FR3013892A1 - DEVICE FOR INTEGRATING AN ELECTRIC FUSE ON AN ELECTRICAL CABLE, ESPECIALLY ON BOARD AN ELECTRIC VEHICLE - Google Patents

Abstract

The invention relates to a device (1) for integrating a fuse (2) into an electric cable (4) comprising: two conductive elements (3a, 3b) to which the ends (4a, 4b) of a electric cable (4), - two body members (9a, 9b) of insulating material each having: - an assembly part (10a, 10b) at an assembly part (10b, 10a) of the other element of body, and - a connecting portion (11a, 11b) having an opening (12a, 12b) through which the electric cable (4) passes, - an inner housing (13a, 13b) receiving the conductive element (3a, 3b) and the end (4a, 4b) of the electric cable. The conductive elements (3a, 3b) are introduced into the body members (9a, 9b) through the openings (12a, 12b), after crimping the cable (4). Locking means (14a, 15a, 16a, 14b, 15b, 16b) of each conductive element (3a, 3b) inside the housing (13a, 13b) provide electrical contact with the fuse (1).

Description

DEVICE FOR INTEGRATING AN ELECTRIC FUSE ON AN ELECTRICAL CABLE, ESPECIALLY ON BOARD AN ELECTRIC VEHICLE. The invention relates to a device for integrating an electric fuse on an electric cable, in particular on an electric cable embedded in an electric vehicle. A fuse cut-off device, also called a fuse, is a safety device whose function is to open, by melting a calibrated element, an electrical circuit into which it is introduced, when the electric current therein reaches a dangerous intensity value (or more generally a given intensity value) for a given time, thus reducing the intensity of this current to zero. The fuses are usually housed in a housing that supports these fuses and allows them to be connected to the electrical circuit. Fuses are thus present in a large number of electrical circuits, including electrical motor circuits, in particular motor vehicle electric motor.

The invention applies to electric fuses of cylindrical cartridge type unlike those usually used in the automobile. Electric vehicles are equipped with an electric cable for recharging the battery. In order to protect the battery charger from a short electrical circuit, a fuse is usually included in the charger. Such a fuse therefore does not protect the electrical cable, including the electrical cable embedded in the vehicle, which can then be damaged in case of a short circuit, which would require complex and expensive replacement operations. An integration of a fuse could be considered further upstream, for example at the vehicle socket, embedded in the bodywork. However, this would involve increasing the volume of the catch, which is not desirable or difficult to achieve. Another solution is to integrate a fuse to the power cable, between the socket and the battery, which allows including more effective protection of the electric cable. However, the device for integrating the fuse with the electric cable must withstand the vibrations of the vehicle and be sufficiently watertight to prevent penetration of moisture present on rainy days or daily in humid climates. There are many devices for integrating a fuse into an electrical cable. These devices generally comprise two interlocking body parts, within which the fuse is located, each body portion comprising a conductive element electrically connecting the fuse to one end of the electrical cable. The proposed devices have the disadvantage of requiring a crimping of the electric cable on the conductive element after introduction of the electric cable inside a body part. Such an assembly may result from the arrangement of the conductive elements inside the two body parts, such as for example in the devices described in the documents US 5,018,991, US 3,778,741 or US 3,551,869, or may resulting from an overmolding of the body parts on the conductive element, as described in US 4,734,059. In any case, such an assembly complicates the manufacture of the device, especially in large series. In addition, it may be difficult to crimp the electrical cable which is resistant. Finally, the body parts of some devices are not assembled sufficiently tight or resistant. There is therefore a need for a device for integrating a fuse to an electric cable that is reliable and can be achieved in a simple manner, especially in large series. There is also a need for a device for integrating a fuse with an electric cable that is waterproof. For this purpose, the object of the invention relates to a device for integrating a fuse, in particular of cylindrical cartridge type, into an electrical cable comprising: two conductive elements each comprising an end forming an electrical contact and a suitable end to be crimped at one end of an electrical cable, two body members of insulating material extending in an axial direction, each body member having: - an assembly portion at a first end, shaped to be assembled by interlocking in said axial direction at an assembly portion of a first end of the other body member, and - a connecting portion at a second end having an opening, - an internal housing receiving in said axial direction said conductive member and for receiving at least a part of a fuse, characterized in that the opening of each connecting part nt is shaped to allow insertion of said conductive member within the housing of a body member through said opening and in that the body members and the conductive members comprise locking means of each conductive member to the interior of the housing of a body member in a locking position in which, the two body members being assembled, the distance separating the electrical contact ends of the conductive elements is equal to or less than a distance separating the contact terminals electric fuse intended to be housed inside the body elements. Such an arrangement allows the crimping of the conductive elements at the ends of the electric cable prior to mounting the conductive elements inside the body elements, while ensuring the electrical contact between the fuse and the conductive elements through the locking means. This allows the crimping of the electric cable in good conditions, without being hindered by the presence of the body elements around the electric cable, and also allows the production of large amounts of electrical cables crimped in conductive elements. In particular, for a simpler embodiment, particularly in large series, the conductive elements may be identical. The distance between the electrical contact terminals and the fuse is generally the length of the fuse. It will therefore be determined according to the type of fuse to be received by the integration device according to the invention. The integration device is more particularly intended for fuses of cylindrical or near shape comprising a body of glass or ceramic and whose ends are electrically conductive.

