AUTOMOTIVE POWERTRAIN UNIT EQUIPPED WITH A FIXED ELECTRICAL BOX UNDERNEATH

Abstract

Motor vehicle powertrain comprising an electrical housing (10) fixed by screws (34, 40) below the unit, and an intermediate support (26) fixed to the unit by a first set of screws (34) arranged along a substantially horizontal axis, receiving the housing (10) by a second set of screws (40) which are arranged along a substantially vertical axis and engaged from below. Figure 3

Description

Title of the invention: AUTOMOBILE POWERTRAIN EQUIPPED WITH A FIXED ELECTRICAL BOX UNDERNEATH

[0001] The present invention relates to a motor vehicle powertrain equipped with an electrical box fixed underneath, as well as a method of assembling this vehicle and a motor vehicle comprising such a powertrain.

[0002] A known type of electric vehicle powertrain, shown in particular by document CN-U-216761427, comprises an electric machine receiving a speed reducer disposed at one end, and electronic boxes including a machine controller, an on-board battery charger, a DC-DC current converter and a power distributor which are fixed directly on this group.

[0003] Furthermore, it is known to provide vehicles with a front subframe forming a rigid platform supporting this type of powertrain, receiving on the sides the suspension arms of the drive wheels, and at the rear of the unit a steering box comprising a rack arranged transversely. The rigid front subframe connects these elements to the vehicle body, which can transmit significant forces during driving.

[0004] A known type of front cradle, presented in particular by document FR-A1-3128686, comprises two superimposed sheets welded together forming a box receiving the steering box and the suspension arms, which extend forward by two added longitudinal members.

[0005] Generally, powertrains are prepared in a workshop on a transport pallet which, in an assembly line, moves to a succession of workstations to receive its equipment in order to form an assembly ready to be assembled on the vehicle.

[0006] However, for an electrical box fixed under the powertrain mounted on its pallet, there is no access to vertically arranged screws for tightening from below or above. In this case, it is known to fix the box by horizontally arranged screws that screw into a vertical face formed under the powertrain.

[0007] However, after the powertrain is mounted in the vehicle on its cradle, in some cases the horizontal bolts may be located opposite components, for example opposite the steering box, which, during maintenance or repair, prevent the passage of a tool to access them. It is necessary then major dismantling of the vehicle is required to access these screws, for example removing the subframe with the steering box, which represents a delicate, long and costly operation.

[0008] It should be noted that electrical boxes fixed under the powertrain, for example a current converter which powers an electric steering without mechanical link, located just in front of the steering box, are under the vehicle more exposed to water spray and gravel impacts which can lead to repair operations.

[0009] The present invention is specifically intended to avoid these problems of the prior art.

[0010] For this purpose, it proposes a motor vehicle powertrain comprising an electrical housing fixed by screws below the unit, this powertrain being remarkable in that it includes an intermediate support fixed to the unit by a first set of screws arranged along a substantially horizontal axis, receiving the housing by a second set of screws which are arranged along a substantially vertical axis and engaged from below.

[0011] One advantage of this powertrain is that during vehicle assembly It allows the electronic housing to be prepared with its intermediate support connected by the second set of vertical screws, forming a sub-assembly which is then easily fixed under the powertrain placed on an assembly pallet, thanks to free lateral access to the first set of screws arranged horizontally above this pallet.

[0012] The powertrain assembly then allows, during maintenance operations, easy access under the vehicle to the second set of vertical screws to detach the housing from its intermediate support. This provides easy access to the housing for disassembly and reassembly during maintenance operations.

[0013] The powertrain according to the invention may further comprise one or more of the following characteristics, which may be combined with each other.

[0014] Advantageously, the intermediate support is formed by a folded sheet metal.

[0015] Advantageously, the intermediate support comprises an upper part resting on the top of the case, forming a band which extends at each end with a vertical part coming onto one side of the case.

[0016] In this case, advantageously the upper part of the support has legs arranged in a vertical plane, each receiving a screw from the first set of screws.

[0017] Advantageously, the legs are arranged along two parallel planes spaced apart.

[0018] Advantageously, the vertical parts of the support receive the screws from the second set of screws.

[0019] In this case, advantageously, the base of the vertical parts has studs fitted above edges protruding from the housing, each of which receives from below a screw from the second set of screws.

[0020] Advantageously, the second set of screws comprises three screws arranged in a triangle.

[0021] The invention also relates to a method of assembling a powertrain comprising any one of the preceding claims, remarkable in that it includes a step of preparing a sub-assembly comprising the housing assembled on its support by the second set of screws, then a step of fixing this sub-assembly on the powertrain by the first set of screws.

[0022] The invention further relates to a motor vehicle remarkable in that it comprises a powertrain including any of the preceding characteristics including an electric traction machine.

[0023] The invention will be better understood and other features and advantages will become more apparent upon reading the following description given by way of example, with reference to the accompanying drawings in which:

[0024] [Fig-1] shows the casings of an electric powertrain according to the invention positioned on the front cradle of a vehicle;

[0025] [Fig.2] shows the housings of this group with the electrical box on a pallet of assembly line;

[0026] [Fig.3] presents the electrical box with its intermediate support of this group;

[0027] [Fig.4] is a rear view of this housing fixed to the casing of the electric machine; and

[0028] [Fig.5] presents the underside of the vehicle showing access to the electrical box.

