Vehicle floor structure equipped with side protection devices

Abstract

The invention relates to a vehicle floor structure (10) formed of a front portion comprising a cab chassis (120) and a rear portion comprising two side members (140) and a plurality of cross members (143) connecting the side members, the side members of the rear portion being integral with a subframe of the cab chassis, characterized in that each side member (140) is equipped with a lateral protection device (20) comprising: - a protective beam (22) one end (220) of which is integral with the cab chassis, said protective beam extending parallel to the side member from the cab chassis over a portion of the length of the rear portion, and, - extending from each cross member (143) located at the level of the portion of the length of the rear portion, a shock absorber housing (24) integral with the protective beam and the side member. Abstract figure: Figure 2

Description

Title of the invention: Vehicle floor structure equipped with side protection devices

[0001] The invention relates to a vehicle floor structure equipped with lateral protection devices, in particular an energy storage module or a sensitive element to be protected.

[0002] For several years, the impact of vehicles on environmental conditions has been a central concern for car manufacturers and their customers. In particular, electric vehicles, whether for private or commercial use, now appear as a necessity to meet increasingly stringent requirements for reducing pollutant emissions.

[0003] Some utility vehicles have a floor structure consisting of a front section comprising a cab chassis and a rear section comprising two longitudinal members and a plurality of cross members connecting the longitudinal members. The rear section is designed to be fitted at the factory, or by bodybuilders, with a structure adapted to the customer's needs. This structure rests on the longitudinal members and cross members of the rear section while being fixed to it. The structure may be an enclosed unit, refrigerated or not, a tipper body with sideboards, or a simple flatbed.

[0004] When a utility vehicle of this type, also called a chassis-cab vehicle, includes an electric traction battery, the chassis must provide protection for the battery, particularly against side impacts, regardless of the structure fitted to the rear of the chassis-cab. This protection is essential to keep the battery securely attached to the vehicle in the event of a side impact and thus prevent damage to the battery and the associated drawbacks, namely environmental risks related to chemical leaks, fire risks due to significant battery degradation, and the costs of battery replacement and repair.

[0005] Document EP2729348B1 describes a vehicle floor structure comprising two main side members connected by cross members between which energy storage modules are arranged. This structure is integrated into the vehicle. The cross members include crumple zones with defined behavior. Two secondary side members are also provided, located laterally outside the main side members and connected by two upper cross members extending above the main and secondary side members. These upper cross members are integral with a horizontal upper face of the side members and may or may not be fixed to the main side members. The upper cross members also have crumple zones. These cross members are located transversely between the primary and secondary side members. Due to this arrangement, the upper cross members can become detached from the side members in the event of a side impact, which is undesirable. In one embodiment, additional deformation zones located between the primary and secondary side members extend transversely in the same plane as these side members but are not aligned with the cross members. While these zones absorb energy, they can also cause deformation of the primary side members and degradation of the energy storage modules, which is undesirable. The structure described in this document also has the disadvantage of being specific: it cannot be adapted to an existing vehicle floor structure.

[0006] Document DE102018206118 describes a battery mounting structure located between the vehicle body side members. This structure comprises longitudinal and transverse beams and is connected to the vehicle side members by deformable crash-box-type housings positioned between the longitudinal beams and the vehicle side members, aligned with the cross members. In one embodiment, the deformable housings are connected to longitudinal beams that are fixed beneath the vehicle side members. However, there is a risk of the mounting structure becoming detached in the event of a collision, particularly if the mounting structure's attachments to the vehicle side members fail. This is because the vehicle side members are not protected in the event of a collision, and therefore the vehicle structure is susceptible to damage.Furthermore, the distance between the side members determines the vehicle's width and the available space for battery installation, depending on the vehicle's transverse dimensions. Consequently, the battery volume is limited, which also limits the vehicle's range.

[0007] There is therefore a need for a vehicle floor structure that provides effective protection for a battery or sensitive component, in particular limiting the risk of the battery or sensitive component becoming detached. There is also a need to easily modify an existing vehicle floor structure to add battery protection. Finally, there is a need for a vehicle floor structure that can be repaired at a lower cost following a side impact.

