DYNAMIC LOOP SUPPORT AND GUIDANCE SYSTEM FOR AN AUTOMOTIVE CABLE HARNESS

Abstract

A system for retaining and guiding the starting point of a dynamic loop of an electrical wiring harness (58) of a motor vehicle, comprising a metal support bracket, cable ties (40) for securing the harness (58) to this support, a guide cradle (20) for the harness (58) mounted on the support bracket, having a guide surface that precisely receives the harness (58), and comprising at least two cable ties (40) offset along the axis of the harness (A), which simultaneously secure the harness (58) to the guide surface and the cradle (20) to the support bracket. Figure 1

Description

Title of the invention: SYSTEM FOR RETAINING AND GUIDING A DYNAMIC LOOP OF AN AUTOMOBILE CABLE HARNESS

[0001] The present invention relates to a system for maintaining and guiding the start of a dynamic loop of an electrical wiring harness of a motor vehicle, as well as a motor vehicle equipped with such a system for maintaining and guiding the start of a dynamic loop.

[0002] A known type of retaining a bundle of electrical cables, particularly for a motor vehicle, presented in particular by document FR-A1-2899301, comprises a metal tab formed in a sheet metal including a hole receiving a screw for fixing a plastic collar.

[0003] The collar forms a loop comprising two half-loops connected on one side by a hinge, allowing them to be spread apart to open the loop and receive the wiring harness. The opposite side of the half-loops has a clip-lock system that closes the loop to hold the harness inside. A raised area on the outside of the loop, near the hinge, has a hole for the screw that secures it to the metal tab.

[0004] Another known type of cable harness holder, shown in document EP-A1-3015317, comprises a plastic clip with a housing for an elongated tab on a metal support. At the end of its sliding motion, the clip is locked by clipping a stop into a hole in the tab. The clip includes a collar attachment that surrounds the harness to hold it onto the metal tab.

[0005] In all cases, a plastic element is obtained surrounding the electrical cable bundle, which can protect its outer surface in the event of movements or vibrations of the bundle generating friction in the collar. However, some automotive vehicle wiring harnesses, which may include relatively heavy electrical cables, have dynamic loops connected to an element mounted on elastic vibration-filtering supports, to follow the movements of this element.

[0006] In particular, the powertrain of a hybrid or electric vehicle, generally fixed by elastic supports to filter the vibrations generated by the operation of the electric machine, to avoid transmission of noise to the body of the vehicle, requires for its supply dynamic loops of high-voltage cable harnesses which start from a fixed point on the body of the vehicle.

[0007] In addition, the movements of the vehicle during driving also generate accelerations which are applied to the dynamic loop, adding movements and mechanical stresses.

[0008] In this case, the collar forming the last fixed point of the beam at the start of the dynamic loop is subjected to high mechanical stresses generated by the movements of this loop, presenting a mass which can be significant, which poses problems of guiding the axis of the start of the loop along an orientation which must remain fixed, of the mechanical resistance of the collar to hold over time with repeated stresses, and of the choice of its materials and its shape to avoid damaging the surfaces of the beam.

[0009] The type of electrical harness support described in prior art documents, involving clamping by a single collar, does not provide the necessary guidance for the orientation of the harness for the initiation of a dynamic, oscillating loop. This results in a risk of the harness's starting axis pivoting at the collar, leading to mechanical stresses within the harness, friction, and wear on its surface, with risks of failure and short circuits that could cause a fire.

[0010] It should be noted that the calculations and validation tests of a system for maintaining and guiding the start of dynamic loops require numerous endurance tests, with updates to these tests after each modification of the assembly, which represents a high cost and maintains a risk of defects on this delicate problem to solve.

[0011] The present invention is specifically intended to avoid these problems of the prior art.

[0012] To this end, it proposes a system for maintaining and guiding a loop start dynamics of a motor vehicle electrical cable harness, comprising a metal support bracket and harness clamps on this support, this system being notable in that it includes a harness guide cradle placed on the support bracket, having a guide surface that receives this harness in a fitted manner, and at least two clamps offset along the axis of the harness, which simultaneously fix the harness on the guide surface and the cradle on the support bracket.

[0013] One advantage of this holding system is that by arranging two collars one after the other along the clamping axis of the beam, which is guided in its cradle, a combination of means is obtained giving, in the cradle conforming to the shape of the beam, precise guidance of this beam along its axis on a part of its contour and with a length large enough to prevent any oscillation of this beam axis around the starting point of the dynamic loop.

[0014] The metal support of the cradle provides rigidity to the cradle, thus ensuring simple and effective support and guidance over a sufficient length for the starting point of the dynamic loop, which can oscillate significantly, preventing mechanical stress and surface wear. Furthermore, the clamps secure all three elements simultaneously, resulting in a limited number of components and a rapid assembly time.

