FR3055169A1 - IMPROVED ELECTRIC CIRCUIT FOR MOTOR VEHICLE - Google Patents

Abstract

The invention relates to an electric circuit, in particular for a motor vehicle, comprising: at least one conductor (2) comprising a core surrounded by a sheath (22), the sheath (22) being interrupted so as to delimit two ends of interruption (24) of the sheath defining a stripped portion of the conductor core, and - an electrical connection device (10) connected to the core of the conductor (2). The electrical connection device (10) comprises a connection member (12) comprising a first branch (14) forming a connecting lug, and a second connecting leg (16) intended to be connected to the driver's core. (2). The electrical connection device further comprises a tube comprising an intermediate portion (28) crimped by magnetic pulse crimping on the stripped portion of the core, the connecting branch (16) being crimped on the intermediate portion (28) of the tube (18), so that the connecting branch (16) is connected to the core of the conductor (2) via the tube (18).

Description

055 169

57772 ® FRENCH REPUBLIC

NATIONAL INSTITUTE OF INDUSTRIAL PROPERTY © Publication number:

(to be used only for reproduction orders)

©) National registration number

COURBEVOIE © Int Cl ⁸ : H01 R4 / 24 (2017.01)

PATENT INVENTION APPLICATION

A1

©) Date of filing: 16.08.16. @ Applicant (s): LEONI WIRING SYSTEMS FRANCE ©) Priority: - FR. @ Inventor (s): LAURINO ADRIEN, FERRIERES LAURENT, BAUDEL BASTIEN and MAZIERE JEAN (43) Date of public availability of the FRANÇOIS. request: 23.02.18 Bulletin 18/08. ©) List of documents cited in the report preliminary research: Refer to end of present booklet (© References to other national documents ® Holder (s): LEONI WIRING SYSTEMS FRANCE. related: ©) Extension request (s): ©) Agent (s): LLR.

(b4) IMPROVED ELECTRICAL CIRCUIT FOR A MOTOR VEHICLE.

FR 3 055 169 - A1 _ The invention relates to an electrical circuit, in particular for a motor vehicle, comprising:

- at least one conductor (2) comprising a core surrounded by a sheath (22), the sheath (22) being interrupted so as to delimit two interrupting ends (24) of the sheath defining a stripped portion of the core of the driver, and

- an electrical connection device (10) connected to the core of this conductor (2).

The electrical connection device (10) comprises a connection member (12) comprising a first branch (14) forming a connection terminal, and a second branch (16), known as a connection, intended to be connected to the core of the conductor (2).

The electrical connection device further comprises a tube comprising an intermediate part (28) crimped by crimping by magnetic pulse on the stripped portion of the core, the connecting branch (16) being crimped on the intermediate part (28) of the tube. (18), so that the connecting branch (16) is connected to the core of the conductor (2) via the tube (18).

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The present invention relates to an electrical circuit, in particular for a motor vehicle.

A motor vehicle comprises several electrical members which are supplied by a battery connected to these by electrical conductors, most often cables or cable bundles.

In particular, it is known to connect to the vehicle battery, on the one hand, an alternator, by means of a driver and, on the other hand, a starter, by means of a bypass of this same driver.

Usually, the conductor is an electric cable having a core of twisted copper wires or essentially comprising copper. An insulating sheath surrounds the core for almost its entire length. It is said that an element essentially comprises a material when it comprises more than 50% by mass of this material.

It is known to make the bypass mentioned above by means of an electrical connection device made of electrically conductive material.

This electrical connection device comprises, on the one hand, a first branch forming a terminal for connecting the starter to the conductor and, on the other hand, a second connecting branch intended to be connected to the core of the conductor.

Usually, the electrical connection device is made of copper or a material essentially comprising copper.

The conductor sheath connecting the battery to the alternator is interrupted so as to delimit a stripped part of the copper core extending between first and second interruption ends of the sheath. The connecting branch (copper) of the electrical connection device is crimped on the stripped part of the core (copper) of the conductor connecting the battery to the alternator. If necessary, this crimping is completed by a tinning of the connection of the electrical connection device / core of the conductor.

