FR3069981A1 - BROOM DOOR FOR MOTOR VEHICLE STARTER - Google Patents

Abstract

Brush holder (10) for a starter (201) of a motor vehicle, the brush holder (10) being provided with an X axis and comprising: a support plate (12) comprising a metal plate (121) having a first polarity; a brush (15.1, 15.2, 15.3, 15.4) having a second polarity different from the first polarity; a broom (13.1, 13.2, 13.3, 13.4) fixed on the support plate (12), the broom cage (13.1, 13.2, 13.3, 13.4) comprising a cage body (39) receiving the broom (15.1). , 15.2, 15.3, 15.4), a first spring (35) adapted to act on the blade (15.1, 15.2, 15.3, 15.4) to slide it into the cage body (39); a melting element (122) which is interposed between the brush cage (13.1, 13.2, 13.3, 13.4) and the support plate (12). It is provided that the brush holder (10) further comprises a second spring (40) configured for the brush cage (13.1, 13.2, 13.3, 13.4) to pivot relative to the support plate (12) under the action the first spring (35) and the second spring (40) when the melting element (122) melts.

Description

BRUSH HOLDER FOR MOTOR VEHICLE STARTER

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a brush holder for a motor vehicle starter and a starter comprising such a brush holder.

TECHNOLOGICAL BACKGROUND

Motor vehicles comprising a heat engine also include a device for starting this heat engine, called a starter.

There is shown in Figure 1 a section of a starter 201 for an internal combustion engine of a motor vehicle according to the prior art.

This starter 201 comprises a contactor 217 and an electric motor 1 provided on the one hand with a rotor 202, also called armature, comprising an axis X and which can rotate around this axis, and on the other hand, with a stator 211 , also called inductor, placed around the rotor 202. This stator 211 comprises a yoke 7 of the starter and comprises at least one pole piece 204 for the installation of an inductor winding 4 or magnets.

The rotor 202 comprises a rotor body 207, an armature winding 208 wound in notches of the rotor body 207 and an armature shaft 214.

The armature winding 208 forms, on either side of the rotor body 207, a front bun 209 and a rear bun 210.

The rotor 202 is provided, at the rear, with a collector 212 supported by the armature shaft 214 comprising a plurality of contact parts electrically connected to the conductive elements, formed in the example considered by wires or pins, armature winding 208. The manifold 212 of the electric motor 206 is surrounded by the cylinder head 7.

Brushes 15.1, 15.2, 15.3 and 15.4 of which only two, namely 15.1 and 15.3 are visible in FIG. 1, are provided for the electrical supply of the armature winding 208. The brushes 15.1, 15.2, 15.3 and 15.4 forming a group and are each carried by a brush holder 10 sandwiched between the cylinder head 7 and a cover 216 forming a rear bearing for the rotor shaft of the electric machine. At least one of the group brushes being connected to the starter ground here, for example 15.2 and 15.4 and at least one of the group brushes being connected to the contactor 217 here, for example 15.1 and 15.3. A group of 4 brushes is provided here 15.1 - 15.4. However, the brushes can also be, for example, two, six or eight in number.

The contactor 217 comprises a terminal 229 connected via an electrical connection element, for example a wire 230, to an electrical supply of the vehicle.

The contactor comprises a terminal 3 connected via an electrical connection element, for example a wire 226 to at least one of the brushes 15.1 - 15.4. One could also provide that the terminal 3 is connected via the inductor winding 4 to at least one of the brushes.

The brushes 15.1 - 15.4 rub against the collector 212 when the rotor 202 is in rotation.

The starter 201 further includes a launcher 219 slidably mounted on a drive shaft 218 and capable of being rotated around the axis X by the rotor 202.

The launcher 219 comprises a drive element forming a pinion 221 and intended to engage on a drive member 274 of the combustion engine. This drive member is for example a toothed crown.

A speed reducer assembly 220 can be interposed between the rotor 202 and the drive shaft 218. In any event, the rotor 202 can cause the rotation of the pinion 221 by its rotation. The rotation of the rotor also corresponds to that of the collector 212 within the brush holder device 10. According to one type of starter the collector rotates clockwise relative to the brushes, according to another type of starter, the collector rotates counterclockwise relative to the brushes.

The launcher 219 also includes a pinion holder which is not visible in FIG. 1. The pinion 221 can be sliding in translation along the axis x on this pinion holder or fixed on this pinion holder.

