Electric or hybrid vehicle with electric cables connecting the machine to the battery

Abstract

Hybrid or electric motor vehicle comprising, at the front of the vehicle, a cradle (6) arranged under a powertrain (2) equipped with an electric traction machine, a traction battery (12) arranged under the passenger compartment of the vehicle, power cables (14) connecting the battery (12) to the electric machine, and comprising a support (18) fixed to the cradle (6), holding in place the cables (14) between the powertrain (2) and the battery (12), the support (18) comprising a force-limiting system so that, when the cradle (6) is pushed back under the effect of a front impact with a movement of the cables (14) which apply to the support (18) a force exceeding a threshold, this support (18) undergoes a detachment, a breakage or a programmed crumpling, releasing its hold of the cables (14).

Description

[0001] DESCRIPTION

[0002] Title: ELECTRIC OR HYBRID VEHICLE WITH ELECTRIC CABLES CONNECTING THE MACHINE TO THE BATTERY

[0003] 001. The present invention claims priority from French application No. 2210748 filed on 18.10.2022, the content of which (text, drawings and claims) is incorporated here by reference.

[0004] 002. The present invention relates to an electric or hybrid motor vehicle comprising an electric traction machine arranged at the front of the vehicle, connected by electric power cables to a battery arranged under the passenger compartment.

[0005] 003. A known type of electric motor vehicle, presented in particular by document FR-A1 -3108067, comprises in the front engine compartment of the vehicle a cross member fixed by its ends to two side rails.

[0006] 004. A power unit comprising an electric traction machine arranged in a transverse direction of the vehicle, and a reducer driving the front wheels of the vehicle, is fixed under the cross member by elastic connections. Stops comprising flexible end-of-travel elements are fixed to the power unit to limit its maximum travel in order to keep this unit within a defined space.

[0007] 005. The powertrain comprises a housing comprising power electronics directly fixed on top of the electric machine, to obtain a connection transmitting the power which is very short. The housing receives the electrical energy from a traction battery via electric power cables having a large cross-section in order to transmit a high amperage.

[0008] 006. In the case of a flat battery box fixed under the passenger compartment of the vehicle, the power cables then run from the powertrain, to pass under the front bulkhead separating the passenger compartment from the engine compartment, and reach the front face of the battery box. For vehicles with a front subframe forming a rigid platform arranged under the powertrain, which supports the suspension arms of the front axle, the power cables then pass above the rear part of this subframe.

[0009] 007. For these vehicles comprising an electric machine at the front and a battery further back under the passenger compartment, it is known to hold the power cables above the rear part of the cradle, by a support fixed directly on this cradle. We then obtain for these cables of large section, presenting a fairly high rigidity, a first length between the powertrain and the support, then a second length going from this support to the battery.

[0010] 008. Generally, for their approval, vehicles are subjected to frontal impact tests on a transverse wall or on a laterally offset obstacle, which cause the entire powertrain to move backward. In order to prevent mechanical components from entering the passenger compartment, which could be dangerous for passengers, the powertrain moves backward and the rear part of the subframe slides under the bulkhead that protects the passenger compartment.

[0011] 009. In this case, we obtain a reduction in the length available for the power cables, and a recoil of their support fixed on the cradle which moves the intermediate holding point causing a pronounced bending of these cables which are relatively rigid, by applying high stresses on them. In addition, the guidance of the cables by the support causes unforeseen bends of these cables which can cause problems of high pressure on the environment which can damage the cables or their connections, cables which are no longer functional or dangerous short circuits.

[0012] 010. The present invention aims in particular to avoid these problems of the prior art.

[0013] 011. To this end, it proposes a hybrid or electric motor vehicle comprising at the front of the vehicle a cradle arranged under a powertrain equipped with an electric traction machine, a traction battery arranged under the passenger compartment of the vehicle, power cables connecting the battery to the electric machine, and comprising a support fixed to the cradle, providing support for the cables between the powertrain and the battery, this vehicle being remarkable in that the support comprises a force limitation system, which, when the cradle moves back under the effect of an impact on the front of the vehicle with a movement of the cables which apply a force exceeding a threshold to the support, this support undergoes a detachment, a rupture or a programmed bending by releasing the support for the cables.

[0014] 012. An advantage of this vehicle is that by a simple adaptation of the power cable support, which can be done economically, by adapted shapes of this support, one automatically obtains during a sufficient recoil of the powertrain causing a displacement of the highly rigid power cables, a relaxation of this support. 013. With this relaxation of the connection between the cables and the cradle during the recoil of this cradle, one obtains cables which can take, depending on their rigidity, freer bends, with larger bend radii, which limits the stresses applied to them. The power cables are better protected against pressures on the environment, which can cause in particular damage to the insulation or ruptures, which makes it possible to avoid serious incidents such as a fire. These cables can remain operational.

[0015] 014. The hybrid or electric motor vehicle according to the invention may also include one or more of the following characteristics, which may be combined with each other.