However, in order to reduce the weight and the cost of the cables, it is desired to replace cables with a core of twisted wires essentially comprising aluminum for cables with a core essentially comprising copper.

However, aluminum is a material which is not very suitable for crimping, in particular compared to copper, because of its mechanical properties, particularly its mechanical relaxation. In addition, layers of alumina are formed superficially on the crimped aluminum. As a result, the connection between a conductor composed of aluminum wires and a terminal element is preferably carried out by welding. The welding methods used call, depending on the applications, on means such as electric welding means, by friction, or more commonly by ultrasound.

Document FR 3 022 406 discloses an electrical circuit comprising a connection device comprising an electrical connection member.

To connect the connection device to the conductor, the sheath of this conductor is interrupted so as to delimit two interruption ends of the sheath delimiting a stripped portion of the conductor's core.

The connection member comprises a first branch forming a connection terminal and a second branch having a substantially planar end, intended to be electrically connected with the stripped portion of the core of the conductor.

The second connecting branch has one end connected to the first branch forming a terminal by a curved intermediate part having a curvature substantially complementary to that of the sheath surrounding the core so as to be able to cover the end of this sheath.

In this way, the substantially planar free end of the second connecting branch is easy to weld to the core of the aluminum conductor, which avoids a crimping operation, while the second connecting branch can be covered by means sealing covering the curved intermediate part and the end of the sheath on which this intermediate part extends. The core of the aluminum conductor is thus protected over its entire length from the risks of oxidation, dust and liquids.

The electrical circuit of FR 3 022 406 makes it possible to substitute cables with a core of twisted wires essentially comprising aluminum for cables with a core essentially comprising copper, but its manufacture can prove to be complex. In particular, because of the relatively complex shape of the curved intermediate part, its manufacture and its covering by sealing means can prove to be delicate.

The object of the invention is therefore to provide an electrical circuit making it possible to carry out a derivation of a core conductor essentially comprising aluminum which is simple to manufacture while effectively protecting the core of the conductor.

To this end, the subject of the invention is an electrical circuit, in particular for a motor vehicle, comprising:

at least one conductor comprising a core surrounded by a sheath, the sheath being interrupted so as to delimit two ends of interruption of the sheath delimiting a stripped portion of the core of the conductor, an electrical connection device connected to the core of this conductor, the electrical connection device comprising a connection member comprising a first branch forming a connection lug, and a second branch, called a connection branch, intended to be connected to the core of the conductor, characterized in that the device electrical connection further comprises a tube comprising an intermediate part crimped by crimping by magnetic pulse on the stripped portion of the core, the connecting branch being crimped on the intermediate part of the tube, so that the connecting branch is connected to the conductor core through the tube.

Thanks to the fact that the electrical connection device comprises a tube crimped by crimping by magnetic impulse on the stripped portion of the core of the conductor, as well as a connection member crimped on the tube, the connection member is electrically connected and the core of the conductor without directly crimping the connection member on the conductor, by means of an element which is particularly easy to manufacture.

In addition, due to its simple form, the tube can be easily covered by sealing means at its ends, so as to effectively protect the stripped portion of the core of the conductor from the risks of oxidation, dust and liquids.

According to a particular embodiment of the invention, each connecting end of the tube covers a corresponding interrupting end of the sheath.

In order to avoid, or at least limit, the corrosion of the core of the conductor, each connection end of the tube is crimped on the interruption end of the sheath by crimping by magnetic pulse.

In order to avoid, or at least limit, corrosion of the core of the conductor, the circuit further comprises at least one sealing sleeve extending between a connecting end of the tube, so as to cover this end, and the corresponding interrupt end of the conductor sheath.

Preferably, the connection member is made of a material essentially comprising copper or brass.

Preferably, the tube is made of a material essentially comprising copper.

In order to lighten the circuit, the conductor's core consists essentially of aluminum and is, for example, made of twisted wires.

