure of a light tricycle-type vehicle with a reinforced central longitudinal beam

Abstract

The invention relates to a welded steel body structure (100) for a light, electrically powered tricycle-type vehicle, comprising a subframe (110) including two side members (112), two front (113) and rear cross members extending fixedly between the front and rear ends of said side members, a central side member (114) extending fixedly between said front and rear cross members, and an intermediate reinforcing cross member (115) extending fixedly on either side of said central side member between said side members; characterized in that it also includes a reinforcement device (200) comprising a U-shaped cross-section portion (210) partially enveloping a predicted failure zone of said central side member located between said front cross member and said intermediate reinforcing cross member. Figure to be published with the abbreviation: Fig. 3

Description

Title of the invention: Body structure with reinforced central longitudinal member for a light tricycle-type vehicle technical field

[0001] The invention relates generally to lightweight, electrically powered tricycle-type vehicles with a compact size particularly suited to urban use. More specifically, it relates to a welded steel body structure for such a vehicle. Previous technique

[0002] The continued increase in the number of vehicles in circulation poses many congestion problems related to the movement and parking of these vehicles, particularly in city centre areas.

[0003] In order to facilitate traffic and parking, an ever-increasing number of users are turning to motorized two-wheeled vehicles such as motorcycles or scooters, but these do not offer the same level of safety and protection against the weather to the driver and any passenger.

[0004] For these reasons, recent years have seen the appearance on the market of light electric-powered tricycle-type vehicles whose reduced dimensions are particularly suited to use in urban environments.

[0005] These light tricycle-type vehicles are generally equipped with a welded body structure classically comprising a subframe including two side rails, two front and rear cross members extending fixedly between the front and rear ends of said side rails, a central side rail extending fixedly between said front and rear cross members, and an intermediate reinforcing cross member extending fixedly on either side of the central side rail between the side rails.

[0006] Such a body structure also includes a cab sub-assembly resting on the front part of the underbody and comprising a central strut intended to support the steering column and extending diagonally upwards and forwards from the central area of ​​the front crossmember and the front end of the central side member of the underbody.

[0007] The rear portion of such a cab sub-assembly may further include a box defining a housing for a propulsion battery pack providing power to the vehicle's electric machine and on which the driver's seat is generally intended to rest fixedly.

[0008] Such a box is classically formed of a tubular metal frame covered by an outer envelope of thin sheet metal covering, this frame comprising an upper frame supported in particular by two uprights extending fixedly between the intermediate cross member of reinforcement of the base and the front edge of this upper frame.

[0009] In the event of a violent frontal impact with an obstacle such as a wall or another vehicle, the front wheel, acting as a rigid point, is driven rearward and strikes the central portion of the front crossmember of the underbody. This crossmember transmits almost all of the impact forces to the central side member of the underbody, the front end of which first deforms elastically and then detaches by tearing, at a rupture zone located between the front crossmember and the intermediate reinforcing crossmember, from the rest of the central side member. This front end of the central side member then continues its rearward movement, coming into contact with the outer casing of the body, which it pulls along with it until it impacts the battery pack.

[0010] Such damage to the integrity of the battery pack can cause the deterioration of some of its electrochemical cells and thus generate serious consequences for the safety of the driver, in particular when they cause an explosion, a fire or an acid leak. Description of the invention

[0011] The present invention therefore aims to improve the situation.

[0012] For this purpose, it proposes a welded mechanical body structure for a light electrically powered tricycle-type vehicle, comprising a base including two lateral longitudinal members, two front and rear cross members extending fixedly between the front and rear ends of said lateral longitudinal members, a central longitudinal member extending fixedly between said front and rear cross members, and an intermediate reinforcing cross member extending fixedly on either side of said central longitudinal member between said lateral longitudinal members; characterized in that it also includes a reinforcement device comprising a U-shaped section portion partially enveloping a predicted failure zone of said central longitudinal member located between said front cross member and said intermediate reinforcement cross member.

[0013] This U-shaped section portion of the reinforcement device thus makes it possible to increase locally, at the level of the predicted failure zone, the rigidity of the central spar so as to reduce the risk of separation by tearing of its front end portion from the rest of this central spar.