[0029] Throughout the document the upper or top direction, along the vertical axis Z, is relative to a vehicle placed on a horizontal ground, the front direction AV along the longitudinal axis X is relative to its direction of travel.

[0030] Figure 1 shows the housing of an electric powertrain machine. electric 2, comprising on one side following the transverse direction of the vehicle Y a transmission 4, which is placed on a front cradle 8 receiving at the rear of this group a steering box 6 having an electrical connection with the steering wheel.

[0031] A flat electrical box 10 of overall parallelepiped shape, comprising a DC / DC direct current converter which supplies the electric steering via a cable bundle 12 to deliver a power current with an appropriate voltage, is fixed flat under the machine housing 2, just in front of the steering box 6 in order to provide a short electrical connection between them.

[0032] Figure [Fig. 2] shows the housings 2, 4 with the electrical box 10 arranged underneath, placed on an assembly pallet 14 which does not allow vertical access under this case.

[0033] Figures 3 and 4 show the electrical housing 10 comprising a horizontal upper face 20, two lateral faces 22 parallel to the longitudinal axis X, the face on the right side of the vehicle having a connector 24, and a rear face 18 showing the start of the harness 12.

[0034] An intermediate support 26 formed by a folded sheet metal fitted onto the housing 10, has an upper part 28 forming an elongated band along the transverse direction Y, which extends at each end after a fold by a vertical part 32 arriving at the bottom of the housing.

[0035] The support 26 has three tabs 30 arranged in a plane perpendicular to the longitudinal axis X, each receiving a screw from a first set of screws 34 screwed onto vertical faces of the machine housing 2 from the rear side.

[0036] The upper band of the support 28 has on its front edge a first tab 30 bent upwards, each of its ends has on its rear edge a lateral tab 30 bent outwards from the vehicle, which gives a fixing of this support on two parallel planes spaced from the machine casing 2 ensuring stability.

[0037] A rigid fixing of the support 26 is obtained, easily accessible by the first set of screws 34 arranged horizontally, for a powertrain placed on the pallet 14 of an assembly line of this group.

[0038] The support 26 has at the base of its vertical parts 32 three studs 36, comprising two studs on the right side and one stud on the left side, fitted above a lip 38 protruding from the base of the housing 10, which each receive a vertical screw coming from below from a second set of screws 40. The support thus rigidly holds the housing 10 by covering it and fixing it on its two sides by three screws 40 arranged in a triangle which ensures the stability of the fixing.

[0039] Figure 5 shows the electrical box 10 covered underneath on its rear part by the cradle 8, but leaving free vertical access to the second set of screws 40 which allows them to be easily unscrewed during a maintenance operation on the vehicle to extract this housing.

[0040] During the assembly of the powertrain, a simple assembly of the sub-assembly formed by the housing 10 with its intermediate support 26 under this group placed on a pallet 14 is obtained, with the first set of screws 34 coming opposite the steering box 6 after its assembly in the vehicle, and which are then no longer accessible without significant disassembly.

[0041] We then have quick access to the second set of screws 40 under the vehicle to detach the housing 10 from its intermediate support 26, which in the lower part of the vehicle is exposed to projections, in order to carry out a revision or an exchange.

Claims

Demands

1. Motor vehicle powertrain comprising an electrical housing (10) fixed by screws (34, 40) below the unit, characterized in that it comprises an intermediate support (26) fixed to the unit by a first set of screws (34) arranged along a substantially horizontal axis (X), receiving the housing (10) by a second set of screws (40) which are arranged along a substantially vertical axis (Z) and engaged from below.

2. Powertrain according to claim 1, characterized in that the intermediate support (26) is formed by a bent sheet metal.

3. Powertrain according to claim 1 or 2, characterized in that the intermediate support (26) has an upper part (28) placed on top of the housing (10), forming a band which extends at each end by a vertical part (32) coming onto one side of the housing (10).

4. Powertrain according to claim 3, characterized in that the upper part (28) of the support (26) has tabs arranged in a vertical plane (30) each receiving a screw from the first set of screws (34).

5. Powertrain according to claim 4, characterized in that the legs (30) are arranged along two parallel planes spaced apart.

6. Powertrain according to any one of claims 3 to 5, characterized in that the vertical parts (32) of the support (26) receive the screws of the second set of screws (40).

7. Powertrain according to claim 6, characterized in that the base of the vertical parts (32) has studs (36) fitted above rims protruding from the housing (38), each of which receives from below a screw from the second set of screws (40).

8. Powertrain according to any one of the preceding claims, characterized in that the second set of screws (40) comprises three screws arranged in a triangle.

9. A method for assembling a powertrain according to any one of the preceding claims, characterized in that it comprises a step of preparing a subassembly including the housing (10) assembled onto its support (26) by the second set of

10. screws (40), then a step of fixing this sub-assembly onto the powertrain by the first set of screws (34). Motor vehicle, characterized in that it comprises a powertrain according to any one of claims 1 to 8 comprising an electric traction machine (2).