The invention also relates to a method for manufacturing an electrical circuit, in particular for a motor vehicle, characterized in that:

the sheath of a conductor comprising a core surrounded by a sheath is interrupted so as to delimit two ends of interruption of the sheath delimiting a stripped portion of the core of the conductor, a tube is placed around it with radial clearance from the stripped portion of the core, an intermediate part of a tube is crimped by magnetic pulse crimping onto the stripped portion of the core, and a connecting branch is crimped onto the intermediate part of the tube 'a connection member comprising this connecting branch and a first branch forming a connection terminal, so that the connecting branch is connected to the core of the conductor via the tube.

In order to avoid, or at least limit, corrosion of the core of the conductor, the tube having two ends and each end of the tube covering a corresponding interruption end of the sheath, each crimp is crimped by magnetic pulse. end of the tube on the corresponding interruption end of the sheath.

In order to avoid, or at least limit, corrosion of the core of the conductor, the tube having two ends and each end of the tube covering a corresponding interruption end of the sheath:

a heat-shrinkable sealing sleeve is placed with radial clearance around one end of the tube and the corresponding interruption end of the conductor sheath, the sleeve is heated so that it retracts and first and second ends of this sleeve come into sealed contact with the end of the tube and the corresponding interruption end of the sheath respectively, and the preceding steps are repeated for the other end of the tube.

The invention will be better understood on reading the appended figures, which are provided by way of examples and have no limiting character, in which:

- Figure 1 is a schematic view of an electrical circuit according to the invention;

- Figure 2 is a perspective view of part of the electrical circuit of Figure 1 according to a first embodiment of the invention;

- Figures 3 to 5 are perspective views of the electrical circuit of Figure 2 at different stages of its manufacture;

- Figure 6 is a perspective view of part of the electrical circuit of Figure 1 according to a second embodiment of the invention.

FIG. 1 shows an electrical circuit 1, according to the invention, for a motor vehicle.

This circuit 1 comprises an electrical conductor 2 connecting a battery 4 of a vehicle to an alternator 6 of this vehicle.

The circuit 1 also includes a starter 8 also connected to the battery 4 by means which will be described below. In a manner known per se, the alternator 6 is driven by a heat engine of the vehicle and the starter 8 is intended to drive this heat engine to start it.

The circuit 1 further comprises an electrical connection device 10 of electrically conductive material shown in more detail in Figures 2 and 6 respectively according to first and second embodiments. In these figures, part of the electrical conductor 2 has also been shown.

In the first embodiment of the invention shown in FIG. 2, the electrical connection device 10 comprises a first connection member 12 comprising a first branch forming a connection terminal 14 and a second branch, called the connecting branch 16, intended to be connected to the core of the conductor 2 via a tube 18 as will be seen below.

The circuit 1 also includes a second conductor 19 connecting the connection lug 14 of the electrical connection device 10 to the starter 8. If necessary, the starter 8 can be connected directly to the connection lug 14 of the electrical connection device 10, without the second conductor 19.

Thus, the electrical connection device 10 forms a bypass from the first conductor 2 connecting the battery 4 to the alternator 6 to the starter 8 using the second conductor 19.

The first conductor 2 comprises a core 20 (visible in FIG. 3 illustrating a step in manufacturing the electrical circuit 1) surrounded by a sheath 22.

The sheath 22 is interrupted so as to delimit two interrupting ends 24 of the sheath, delimiting a stripped portion 26 of the core, visible in FIG. 3. The sheath 22 is made essentially, in a manner known per se, of polymer .

The second conductor 19 is similar to the first conductor 2, but it does not include a stripped portion between two ends of sheath interruption. However, conventionally, the second conductor 19 has two stripped ends to allow electrical connection to the electrical connection device 10 respectively (by means of the connection lug 14) and the starter 8.

The electrical connection device 10 comprises, in addition to the connection member 12, the tube 18 placed around the stripped portion of the core 26. Advantageously, the length of the tube 18 is chosen so that each end 30 of the tube covers a corresponding interruption end 24 of the sheath.

