VEHICLE REAR AXLE ATTACHMENT DEVICE

Abstract

The invention relates to a device for attaching a rear axle to the floor of a vehicle, comprising a floor reinforcement crossmember (14) positioned transversely between two parallel lateral floor members (7) at least at the level of a mounting zone for a rear axle attachment member (5) on each member (7), characterized in that it comprises a connecting member (13) between each end of the crossmember (14) and the members (7), said member (13) being configured (16) to define a receiving recess (19) for the base (18) of the attachment member (5). The invention also relates to a vehicle equipped with such a device. Figure to be published with the abstract: Fig. 2

Description

Title of the invention: DEVICE FOR FIXING A VEHICLE REAR AXLE

[0001] The invention relates to a device for fixing a rear axle of a vehicle.

[0002] Here, the term vehicle designates a car, a van, a truck, a public transport vehicle, a public works or agricultural machine.

[0003] More and more vehicles are either 100% electric or hybrid. As a result, the weight of the vehicle increases with the addition of batteries compared to the weight of the same model of fully thermal vehicle. Although this increase in weight affects all types of vehicles, it is particularly noticeable for city and compact vehicles, that is to say for vehicles with a length of less than 4.5 m. Thus, the axles which form the element supporting the wheels and ensuring the connection between the wheels and the chassis or floor of the vehicle must withstand forces greater than those encountered for a thermal vehicle of the same type. This is particularly true for the rear axles of vehicles, the batteries being generally housed on the rear part of the chassis. DE-B-102017 207 623 discloses a corner reinforcement of a rear axle cross member of a vehicle with a hollow cross section.The cross member is connected by its front and rear edges to the floor parts, thus forming, together with the corner reinforcement, a three-layer structure of material. Such a solution is particularly intended to reinforce the rigidity of the rear axle of a vehicle.

[0004] The invention proposes another solution making it possible to improve the strength of the attachment of the rear axle to the floor of the vehicle while preserving the rigidity of the axle.

[0005] To this end, the invention relates to a device for fixing a rear axle to the floor of a vehicle comprising a floor reinforcement crossmember positioned transversely between two lateral and parallel side members of the floor at least at one zone of fixing of a member for fixing the rear axle on each side member, characterized in that it comprises a connecting member between each end of the crossmember and the side members, said member being configured to define a housing for receiving the base of the fixing member.

[0006] Thus, thanks to the invention, the connection between the cross member and the floor is reinforced by the connecting member. This member not only makes it possible to define a support on the side member at the level of the fixing member, but also creates an extra thickness of material at the level of the fixing zone by providing several welding points at this level. This creates a reinforcement between the cross member and each side member which optimizes the maintenance of the rear axle on the floor without affecting the rigidity of the axle while absorbing the forces generated by the weight of the batteries.

[0007] According to advantageous but not mandatory aspects of the invention, such a fixing device may comprise one or more of the following characteristics:

[0008] The connecting member comprises a concave end defining the receiving housing of the base of the fixing member, the latter being cylindrical with a circular base.

[0009] The edges of the concavity of the connecting member form two tabs sized to surround by complementary shape at least partially the fixing member when the latter is in place on the fixing zone.

[0010] The shape and dimensions of the concavity of the connecting member are adapted to surround the base of the fixing member over at least 30% of its circumference.

[0011] The legs of the connecting member each define at least one welding point between at least the spar and the connecting member.

[0012] The connecting member is welded, by its end opposite the concave one, to the crosspiece.

[0013] The connecting member is a single piece and made in one piece with the floor reinforcement crosspiece.

[0014] the invention also relates to a vehicle equipped with a device for fixing the rear axle to the floor in accordance with at least one of the preceding characteristics.

