EP2706616A1 - Method for assembling a connection device on an exposed terminal segment of an electrical cable and assembly comprising such a device securely assembled on such a cable segment - Google Patents

Abstract

The method involves introducing a stripped end section (6) into a tubular portion (13) via an insertion opening (16). The tubular portion is securely assembled on the stripped end section. First, second and third zones (40-42) of the tubular portion are crimped with first, second and third portions (43, 44, 56) of the stripped end section such that the portions of the stripped end section comprise first, second and third predetermined degree of compression, where the third predetermined degree of compression is higher than the first predetermined degree of compression. An independent claim is also included for an assembly for assembling a connecting device on a stripped end section of an electric cable.

Description

The invention relates to methods of assembling a connection device on a terminal section stripped of an electric cable.

The invention also relates to assemblies comprising such a connection device integrally assembled on such a terminal section stripped of an electric cable.

We already know, including the US patent US 3,955,044 , such a method and such an assembly, which comprises a connecting device provided with a portion to be crimped or crimped on a cable and a flat portion adapted to cooperate with a screw terminal.

The cable is introduced, at a stripped end section, into the tubular portion of the connection device and is integrally joined by crimping this tubular portion on this denuded terminal section.

The assembly method of this device on this bare end section comprises a single crimping step performed using a crimping device provided with two jaws, including a substantially flat lower jaw and an upper jaw comprising several bearings.

Thus, with the same crimping force applied during a single crimping step implemented by a single pair of jaws, the stripped end portion and the tubular portion are crimped together in stages, with the stripped end section having a variable and gradual compression ratio between a portion farthest from an opening opening in the tubular portion and a portion closest to this opening, but not in the immediate vicinity of the latter.

The invention aims to improve the methods of assembling a connection device on a terminal section stripped of an electric cable while being particularly simple, convenient and economical to implement.

• fournir un dit dispositif de connexion et un dit câble électrique ;
• introduire ledit tronçon terminal dénudé dans ladite portion tubulaire par ladite ouverture d'introduction ;
• assembler solidairement ladite portion tubulaire sur ledit tronçon terminal dénudé ;

ledit procédé étant caractérisé en ce que ladite étape d'assembler solidairement comporte :

• une première étape de sertissage d'une première zone de ladite portion tubulaire avec une première portion dudit tronçon terminal dénudé se trouvant dans ladite première zone, laquelle première zone est la plus éloignée de ladite ouverture d'introduction, ladite première étape de sertissage étant configurée de telle sorte que ladite première portion sertie dudit tronçon terminal dénudé présente un premier taux de compression prédéterminé ;
• une deuxième étape de sertissage d'une deuxième zone de ladite portion tubulaire avec une deuxième portion dudit tronçon terminal dénudé se trouvant dans ladite deuxième zone, laquelle deuxième zone est la plus proche de ladite ouverture d'introduction, ladite deuxième étape de sertissage étant configurée de telle sorte que ladite deuxième portion dudit tronçon terminal dénudé présente un deuxième taux de compression prédéterminé inférieur audit premier taux de compression prédéterminé ;
• une étape de poinçonnage d'une troisième zone de ladite portion tubulaire avec une troisième portion dudit tronçon terminal dénudé se trouvant dans ladite troisième zone, laquelle troisième zone est entre lesdites première et deuxième zones, ladite étape de poinçonnage étant configurée de telle sorte que ladite troisième portion dudit tronçon terminal dénudé présente un troisième taux de compression prédéterminé supérieur audit premier taux de compression prédéterminé.

The invention thus has, in a first aspect, a method of assembling a connection device on a terminal section stripped of an electric cable, said connection device comprising a conductive element having a tubular portion and an opening introduction method by which it is planned to introduce in said tubular portion said denuded end section, said method comprising the steps of:

• providing a said connection device and an electrical cable;
• introducing said denuded end portion into said tubular portion through said insertion opening;
• integrally joining said tubular portion on said stripped end portion;

said method being characterized in that said step of assembling together comprises:

• a first step of crimping a first zone of said tubular portion with a first portion of said stripped end portion in said first zone, which first zone is furthest from said insertion opening, said first crimping step being configured such that said first crimped portion of said stripped end portion has a first predetermined compression ratio;
• a second step of crimping a second zone of said tubular portion with a second portion of said stripped end portion in said second zone, which second zone is closest to said insertion opening, said second crimping step being configured such that said second portion of said stripped end section has a second predetermined compression ratio less than said first predetermined compression ratio;
• a step of punching a third zone of said tubular portion with a third portion of said denuded end portion in said third zone, which third zone is between said first and second zones, said punching step being configured such that said third portion of said stripped end section presents a third predetermined compression ratio greater than said first predetermined compression ratio.

The crimping of the first zone of the tubular portion on the first portion of the stripped end portion, which is implemented with first predetermined crimping parameters, makes it possible to hold this first portion firmly in the connection device, without worrying about any flexibility of this first portion relative to the connection device. In other words, the first portion of the stripped end portion is locked in the first zone of the tubular portion and has a first compression ratio said mean means.

The crimping of the second zone of the tubular portion on the second portion of the stripped end section, which is implemented with second predetermined crimping parameters, makes it possible to maintain this second portion in the connecting device, while ensuring a certain flexibility of this second portion relative to the connection device. In other words, the second portion of the bare terminal section is fixed in the second zone of the tubular portion while allowing the electrical cable to be folded at and in the immediate vicinity of this second portion, the latter portion having a second compression ratio, which is said to be low here. .