[0008] To this end, the invention relates to a vehicle floor structure formed of a front part comprising a cab chassis and a rear part comprising two longitudinal members and a plurality of cross members connecting the longitudinal members, the longitudinal members of the rear part being integral with a subframe of the cab chassis, characterized in that each longitudinal member is equipped with a lateral protection device comprising: - a protective beam, one end of which is integral with the cab chassis, said protective beam extending parallel to the side member from the cab chassis on a portion of the length of the rear part, and, - in the extension of each cross member located at the level of the portion of the length of the rear part, a shock absorber housing attached to the protection beam and the longitudinal member.

[0009] Each side protection device thus comprises a side protection beam and one or more shock-absorbing housings, typically at least two. Since the shock-absorbing housings are positioned in line with the cross members, in the event of a side impact the forces exerted on the beams are optimally transferred to the cross members of the floor structure, thus protecting the side members. Furthermore, the front and rear sections of the floor structure can be common to several types of vehicle (internal combustion or electric vehicles), with the side protection devices being added to the rear section and not forming part of it.

[0010] The side members may have a longitudinal cavity. In this case, an internal reinforcement may advantageously be fixed inside the cavity of the side member in the transverse extension of each shock absorber housing, this internal reinforcement extending from one side wall of the cavity to an opposite side wall thereof in a transverse direction. This improves the transfer of forces between the shock absorber housings and the cross members while limiting the crushing of the side member.

[0011] In particular, each internal reinforcement may include at least two abutment walls applied against each lateral wall of the cavity. This improves the compressive strength of the internal reinforcements.

[0012] Preferably, each side protection device can be attached to the floor structure in a removable manner (for example, using screw-nut systems) for easier assembly / disassembly. After-sales repairs in the event of minor impacts are thus faster and less expensive than with a welded solution. It is simply a matter of unscrewing the damaged side protection device and replacing it with a new one. A welded solution would require lengthy and costly bodywork (cutting, welding, painting, etc.). This removable solution also makes it possible to maintain an identical factory process for both thermal and electric floor structure versions.Since the side protection devices are fitted at the end of the vehicle manufacturing cycle, this avoids, for example, problems with the accessibility of welding clamps for making a number of weld points on the floor structure, which would not be the case with a further upstream fitting of the side protection devices... .

[0013] Thus, advantageously, each shock absorber housing can be attached to a side member using screw-nut systems. This allows for easy mounting / dismounting of the dis Positive lateral protection features on the floor structure. In one embodiment, the nut of each screw-nut system can be attached to an internal reinforcement. This facilitates the assembly of the internal reinforcements and shock-absorbing housings to the side members.

[0014] Advantageously, each protective beam can be attached to the cab frame using screw-nut systems. This also facilitates the assembly of the protective beam to the floor structure. In one embodiment, the screw of each screw-nut system can be fixed to the cab frame or to a reinforcing piece fixed to the cab frame. This further facilitates the assembly of the protective beam to the floor structure by pre-positioning and pre-holding the beam relative to the cab frame, by inserting the screws into holes provided for this purpose in flanges or a plate fixed to the end of the protective beam.

[0015] The parts of the side protection device can be joined together by welding when they are made of the same material, or by screwing or riveting when they are made of different materials. However, it is preferable to use the same material for the different parts of a side protection device.

[0016] It is therefore possible to make each lateral protection device from a material different from that of the floor structure stringers, the latter being typically made of steel. Although this is not preferred, each lateral protection device can nevertheless be made of steel: assembly by welding to the stringers is then feasible.

[0017] Thus, each side protection device can be made of aluminum or steel. Aluminum, and in particular extruded aluminum, is preferred to reduce weight compared to a steel solution and to lower tooling costs (tooling for an aluminum part, especially extruded aluminum, is less expensive than tooling for profiling a steel part). Manufacturing the side protection device components from extruded aluminum also allows for variations in the thickness of the different walls. This makes it possible to optimize the device's weight by applying greater thicknesses in areas subjected to high impact stress. It is also easier to work with the shape and number of walls inside each component of the side protection device.

[0018] For better shock absorption, each protective beam may have at least one cavity extending parallel to the longeron, and each shock absorber housing may have at least one cavity extending perpendicular to the longerons.

[0019] By way of example, each protective beam or each shock-absorbing housing may have several cavities separated by an internal wall. Advantageously, these The walls then extend parallel to the plane containing the stringers and crossbeams. Thus, in the event of an impact, these internal walls contribute to the transfer of forces.