It is understood that the ends of the electric cable crimped to the conductive elements extend in the axial direction, as well as the fuse after its introduction into the inner housing of the body elements of the device according to the invention. Each internal housing receiving a portion of the fuse, these housings are advantageously arranged in the extension of one another when the body members are assembled and have the same or similar shapes and dimensions so as to form a single housing when the elements of bodies are assembled. Advantageously, this single housing has a shape substantially complementary to the shape of the fuse, thus limiting the movements of the fuse inside the housing. Advantageously and in a nonlimiting manner, each connecting portion of a body member may have sealing means disposed on an outer face of said connecting portion to ensure a seal, particularly with water, between the end of the electric cable adapted to be crimped to the conductive element and the opening of the connecting portion. This arrangement makes it possible to prevent water penetration inside the housing of the integration device along the electric cable and thus to avoid a short circuit inside the device when it is used in an environment wet. These sealing means may comprise a seal housed in a shoulder of an outer face of a connecting portion, around the periphery of the opening of said connecting portion. Such a seal, also called wire seal, is thus disposed on the periphery of the end of the electric cable crimped to the conductive element and passing through the opening. The body joining parts may comprise male and female parts of complementary shape or be male and female parts of complementary shape. For example, an assembly part may be a female assembly part, for example a hollow sleeve, the other assembly part being a male assembly part, having for example a tubular male part of external shape complementary to the sleeve, this tubular male part being inserted inside the female sleeve. The invention is however not limited to this particular arrangement. Advantageously, in order to simplify the realization of the device, these body elements may have axial symmetry.

Interlocking with tight fitting of the two body members may be sufficient to achieve the desired seal, including watertightness, and also to provide sufficient pressure for electrical continuity with the fuse.

However, in order to improve the tightness of the assembly, the integration device according to the invention may comprise sealing means arranged between the assembly parts of the body elements. In particular, a seal may be disposed between radial faces in contact with said assembly parts. By way of example, in the case of female and male coupling parts of the sleeve / tubular portion type as described above, a seal may be arranged on the periphery of the tubular part and abut axially against the end of the sleeve. The body members may be shaped so that their interlocking is sufficiently adjusted to ensure their joining. However, in order to improve the joining of the two body members, the integration device according to the invention may comprise locking means of the two assembled body members, in particular axial locking means.