The punching of the third zone of the tubular portion on the third portion of the stripped end section, which is implemented with predetermined punching parameters, makes it possible to compact (more than with a crimping) the material of the tubular portion forming this third zone together with the material of the electric cable forming the third portion. In other words, the third portion of the stripped end section is compacted with the third zone of the tubular portion and has a third compression ratio said strong here; so as to ensure permanent electrical contact between the connection device and the electrical cable.

The method according to the invention therefore provides a particularly effective mechanical and electrical fastening between the connecting device and the electric cable by means of a double crimping, performed under predetermined crimping parameters which are distinct, respectively to distance and near the introduction opening, combined with a punching, made between the two zones and crimped portions under predetermined punching parameters which are distinct from the predetermined crimping parameters.

Note that here is meant by crimping and punching steps to obtain a separate distribution of material crimped elements and punched. Indeed, it will be admitted that the compactness of a zone / punched portion has an external perimeter ratio of this zone / portion on the smallest height passing through the center of gravity (here the geometric center) of this zone / portion, which is greater than or equal to about 6; while the compactness of a crimped area / portion has an outer perimeter ratio of this area / portion on the smallest height passing through the center of gravity of that area / portion, which is less than about 6.

It will also be noted that the crimping and / or punching parameters are defined in particular by a closing edge of crimping and / or punching devices and by the imprint shape of such devices. It is these parameters that characterize the compression ratios obtained, also called section reduction rate. These parameters of course also depend on the diameter of the conductive core of the electric cable.

Note further that the method according to the invention is particularly efficient while remaining particularly simple, convenient and economical to implement.

• lesdites première et deuxième étapes de sertissage sont mises en oeuvre en même temps et sont suivies de ladite étape de poinçonnage ;
• lesdites première et deuxième étapes de sertissage et ladite étape de poinçonnage sont mises en oeuvre en même temps ;
• ladite première étape de sertissage est configurée de telle sorte que ledit premier taux de compression est compris dans l'intervalle [10% ; 30%] ;
• ladite deuxième étape de sertissage est configurée de telle sorte que ledit deuxième taux de compression est compris dans l'intervalle [2% ; 20%] ; et/ou
• ladite étape de poinçonnage est configurée de telle sorte que ledit troisième taux de compression est compris dans l'intervalle [25% ; 45%].

According to preferred, simple, convenient and economical characteristics of the assembly method according to the invention:

• said first and second crimping steps are performed at the same time and are followed by said punching step;
• said first and second crimping steps and said punching step are performed at the same time;
• said first crimping step is configured such that said first compression ratio is in the range [10%; 30%] ;
• said second crimping step is configured such that said second compression ratio is in the range [2%; 20%]; and or
• said punching step is configured such that said third compression ratio is in the range [25%; 45%].

It will be noted that in the case where the first and second crimping steps are implemented at the same time and are followed by the punching step, electrical connection performance is obtained which is much greater than the performance of punching which would be realized alone.

Indeed, the first and the second crimping, already performed when the punching is done, maintain longitudinally the end section of the electric cable. Therefore, during punching, the terminal section of the electric cable can not flow outside the punching area, or in any case can only flow in a particularly limited manner.

As a result, the end section of the electrical cable in the punching zone is subjected to intense deformation, which favors the quality of the electrical connection, particularly when the electrical cable is made of aluminum, since the fracture is then particularly effective. the alumina layer present on the surface.

The subject of the invention is also, in a second aspect, an assembly comprising a connection device integrally assembled on a terminal section stripped of an electric cable, said connection device comprising a conductive element having a tubular portion and an opening of introduction by which said stripped end portion is introduced into said tubular portion, said assembly being characterized in that said tubular portion comprises a first crimped area with a first portion of said stripped end portion being in said first area, said first area being the most remote from said introductory opening, and with said first portion having a first predetermined compression ratio; said tubular portion further comprises a second zone crimped with a second portion of said stripped end section located in said second zone, said second zone being closest to said introducing opening, and with said second portion having a second predetermined compression ratio less than said first predetermined compression ratio; and said tubular portion further comprises a third punched area with a third portion of said stripped end portion in said third area, said third area being between said first and second areas, and with said third portion having a third predetermined compression ratio greater than said first predetermined compression ratio; whereby said tubular portion and said stripped end portion are crimped and punched together.

The first compression ratio, referred to herein as the mean, of the first portion of the stripped end portion is indicative of the crimping of the first zone of the tubular portion on this first portion, which is implemented with predetermined first crimping parameters, and the maintenance integral with this first portion in the connection device, without being concerned about any flexibility of this first portion relative to the connection device. In other words, the first portion of the stripped end portion is locked in the first zone of the tubular portion.

The second so-called low compression ratio of the second portion of the stripped end section is indicative of the crimping of the second zone of the tubular portion on this second portion, which is implemented with predetermined second crimping parameters, and the maintenance of this second portion in the connection device, while ensuring a certain flexibility of this second portion relative to the connection device. In other words, the second portion of the bare end section is fixed in the second zone of the tubular portion while allowing the folding of the electric cable at and in the immediate vicinity of this second portion.

The third compression ratio, referred to here as the loudness, of the third portion of the stripped end section is indicative of the punching of the third zone of the tubular portion on this third portion which is implemented with predetermined punching parameters, and compaction ( stronger than with crimping) the material of the tubular portion forming this third zone together with the material of the electric cable forming the third portion. In other words, the third portion of the bare end portion is compacted with the third zone of the tubular portion so as to ensure permanent electrical contact between the connection device and the electrical cable.

The assembly according to the invention thus has a particularly powerful mechanical and electrical fastening between the connecting device and the electric cable thanks to a double crimping, providing two predetermined and distinct compression ratios, respectively at a distance and near the opening introduction, combined with punching, performed between the two zones and crimped portions and providing a predetermined compression ratio and greater than the two compression ratios resulting from crimping.