More particularly, the tube 18 has an intermediate part 28 crimped by crimping by magnetic pulse on the stripped portion 26 of the core, as can be seen in FIG. 4 and in FIG. 5 illustrating a step in manufacturing the electrical circuit 1 .

As can be seen in Figure 2, the connecting branch 16 is crimped on the intermediate part 28 of the tube 18, so that the connecting branch 16 is connected to the core 20 of the conductor 2 via the tube 18. This ensures the electrical connection between the first connection member 12 and the tube 18.

Preferably, the first connection member 12 is made of a material essentially comprising copper or brass, the tube 18 being made of a material essentially comprising copper, these materials being good electrical conductors while being suitable for crimping.

In the embodiments described and shown in the figures, the core of the conductor 2 is made of twisted wires and essentially comprises aluminum. It is then preferable to isolate from their external environment the junctions between the ends 30 of the tube and the interruption ends of the sheath 24, using sealing means which are shown in FIG. 2.

The sealing means associated with each interruption end 24 of the sheath comprise, at each end 30 of the tube 18, a sleeve 32 extending so as to cover this end 30, as well as the corresponding interruption end 24 of the sheath of the conductor 2. Each sleeve 32 therefore extends beyond the interruption end of the sheath 24.

The sleeves 32 thus protect the stripped portion 26 of the core of the conductor 2 from the risks of oxidation, dust and liquids. The aluminum essentially forming the core 20 of the conductor 2 therefore retains its excellent electrical conduction properties.

The second embodiment of the invention will be described below with reference to FIG. 6. In this figure, elements similar to those of the preceding figures are designated by identical references.

In the second embodiment of the invention shown in FIG. 6, each end 30 of the tube 18 is crimped on the corresponding interrupting end 24 of the sheath by crimping by magnetic pulse. This offers the possibility of dispensing with the use of the sealing sleeves 32. In fact, the crimping by magnetic pulse of the end 30 of the tube 18 on the sheath 22, at the level of the interrupting end 24, effectively protects the stripped portion 26 of the core of the conductor 2 from the risks of oxidation, dust and liquids. However, it is also possible to add additional sealing means, and in particular sleeves as in the first embodiment of the invention.

We will now describe a method of manufacturing the part of the electrical circuit 10 according to the first embodiment of the invention with reference to Figures 3 to 5.

During a first step, the sheath 22 of the conductor 2 comprising the core 20 surrounded by the sheath 22 is interrupted so as to delimit the two interruption ends of the sheath 24 delimiting a stripped portion 26 of the core of the driver. The configuration shown in FIG. 3 is thus obtained.

Then, with a radial clearance, the tube 18 is placed around the stripped portion 26 of the core. Preferably, the tube 18 having two ends, each end 30 of the tube covers a corresponding interruption end 24 of the sheath.

The intermediate portion 28 of the tube is then crimped by magnetic pulse crimping onto the stripped portion 26 of the core. The configuration shown in FIG. 4 is thus obtained.

Preferably, with a radial clearance, the heat-shrinkable sealing sleeve 32 is placed around the end 30 of the tube and of the corresponding interruption end 24 of the sheath of the conductor 2. The configuration shown in the diagram is thus obtained. figure 5.

Then, the sleeve 32 is heated so that it retracts and that the first 34 and second 36 ends of this sleeve come into tight contact with the end 30 of the corresponding tube and the corresponding interruption end 24 of the sheath respectively. .

These last two steps are then repeated at the other end 30 of the tube.

Finally, the connecting branch 16 of the connection member 12 is crimped onto the intermediate part of the tube 30, so that the connecting branch 16 is connected to the core 20 of the conductor by means of the tube 18.

It will be noted that the succession of steps for placing and heating the sealing sleeves 32 can also be carried out after the crimping of the connecting branch 16 of the connection member 12 on the intermediate part 28 of the tube.

For the manufacture of the part of the electrical circuit 10 according to the second embodiment of the invention, each end of the tube 30 is crimped, by crimping by magnetic pulse, onto the corresponding interrupting end 24 of the sheath. This step can be carried out either before or after crimping the intermediate part 28 of the tube on the stripped portion of the core 26.