[0015] The invention will be better understood and other advantages thereof will appear more clearly on reading the description which follows, given solely by way of non-limiting example and with reference to the appended drawings in which:

[0016] [Fig-1] is a simplified and partial perspective view of a rear axle of vehicle fixed to the floor of the vehicle and conforming to an embodiment of the invention,

[0017] [Fig.2] is an enlarged view of detail II in [Fig. 1],

[0018] [Fig.3] is an enlarged perspective view of part of the area of connection illustrated in [Fig.2], without the rear axle and without the fixing member and

[0019] [Fig.4] is a perspective and partial view according to arrow IV in [Fig.3] of a part of the connection area illustrated in [Fig.3].

[0020] [Fig.l] illustrates a portion of the rear floor or chassis 1 of a vehicle with a rear vehicle axle 2 mounted on the floor 1. On current vehicles, the support of the entire weight of the vehicle is generally ensured by a so-called monocoque chassis which forms a single element with the bodywork. Also, the terms floor or chassis will be used interchangeably hereinafter. For the record, an axle, rear or front, supports the wheels and ensures the connection of the latter with the chassis 1. In Figures 1 to 4, the floor 1 is seen from its lower face 3, that is to say the face oriented in the direction of the vehicle's traffic lane. The axle 2 is mounted on the floor 1 at dedicated areas 4, configured for the passage of the wheels. Here, the axle 2 is shown without the wheels, only part of the suspension and braking elements are visible. The axle 2 is a multi-link type rear axle. Alternatively, it could be of another type. It is fixed to the floor 1 by fixing members 5, here four in number, distributed in pairs, parallel and arranged on either side of the ends of the axle 2 which support the wheels. The fixing members 5 are connected to the floor 1 at the level of fixing zones 6 provided on the floor 1. The fixing zones 6 are delimited, on each side of the floor 1, by edges reinforced by elements called side members 7 and defining the outer edges of the floor 1. The side members 7 are capped at the level of each zone 6 by reinforcement pieces called side member reinforcement 8, one of which is visible in [Fig.3].The securing of each fixing member 5 to the floor 1 at the level of zone 6 is obtained by a bolt 9 passing through the fixing member 5, the side member reinforcement 8, the side member 7 and screwed into a nut 10 placed under the side member 7.

[0021] As is apparent from Figures 1 and 2, the fixing members 5 are here of cylindrical shape with a circular base. Subsequently, the term cylinder will also be used to designate the fixing members. Alternatively, the fixing members are of another shape and / or dimensions, for example cylindrical with a non-circular base. Likewise, their number may be different. The cylinders 5 are advantageously configured as damping elements. For this purpose they are, at least in part, made of elastomer, which makes it possible to limit the vibrations transmitted by the rear axle 2 to the floor 1.

[0022] [Fig. 2] is a larger scale view of the detail of [Fig. 1] in which a fixing member 5 integral with an arm 11 constituting the rear axle 1 can be seen. The fixing member 5 is mounted on the side member reinforcement 8 and held in position by the bolt 9. The head of the latter is supported and blocked in translation by a locking tab 12 placed on the upper outlet of the cylinder 5. A connecting member 13 is positioned in the extension of a reinforcing crossmember 14. Such a crossmember 14 transversely connects the lateral and parallel edges of the floor 1, therefore the side members 7, at the level of the fixing zone 6 of the rear axle 1. The purpose of such a crossmember 14 is to stiffen and reinforce the structure of the floor 1 at the level of the fixing zone 6 of the rear axle 1. Each end of the crossmember 14 is equipped with a connecting member 13.Each member 13 provides the connection between one end of the crosspiece 14 and the spar reinforcement 8 in place on the spar 7 located in the extension of this end.

[0023] The connecting member 13 is, in the example, a part with a cross-section of a shape complementary to that of the end of the crosspiece 14, therefore here in a U. The dimensions of the member 13 are slightly greater than those of the end of the crosspiece 14, which allows the member 13 to cover the end of the crosspiece 14. The edges of the member 13, along its length, are folded outwards, thus defining tabs 15 allowing the fixing, for example by welding, of the member 13 on the floor 1. The lateral edges of one end 16 of the member 13 intended to be in contact with the side member reinforcement 8 are also folded outwards and define tabs 17 for fixing, for example by welding, on the side member 7, as is apparent from [Fig.3].