It will also be noted that the crimping and / or punching parameters are defined in particular by a closing edge of crimping and / or punching devices and by the imprint shape of such devices. It is these parameters that characterize the compression ratios obtained, also called section reduction rate. These parameters of course also depend on the diameter of the conductive core of the electric cable.

It will be noted that the assembly according to the invention is particularly efficient while remaining particularly simple, convenient and economical.

• ledit premier taux de compression prédéterminé est compris dans l'intervalle [10% ; 30%] ;
• ledit deuxième taux de compression prédéterminé est compris dans l'intervalle [2% ; 20%] ;
• ledit troisième taux de compression prédéterminé est compris dans l'intervalle [25% ; 45%] ;
• ladite première zone de ladite portion tubulaire et ladite première portion dudit tronçon terminal dénudé et/ou ladite deuxième zone de ladite portion tubulaire et ladite deuxième portion dudit tronçon terminal dénudé ont, en section, une forme en B ;
• ladite première zone de ladite portion tubulaire et ladite première portion dudit tronçon terminal dénudé et/ou ladite deuxième zone de ladite portion tubulaire et ladite deuxième portion dudit tronçon terminal dénudé ont, en section, une forme hexagonale ;
• ladite troisième zone de ladite portion tubulaire et ladite troisième portion dudit tronçon terminal dénudé ont, en section, une forme en croissant ;
• ledit câble électrique comporte une âme conductrice en aluminium ; et/ou
• ledit dispositif de connexion comporte un fourreau disposé dans ladite portion tubulaire et dans lequel est introduit ledit tronçon terminal dénudé, ledit fourreau comportant une pluralité de perforations et étant en une matière plus dure que l'aluminium de sorte que ledit fourreau déforme ledit tronçon terminal dénudé, avec ladite âme conductrice en aluminium qui est incrustée dans lesdites perforations dudit fourreau.

According to preferred, simple, convenient and economical characteristics of the assembly according to the invention:

• said first predetermined compression ratio is in the range [10%; 30%] ;
• said second predetermined compression ratio is in the range [2%; 20%];
• said third predetermined compression ratio is in the range [25%; 45%];
• said first zone of said tubular portion and said first portion of said stripped end portion and / or said second zone of said tubular portion and said second portion of said stripped end portion have a B-shaped section;
• said first zone of said tubular portion and said first portion of said stripped end portion and / or said second zone of said tubular portion and said second portion of said stripped end portion have, in section, a hexagonal shape;
• said third zone of said tubular portion and said third portion of said denuded end portion have a crescent-shaped section;
• said electric cable comprises a conductive core of aluminum; and or
• said connecting device comprises a sheath disposed in said tubular portion and into which said bare terminal section is introduced, said sheath comprising a plurality of perforations and being made of a material harder than aluminum so that said sheath deforms said bare terminal section; with said aluminum conductive core which is embedded in said perforations of said sheath.

• la figure 1 représente schématiquement un démarreur de véhicule, ici un véhicule de type poids lourd, connecté à une batterie de ce véhicule par l'intermédiaire d'au moins un ensemble conforme à l'invention ;
• la figure 2 est une vue en perspective isolée d'une cosse de connexion conforme à l'invention, telle que reçue dans un atelier d'assemblage de l'ensemble, visible sur la figure 1, la cosse de connexion étant alors équipée d'un bouchon de protection ;
• la figure 3 est une vue en coupe médiane de la cosse de la figure 2 ;
• la figure 4 est une vue en perspective de la cosse visible sur les figures 2 et 3 et d'une broche de déformation ayant servie à conformer une paroi de fond de cette cosse ;
• la figure 5 est une vue en coupe de la cosse visible sur les figures 2 et 3, après expansion de la paroi de fond, avec la broche de déformation encore introduite dans cette cosse ;
• la figure 6 est une vue partielle en perspective éclatée de la cosse visible sur les figures 2 et 3, montrant un élément conducteur et un fourreau perforé ;
• la figure 7 est une vue partielle en perspective de la cosse visible sur les figures 2 et 3, et d'un câble électrique à distance de la cosse et pourvu d'un tronçon terminal dénudé ;
• la figure 8 est une vue en coupe de la cosse visible sur la figure 7, avec le tronçon terminal dénudé introduit dans la cosse ;
• la figure 9 est une vue semblable à la figure 8, mais montrant de manière schématique un dispositif de sertissage configuré pour sertir plusieurs zones de la cosse sur plusieurs portions du tronçon terminal dénudé du câble électrique ;
• la figure 10 est une vue semblable à la figure 8, mais montrant de manière schématique un dispositif de poinçonnage configuré pour poinçonner une zone de la cosse sur une portion du tronçon terminal dénudé du câble électrique, pour former l'ensemble visible sur la figure 1 ;
• la figure 11 est une vue partielle en perspective de l'ensemble visible sur la figure 1 ;
• la figure 12 est une vue en coupe partielle de l'ensemble visible sur la figure 11 ;
• la figure 13 est une vue en coupe repérée XIII-XIII sur la figure 12, montrant une première zone de la cosse sertie sur une première portion du tronçon terminal dénudé du câble électrique ;
• la figure 14 est une vue en coupe repérée XIV-XIV sur la figure 12, montrant une deuxième zone de la cosse sertie sur une deuxième portion du tronçon terminal dénudé du câble électrique ; et
• la figure 15 est une vue en coupe repérée XV-XV sur la figure 12, montrant une troisième zone de la cosse poinçonnée sur une troisième portion du tronçon terminal dénudé du câble électrique.