The launcher 219 further comprises a free wheel 222 and a pulley washer 223 defining between them a groove 224 for receiving the end 225 of a fork 227.

This fork 227 is produced for example by molding a plastic material.

The fork 227 is actuated by the contactor 217 to translate the launcher 219 relative to the drive shaft 218, along the axis X, between a first position in which the launcher 219 is disengaged from the ring gear 274 and a second so-called engagement position in which the launcher 219 drives the combustion engine via the pinion 221.

So that the pinion 221 can drive the ring gear of the heat engine 274, the teeth of the pinion must, after translation of the pinion and the starter along the X axis, reach the position of engagement. According to this engagement position, a tooth of the pinion is arranged between two teeth of the crown.

The pinion 221 then drives the crown 274 in a direction called positive direction which has the effect of causing when the pinion 221 rotates at a certain speed, the starting of the heat engine.

After the engine has started, the crown 274 continues to rotate in said positive direction. It then drives the pinion but not the rotor 202 thanks to the freewheel 222.

In fact, the freewheel 222 is disposed between the rotor 202 and the pinion 221 to allow transmission of the torque from the rotor 202 to the pinion 221 and the crown 274 when the latter is driven in the positive direction by the pinion. On the contrary, when the crown 274 rotates in the positive direction and drives the pinion 221, the rotor 202 is not driven.

FIG. 2 shows in a simplified representation an example of a starter motor 1 comprising a fuse 2 connected upstream with respect to the brushes, the current going from the brushes to the collector 212. For example, the fuse 2 is mounted in series between the terminal supply 3 and windings 4.1, 4.2, 4.3, 4.4 of the winding 4 of said motor. The fuse is intended to blow to cut off the electrical supply to the motor when it is traversed by a maximum predetermined current. This is to prevent damage to the starter or its surroundings due to the heat produced by an overcurrent. Such an overcurrent appears in particular in the case where the rotor of the motor is locked in rotation. When the machine is running at no load or at low load (that is to say, it operates between 0 and 25% of the nominal load), the no load speed of the rotor also causes the electric motor to heat up 1 likely to damage the starter 201 over time. This heating, due in particular to the mechanical friction between the brushes 15.1 to 15.4 and the collector 212, occurs for example in the event of a malfunction and that the pinion does not enter the crown. However, in this case, the current flowing through the fuse may be too low to cause the fuse 2 to blow, even over a long period. Even so, this overheating can reach 200 ° at the cylinder head or 300 ° at the brushes and can ignite starter components including starter sheaths, the brush holder and cause a fire in the car or component deformations in the car due to overheating or flames. There is therefore a need to cut the starter circuit to suppress the supply of the electric motor in order to reduce the risk of fire when the heating to cause a temperature in the starter exceeding a threshold value corresponding to a temperature below the temperature. critical that could ignite sheaths or the brush holder. .

A first solution consists in choosing a fuse 2 capable of blowing both when a no-load current flows through the fuse for a duration exceeding a first predetermined duration and when a current flows through the rotary electrical machine having its rotor blocked for a duration exceeding a second predetermined duration. Such fuses are however much larger than a standard size fuse, which makes their integration almost impossible in the starter.

The document FR2977408 describes a second solution comprising a compact thermal protection system 5 making it possible to cut the electrical supply to the motor in the two aforementioned cases (in the event of blockage and in the event of operation at low load). To this end, this system 5 comprises a heat-sensitive member and a contact blade capable of establishing, following a deformation of the heat-sensitive member, a short circuit between a positive polarity to which the positive brushes are connected 15.1 ,

15.3 and the starter cylinder head 7 connected to earth with the brushes 15.2 and 15.4. However, a spring inside the brush cage implies, at iso diameter of the cylinder head, the use of a shorter brush and therefore a more limited life of the starter. The use of reinforced starters to restart a heat engine when it has just been stopped for example at a red light requires a number of brush cycles greater than the brushes of this prior art.

A third solution is described in Figures 3 to 9. More specifically Figure 3 shows a brush holder 10 according to the third solution for a motor vehicle starter operating with a fuse 2 connected upstream relative to the brushes, the current going from the brushes towards the collector 212. This brush holder 10 comprises a support plate 12 of substantially annular shape on which is fixed a set of cages 13.1-13.4 each serving as a housing for a brush 15.1-15.4. An axis X of the support plate 12 corresponds to the axis of the brush holder 10.