[0016] 015. Advantageously, the support is formed by a cut and folded sheet metal.

[0017] 016. Advantageously, the support has a clip fixed on it which receives the cables.

[0018] 017. According to an embodiment for a traction of the cables on the support exceeding the force threshold, these cables are released from the clip by a detachment.

[0019] 018. In this case, advantageously the clip comprises grooves each having a section forming an arc of a circle exceeding 180°, receiving a cable held by clipping up to the force threshold.

[0020] 019. According to another embodiment, for traction of the cables on the support exceeding the force threshold, this clip detaches from the support by a break.

[0021] 020. In this case, advantageously the staple is fixed to the support by tenons which break beyond the force threshold. 021. Advantageously, the tenons have incipient breaks at the break point.

[0022] 022. According to another embodiment, for traction of the cables on the support exceeding the force threshold, this support comprises shapes undergoing folding.

[0023] 023. In addition, advantageously the shapes undergoing folding include a groove reducing the thickness of the support at the level of this folding.

[0024] 024. The invention will be better understood and other characteristics and advantages will appear more clearly on reading the description below given by way of example, with reference to the appended drawings in which: 025. [Fig. 1] is a vertical sectional view along a median longitudinal plane of an electric vehicle according to the prior art;

[0025] 026. [Fig. 2] is a detail view of the power cable support between the powertrain and battery of this vehicle;

[0026] 027. [Fig. 3] is a longitudinal sectional view of this vehicle after a front impact;

[0027] 028. [Fig. 4] is a detailed longitudinal sectional view of a vehicle according to the invention after a front impact

[0028] 029. [Fig. 5] is a view of a cable support of this vehicle performing a disengagement, presented successively with and without the cables;

[0029] 030. [Fig. 6] is a side view of the clip of this support, presented successively with the cables fitted then unfitted;

[0030] 031. [Fig. 7] is a detailed view of a first variant of support performing a folding, presented successively in front view and in side view;

[0031] 032. [Fig. 8] is a detailed view of this type of support with a different inclination of a folding groove, presented successively before and after folding;

[0032] 033. [Fig. 9] is a view of a second variant of support achieving a break;

[0033] 034. [Fig. 10] successively shows a rear view of the clip of this support and the breakage of the fixings of this clip; and

[0034] 035. [Fig. 11] shows the breakage of another type of attachment of this clip. 036. Throughout the document, the above reference relates to the vertical direction of a vehicle placed on horizontal ground. 037. Figure 1 shows an electric vehicle comprising, in the front engine compartment, a powertrain 2 comprising an electric machine arranged in the transverse direction of the vehicle, which is fixed under a crossmember 4 connected to the front side members. A cradle 6 constitutes a highly rigid platform which is fixed in the engine compartment, at the level of the floor of the vehicle, to support various mechanical components as well as the suspensions of the front wheels.

[0035] 038. The engine compartment covered by a hood 8, is separated from the passenger compartment by an apron 10 forming a rigid sheet which protects the passengers. A traction battery 12 arranged in a watertight box, forms a flat assembly which is fixed under the floor of the passenger compartment.

[0036] 039. The top of the powertrain 2 comprises power electronics connected to two power cables 14 which have at their rear end a connector 16 connected to the front face of the battery 12.

[0037] 040. A support 18 fixed to the rear of the cradle 6, holds the two power cables 14 which pass under the apron 10, between the power unit 2 and the rear connector 16 in order to guide them to avoid vibrations and friction on the surrounding organs which could damage them. The cables 14 form a slight upward curve at the level of the clip 18.

[0038] 041. Figure 2 shows the support 18 formed by a cut and folded sheet metal, comprising a horizontal base 22 welded flat on a rear edge 20 of the cradle 6, then a rising part 24 ending in an elongated leg 26 which is substantially vertical. A clip 30 fixed by holes 28 on the elongated leg 26, firmly holds the two cables 14 on the support 18 which is rigid.

[0039] 042. Figure 3 shows the recoil of the power unit 2 under the effect of a significant front impact, which causes the front of this unit to pivot upwards. The recoil of the power unit 2 and the cradle 6 results in a reduction in the length available for the cables 14 between this unit and the battery 12, which forces the cables to greatly accentuate their upward curvatures at the clip 18 to absorb longitudinal compression. The cables 14 are not free, a strong stress is obtained on these cables which forces them into a position which can press them against neighboring surfaces, causing damage.

[0040] 043. Figure 4 shows, for the same recoil of the powertrain 2, on a vehicle according to the invention, the cables 14 delivering, through their deformation, a tensile force on the support 18 greater than a threshold, which caused a release of the support by detachment, by rupture of the support, or by its bending in the case of a support comprising an incipient bend. In this way, it is possible to avoid imposing too high a stress on the cables 14; they are freer to take natural bends, resulting in less pressure on their environment. They are less likely to be damaged.

[0041] 044. Figures 5 and 6 show a support 18 comprising a clip 30 made by molding a plastic material, fixed flat on the vertical leg of this support 26, comprising two parallel grooves 40 arranged in a substantially horizontal direction.