We will now continue the description of the invention by the description of an exemplary embodiment, given below by way of illustration and not limitation, with reference to the accompanying drawings in which:

• the figure 1 schematically represents a vehicle starter, here a truck type vehicle, connected to a battery of this vehicle through at least one assembly according to the invention;
• the figure 2 is an isolated perspective view of a connecting terminal according to the invention, as received in an assembly workshop of the assembly, visible on the figure 1 , the connection lug being then equipped with a protective cap;
• the figure 3 is a median sectional view of the pod of the figure 2 ;
• the figure 4 is a perspective view of the visible pod on the Figures 2 and 3 and a deformation pin having served to form a bottom wall of this lug;
• the figure 5 is a sectional view of the visible pod on the Figures 2 and 3 after expansion of the bottom wall, with the deformation pin still inserted into this pod;
• the figure 6 is a partial perspective exploded view of the visible pod on the Figures 2 and 3 showing a conductive element and a perforated sheath;
• the figure 7 is a partial perspective view of the visible pod on the Figures 2 and 3 , and an electrical cable remote from the pod and provided with a bare terminal section;
• the figure 8 is a sectional view of the pod visible on the figure 7 , with the bare terminal section introduced into the pod;
• the figure 9 is a view similar to the figure 8 , but schematically showing a crimping device configured to crimp several areas of the lug on several portions of the bare terminal section of the electric cable;
• the figure 10 is a view similar to the figure 8 , but schematically showing a punching device configured to punch an area of the terminal on a portion of the bare terminal section of the electrical cable, to form the visible assembly on the figure 1 ;
• the figure 11 is a partial perspective view of the visible set on the figure 1 ;
• the figure 12 is a partial sectional view of the visible set on the figure 11 ;
• the figure 13 is a sectional view marked XIII-XIII on the figure 12 , showing a first zone of the lug crimped on a first portion of the bare terminal section of the electric cable;
• the figure 14 is a sectional view marked XIV-XIV on the figure 12 , showing a second zone of the terminal crimped on a second portion of the bare terminal section of the electric cable; and
• the figure 15 is a sectional view marked XV-XV on the figure 12 , showing a third zone of the terminal punched on a third portion of the bare terminal section of the electrical cable.

The figure 1 schematically represents a motor vehicle 100 of the heavy truck type, comprising a starter 5 configured to launch a ring of a heat engine (not shown) of the vehicle 100, which starter 5 is formed by a rotating electrical machine connected to a battery 2 via an electrical connection assembly 1.

The electrical connection assembly 1 is here provided with two connection lugs 3 and an electric cable 4 with a conductive core 35 of aluminum ( figure 7 ) on which are integrally assembled the two connection terminals 3.

The conductive core 35 here comprises a plurality of strands ( figure 8 ) in aluminium.

The cable 4 has two opposite ends each forming a stripped end portion 6 ( figure 7 ) where the pods are crimped and punched 3.

We will describe in detail pod 3 with reference to Figures 2 and 3 , where a protective cap 8 is mounted on this lug 3.

The lug 3 comprises a conductive element 7 and a metallic tubular insert monobloc 9.

The conductive element 7 comprises a tubular portion 13 extending in a longitudinal general direction, a flat portion 15 connected to the tubular portion 13 by a transition portion 14 and an insertion opening 16 opposite the portion of transition 14.

The tubular portion 13 is hollow and provided with an outer face 18 and an inner face 19, which delimits an internal space 20 of the tubular portion 13.

The tubular portion 13 further comprises a first tubular section 22 having a large internal diameter, also called second internal diameter, a second tubular section 23 having a small internal diameter, also called first internal diameter, which is smaller than the second internal diameter, and an annular shoulder 17 connecting the first tubular section 22 to the second tubular section 23.

The first tubular section 22 is situated between the annular shoulder 17 and the insertion opening 16.

The second tubular section 23 is located between the annular shoulder 17 and the transition portion 14.

The second tubular section 23 here has a length less than the first internal diameter and the first tubular section 22 here has a length greater than the second internal diameter.

The tubular portion 13 comprises an insertion chamfer 24 formed on the first tubular section 22, at the level of the insertion opening 16.

The transition portion 14 connects the second tubular section 23 of the tubular portion 13 to the flat portion 15.

This transition portion 14 forms a bottom wall of the tubular portion 13, which bottom wall has an inner face 21 facing the internal space 20.

The bottom wall is here straight, substantially perpendicular to the longitudinal general direction of the tubular portion 13 and substantially perpendicular to the flat portion 15.

The flat portion 15 forms a mechanical and electrical contact pad configured to cooperate with a predetermined electrical terminal (not shown).

This predetermined electrical terminal belongs here to either the battery 2 or the starter 5.

The flat portion 15 has a generally parallelepipedal shape, has a predetermined width, and is provided with a hole 12 formed centrally and configured to receive a fastener (not shown), for example a bolt having a screw and a nut.

It should be noted that this bolt belongs, in one case to the battery 2 and in the other case to the starter 5.

The one-piece tubular insert 9 comprises a sheath 32 and a flared ring 39 located at one end of the sheath 32.

The sheath 32 is located in the internal space 20 of the tubular portion 13, at the level of the first tubular section 22.

The sheath 32 comprises a split body 60 having a generally cylindrical shape ( figure 6 ).

The body 60 has an external diameter (when this body 60 is not subjected to any stress) substantially similar to or even slightly greater than the second internal diameter of the first tubular section 22 of the tubular portion 13 ( figure 6 ).

The body 60 has an inner face 33 and an outer face 34, which comes into contact with the inner face 19 of the tubular portion 13.