These locking means may advantageously be arranged on external parts of the body elements. These locking means may comprise locking elements shaped to engage and block any axial movement following rotation of the body members. Such a configuration is however not preferred because it can induce a twisting of the electrical cable passing through the opening of the body member, which is undesirable. Advantageously, in order to avoid torsion of the electric cable, the locking means may comprise at least one locking element integral with a body member cooperating with a locking element integral with the other body element, the locking elements being shaped to be engaged following a movement of axial approximation of the body elements. Advantageously and in a nonlimiting manner, the locking means may comprise: at least two tabs integral with each conductive element, each spaced apart with respect to said axial direction, the free ends of said tongues being directed towards the end of conducting element suitable to be crimped at one end of an electrical cable, said tongues being shaped to return to their spaced apart position after being brought closer to the axial direction, - a radial abutment inside each inner housing of an element of body, these locking means being shaped so that said free ends of the tongues bear against said radial stops when the body members are assembled and the conductive elements are housed inside said body members. These tongues thus have sufficient elasticity and shape memory to be able to approach the axis of the conductive elements during their passage through the opening of the body element, and then to move apart again and to block the conductive element. while abutting against the radial stops. They thus allow easy insertion of each conductive element inside the inner housing of a body element, and then its axial locking. The spacing of the tongues relative to the axial direction may be sufficient to ensure contact between their free end and the radial abutment. Such tongues can be made in a simple manner, in particular by stamping the conductive element, which is for example copper or any other suitable metal or conducting alloy.

Advantageously, these tongues are axially symmetrical, for a balanced distribution of the support of the tongues on the body element. Advantageously and in a nonlimiting manner, the body elements may be made of a polymer material, in particular a rigid or hard polymer material that is electrically insulating. It may especially be a polymer having a sufficient rigidity not to deform at operating temperatures, which may range from -30 ° C to + 100 ° C, such as for example polybutylene terephthalate (or polybutylene terephthalate) more commonly referred to as PBT, which is a thermoplastic polymer belonging to the polyester family. The invention is however not limited to this particular polymer, any other polymer having the adequate rigidity can be used.

The use of a polymeric material allows a simple and inexpensive embodiment of the body elements, for example by molding. The invention also relates to a method of mounting an integration device according to the invention comprising: crimping ends of electrical cable to conductive elements, introduce each conductive element inside the housing of a body member through the opening of the connecting portion until said conductive member is in the locking position inside said housing and maintained in this position by the locking means. The crimping step may be preceded by a step of positioning a seal on the electrical cable, which will then be positioned against a shoulder of an outer surface of the connecting portion of a body member to to ensure a seal between the electric cable, specifically the sheath of the electric cable, and the body member. The invention also relates to a motor vehicle comprising a device for integrating a fuse according to the invention onto a part of the electrical cable inside the vehicle. Advantageously, the vehicle is an electric or hybrid vehicle comprising an electric motor and the integration device is mounted on an electrical cable connecting a battery charger on the vehicle to the cable connection socket, for example embedded in the body.

The invention is now described with reference to the accompanying non-limiting drawings, in which: FIG. 1 is an exploded perspective representation of a device for integrating a fuse according to one embodiment of the invention; FIG. 2 is a representation partially in axial section of the device represented in FIG. 1, in assembled position, a fuse being placed inside the device, FIGS. 3 and 4 are cross-sectional views of a body element of FIG. device shown in Figures 1 and 2, showing the steps of mounting this body member. In the present description, the axial direction X corresponds to a longitudinal direction of the assembled integration device, in which direction extends the electric cable in which the device is integrated. Figures 1 and 2 show an integration device 1 of a fuse 2 of electrical protection. This fuse 2 is a cylindrical fuse body glass or ceramic whose ends form electrical contacts or terminals 2a, 2b. The integration device 1 comprises two conductive elements 3a, 3b each connected to an end 4a, 4b respectively of an electric cable 4 to which the fuse 2 must be integrated. The conductive elements 3a, 3b shown in the figures are identical: the same parts of these conductive elements will be designated by the same reference numbers followed by the letters "a" and "b" to indicate their membership in the conductive elements 3a and 3b respectively.