As can be seen in Figure 3, the brush holder comprises springs 35 mounted on antennas 37. Each spring 35 has a coiled portion formed by a plurality of turns. The rolled-up part ends in an arm 351 intended to come into abutment against at least part of the rear face of the brush 15.1-15.4. In this case, the arm 351 is terminated by two parts 352 in contact against bearing faces 38 located on either side of the zone for fixing a braid 24.1-24.4 electrically conductive to the brush. The attachment area between the braid 24.1-24.4 and the broom

15.1-15.4 is set back from the bearing faces 38 in order to maximize a functional distance for using the brushes 15.1-15.4. The brushes 15.115.4 have alternating polarities. So for example brushes 15.1 and

15.3 of positive polarity are electrically connected, via their respective braid

24.1, 24.3 to a supply wire coming from the starter contactor.

As is clearly visible in FIGS. 4 and 5, the support plate 12 is a single piece comprising a metal plate 121 and overmolded layers 122 produced on either side of the metal plate 121. The overmolded layers 122 are produced by means of a plastic material ensuring good electrical insulation. The overmolded layers 122 at least partially protect the brush support face as well as the opposite face. The overmolded layers 122 cover all the risk areas of the metal plate 121, that is to say, all the areas where a short circuit could appear.

The overmolded layers 122 are heat sensitive and deformable from a predetermined temperature. The predetermined temperature corresponds to a temperature above which the starter and / or its environment would be liable to be damaged. For example, the predetermined temperature is greater than 200 ° C, for example 265 °. Different plastics can be used depending on the applications and the constraints imposed on them. Typically, the plastic material used for the overmolded layers 122 is a thermoplastic material such as a polyamide PA4.6 or PA6.6 or a polypropylene PPS loaded with glass fiber between 40 and 50%. The metal plate 121 is typically obtained by stamping from a steel to be cut such as for example FePO5. In addition, the central part of the plate 12 has an orifice 14 through which the brush holder 10 is mounted around the rotor shaft of the starter. The plate 12 includes openings 33 for the passage of fixing lugs 32 of the cages 13.1-13.4.

The brushes 15.1 and 15.3 and their corresponding cage 13.1 and 13.3 are electrically isolated from the negative polarity for correct operation of the starter by the overmolded layers 122 which cover the openings 33 receiving the legs of the cages of positive polarity 13.1, 13.3, as well as at least in part the inner contour of the plate 12. The braids 24.1 and 24.3 may also be covered with an insulating sheath.

Furthermore, the brushes 15.2 and 15.4 of negative polarity intended for the current return are electrically connected to the ground of the machine by means of their respective braid 24.2, 24.4 welded to the metal plate 121. The flexible braids 24.1-24.4 are advantageously in copper or copper alloy to facilitate welding on the plate 121.

For example, the openings 33 receiving the tabs 32 of the cages of negative polarity 13.2 and 13.4 as well as the zones of the internal contour of the plate 12 in contact with the other tabs 32 of these cages 13.2, 13.4 may not be electrically insulated, in so that an electrical contact can occur between the cages of negative polarity 13.2, 13.4 and the plate 121 via the lugs 32. This contact is not harmful to the operation of the starter, insofar as it participates in establishing contact between the parts intended to be at the same potential, in this case the ground potential in this application.

The tabs 32 of the cages of positive polarity 13.1, 13.3 may be covered at least in part with an insulating layer sensitive to heat. This layer forming a deformable member can be made of the same type of material as that of the overmolded layers 122.

Each brush 15.1-15.4 is slidably mounted inside a cage

13.1-13.4 which is open on the side of the X axis to allow electrical contact of the brushes 15.1-15.4 with blades (not shown) carried by the collector 212.

Figures 6 and 7 each illustrate one of the cages 13.1-13.4 of a certain type of starter depending on whether the manifold 212 rotates counterclockwise or clockwise relative to the brushes.

The cage 13.1-13.4 is produced by folding a thin sheet plate so as to substantially form an omega, the end branches of which are fixed to the plate 12.

Each cage 13.1-13.4 thus has two side walls 17, 18 which are parallel to one another connected to each other by an upper wall 19. It also includes two flanges 20, 21 corresponding to the branches of the omega stem from the lower edges of the side walls 17, 18 of the broom cage 13.1-13.4. One of the side walls 17 has a notch 23 to allow the passage of the braid 24.1-24.4 of the brush housed in the corresponding cage 13.1-13.4. The other side wall 18 has an opening 25 to allow the passage of the arm of the corresponding spring. On the side of the face opening on the side of the collector 212, each brush cage

13.1-13.4 may include flaps 28, 29 extending on either side of the brush to prevent dust generated by friction with the collector blades from affecting the operation of the brush holder 10. One of the flaps 28 has a recess 30 located in the extension of the notch 23 to allow the passage of the braid 24.1-24.4 closest to the collector. Each cage 13.1-13.4 further comprises a system 31 for fixing to the plate 12. Each fixing system 31 is formed by two pairs of fixing lugs 32. The lugs 32 of each pair come from two opposite edges. screw edges 20, 21.