[0014] According to preferred characteristics of said case structure according to the invention: - said U-shaped section includes a central base covering the underside of said predicted failure zone, as well as two lateral panels folded over with respect to said base and covering the lateral faces of said predicted failure zone; - said reinforcement device also includes a flat T-shaped portion extending in front of the first U-shaped section portion and comprising a leg extending longitudinally forward from said central sole, covering the front end portion of the lower face of said central longitudinal member, as well as a head extending transversely in front of said leg, covering the lower face of the central portion of the lower face of said front cross member; - said reinforcement device is fixed by welding to said central longitudinal member and to said front crossmember by several weld beads; - said weld beads comprise two longitudinal beads extending along the upper edges of said side panels and welded to the lateral faces of said central longitudinal member, two longitudinal beads extending along the lateral edges of said leg and welded to the lower face of said central longitudinal member, two longitudinal beads extending along the lateral edges of said head and welded to the lower face of said front cross member, and one transverse bead extending along the front edge of said head and welded to the lower face of said front cross member; - said reinforcement device has a recess in the central area of ​​said head of the flat T portion; - said reinforcement device has a centering hole provided in said jamb of the flat T-shaped portion; - said reinforcement device is obtained by cutting and folding from a sheet of metal sheet; and / or - said sheet of metal has a thickness of between 3 and 4 millimeters.

[0015] The invention also relates, in a second aspect, to a light electrically powered tricycle-type vehicle comprising such a body structure. Brief description of the drawings

[0016] The description of the invention will now be continued by a detailed description of an example embodiment, given below by way of illustration but not limitation, with reference to the accompanying drawings, on which: - [Fig.l] represents a partial perspective top view of a body structure according to the invention, of a light electrically powered tricycle-type vehicle; - [Fig.2] is an enlarged perspective view from another angle of the front part of the body structure of [Fig.1]; - [Fig. 3] represents a partial perspective view from below of the front part of the body structure of [Fig. 1]; and - [Fig.4] is a perspective of the reinforcement device included in the body structure of [Fig.1]. Description of the implementation methods

[0017] Fig. 1 represents a partial view of the body structure 100 of a light electrically powered tricycle-type vehicle according to the invention.

[0018] A direct orthogonal frame XYZ is defined with respect to this vehicle, comprising three axes perpendicular in pairs, namely: - a horizontal longitudinal axis X, parallel to the ground and oriented according to the general direction of movement of the vehicle; - a horizontal transverse axis Y, also parallel to the ground and perpendicular to the X axis; and - a vertical axis Z, perpendicular to the ground as well as to the horizontal XY plane.

[0019] In the following description, and by convention, the terms "lower," "upper," "front," and "rear" shall be understood in relation to the overall orientation of the vehicle. The terms "lower" and "low" shall indicate a closer proximity to the ground in the vertical direction than the terms "upper" or "high." The term "front" shall indicate a forward-facing position of a vehicle in the horizontal direction, and the term "rear" shall indicate a rear-facing position of a vehicle in the same horizontal direction.

[0020] The terms "external" and "internal" will be used to define the relative position of an element with reference to the vehicle's median vertical longitudinal plane. The element closest to this plane will thus be described as internal, as opposed to the other element further from this same plane, which will be described as external.

[0021] Furthermore, the term "substantially" will be used to indicate that a slight deviation is permitted from a predetermined nominal position or arrangement, while remaining within the scope of the invention. For example, "substantially vertical" will indicate that a deviation of approximately 20° from a strictly perpendicular orientation is permitted within the scope of the invention.

[0022] Made from metal parts assembled together by mechanical welding, the body structure 100 includes a platform or body base 110.

[0023] This subframe 110 comprises two side rails 111, 112, a front cross member 113 extending fixedly between the front ends of these side rails 111, 112 to which it is welded, and a rear cross member not visible in the figures and extending fixedly between the front ends of these lateral stringers 111, 112 to which it is welded.