The body 60 is mounted slightly compressed in the inner space 20 of the tubular portion 13 (through the slot).

The sheath 32 also has a plurality of perforations 59 formed in the body 60.

Note that this sheath 32 is configured to deform the bare terminal section 6, with the conductive core 35 ( figure 7 ) of aluminum cable 4 which is embedded in these perforations 59 (see below).

The flared ring 39 is located at the end of the sheath 32 in the immediate vicinity of the insertion opening 16 and thus of the insertion chamfer 24.

The flared ring 39 has a profile similar to that of the introduction chamfer 24, against which this flared ring 39 bears.

It will be noted that the flared ring 39 delimits the insertion opening 16 of the conductive element 7.

It will be further noted that the flared ring 39 is configured to facilitate the introduction of the stripped terminal section 6 of the cable 4 into the internal space 20 of the tubular portion 13.

A predetermined amount of contact grease 10 is introduced into the inner space 20 of the tubular portion 13 at and against the bottom wall thereof.

This contact grease 10 is configured to improve the electrical conductivity between the conductive core 35 ( figure 7 ) of the cable 4, the insert 9 and the conductive element 7.

The plug 8 is mounted on the outer face 18 of the tubular portion 13, at the first tubular section 22 and facing the opening 16, so as to plug the internal space 20 of the tubular portion 13.

We will now describe the manufacturing process of the pod 3, with reference to Figures 4 to 6 .

The conductive element 7 is made from an initial cylindrical metal tube having a predetermined internal diameter corresponding to the first internal diameter of the second tubular section 23 of the tubular portion 13.

Two opposite walls of the cylindrical tube are flattened (brought together until contacting) at an end opposite to the insertion opening 16 so as to form the flat portion 15. This flattening creates a first configuration of the transition portion 14 (inclined orientation of the bottom wall) and thus closes the internal space 20 of the opposite side to the insertion opening 16.

Then, the tubular portion 13 is formed by expansion over a predetermined length to form, on the one hand the first tubular section 22 having the second internal diameter, and on the other hand the annular shoulder 17 (on the inner face 19), which shoulder delimits the first and second sections 22 and 23 of the tubular portion 13.

Then, the transition portion 14 is deformed so that the bottom wall of the tubular portion 13 is straightened from the inclined orientation that it had at the end of the flattening step to the straight orientation visible on the drawings.

These deformations are carried out with a deformation spindle 25 ( Figures 4 and 5 ), here an expansion pin, configured to be inserted into the internal space 20 of the tubular portion 13 by its insertion opening 16.

These deformations are furthermore made with a matrix (not shown) configured so that the tubular portion 13 is sandwiched between this matrix and the expansion pin 25. The matrix therefore applies to the outer face 18 of the tubular portion 13.

This expansion pin 25 comprises a body provided with a first cylindrical portion 26 having a first outer diameter greater than the second internal diameter of the first tubular section 22, a second cylindrical portion 27 having a second similar external diameter (at the introductory game near) to the second internal diameter of the first tubular section 22 and a third cylindrical portion 28 having a third similar outer diameter (to the introductory clearance near) to the first internal diameter of the second tubular section 23.

The first cylindrical portion 26 is connected to the second cylindrical portion 27 by a first annular shoulder 29 and the third cylindrical portion 28 is connected to the second cylindrical portion 27 by a second annular shoulder 30.

The third cylindrical portion 28 has at its end which is on the opposite side to the side connected to the second shoulder 30, a face 31 which is flat.

Note that the second cylindrical portion 27 together with the first annular shoulder 29 have substantially the same length as the length of the tubular insert 9.

It will be further noted that the second shoulder 30 is configured to form, together with the matrix, the shoulder 17 of the tubular portion 13.

It will also be noted that the plane face 31 is configured to form the internal face 21 of the bottom wall of the tubular portion 13.

The deformation step by expansion with the spindle 25 is carried out by introduction of this pin 25 with the second cylindrical portion 27 which comes into contact with the inner face 19 at its first tubular portion 22 to expand the latter, with the shoulder 29 which comes into contact with the inner face 19 near the insertion opening 16 to create the insertion chamfer 24, with the shoulder 30 which forms the shoulder 17, and with the flat face 31 which comes against the transition portion 14 to straighten it and thus form the right bottom wall and thus the inner face 21.

The conductive element 7 is therefore mainly formed by deformation and expansion of the initial cylindrical tube via the expansion pin 25 and the die (not shown).

It will be noted that the expansion pin 25 leaves on the bottom wall 21 a flat zone, generally of length at least equal to one third of the diameter of the bottom wall 21 (see the part of the face 31 in contact with the wall of FIG. bottom 21 on the figure 5 ).

It is recalled that it is here considered that the bottom wall 21 extends substantially perpendicular to the longitudinal direction of the tubular portion 13 when a flat area of length at least equal to one third of the diameter of the bottom wall 21 has an angle with respect to the longitudinal direction of the tubular portion 13 in the range [80 °; 100 °].

The one-piece tubular insert 9 (provided with the sheath 32 and the flared ring 39) is then supplied and introduced into the internal space 20 of the tubular portion 13 through the insertion opening 16.

It will be noted that the introduction of this insert 9 is facilitated by the introduction chamfer 24.

The insert 9 is introduced until it comes into abutment on the annular shoulder 17, and with the flared ring 39 which takes place in the insertion chamfer 24.

The inner face 19 of the tubular portion 13 is opposite the outer face 34 of the sheath 32.

A predetermined quantity of contact grease 10 is introduced into the internal space 20 against the inner face 21.