As can be seen in Figures 5 or 6, the upper wall 19, the two side walls 17 and 18 (and the flanges 20, 21 just for the 4645) form a cage body 39 in which the brush 15.1-15.4 slides. .

A tab 32 of each pair crosses the plate 12 right through the opening 33 made according to its thickness. The other tab 32 of each pair is in abutment against one side of the interior contour of square shape delimiting the orifice 14. The legs 32 of each pair are folded towards one another against the plate 12. Alternatively, the system fixing 31 comprises at least one rivet passing through the plate 12 and an end wall 20, 21 of the brush cage.

Furthermore, the spiral spring 35 associated with each cage 13.1-13.4 biases the brush 15.1-15.4 corresponding radially towards the contact blades of the collector carried by a body of the collector made of electrically insulating material, such as plastic. Each spring 35 is in this case mounted around a holding system 37 here formed by a pin extending axially relative to the axis X. This pin 37 called antenna is obtained by folding one of the walls of end 20 of each cage 13.1-13.4.

The cage 13.1-13.4 illustrated in Figure 7 differs from that illustrated in Figure 6, in that when looking from the X axis outward, the antenna 37 is disposed to the right of the two side walls and the upper wall forming the cage body 39 for housing the brush while for the cage

13.1-13.4 illustrated in FIG. 6 the antenna 37 is arranged to the left of the cage body 39.

This different arrangement may in particular be due to the direction of rotation of the collector 212. Indeed, when we look at the brush of the X axis towards the outside, it comprises two parts which are superimposed, namely a start part on which the rotating collector blades arrive first and an end portion from which the collector blades will detach which can cause an electric arc. In order to avoid this electric arc, it is expected that the end part has a higher electrical resistance than the start part. Thus, the starting part will be connected to the braid and the antenna 37 will be located on the other side.

There are thus defined two versions of cages called version 1 shown in Figure 6 and version 2 shown in Figure 7, these two versions being chosen according to the direction of rotation of the collector relative to the brushes.

For example, the version 2 cage is adapted for a clockwise rotation of the collector when looking in FIG. 1 from left to right along the X axis and the version 1 cage is adapted for an anti-clockwise rotation direction of the collector when looking in Figure 1 from left to right along the X axis.

The following describes, with reference to FIGS. 8 and 9, the activation of the starter fuse 2 in the event of overheating to ensure its protection. In normal operation, that is to say when the deformation temperature of the overmolded layers 122 has not yet been reached, the tabs 32 of the cages 13.1, 13.3 of positive polarity are isolated from the plate 12 while the spring 35 which is mounted compressed applies a force F1 against the brush 15.1, 15.3 so as to keep it constantly in contact with the blades of the collector. In reaction, the spring 35 also applies a force F2 to the cage 13.1, 13.3 via the antenna 37. The cages 13.1 and 13.3 cannot however move relative to the plate 12 due to the rigid nature of the assembly. When overheating occurs, for example caused by an idle operation of the starter for a long time, the deformation temperature of the insulating layers 122 is reached. The reaction force F2 exerted by the spring 35 on the antenna 37 then generates a pivoting of the cages of positive polarity 13.1 and 13.3 relative to the plate 12, so that at least one lug 32 of a cage 13.1, 13.3 comes into contact with the plate 121 connected to earth to establish a short circuit. This short circuit generates a considerable increase in the current flowing through the machine, which has the effect of blowing the fuse 2 of the starter causing the power to the engine to stop. This thus ensures protection of the starter while the current flowing through the machine during an idle operation of the engine causing overheating does not normally allow the fuse 2 to melt.

A fourth solution illustrated in FIG. 10 differs from the third solution in that, instead of the lug 32 of a cage 13.1, 13.3 which comes into contact with the plate 121 connected to ground to establish a short circuit. , it is the body 39 of the cage 13.1, 13.3 which comes into electrical contact with the cylinder head 7 under the effect of the spring which causes it to tilt. For example, the upper wall 19 or one of the side walls 17 or 18 comes into contact with the cylinder head 7.