[0024] The end 16 of the connecting member 13 is configured to define a receiving housing 19 for the base 18 of the fixing member 5. This receiving housing 19 has a shape complementary to the base 18 of the fixing member 5, i.e. here concave. Subsequently, the terms and expressions “housing”, “receiving housing”, “concavity”, “concave part” will be used indiscriminately and designated by the reference 19. The concavity 19 is in the example semi-circular with a diameter slightly greater than the external diameter of the base 18 of the cylinder 5. The concave part 19 comes to bear, by cooperation of shape, on at least a portion of the circumference of the base 18 of the cylinder 5. As appears in figures 3 and 4, the concavity 19 is produced in the central part of the end 16 of the member 13. Edges 20 of the concavity 19 are thus defined, the length and width of which are variable and form support tabs for the member 13 on the reinforcement 8.The support legs 20 surround the base 18 of the cylinder 13 over at least 30% of its circumference when the cylinder 13 is in place on the reinforcement 8. It is understood that depending on the dimensions and shapes of the support legs 20, the base 18 of the member 13 is more or less surrounded.

[0025] As is apparent from Figures 2 to 4, the support tabs 20 have sufficient dimensions to allow the production of at least one welding point, advantageously two, on each tab 20. As appears in [Fig. 4], at the level of the fixing zone 6 the connecting member 13 produces, by being in support on the side member reinforcement 8 and the side member 7, a triple thickness of material. Such a surplus of material at the level of the fixing zone 6 of the rear axle 2 on the floor 1 reinforces the rigidity and the solidity of the floor 1 at the level of this fixing zone 6. The presence of the support tabs 20, of the tabs 15 and 17 easily allows optimal fixing by welding, or by another technique known per se, of the member 13 to the floor 1.

[0026] Thanks to the invention with reduced cost, minimal weight and space requirement, without affecting the nominal space requirement of the floor 1, the connection between the floor 1 and the rear axle 2 is reinforced by establishing an additional connection between the reinforcing cross member 14 of the floor 1 and the fixing zone 6 of the rear axle 2. Here the invention is described for a multi-link type rear axle of a motor vehicle. As a variant it is applied to a rear or front axle of another type and / or for a vehicle receiving significant loads other than a hybrid, electric, motor vehicle or not, for example a trailer.

Claims

Claims

1. Device for fixing a rear axle (2) to the floor (1) of a vehicle comprising a reinforcing cross member (14) of the floor (1) positioned transversely between two lateral and parallel side members (7) of the floor (1) at least at one fixing zone (6) of a fixing member (5) of the rear axle (2) on each side member (7), characterized in that it comprises a connecting member (13) between each end of the cross member (14) and the side members (7), said member (13) being configured to define a receiving housing (19) of the base (18) of the fixing member (5).

2. Device according to claim 1, characterized in that the connecting member (13) comprises a concave end (16) defining the receiving housing (19) of the base (18) of the fixing member (5), the latter being cylindrical with a circular base.

3. Device according to claim 2, characterized in that the edges of the concavity of the connecting member (13) form two tabs (20) sized to surround by complementary shape at least partially the fixing member (5) when the latter is in place on the fixing zone (6).

4. Device according to claim 3, characterized in that the shape and dimensions of the concavity of the connecting member (13) are adapted to surround over at least 30% of its circumference the base (18) of the fixing member (5).

5. Device according to claim 3, characterized in that the legs (20) of the connecting member (13) each define at least one welding point between at least the spar (7) and the connecting member (13).

6. Device according to claim 1, characterized in that the connecting member (13) is in one piece and made in one piece with the reinforcing crosspiece of the floor.

7. Device according to claim 2, characterized in that the connecting member (13) is welded, by its end opposite the concave end (16), to the crosspiece (14).

8. The invention also relates to a vehicle equipped with a device for fixing a rear axle (2) to the floor (1) of the vehicle according to any one of the preceding claims.

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