[0024] As can be seen more clearly in Figures 2 and 3, the underframe 110 also includes a central longitudinal member 114 extending fixedly between the front cross members 113 and rear cross members to which it is welded, an intermediate reinforcing cross member 115 extending fixedly on either side of the central longitudinal member 114 between the lateral longitudinal members 111, 112 to which it is welded, as well as several intermediate reinforcing longitudinal members extending fixedly between two cross members to which they are welded, including in particular two longitudinal members 117, 118 extending between the front cross member 113 and the reinforcing cross member 115 symmetrically on either side of the central longitudinal member 114.

[0025] Again with reference to [Fig.1], the body structure 100 also includes a cab sub-assembly 120 resting on the front part of the underbody 110, as well as a loading sub-assembly 140 resting on the rear part of this underbody.

[0026] The cab subassembly 120 includes two side frames 121, 122 each defining an access opening to the vehicle's passenger compartment, as well as a central strut 123 extending diagonally upwards and forwards from the central area of ​​the front crossmember 113 and the front end of the central side member 114 of the underbody 110.

[0027] This cab sub-assembly 120 also includes a steering column 124 comprising a tubular metal cylindrical sleeve welded to the top of the central strut 122 and extending along an axis forming a predetermined angle with the vertical determining the caster angle.

[0028] This steering column 124 is traversed by the steering shaft, not shown, of the front steering fork 125 of the vehicle partially visible on [Fig.1] and conventionally provided with at least one lateral suspension arm at the lower end of which a front wheel 126 is articulated for free rotation.

[0029] The rear portion of the cab sub-assembly 120 further includes a box 130, of rectangular parallelepiped shape extending over the width of the underbody 110 while being backed against the loading sub-assembly 140, and defining a housing for a propulsion battery pack B ensuring the supply of the vehicle's electric machine.

[0030] This box 130, on which a seat not shown for the driver of the vehicle is intended to rest fixedly, comprises a tubular chassis including a horizontal upper frame 132 supported in particular by two uprights 133, 134 (see [Fig.2]) extending fixedly between the intermediate reinforcing cross member 115 of the base 110 and the front edge of this upper frame 132, being arranged symmetrically on either side of the central longitudinal member 114.

[0031] The box 130 also includes an outer sheet metal cover covering the front, top and side faces of this frame and of which only the top wall 135 is shown in [Fig.2].

[0032] According to the invention and with reference to [Fig.3], the body structure 100 includes a reinforcement device 200 fixedly attached by welding to the front portion of the central longitudinal member 114 and to the central portion of the front cross member 113 of the underbody 110.

[0033] Represented alone on [Fig.4], this reinforcement device 200 is obtained by cutting and folding from a sheet of metal sheet, advantageously made of a high strength and high yield strength steel such as for example HD380LA, and having a thickness preferably between 2 and 4 millimeters.

[0034] With reference to these figures 3 and 4, the reinforcement device 200 comprises a U-shaped section portion 210 partially enveloping a predicted failure zone of the central longitudinal member 114 located between the front cross member 113 and the intermediate reinforcing cross member 115.

[0035] More specifically, this portion 210 includes a central sole 211 covering the lower face of this predicted failure zone, as well as two lateral panels 212, 213 folded over by folding in relation to this sole 211 and covering the lateral faces of this same predicted failure zone.

[0036] This U-shaped section 210 thus makes it possible to increase locally, at the level of a predicted failure zone, the rigidity of the central spar 114 so as to reduce the risk of separation by tearing of its front end portion from the rest of this central spar 114 and therefore of damage to the integrity of the battery block B housed in the box 130.

[0037] Still with reference to figures 3 and 4, the reinforcement device 200 also includes a flat T-shaped portion 220 extending in front of the U-shaped section portion 210.

[0038] More specifically, this flat T-shaped portion 220 includes a leg 221 extending longitudinally forward from the central sole 211, covering the front end portion of the lower face of the central longitudinal member 114, and a head 222 extending transversely forward from the leg 211, covering the lower face of the central portion of the lower face of the front cross member 113.

[0039] This flat portion in T 220 thus makes it possible to create a connection point with the front cross member 113 and therefore to increase the overall inertia of the reinforcement device 200.