[0015] The holding and guiding system according to the invention may further comprise one or more of the following features, which may be combined with each other.

[0016] Advantageously, the cradle's guiding surface covers substantially half of the beam contour.

[0017] Advantageously, each clamp passes successively through an opening in the cradle and through a hole in the support bracket, then passes back through the support bracket and the cradle to close on itself and tighten the beam.

[0018] Advantageously, the cradle has on one side opposite the guide surface a housing comprising a contour having bosses, allowing the support leg to slide in the housing and under these bosses.

[0019] In this case, advantageously the cradle includes an elastic ratchet which at the end of the sliding of the support leg in its housing falls into a hole in this leg to lock the support.

[0020] Advantageously, each collar comprises a band including grooves, fitting into a stop block fixed to one end of the band which has an elastic ratchet locking onto these grooves.

[0021] According to one embodiment, the cradle comprises two guiding surfaces for two parallel beams, each beam comprising its two spaced clamping collars.

[0022] In this case, advantageously between the two beams the cradle has common openings and the support leg has common holes, each forming a passage receiving at the same time a collar of each beam.

[0023] The invention also relates to an electric or hybrid motor vehicle having a powertrain equipped with an electric traction machine, remarkable in that it includes a holding system comprising any one of the preceding claims, starting from a dynamic loop of two cable bundles supplying this electric machine.

[0024] The invention further relates to a method for mounting electrical harnesses in a motor vehicle, remarkable in that it successively comprises a step of preparing a sub-assembly including the cradle and the clamps positioned on the support bracket of a retaining system including any one of the preceding characteristics, and a step of fixing this sub-assembly. on the vehicle, and a step of positioning the beams in the guide surfaces and tightening the two clamps per beam.

[0025] 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:

[0026] [Fig-1] presents a holding and guiding system according to the invention receiving two parallel departures of dynamic beam loops;

[0027] [Fig.2] presents the metal support alone of this system;

[0028] [Fig.3] presents the cradle alone of this system; and

[0029] [Fig.4] shows the clamping collars of the beams and the cradle on the metal support.

[0030] Figures 1 and 2 show a system for maintaining and guiding the starting points of dynamic loops of two bundles 58 forming the power supply of an electric traction machine of an electric or hybrid vehicle, arranged along two parallel axes A, fixed by clamps 40 in a cradle 20 held on a metal support formed by a cut and folded sheet 2.

[0031] The metal support 2 comprises a flat base 50 placed on a profile 52 linked to the body of the vehicle, comprising a hole 8 receiving a screw and a clamping nut 56 on this profile, and comprising on each side a folded edge 54 framing the profile to form a rotational lock around this screw.

[0032] The base 50 of the metal support 2 extends into an elongated tab 10 facing forward AV, bent at an angle of approximately 60°, which moves away from the profile 52 to receive on the face facing this profile a cradle 20 comprising two guide surfaces receiving the parallel departures of the beam loops 58.

[0033] The leg 10 successively comprises a first rear pair of holes 12, a second intermediate pair of holes 14 and a third pair of holes 16, which are for each pair arranged symmetrically with respect to the longitudinal axis S of this leg.

[0034] Figures 3 and 4 show the cradle 20, symmetrical with respect to the longitudinal axis S, receiving the beams 58 on its front face, which is formed by molding in plastic. The cradle 20 has a rectangular rear housing comprising a contour 22 having two bosses 24 on each side allowing the tab 10 to engage below these bosses by sliding along the longitudinal axis S towards the front direction AV, to form a guide for the tab which, at the end of its insertion, is fitted into the housing.

[0035] The rear face of the cradle 20 has, towards the front, two symmetrically arranged elastic pawls 26, protruding into the support tab 10, each comprising a straight front face and an inclined rear face allowing, during the insertion of the leg in the cradle housing first a separation of the pawls, and then their descent by elastic return in the second pair of leg holes 14 to ensure the locking of the cradle.

[0036] The front face of the cradle 20 has two semi-circular guide surfaces 28 arranged along the two parallel axes A, each having a radius of curvature adapted to receive a beam 58 in a fitted manner.

[0037] Each bundle 58 receives two clamping collars 40, offset laterally along the axis A of this bundle, each comprising a band 42 having transverse grooves, and at the end of this band a stop block 44 having an elastic ratchet which fits into grooves to ensure the locking of the band after the bundle is tightened.