This step notably makes it possible to dispense with the steps of placing and heating the sealing sleeves 32.

The invention is not limited to the embodiments presented and other embodiments will be apparent to those skilled in the art.

In particular, the invention can be applied to a conductor having a core essentially comprising copper.

It is also possible to connect the connecting branch of the connection member to the tube by crimping with magnetic pulse, or even to weld it by friction welding or ultrasound.

Claims (11)

1. Electric circuit, in particular for a motor vehicle, comprising: at least one conductor (2) comprising a core surrounded by a sheath (22), the sheath (22) being interrupted so as to delimit two interruption ends of the sheath (24) delimiting a stripped portion (26) of the conductor core, an electrical connection device (10) connected to the core of this conductor (2), the electrical connection device (10) comprising a connection member (12) comprising a first branch (14) forming a terminal connection, and a second branch (16), called a link, intended to be connected to the core of the conductor (2), characterized in that the electrical connection device further comprises a tube comprising an intermediate part (28) crimped by crimping by magnetic impulse on the stripped portion (26) of the core, the connecting branch (16) being crimped on the intermediate part (28) of the tube (18), so that the connecting branch (16) is connected to the core of the conductor (2) through iaire of the tube (18). 2. An electrical circuit according to claim 1, in the tube (18) having two ends (30), each end (30) of the tube covers a corresponding interruption end (24) of the sheath. 3. The electrical circuit according to claim 2, wherein each end (30) of the tube is crimped onto the corresponding interrupting end (24) of the sheath (22) by crimping by magnetic pulse. 4. Electrical circuit according to any one of the preceding claims, further comprising at least one sealing sleeve (32) extending between one end (30) of the tube, so as to cover this end (30), and l 'interrupt end (24) corresponding to the conductor sheath (2). 5. An electrical circuit according to any one of the preceding claims, in which the connection member (12) is made of a material essentially comprising copper or brass. 6. Electrical circuit according to any one of the preceding claims, in which the tube (18) is made of a material essentially comprising copper. 7. Electrical circuit according to any one of the preceding claims, in which the conductor core (2) essentially comprises aluminum and is, for example, made of twisted wires. 8. Electrical circuit according to any one of the preceding claims, in which the sheath (22) is made of polymeric material. 9. Method for manufacturing an electrical circuit (10), in particular for a motor vehicle, characterized in that: the sheath of a conductor (2) comprising a core (20) surrounded by a sheath (22) is interrupted so as to delimit two interrupting ends (24) of the sheath delimiting a stripped portion (26) of the core of the conductor, with a radial clearance, a tube (18) is placed around the stripped portion (26) of the core, an intermediate part (28) of the tube is crimped onto the portion by magnetic pulse crimping stripped (26) of the core, and there is crimped, on the intermediate part of the tube (18), a connecting branch (16) of a connection member (12) comprising this connecting branch (16) and a first branch (14) forming connection lug, so that the connecting branch (16) is connected to the core (20) of the conductor via the tube (18). 10. A method of manufacturing an electrical circuit (10) according to claim 9, in which the tube (18) having two ends (30) and each end (30) of the tube covering a corresponding interruption end (24) of the sheath, each end of the tube (30) is crimped by magnetic pulse crimping onto the corresponding interrupting end (24) of the sheath. 11. A method of manufacturing an electrical circuit (10) according to claim 9 or 10, in which the tube (18) having two ends (30) and each end (30) of the tube covering an interrupting end (24 ) corresponding sheath: a heat-shrinkable sealing sleeve (32) is placed with a radial clearance around one end (30) of the tube and the corresponding interruption end (24) of the conductor sheath, the sleeve is heated ( 32) so that it retracts and that first (34) and second ends (36) of this sleeve come into sealed contact with the end (30) of the tube and the corresponding interrupting end (24) respectively the sheath, and the previous steps are repeated at the other end (30) of the tube. 1/2