To simplify the description, these elements being identical, only the conductive element 3a is described below. The conductive element 3a is made of electrically conductive material, for example copper. It can be formed by stamping. The conductive element 3a comprises an electrical contact end 5a and an opposite end 6a to which is crimped a stripped end 4a of the electrical cable 4. The electrical contact ends 5a, 5b of the two conductive elements 3a, 3b respectively, are shaped to define a space receiving the terminals 2a, 2b respectively, fuse 2, as visible in Figure 2. The invention is however not limited to this particular form and any other form of electrical contact capable of establishing an electrical contact with a fuse terminal can be considered. The crimping end 6a usually has two tabs 7a, which can be folded and tightened (crimped) around the stripped end 4a of the cable 4, and two tabs 8a can be tightened around the sheath of the cable 4 (see FIG. 2). Any other element allowing crimping could however be considered. The conductive elements 3a, 3b are arranged inside a body formed of two body members 9a, 9b, which extend in the axial direction X. The two body members 9a, 9b are made of insulating material, preferably a polymer, for example PBT. These body members 9a, 9b can thus be made by molding. Each body member 9a, 9b has: an assembly portion 10a, 10b respectively, located at a first end, a connecting portion 11a, 1 1b respectively, located at a second end and having an opening 12a, 12b respectively at through which passes the electric cable 4 whose end 4a, 4b respectively is crimped to a conductive element 3a, 3b respectively, an inner housing 13a, 13b respectively, receiving in the axial direction X, the conductive element 3a, 3b respectively , the end 4a, 4b of electric cable 4 which is crimped thereon and at least a part of the fuse 2.

The joining parts 10a, 10b are shaped to be assembled by interlocking in the axial direction X. In the example shown, the assembly part 10a is a female assembly part forming a cylindrical sleeve and the assembly part 10b is a male portion of complementary hollow cylindrical tubular shape of the sleeve and coming to fit inside the sleeve, as visible in Figure 2. It will be noted that the inner housing 13a, 13b of each body element 9a, 9b, respectively, extends over the entire length of these elements. In other words, these inner housings 13a, 13b pass axially through each body member 9a, 9b. In addition, they are arranged in the extension of one another when the body members 9a, 9b are nested, so that the fuse 2 is placed partly inside the inner housing 13a and partly to the inside. inside the inner housing 13b. The housings 13a, 13b are preferably of the same shape and size. In Figure 2, it is noted that most of the fuse 2 is housed in the inner housing 13b of the body member 3b, the assembly portion 10b is male. The invention is however not limited by this embodiment and it is conceivable that the fuse is fully threaded into one of the two bodies, which is then itself fitted into the other body. The opening 12a, 12b of each connecting portion 11a, 1 1b respectively, is shaped to allow the insertion of a conductive member 3a, 3b respectively, within the respective housing 13a, 13b by this opening 12a, 12b. In other words, the openings 12a, 12b are of dimension equal to or greater than the external dimensions of a conductive element 3a, 3b. The connecting portions 1a and 1b of the body members may be identical, as in the example shown. Finally, the body members 9a, 9b and the conductive elements 3a, 3b comprise locking means for each conductive element 3a, 3b inside the corresponding housing 13a, 13b.

These locking means are formed to block each conductive element 3a, 3b in a locking position in which, when the two body members 9a, 9b are assembled, the distance separating the electrical contact ends 5a, 5b of the conductive elements is equal or less than the distance between the terminals 2a, 2b of the fuse 2 housed inside the body members 9a, 9b. When this distance is smaller than the distance separating the terminals 2a, 2b of the fuse 2, it is, however, advantageously large enough to allow the assembly, in particular the sealed assembly, of the two body members 9a, 9b in the presence of a fuse. 2.