[0038] Each guide surface 28 has, on each side of the axis of symmetry S, two openings 30, 32, 34 which frame the bundle 58 to allow the passage of the band 42 of a clamping collar 40. The opening disposed between the two guide surfaces 28 is common for these two surfaces which makes it possible to bring the two bundles 58 as close as possible to each other in order to reduce the size of the holding system.

[0039] The band 42 of each collar 40 of the bundle 58 arranged towards the rear enters successively into a rear opening 30 of the cradle 20 then into a rear bore of the lug 12, to return to an intermediate bore of the lug 14 then into a common opening of the cradle 32, and finally enters the stop block 44 ensuring both the clamping of this bundle in the rear guide surface of the cradle 28 and the clamping of the assembly on the lug 10.

[0040] In the same way, the band 42 of each collar 40 of the bundle 58 arranged towards the front enters successively into a common opening of cradle 32 then into an intermediate hole of lug 14, to return by passing in front of the front end of lug 10 into a front opening of cradle 34, then enters the stop block 44 ensuring the clamping of this bundle in the front guide surface of cradle 28 and of the assembly on lug 10.

[0041] Advantageously, a sub-assembly is prepared comprising the collars 40 remaining open, engaged in the cradle openings 30, 32, 34 and the lug holes 12, 14 which hold the sub-assembly in place thanks to a certain rigidity of these collars, which makes it possible to supply a single element in the vehicle assembly workshop which after its fixing on the body of this vehicle is ready to receive the harnesses 58.

[0042] Initial guidance of the dynamic loop of each beam 58 is obtained in a simple manner in guide shapes 28 having a rounded shape fitted to the contour of the beam, along a length corresponding to the width of the cradle 20 and at the distance between the two collars 40 apart tightening this bundle, with contact surfaces of the cradle and the collars made of a plastic material that is not aggressive.

[0043] In this way, economically, with simple components including standard mass-produced collars 40, effective support of the start of the dynamic loops along their axis A is ensured by the rigid metal support 2, which avoids any risk of oscillation around this support, and protection of the surfaces of the bundles 58 by the flexible tightening of the bands of the collars 42 on fitted surfaces of the cradle 20 made of plastic materials.

Claims

Demands

1. A system for retaining and guiding a dynamic loop start of an electrical wiring harness (58) of a motor vehicle, comprising a metal support bracket (10) and clamps (40) for the harness (58) on this support (10), characterized in that it comprises a harness (58) guide cradle (20) placed on the support bracket (10), having a guide surface (28) that receives this harness (58) in a fitted manner, and at least two clamps (40) offset along the axis of the harness (A), which simultaneously fix the harness (58) on the guide surface (28) and the cradle (20) on the support bracket (10).

2. Retaining system according to claim 1, characterized in that the guiding surface (28) of the cradle (20) covers substantially half of the contour of the beam (58).

3. Retaining system according to claim 1 or 2, characterized in that each clamp (40) passes successively through an opening (30, 32, 34) through the cradle (20) and through a hole (12, 16) through the support tab (10), then passes back through the support tab (10) and the cradle (20) to close on itself and tighten the bundle (58).

4. A support system according to any one of the preceding claims, characterized in that the cradle (20) has on a side opposite the guide surface (28) a housing comprising a contour (22) having bosses (24), allowing the support leg (10) to slide in the housing and under these bosses (24).

5. Retaining system according to claim 4, characterized in that the cradle (20) has an elastic ratchet (26) which at the end of sliding the support leg (10) in its housing falls into a hole (16) in this leg (10) to lock the support (20).

6. A retention system according to any one of the preceding claims, characterized in that each collar (40) comprises a band (42) including grooves, fitting into a stop block (44) fixed to one end of the band (42) which has an elastic ratchet locking onto these grooves.

7. A support system according to any one of the preceding claims, characterized in that the cradle (20) comprises two guiding surfaces (28) of two parallel bundles (58), each bundle (58) comprising its two spaced clamping collars (40).

8. Retaining system according to claim 7, characterized in that between the two beams (58) the cradle (20) has common openings (32) and the support tab (10) has common holes (14), each forming a passage receiving at the same time a collar (40) of each beam (58).

9. Electric or hybrid motor vehicle having a powertrain equipped with an electric traction machine, characterized in that it includes a holding system according to any one of the preceding claims, starting from a dynamic loop of two cable bundles (58) supplying this electric machine.

10. Method of mounting electrical harnesses (58) in a motor vehicle, characterized in that it successively presents a step of preparing a sub-assembly comprising the cradle (20) and the clamps (40) positioned on the support bracket (10) of a retaining system according to any one of claims 1 to 8, a step of fixing this sub-assembly on the vehicle, and a step of positioning the harnesses (58) in the guide surfaces (28) and clamping surfaces of the two clamps (40) per harness (58).

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