[0020] Advantageously, each protective beam and each shock-absorbing housing can extend over a height, measured perpendicular to a plane containing the side members and cross members, equal or substantially equal to the height of the side members. This allows for better absorption of the energy of an impact and a better distribution of this energy over all the side members and cross members.

[0021] The floor structure according to the invention may also include a support structure for at least one energy storage module attached to the floor structure, beneath it. The support structure then extends between the stringers and cross members of the rear section over a portion of its length. In this case, the lateral protection devices extend along the entire length of this portion of the rear section.

[0022] The invention also relates to a motor vehicle comprising a floor structure according to the invention. The invention is particularly suited to electric or hybrid utility vehicles.

[0023] Other features and advantages of the invention will become apparent from the following description of several particular embodiments of the invention, given by way of example but not limitation, with reference to the accompanying drawings in which:

[0024] [Fig-1] [Fig.1] is a perspective view of a vehicle floor structure according to one embodiment of the invention.

[0025] [Fig.2] [Fig.2] is an enlarged view of part of [Fig.1].

[0026] [Fig. 3] [Fig. 3] shows an exploded view of a side protection device of a floor structure according to an embodiment of the invention.

[0027] [Fig.4] [Fig.4] represents a partial view from below of the floor structure according to an embodiment of the invention.

[0028] [Fig.5] [Fig.5] represents a partial top view of a floor structure according to an embodiment of the invention.

[0029] [Fig.6] [Fig.6] is an enlarged view of the floor structure of [Fig.5].

[0030] [Fig.7] [Fig.7] is a cross-section of [Fig.3] taken along a traverse.

[0031] In this description, the terms front, rear, upper, and lower refer to the front and rear directions of the vehicle when the floor structure according to the invention is mounted on the vehicle. The X, Y, and Z axes correspond respectively to the longitudinal (front to rear), transverse (oriented to the right of the vehicle), and vertical axes of the vehicle, the latter resting on the ground. The vertical direction thus corresponds to the direction of gravity.

[0032] Fig. 1 represents a vehicle floor structure 10 formed of a front part 12 comprising a cab chassis 120 and a rear part 14 comprising two longitudinal members 140, 141 and a plurality of cross members 143 connecting the longitudinal members 140, 141. The longitudinal members 140, 141 of the rear part 14 are integral with a subframe 121 of the cab chassis 120.

[0033] Typically, for increased rigidity, stringers and crossbeams, usually made of steel, are elongated hollow pieces, preferably with a closed cross-section, for example, rectangular or parallelepiped-shaped. These elongated pieces can be formed from two parts joined together, defining an internal cavity extending along their longitudinal direction. The internal cavity 144 of the stringers thus extends along the longitudinal direction of the floor structure 10, while the internal cavity 145 of the crossbeams extends along the transverse direction of the floor structure 10. These two parts can comprise a first part with a U-shaped cross-section, the opening of which is closed by the second, substantially flat, part. However, the invention is not limited to a particular shape of the two parts forming a stringer or crossbeam.

[0034] According to the invention, the floor structure 10 is equipped on each of its sides by a lateral protection device 20, fixed to a longitudinal member 140, 141.

[0035] As shown in Figures 2 and 3, each side protection device 20 comprises a protective beam 22, one end 220 of which is fixed to the cab frame 120 and the other end 221 is free. The protective beam 22 extends parallel to the side members 140, 141 from the cab frame 120 along a portion of the rear part of the floor structure 10.

[0036] Each side protection device 20 further comprises, extending from each cross member 143 located at the length of the rear section 14, a shock absorber housing 24. This housing is integral with the protective beam 22 and the longitudinal member 140 or 141 to which the side protection device 20 is attached. Thus, each shock absorber housing 24 is aligned with a cross member 143 in the transverse direction, thereby transferring the shocks experienced by the protective beam 22 from one side of the vehicle to the other via the cross members 143.