However, there is a need to further increase the reliability of the third solution or the fourth solution.

Indeed, it is possible that the tilting of the cage cannot take place and that the short circuit continues without triggering the melting of the fuse. For example, if the spring breaks. This is particularly the case if the cage is broken and the current flows through the spring and the antenna to go from the positive brush to the plate 12. This causes the spring to collapse under the effect of the current.

OBJECT OF THE INVENTION

The object of the invention is to meet this need while remedying at least one of these aforementioned drawbacks.

According to the invention, a brush holder is provided for a motor vehicle starter, the brush holder being provided with an X axis and comprising:

a support plate comprising a metal plate having a first polarity;

a brush having a second polarity different from the first polarity;

a broom cage fixed on the support plate, the broom cage comprising a cage body receiving the broom,

a first spring capable of acting on the brush to make it slide in the cage body;

a fusion element which is interposed between the broom cage and the metal plate;

According to a general characteristic, the brush holder further comprises a second spring configured so that the brush cage tilts relative to the support plate under the action of the first spring and the second spring when the melting element melts.

A systematic tilting of the broom cage is thus obtained. It can be provided that the brush holder is integrated into a starter comprising a cylinder head. In this case, an arrangement of the cage is provided on the plate so that the tilting can allow a short circuit between the cage and the cylinder head or between the cage and the support plate, this direct short circuit allowing a sufficient current flow. to melt the fuse electrically connected upstream relative to the brushes, the current going from the brush to the collector. This is advantageous because when the fuse is blown the risk that the starter catches fire is very low.

The brush holder can comprise, in addition to the plate and the brush cage, other brush cages each receiving a brush of second polarity as well as other brush cages receiving brushes of first polarity. Provision may be made for a second spring to be provided, for example to facilitate the tilting of the other cages of second polarity.

The first polarity being different from the second polarity, the fusing element can be electrically insulating. For example, one can predict that the first polarity is negative or neutral and that the second polarity is positive.

According to other characteristics taken individually or in combination:

- The second spring exerts forces directly on the body of the broom.

Thus the tilting of the broom is simpler since the forces of the second are exerted directly on the body of the broom.

- The second spring exerts forces in the radial direction in the direction of the center towards the external periphery of the support plate.

This is an embodiment allowing in particular a short circuit between the broom and the cylinder head.

- The second spring exerts forces in the radial direction in the direction of the external periphery towards the center of the support plate.

This is an embodiment allowing in particular a short circuit between the brush cage and the support plate.

the second spring comprises two ends, a first end bearing on the support plate and a second bearing on the body of the brush cage, the second spring being mounted prestressed so as to exert a force on the support plate and the cage body. In this case, one can for example provide that the spring is either isolated from the support plate or from the cage or is non-conductive because the support plate and the cage are of different polarities.

the second spring is of the X-axis spiral spring type.

This is a simple embodiment to set up using an additional spring for each brush cage for which a more reliable tilting is desired.

the brush holder comprises, in addition to the broom cage called the first broom cage, a second broom cage comprising a cage body and the second spring comprises two ends, a first end exerting a first force on the body of the first cage brush and a second end exerting a second force on the body of the second brush cage.

Thus with a single additional spring, the tilting of several brush cages is allowed.

- The two brush cage bodies on which the forces of the second spring are exerted each include a groove for receiving the second spring, the two grooves facing the axis X and being arranged on the outer periphery of their cage body respective.

- the two brush cage bodies on which the forces of the second spring are exerted each comprise a groove for receiving the second spring, the two grooves facing the axis X and being arranged on the internal periphery of their cage body respective.

- the second spring is of type C spring.

It is a spring allowing at a reduced cost a tilting of at least two cages with high reliability.

- the second spring is of the O-spring type.

It is a spring allowing, with a reduced cost, a tilting of several cages over a large angular sector in the axial plane of the brush holder.

- the brush holder comprises, in addition to the brush called the first brush, a second brush for the second brush cage, said second brush having the second polarity and the second spring being conductive, it serves as an electrical conductor between the second brush and the first brush .

In the brush holders, a conductive electrical trace can in principle be provided for connecting brushes of a certain polarity, for example positive. With this type of configuration, a conductive function is added to the spring, which makes it possible to remove this conductive trace in order in particular to reduce costs and increase the reliability of the starter.

the melting element comprises a layer overmolded on the metal plate of the support plate and which in the initial state keeps the cage in position relative to the support plate.