As we see on the figure 7 , the electric cable 4 further comprises the conductive core 35 provided with a plurality of aluminum strands, an insulating sheath 36 of a predetermined thickness enveloping the conductive core 35.

The electric cable 4 comprises an isolated section 37, provided with the core 35 and the sheath 36, and a stripped end section 6 situated at the end of the isolated section 37, which stripped terminal section 6 is devoid of sheath 36.

The stripped end section 6 has a substantially flat end face 38 opposite the insulated section 37.

We will now describe in detail the assembly 1 comprising the lug 3 integrally assembled with the bare terminal section 6 of the electric cable 4, with reference to the Figures 11 to 15 .

The tubular portion 13 has, along what was initially its first tubular section 22 located between the insertion opening 16 and the annular shoulder 17, a first crimped zone 40, a second crimped zone 41 and a third punched zone 42.

The first zone 40 is furthest from the introduction opening 16 while the second zone 41 is closest to it. The third zone 42 is located between the first zone 40 and the second zone 41.

The stripped terminal section 6 has a first portion 43 at a distance from the insertion opening 16, a second portion 44 near this introduction opening 16 and a third portion 56 located between the first portion 43 and the second portion 43. portion 44.

The first zone 40 is crimped on the first portion 43, which has a first compression ratio, also called section reduction ratio (TRS).

This first compression ratio is here in the range [10%; 30%]. Note that this is an average compression ratio.

avec :

• A : la somme des sections des brins de l'âme conductrice 35, avant sertissage et/ou poinçonnage, en mm² ; et
• B : la somme des sections des brins de l'âme conductrice 35, après sertissage et/ou poinçonnage, en mm² (excluant les espaces créés entre les brins sertis et poinçonnés).

It will also be noted that the compression ratios (or section reduction ratio) are here calculated by the following relation: $$\mathit{TRS}\left(\%\right)=\left(1-\frac{B}{\mathrm{AT}}\right)\times 100;$$

with:

• A: the sum of the sections of the strands of the conductive core 35, before crimping and / or punching, in mm ² ; and
• B: the sum of the sections of the strands of the conductive core 35, after crimping and / or punching, in mm ² (excluding the spaces created between the crimped and punched strands).

As illustrated on the figure 13 , the first zone 40 and the first portion 43 have, in section, a general shape in B.

It will be noted that the compactness of the assembly formed of the first zone 40 and crimped portion 43 here has an external perimeter ratio P of these zone and portion on height H the smallest passing through the center of gravity G (here the geometric center) of these area and portion, which is less than about 6, significant of a first crimping.

Here, it is considered that when a zone or portion has a ratio of less than 6, it is in the presence of crimping.

The second zone 41 is crimped on the second portion 44, which has a second compression ratio which is lower than the first compression ratio.

This second compression ratio is here in the range [2%; 20%]. Note that this is a low compression ratio.

As illustrated on the figure 14 the second zone 41 and the second portion 44 have, in section, a hexagonal shape.

It will be noted that the compactness of the assembly formed of the second zone 41 and crimped portion 44 here has an external perimeter ratio P of these zone and portion on height H the smallest passing through the center of gravity G (here the geometric center) of these area and portion, which is less than about 6, significant of a second crimping.

The third zone 42 is punched with the third portion 56, which has a third compression ratio which is greater than the first and second compression ratio.

This third compression ratio is here in the range [25%; 45%]. Note that this is a strong compression ratio.

As illustrated on the figure 15 , the third punched zone 42 and the third portion 56 have, in section, a crescent shape.

It will be noted that the compactness of the assembly formed of the third zone 42 and the portion 56 punched here has an external perimeter ratio P of these zone and portion on height H the smallest passing through the center of gravity G (here the geometric center) of these area and portion, which is greater than about 6, significant of a punching.

Here, it is considered that when a zone or portion has such a ratio greater than or equal to 6, it is in the presence of punching.

We will now describe the method of integral assembly of the assembly 1 with reference to Figures 8 to 10 .

Only the bare terminal section 6 of the cable 4 is introduced through the insertion opening 16 into the terminal 3, the isolated section 37 being opposite this introduction opening 16.

It will be noted that the introduction of this stripped end section 6 into the terminal 3 is facilitated by the flared ring 39.

The stripped terminal section 6 is introduced into the terminal 3 until the end face 38 of the cable 4 comes opposite the internal face 21 of the bottom wall of the tubular portion 13.

A layer of contact grease 10 separates this inner face 21 from the end face 38.

The right bottom wall of the tubular portion 13 allows, once the end face 38 of the cable 4 facing the inner face 21 of this tubular portion 13, to return with good distribution a portion of the contact grease 10 around the first, second and third portions 43, 44 and 56 of the bare terminal section 6.

The conductive core 35 has a diameter substantially equal to the first internal diameter of the second tubular section 23, which makes it possible to guide the stripped terminal section 6 into the internal space 20.

The first zone 40 and the second zone 41 of the first tubular section 22 of the tubular portion 13 are crimped in a single step respectively on the first and second portions 43 and 44 of the stripped end portion 6, by means of a single crimping device 45 configured to obtain distinct compression ratios of the crimped strands of the denuded terminal section 6.

This crimping device 45 has a first lower jaw 46, a first upper jaw 47 opposite the first one. lower jaw 46, a second lower jaw 49 distinct from the first lower jaw 46 and a second upper jaw 50 distinct from the first upper jaw 47 and opposite the second lower jaw 49.

The first lower jaw 46 and the first upper jaw 47 form a first pair of crimping jaws 46, 47, while the second lower jaw 49 and the second upper jaw 50 form a second pair of crimping jaws 49, 50.