[0037] An example of an embodiment of a lateral protection device 20 is shown in [Fig. 3]. Here, the protection beam 22 comprises three cavities 222, 223, 224 separated by two internal walls 225, 226. These cavities 222, 223, 224 extend along the longitudinal direction of the protection beam 22, and are therefore parallel to the stringers 141, 142 when the lateral protection device 20 is assembled to the floor structure 10, as can be seen in [Fig. 1]. The internal walls 225, 226 also extend horizontally (in the XY plane), namely parallel to the direction of a lateral impact for better absorption of its energy. One The ends 220 of the protective beam 22 are fixed to a plate 227 with holes drilled for its attachment to the cab chassis 120. The side protection device 20 further includes three shock absorber housings 24. Each shock absorber housing 24 has one end 240 integral with the protective beam 22 and another end 241 intended to be fixed to a side member 140, 141. In this example, each shock absorber housing 24 has three cavities 242, 243, 244 separated by two internal walls 245, 246. These cavities extend along the longitudinal direction of the shock absorber housings 24 and are therefore perpendicular to the side members 141, 142 when the side protection device 20 is assembled. As with the protective beam 22, the internal walls 245, 246 of the shock absorber housings 24 also extend horizontally, parallel to the direction of a lateral impact.The end 241 of each shock absorber housing 24 is fixed to a plate 247 with holes drilled for its attachment to the side member. In addition, the protective beam and each of the shock absorber housings 24 have a height, measured perpendicular to a plane containing the side members and cross members, in other words measured along the vertical direction, which is equal to or substantially (90 to 99%) equal to the height of the side members.

[0038] In this example, the various parts of the side protection device 20 are advantageously made of aluminum, in particular by extrusion, and are joined together by weld beads. It is then easy to dimension the protective beam 22 and each shock-absorbing housing 24 optimally to absorb the energy of a defined side impact. In particular, a wall thickness and / or height and / or width (measured in the transverse direction when the side protection device is assembled to the floor structure 10) of each part can be determined to be appropriate for absorbing the energy of a defined side impact.

[0039] The invention is not, however, limited to this embodiment, and in particular to the number of shock-absorbing housings 24, which will depend on the length of the protective beam 22 and the number of cross members 143 extending perpendicularly to the stringers on this part of the floor structure. Nor is the invention limited to the number of cavities in each component of a lateral protection device 20. Thus, each component could have one, two, or more cavities depending on the desired resistance. The invention is also not limited to specific dimensions of the components and / or the thickness of their walls, which can be adapted according to the desired shock-absorbing properties. Finally, each of these components could be made of steel rather than aluminum. In this case, when a component has several cavities, it is made of several parts assembled together.

[0040] Regardless of the embodiment of a side protection device 20, it is preferably attached to the floor structure 10 in a removable manner, particularly by means of screw-nut systems. Thus, in the example shown, the end 220 of the protection beam 22 is attached to the cab chassis 120 by screw-nut systems 223, here three in number, while the end 240 of each shock absorber housing 24 is attached to the side member by screw-nut systems 248, here four in number. The invention is, of course, not limited by the number of screw-nut systems 228, 248, which may be chosen according to the desired impact resistance of the assembly.

[0041] To facilitate assembly, the screws of the screw-nut systems 228 can advantageously be secured to the cab frame 120 or to a reinforcing piece 122 attached to the cab frame. This reinforcing piece 122, shown [Fig. 4], is, for example, a steel piece welded to the cab frame 120 and extending vertically. Securing these screws to this reinforcing piece 122 (or to the cab frame 120) allows the side protection device 20 to be pre-positioned and pre-held before the nuts are fitted, by inserting the screws through the holes in the plate 227 at the end 220 of the protection beam. Assembly can also be facilitated by securing the nuts of the screw-nut systems 248 of the shock absorber housings 24 to the side member or to an optional internal reinforcement 30 located inside the cavity 144 of a side member.

[0042] This internal reinforcement 30 is described in more detail with reference to Figures 5 and 6. It is fixed inside the cavity 144 of the longeron 140, 141, extending from each shock-absorbing housing 24. Thus, the floor structure 10 is equipped with as many internal reinforcements 30 as the side protection device 20 has shock-absorbing housings 24. Each internal reinforcement 30 extends from a longitudinal side wall 144a of the cavity 144 of the longeron to an opposite longitudinal side wall 144b of the cavity in the transverse direction. In the example shown in Figures 5 and 6, each internal reinforcement 30 has two buttresses 301, 302 applied against the side wall 144a of the cavity and two buttresses 303, 304 applied against the side wall 144b of the cavity.The docking walls 301, 302 carry the welded nuts of the screw-nut systems 248, which will allow the shock absorber housings 24 to be attached to the longeron. The two other docking walls 303, 304 can be attached to the side wall 144b by spot welds. The internal reinforcement 30 can be made very simply, for example by cutting and bending a sheet of steel or aluminum. In the example, it is formed from a sheet of metal bent into a U-shape, each edge of a flange of the U being bent at approximately a right angle outwards from the U to form a docking wall (see [Fig. 6]).