[0042] 045. Each groove 40 has a section forming an arc of a circle exceeding 180°, which makes it possible to fix a cable 14 therein by interlocking and elastic deformation, with sufficient support in this groove for normal use of the vehicle. In the case of a recoil of the powertrain 2, the tensile force of the cables 14 on the clip 30 exceeding a force threshold, a disengagement of each cable which comes out of its groove 40, shown in the second drawing of figure 6, is obtained, avoiding high stress on it.

[0043] 046. Figure 7 shows the elongated tab 26 comprising at its lower base a transverse groove formed by punching 50, which extends over almost the entire width of this base. A force on the clip 30 fixed on the tab 26 causes, above the force threshold, a bending of this tab at the level of the groove 50 forming a point of weakness, which makes it possible to release the force holding the cables 14 fixed on it.

[0044] 047. Figure 8 shows a similar groove 50, inclined at an angle of 45°, which also extends over almost the entire width of the base. A force on the clip 30 in this case causes the tab 26 to pivot at the level of the groove 50, which makes it possible to release the force holding the cables 14 fixed thereon. 048. In particular for figures 7 and 8 the tab 26 can be formed from a steel or aluminum sheet having a thickness of between 1.5 and 2.5 mm, the groove having a depth of between 1 and 2 mm. 049. Figures 9 and 10 show a clip 30 produced by molding a plastic material, comprising two parallel grooves 40 arranged substantially horizontally, which each receive a cable with significant strength at a level exceeding the force threshold.

[0045] 050. The clip 30 has on its rear face two arm tenons 42, each having a cylindrical base fixed in the clip 30, then passing through the tab 26 to end with two elastic arms 44 having a base comprising a notch forming an incipient break, these arms first moving apart to end with a parallel arrangement between them.

[0046] 051. When fixing the clip 30, the arms 44 are introduced into a hole 28 of the tab 26, moving towards each other by elastic deformation, and then moving apart when the base of these arms is in the hole. The clip 30 is clipped by the tenons 42.

[0047] 052. The second diagram of figure 10 shows during a front impact on the vehicle causing a strong traction of the cables 14 on the clip 30 exceeding a force threshold. The cables 14 remain held in this clip 30, and a rupture of the base of the arms 44 is obtained at the level of the notch 46 forming the start of rupture.

[0048] 053. Figure 11 shows as a variant another tenon 50 comprising a cylindrical base held in the clip 30, passing through a hole in the tab 26, which is extended by a cylindrical stud of larger diameter 52 coming to bear behind this tab to ensure the holding of the clip.

[0049] 054. When a strong stress is applied to the cables 14 applying a traction on the clip 30 exceeding a resistance threshold, the base of each tenon 50, comprising a breaking initiation notch 46, breaks at the level of this notch which releases the clip and the cables.

Claims

CLAIMS 1. Hybrid or electric motor vehicle comprising at the front of the vehicle a cradle (6) arranged under a powertrain (2) equipped with an electric traction machine, a traction battery (12) arranged under the passenger compartment of the vehicle, power cables (14) connecting the battery (12) to the electric machine, and comprising a support (18) fixed to the cradle (6), providing support for the cables (14) between the powertrain (2) and the battery (12), characterized in that the support (18) comprises a force limitation system, which, when the cradle (6) moves back under the effect of an impact on the front of the vehicle with a displacement of the cables (14) which apply to the support (18) a force exceeding a threshold, this support (18) undergoes a detachment, a rupture or a programmed folding by releasing the support of the cables (14).

2. Motor vehicle according to claim 1, characterized in that the support (18) is formed by a cut and folded sheet metal.

3. Motor vehicle according to claim 1 or 2, characterized in that the support (18) comprises a clip fixed thereon (30) which receives the cables (14).

4. Motor vehicle according to claim 3, characterized in that for a traction of the cables (14) on the support (18) exceeding the force threshold, these cables (14) are released from the clip (30) by a detachment.

5. Motor vehicle according to claim 4, characterized in that the clip (30) comprises grooves (40) each having a section forming an arc of a circle exceeding 180°, receiving a cable (14) held by clipping up to the force threshold.

6. Motor vehicle according to claim 3, characterized in that for traction of the cables (14) on the support (18) exceeding the force threshold, this clip (30) detaches from the support (18) by a break.

7. Motor vehicle according to claim 6, characterized in that the clip (30) is fixed to the support (18) by tenons (42) which break beyond the force threshold.

8. Motor vehicle according to claim 7, characterized in that the tenons (42) have fracture incipients (46) at the break.

9. Motor vehicle according to any one of claims 1 to 3, characterized in that for traction of the cables (14) on the support (18) exceeding the force threshold, this support (18) comprises shapes undergoing folding.

10. Motor vehicle according to claim 9, characterized in that the shapes undergoing folding comprise a groove (50) reducing the thickness of the support (18) at the level of this folding.

Images