The locking of the conductive element 3a can be obtained by the production of two tongues or pawls 14a, 15a integral with the conductive element 3a and each spaced apart by a predetermined angle with respect to the axial direction X. These tabs 14a, 15a are disposed on either side of the conductive element 3a with respect to the axial direction X. The free ends of these tongues 14a, 15a are directed towards the end 6a to which the electric cable is crimped, that is to say towards the opening 12a, when the conductive member 3a is mounted within the body member 9a. These tongues 14a, 15a are further shaped so as to return to their spaced position after having been brought closer to the axial direction X after insertion of the conductive elements 3a, 3b into the bodies 9a, 9b. By an appropriate choice of the predetermined angle of spacing of the tongues, the free ends of the tongues 14a, 15a bear against a radial abutment 16a internal to the housing 13a when the conductive element 3a is inside the element. corresponding body 9a. The conductive member 3b has tabs 14b, 15b arranged in the same manner and bearing against a radial abutment 16b of the body member 9b. Thus, when the fuse 2 is disposed within the housings 13a, 13b of the body members 9a, 9b assembled, its terminals 2a, 2b are in contact with the ends 5a and 5b respectively. The distance separating these ends 5a, 5b being equal to or less than the length of the fuse 2, the latter exerts a thrust on the conductive elements 3a, 3b tending to separate them from one another, which has the effect of increasing the thrust of the tabs 14a, 15a and 14b, 15b on their respective radial abutments 16a, 16b. This allows the two conductive elements 3a, 3b and the fuse 2 to be locked axially and to ensure good electrical contact between the fuse terminals 2a, 2b and the ends 5a, 5b of the conductive elements. In the example, the housings 13a and 13b are of generally cylindrical shape and the radial abutments 16a, 16b are radial bearing faces forming part of a recess formed in each housing 13a, 13b, this recess also being of cylindrical shape. but of diameter greater than the diameter of the housing 13a, 13b. In order to ensure watertightness, the integration device 1 further comprises a seal 17 disposed between the connection portions 10a, 10b, more precisely between radial faces facing the connection portions 10a, 10b, as visible in Figure 2. In the example, this seal 17 is mounted on the periphery of the tubular portion of the connecting portion 10b. Two other seals 18a, 18b are further threaded onto the cable 4 on either side of the integration device 1 and are housed in respective shoulders 19a, 19b of an outer face of a portion of connection 11a, 1 lb respectively, around the perimeter of the opening 12a, 12b corresponding (Figures 2 to 4). The body members 9a, 9b may finally be held together by locking means. In the example shown, these locking means are disposed on outer walls of the body members and comprise a locking element 20 integral with the body member 9b which cooperates with a locking element 21 integral with the other element of the housing. body 9a. The locking element 20 is in the form of a tab projecting from the body member 9b axially on the side of the connecting part 10b, the free end of which has a crooked hook shape in the direction of the body element 9b. The locking element 21 is in the form of a projecting stop. When the two body members are brought closer to each other in the axial direction X and fully nested one inside the other, the free hook-shaped end of the locking member 20 engages with the locking member 21 in the form of a stop so as to block any axial movement tending to separate the body members 9a, 9b. The example only represents a single pair of locking elements 20, 21 cooperating together, but it is possible to envisage several of these pairs, for example two pairs located on either side of the body elements 9a, 9b relative to each other. in the axial direction X. The mounting of the integration device 1 can be performed in the following manner. The ends 4a and 4b of the cable 4 are first crimped at the ends 6a, 6b respectively of the conductive elements 3a, 3b. Then, each conductive element 3a, 3b is introduced inside the housing 13a, 13b of the body member 9a, 9b corresponding through the opening 12a, 12b respectively thereof. A conductive member 3b is thus introduced into its body member 9b by introducing its electrical contact end 5b into the opening 12b, as visible in FIG. 3. It is then pushed towards the inside of the body member 9b in the direction of the arrow F 1 of Figure 3. The tabs 14b, 15b are then folded according to the arrows F2 of Figure 3 to pass the opening 12b. When they reach the enlarged portion of the housing 13b, the tongues 14b, 15b return to their initial spacing (arrows F3) and their free ends bear against the radial abutment 16b. It is then no longer possible to extract the conductive element 3b from the body element 9b. The seal 18b, previously threaded on the cable 4, can then be positioned in the shoulder 19b. The same operations are repeated for the body element 9a. A fuse 2 is then positioned inside the inner housing 13b of the body member 9b and the two body members 9a, 9b are brought together axially until the assembly parts 10a, 10b are fully engaged and engaged. locking members 20, 21. It is thus understood that stripped ends of electric cable can be crimped to the chain in conductive elements, which can then be mounted simply and quickly inside the body elements without introducing the body 9a and 9b on the cable before the crimping operation.