The first pair of crimping jaws 46, 47 has a B-shaped recess and is disposed plumb with the outer face 18 of the tubular portion 13, with the B-shaped recess facing the first tubular section 22 , close to the shoulder 17 (in other words away from the insertion opening 16).

This first pair of crimping jaws 46, 47 is configured to crimp the first zone 40 of the tubular portion 13 on the first portion 43 of the stripped end portion 6 according to predetermined first crimping parameters so as to provide the first portion 43 with the first predetermined compression ratio, and to provide the first zone 40 and portion 43, in section, a shape in B.

The second pair of crimping jaws 49, 50 has a hexagon-shaped imprint and is disposed plumb with the outer face 18 of the tubular portion 13, with the hexagon-shaped imprint facing the first section tubular 22, close to the insertion opening 16 (ie away from the shoulder 17).

This second pair of crimping jaws 49, 50 is configured to crimp the second zone 41 of the tubular portion 13 on the second portion 44 of the stripped end portion 6 according to second predetermined crimping parameters so as to provide the second portion 44 with the second predetermined compression ratio (lower than the first compression ratio), and to provide the second zone 41 and portion 44, in section, a hexagonal shape.

The third zone 42 of the first tubular section 22 of the tubular portion 13 is then punched with the third portion 56 of the stripped end section 6, by means of a punching device 51 configured to obtain a strong compression ratio of the punched strands of the bare terminal section. 6.

This punching device 51 comprises a punch 52 and a punching die 53 facing the punch 52.

The punch 52 and the die 53 have a crescent-shaped punching footprint and are arranged in line with the outer face 18 of the tubular portion 13, with the crescent-shaped imprint facing the first tubular section 22, between its first and second zones 40 and 41.

This punch 52 and this die 53 are configured to punch the third zone 42 of the tubular portion 13 on the third portion 56 of the stripped end portion 6 according to predetermined punching parameters so as to provide the third portion 56 with the third compression ratio predetermined (greater than the first and second compression ratio), and to provide the third zone 42 and portion 56, in section, a crescent shape.

It will be noted that the sleeve 32 is crushed by the crimping and punching steps on the stripped end section 6, which is thus deformed and the conductive core 35 is embedded in the perforations 59 of the sleeve 32.

It will be noted that these crimping and / or punching parameters are defined in particular by the closing edge of the crimping and / or punching devices 45 and 51 and by the shape of the imprints thereof. These parameters of course also depend on the diameter of the conductive core 35 of the electric cable 4.

As a variant, this step of deformation of the transition portion is not implemented; and the invention relates to a method of manufacturing a crimp connection device on a stripped end section of electrical cable, comprising the step of providing a conductive element made in one piece and having a tubular portion, an opening of introduction by which it is intended to introduce in said tubular portion said stripped end portion and a flat portion configured to cooperate with a predetermined electrical terminal, said tubular portion being connected at an end opposite said insertion opening, by a transition portion at said flat portion; said method comprising the step of providing a conductive cylindrical tube having a predetermined first internal diameter and having said introduction opening, and the step of at least partially expanding said conductive cylindrical tube to form said tubular portion, which is provided at least a first tubular section having a second internal diameter greater than said first predetermined internal diameter.

• la première zone et la deuxième zone du premier tronçon tubulaire de la portion tubulaire sont serties respectivement sur les première et deuxième portions du tronçon terminal dénudé, en deux étapes successives plutôt qu'en une seule étape, grâce à un unique dispositif de sertissage ou à deux dispositifs de sertissage distincts ;
• les deux sertissages et le poinçonnage sont mis en oeuvre par un même dispositif au même moment ou de manière successive ;
• la première zone et la deuxième zone du premier tronçon tubulaire de la portion tubulaire sont serties sur les première et deuxième portions du tronçon terminal dénudé et les ensembles sertis ont respectivement, en section, une forme hexagonale et en B ;
• la première zone et la deuxième zone du premier tronçon tubulaire de la portion tubulaire sont serties sur les première et deuxième portions du tronçon terminal dénudé et les ensembles sertis ont tous deux, en section, une forme en B ou une forme hexagonale ;
• la troisième zone est poinçonnée avec la troisième portion du tronçon terminal dénudé et l'ensemble poinçonné a, en section, une forme différente d'un croissant, par exemple une forme d'étoile ou une forme en H ;
• l'insert est introduit dans la portion tubulaire de la cosse en même temps que la fabrication de cette dernière, avec la bague évasée qui est déjà formée ou seulement préformée, et, le cas échéant, la bague évasée est finie de former contre le chanfrein d'introduction, par la broche d'expansion ;
• le dispositif de connexion que forme la cosse de connexion est remplacée par un autre dispositif de connexion, par exemple un raccord de connexion pourvu de deux portions tubulaires séparées d'une portion plate ; et/ou
• l'âme conductrice du câble électrique est en cuivre plutôt qu'en aluminium, et le dispositif de connexion est dépourvu d'insert.

In non-illustrated variants:

• the first zone and the second zone of the first tubular portion of the tubular portion are crimped respectively on the first and second portions of the stripped end section, in two successive steps rather than in a single step, thanks to a single crimping device or to two separate crimping devices;
• both crimps and punching are implemented by the same device at the same time or successively;
• the first zone and the second zone of the first tubular section of the tubular portion are crimped onto the first and second portions of the stripped end section and the crimped assemblies have, respectively, in section, a hexagonal shape and B;
• the first zone and the second zone of the first tubular portion of the tubular portion are crimped onto the first and second portions of the bare end portion and the crimped assemblies both have a B-shaped or a hexagonal shape;
• the third zone is punched with the third portion of the denuded end section and the punched assembly has, in section, a shape different from a crescent, for example a star shape or an H shape;
• the insert is introduced into the tubular portion of the pod at the same time as the manufacture of the latter, with the flared ring which is already formed or only preformed, and, if appropriate, the flared ring is finished to form against the introduction chamfer, by the expansion pin;
• the connecting device formed by the connecting lug is replaced by another connection device, for example a connection fitting provided with two separate tubular portions of a flat portion; and or
• the conductive core of the electrical cable is made of copper rather than aluminum, and the connection device is devoid of insert.