[0040] The welding attachment of the reinforcement device 200 to the central longitudinal member 114 and to the front crossmember 113 is ensured by several weld beads shown as dashed lines in [Fig.4], namely: - two longitudinal cords Ci extending along the upper edges of the lateral panels 212, 213 and welded to the lateral faces of the central spar 114; - two longitudinal C2 cords extending along the lateral edges of the jamb 211 and welded to the underside of the central longitudinal member 114; - two longitudinal C3 welds extending along the lateral edges of the head 222 and welded to the underside of the front cross member 113; and - a transverse C4 cord extending along the front edge of the head 222 and welded to the underside of the front cross member 113.

[0041] In order to limit its mass, the reinforcement device 200 advantageously has a recess 230 provided in the central area of ​​the head 222 of its flat T-shaped portion 220.

[0042] Furthermore, and in order to facilitate its proper positioning before its fixing by welding, this reinforcement device 200 also preferably has a centering hole 240 provided in the jamb 211 of its flat T-shaped portion 220.

[0043] According to alternative embodiments not shown, the reinforcement device according to the invention could be shaped differently. For example, it could be devoid of the flat portion T 220.

[0044] Finally, it should be noted that the invention is not limited to the particular embodiments described herein by way of example. A person skilled in the art may, depending on the applications of the invention, make various modifications and variations falling within the scope of the invention's protection.

Claims

Demands

1. Welded mechanical body structure (100) for a light electrically powered tricycle-type vehicle, comprising a subframe (110) including two side members (111, 112), two front (113) and rear cross members extending fixedly between the front and rear ends of said side members (111, 112), a central side member (114) extending fixedly between said front (113) and rear cross members, and an intermediate reinforcing cross member (115) extending fixedly on either side of said central side member (114) between said side members (111, 112); characterized in that it also includes a reinforcement device (200) comprising a U-shaped section portion (210) partially enveloping a predicted failure zone of said central longitudinal member (114) located between said front cross member (113) and said intermediate reinforcement cross member (115).

2. Carriage structure (100) according to claim 1, characterized in that said U-shaped section portion (210) comprises a central base (211) covering the lower face of said intended rupture zone, and two lateral panels (212, 213) folded over with respect to said base (211) and covering the lateral faces of said intended rupture zone.

3. Body structure (100) according to claim 2, characterized in that said reinforcement device (200) also comprises a flat T-shaped portion (220) extending in front of the first U-shaped section portion (210) and comprising a leg (221) extending longitudinally forward from said central sole (211) by covering the front end portion of the lower face of said central longitudinal member (114), and a head (222) extending transversely in front of said leg (211) by covering the lower face of the central portion of the lower face of said front cross member (113).

4. Body structure (100) according to claim 3, characterized in that said reinforcement device (200) is fixed by welding to said central longitudinal member (114) and to said front cross member (113) by several weld beads (Cb C2, C3, C4).

5. Body structure (100) according to claim 4, characterized in that said weld beads (C1, C2, C3, C4) comprise two longitudinal welds (C1) extending along the upper edges of said side panels (212, 213) and welded to the lateral faces of said central spar (114), two longitudinal welds (C2) extending along the lateral edges of said jamb (211) and welded to the lower face of said central spar (114), two longitudinal welds (C3) extending along the lateral edges of said head (222) and welded to the lower face of said front cross member (113), and one transverse weld (C4) extending along the front edge of said head (222) and welded to the lower face of said front cross member (113).

6. Carriage structure (100) according to any one of claims 3 to 5, characterized in that said reinforcement device (200) has a recess (230) provided in the central area of ​​said head (222) of the flat T portion (220).

7. Carcass structure (100) according to any one of claims 3 to 6, characterized in that said reinforcement device (200) has a centering hole (240) provided in said jamb (211) of the flat T portion (220).

8. Carriage structure (100) according to any one of claims 1 to 7, characterized in that said reinforcement device (200) is obtained by cutting and bending from a sheet of metal sheet.

9. Carcass structure (100) according to claim 8, characterized in that said sheet metal has a thickness of between 3 and 4 millimeters.

10. Light tricycle-type vehicle comprising a body structure (100) according to any one of claims 1 to 9.

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