[0043] The floor structure 10 according to the invention thus makes it possible to protect one or more Energy storage modules 40, such as electric battery modules, are typically supported by a support structure 50 which is attached to the floor structure, below it, generally to the side members 140, 141. As shown in Figures 1 and 7, the support structure 50 extends between the side members 140, 141 and the cross members 143 of the rear section over a portion of its length. The support structure 50 also extends partially under the underbody of the cab chassis 120. As shown in these figures, the two side protection devices 20 extend along the entire length of the portion of the rear section over which the support structure 50 extends.Thus, in the event of a side impact, the side protection device 20 can absorb the impact energy, limit the deformation of the floor structure longitudinal member to which it is attached, and thus limit the risk of failure of the fixings of the support structure 50 to this longitudinal member.

[0044] The side protection devices 20 allow for the selection of a support structure 50 designed to contribute to the protection of the energy storage modules 40 or not. It should be noted that this type of side protection device 20 can also be fitted to an internal combustion engine vehicle when a sensitive component (tank or other) that one wishes to protect from side impacts is attached to the floor structure near the cab chassis. The invention can thus be applied to both an internal combustion engine vehicle and an electric vehicle, although use in an electric or hybrid vehicle is preferred.

Claims

Demands

1. A vehicle floor structure (10) formed of a front portion (12) comprising a cab chassis (120) and a rear portion (14) comprising two side members (140, 141) and a plurality of cross members (143) connecting the side members, the side members of the rear portion being integral with a subframe (121) of the cab chassis, each side member (140, 141) being equipped with a side protection device (20) comprising: - a protective beam (22) one end (220) of which is integral with the cab chassis, said protective beam extending parallel to the side member from the cab chassis over a portion of the length of the rear portion, and, - in line with each cross member (143) located at the level of the portion of the length of the rear portion, a shock absorber housing (24) integral with the protective beam and the side member, the floor structure being characterized in that the side members (140,141) have a longitudinal cavity (144) and in that an internal reinforcement (30) is fixed inside the cavity of the spar in the transverse extension of each shock absorber housing (24), this internal reinforcement extending from a lateral wall (144a) of the cavity to an opposite lateral wall (144b) thereof in a transverse direction.

2. Floor structure (10) according to claim 1, characterized in that each internal reinforcement (30) comprises at least two abutment walls (301, 302; 303, 304) applied against each lateral wall (144a, 144b) of the cavity.

3. Floor structure (10) according to any one of claims 1 or 2, characterized in that each shock absorber housing (24) is fixed to a stringer (140, 141) by screw-nut systems (248), optionally the nut of each screw-nut system is integral with an internal reinforcement (30).

4. Floor structure (10) according to any one of claims 1 to 3, characterized in that each protective beam (22) is fixed to the cabin frame (120) by screw-nut systems (228), optionally the screw of each screw-nut system is integral with the cabin frame (120) or with a reinforcing piece (122) integral with the cabin frame.

5. Floor structure (10) according to any one of claims 1 to 4, characterized in that each side protection device (20) is made of aluminium or steel, preferably aluminium.

6. Floor structure (10) according to any one of claims 1 to 5, characterized in that each protective beam (22) has at least one cavity (222, 223, 224) extending parallel to the stringer, and each shock absorber housing (24) has at least one cavity (242, 243, 244) extending perpendicular to the stringers.

7. Floor structure (10) according to any one of claims 1 to 6, characterized in that each protective beam (22) and each shock-absorbing box (24) extends over a height, measured perpendicular to a plane containing the stringers and crossbeams, equal or substantially equal to the height of the stringers.

8. Floor structure (10) according to any one of claims 1 to 7, characterized in that it comprises a support structure (50) for at least one energy storage module (40) fixed to the floor structure (10), below it, the support structure (50) extending between the stringers (140, 141) and the cross members (143) of the rear part (14) over a portion of its length, and in that the side protection devices (20) extend over the entire length of this portion of the rear part.

9. Motor vehicle characterized in that it comprises a floor structure (10) according to any one of claims 1 to 8.

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