The method just described comprises a step of deformation of the transition portion until said transition portion forms a substantially straight bottom wall of the tubular portion, wherein said bottom wall extends substantially perpendicular to the longitudinal general direction of the tubular portion.

It is recalled more generally that the invention is not limited to the examples described and shown.

Claims (15)

A method of assembling a connection device (3) on a stripped end section (6) of an electric cable (4), said connection device (3) comprising a conductive element (7) having a tubular portion (13). ) and an introduction opening (16) by which it is provided to introduce into said tubular portion (13) said stripped end portion (6), said method comprising the steps of: providing a said connection device (3) and an electrical cable (4); - introducing said stripped end portion (6) in said tubular portion (13) by said insertion opening (16); - solidly assemble said tubular portion (13) on said stripped end portion (6); said method being characterized in that said step of assembling together comprises: a first step of crimping a first zone (40) of said tubular portion (13) with a first portion (43) of said stripped end section (6) located in said first zone (40), which first zone (40) ) is furthest from said insertion opening (16), said first crimping step being configured such that said first crimped portion (43) of said stripped end portion (6) has a first predetermined compression ratio; a second step of crimping a second zone (41) of said tubular portion (13) with a second portion (44) of said stripped end portion (6) located in said second zone (41), which second zone (41) ) is closest to said insertion opening (16), said second crimping step being configured such that said second portion (44) of said stripped end portion (6) has a second predetermined compression ratio lower than said first rate predetermined compression; a step of punching a third zone (42) of said tubular portion (13) with a third portion (56) of said denuded end portion (6) located in said third zone (42), which third zone (42) is between said first and second zones (40, 41), said punching step being configured such that said third portion (56) of said stripped end portion (6) has a third predetermined compression ratio greater than said first predetermined compression ratio . Method according to claim 1, characterized in that said first and second crimping steps are carried out at the same time and are followed by said punching step. Method according to claim 1, characterized in that said first and second crimping steps and said punching step are performed at the same time. A method according to any one of claims 1 to 3, characterized in that said first crimping step is configured such that said first compression ratio is in the range [10%; 30%]. A method as claimed in any one of claims 1 to 4, characterized in that said second crimping step is configured such that said second compression ratio is in the range [2%; 20%]. A method as claimed in any one of claims 1 to 5, characterized in that said punching step is configured such that said third compression ratio is in the range [25%; 45%]. Assembly comprising a connection device (3) solidarily assembled on a stripped end section (6) of an electric cable (4), said connection device (3) comprising a conductive element (7) having a tubular portion (13) and an insertion opening (16) through which said stripped end portion (6) is introduced into said tubular portion (13), said assembly (1) being characterized in that said tubular portion (13) comprises a first region (40) crimped with a first portion (43) of said section denuded terminal (6) in said first zone (40), said first zone (40) being furthest from said insertion opening (16), and with said first portion (43) having a first compression ratio predetermined; said tubular portion (13) further comprises a second zone (41) crimped with a second portion (44) of said stripped end section (6) located in said second zone (41), said second zone (41) being the closest said introductory opening (16), and with said second portion (44) having a second predetermined compression ratio less than said first predetermined compression ratio; and said tubular portion (13) further comprises a third zone (42) punched with a third portion (56) of said denuded end portion (6) in said third zone (42), said third zone (42) being between said first and second zones (40, 41), and with said third portion (56) having a third predetermined compression ratio greater than said first predetermined compression ratio; whereby said tubular portion (13) and said stripped end portion (6) are crimped and punched together. An assembly according to claim 7, characterized in that said first predetermined compression ratio is in the range [10%; 30%]. An assembly according to one of claims 7 and 8, characterized in that said second predetermined compression ratio is in the range [2%; 20%]. An assembly according to any one of claims 7 to 9, characterized in that said third predetermined compression ratio is in the range [25%; 45%]. Assembly according to any one of claims 7 to 10, characterized in that said first zone (40) of said tubular portion (13) and said first portion (43) of said stripped end section (6) and / or said second zone ( 41) of said tubular portion (13) and said second portion (44) of said stripped end portion (6) have a B-shaped section. Assembly according to any one of claims 7 to 10, characterized in that said first zone (40) of said tubular portion (13) and said first portion (43) of said stripped end section (6) and / or said second zone ( 41) of said tubular portion (13) and said second portion (44) of said stripped end portion (6) have, in section, a hexagonal shape. Assembly according to any one of claims 7 to 12, characterized in that said third zone (42) of said tubular portion (13) and said third portion (56) of said stripped end section (6) have, in section, a shape in crescent. Assembly according to any one of claims 7 to 13, characterized in that said electric cable (4) comprises a conductive core (35) of aluminum. Assembly according to claim 14, characterized in that said connecting device (3) comprises a sheath (32) disposed in said tubular portion (13) and into which said bare end portion (6) is inserted, said sheath (32) comprising a plurality of perforations (59) and being made of a material harder than aluminum so that said sheath (32) deforms said stripped end portion (6) with said conductive core (35) of aluminum which is embedded in said perforations (59) of said sheath (32).

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