Claims (10)

REVENDICATIONS1. Device for integrating (1) a fuse (2), in particular of the cylindrical cartridge type, with an electric cable (4) comprising: two conductive elements (3a, 3b) each comprising an end (5a, 5b) forming a electrical contact and an end (6a, 6b) capable of being crimped at one end (4a, 4b) of an electric cable, two body members (9a, 9b) of insulating material extending in an axial direction (X) each body member (9a, 9b) having: - an assembly portion (10a, 10b) at a first end, shaped to be interlocked in said axial direction (X) with an assembly portion (10b, 10a) of a first end of the other body member, and - a connecting portion (11a, 11b) at a second end having an opening (12a, 12b), - an inner housing (13a, 13b) receiving next said axial direction (X) said conductive element (3a, 3b) and intended to receive the ego a part of a fuse (1), characterized in that the opening (12a, 12b) of each connecting portion (10a, 10b) is shaped to allow the insertion of said conductive element (3a, 3b) within the housing (13a, 13b) of a body member (9a, 9b) through said opening (12a, 12b) and in that the body members (9a, 9b) and the conductive members (3a, 3b) comprise locking means (14a, 15a, 16a, 14b, 15b, 16b) of each conductive element (3a, 3b) inside the housing (13a, 13b) of a body element in a position of in which, the two body members (9a, 9b) being assembled, the distance separating the electrical contact ends (5a, 5b) of the conductive elements (3a, 3b) is equal to or less than a distance separating the contact terminals electric fuse (2a, 2b) intended to be housed inside the body members (9a, 9b). 2. Integration device (1) according to claim 1, characterized in that each connecting portion (11a, 1 lb) of a body member (9a, 9b) has sealing means (18a, 18b) disposed on an outer face of said connecting portion (11a, 1b) capable of sealing between an end (4a, 4b) of the electrical cable to be crimped to the conductive member and the opening (12a, 12b) of the connecting portion (11a, 1b). 3. Integration device (1) according to one of claims 1 or 2, characterized in that it comprises sealing means (17) arranged between the connecting portions (10a, 10b) of the body elements . 4. Integration device (1) according to one of claims 2 or 3, characterized in that the sealing means comprise a seal (18a, 18b)) housed in a shoulder (19a, 19b) d an outer face of a connecting portion (11a, 1b), around the opening (12a, 12b) of said connecting portion and / or comprising a seal (17) disposed between faces radial contacts in contact with said assembly parts (10a, 10b). 5. Integration device (1) according to any one of claims 1 to 4, characterized in that it comprises locking means (20, 21) of the two body members (9a, 9b) assembled. 6. Integration device (1) according to claim 5, characterized in that the locking means (20, 21) comprise at least one locking element (20) integral with a body member (9b) cooperating with a locking element (21) integral with the other body member (9a), the locking elements (20, 21) being shaped to engage with a movement of axial approximation of the body members. 7. Integration device (1) according to any one of claims 1 to 6, characterized in that the locking means comprise: - at least two tabs (14a, 15a, 14b, 15b) integral with each conductive element ( 3a, 3b), spaced apart with respect to said axial direction (X), the free ends of said tongues being directed towards the end (5a, 5b) of conductive element capable of being crimped at one end of an electric cable, said tongues (14a, 15a; 14b, 15b) being shaped to return to their spaced apart position after being brought closer to the axial direction; - a radial abutment (16a, 16b) within each inner housing (13a, 13b) of a body member, the locking means being shaped so that said free ends of the tongues abut against said radial stops (16a, 16b) when the body members (9a, 9b) are assembled and the elements conduct ers (3a, 3b) are housed inside said body members. 8. Integration device (1) according to any one of claims 1 to 7, characterized in that the body members (9a, 9b) are of polymeric material, in particular of rigid polymeric material. 9. A method of mounting an integration device (1) according to any one of the preceding claims, comprising: crimping ends (4a, 4b) of electric cable to conductive elements (3a, 3b), optionally positioning a seal (18a, 18b) on the electrical cable (4) before crimping, introducing each conductive element (3a, 3b) inside the housing (13a, 13b) of a body element through the opening ( 12a, 12b) of the connecting portion (11a, 11b) until said conductive member (3a, 3b) is in the locking position within said housing (13a, 13b) and held in this position. position by the locking means (14a, 15a, 16a, 14b, 15b, 16b). Motor vehicle, in particular comprising an electric motor, characterized in that it comprises a device (1) for integrating a fuse (2) according to any one of claims 1 to 8 onto a part of an electric cable ( 4) internal to the vehicle.