This overmolded layer can be formed from an electrically insulating material.

The invention also relates to a motor vehicle starter comprising a brush holder as described above.

BRIEF DESCRIPTION OF THE FIGURES

Other characteristics and advantages of the invention will appear on examining the detailed description of modes of implementation and embodiments, in no way limiting, and the appended drawings in which:

FIG. 1, already described, represents a section of a starter according to the state of the art;

FIG. 2, already described, represents a view of the principle of operation of the electric motor of the starter according to the state of the art;

FIGS. 3, already described, represents a view of a brush holder according to the state of the art;

FIG. 4 and 5 already described, respectively represent a view of a plate according to the state of the art;

FIGS. 6 and 7 already described, each represent a certain type of starter depending on whether the manifold 212 rotates counterclockwise or clockwise with respect to the brushes according to the state of the art;

FIG. 8, 9 and 10, already described, show the principle of the tilting of a brush cage according to the state of the art;

FIG. 11 illustrates a brush holder according to a first embodiment of the invention;

FIGS. 12 and 13 illustrate a sectioned broom cage according to the first embodiment of the invention;

FIG. 14 illustrates a brush holder according to a second embodiment of the invention;

FIG. 15 illustrates a brush holder according to a third embodiment of the invention; and

FIG. 16 illustrates the spring of the third embodiment of the invention.

Identical, similar, or analogous elements keep the same reference from one figure to another.

DESCRIPTION OF EXAMPLES OF EMBODIMENT OF THE INVENTION

FIG. 11 illustrates a brush holder according to a first embodiment of the invention. This brush holder 10 can be included in the starter 201 in place of the brush holder of the prior art.

This brush holder 10 is provided with an X axis and comprises:

a support plate 12 comprising a metal plate 121 having a first polarity;

-four brush cages 13.1, 13.2, 13.3, 13.4 of which only the cages 13.1 and 13.2 and 13.3 are visible. These brush cages are fixed to the support plate 12. Each brush cage 13.1, 13.2, 13.3, comprises a cage body 39 for receiving a corresponding brush 15.1, 15.2, 15.3,

for each brush cage, a first spring 35 capable of acting on the brush 15.1,

15.2, 15.3 to slide it into the cage body 39;

a fusion element 122 which is interposed between the brush cage 13.1, 13.2,

13.3 and the metal plate 121. For example, the fusing element 122 comprises a layer which is overmolded on the metal plate 121 of the support plate 12 and which in the initial state keeps the cage in position relative to the plate support 12.

In other words, the brush holder 10 comprises, in addition to the brush cage 13.1 called the first brush cage, at least one second brush cage 13.3 comprising a cage body 39.

In addition, it is expected that the brush holder 10 further comprises a second spring 40. It is for example a spring type spring C. However, it is also possible to provide a spring type spring O This second spring 40 comprises two ends, a first end exerting a first force on the body 39 of the first brush cage 13.1, and a second end exerting a second force on the body 39 of the second brush cage 13.3.

For example, this second spring exerts forces directly on the body 39 of the brush cage 13.1 and 13.3. For example, in the radial direction in the direction from the center towards the external periphery of the support plate 12.

For this, the two cage body 39 with brush 13.1 and 13.3 on which the forces of the second spring are exerted each comprise a groove 41 for receiving the second spring 40, the two grooves facing the axis X and being arranged on the outer periphery of their respective cage body 39.

Furthermore, it can be provided that the two brushes 15.1 and 15.3 of the cages 13.1 and 13.3 both have a second polarity different from the first polarity. In this case, the second spring 40 being conductive, it can serve as an electrical conductor between the second brush 15.3 and the first brush

15.1.

Figures 12 and 13 illustrate the tilting of the brush cage 13.1, relative to the support plate 12 under the action of the first spring 35 and the second spring 40 when the melting element 122 melts.

In FIG. 12, when the melting element 122 is not melted, the cage 13.1 is mounted by means of the fixing lugs 32 on the plate 12. For this, for example, the fixing lugs pass through openings 33 arranged in the plate as in the prior art (cf. FIGS. 4 and 5) and are supported on the metal plate 121 by means of the fusion element 122. This support compensates for the force 63 exerted by the spring on the body 39 of the cage 13.1 as well as the force F2 of the spring 35 visible in FIG. 9 exerted by the antenna on the cage

13.1.

Provision may be made for the fusing element to comprise two layers overmolded on the metal plate 121 of the support plate 12, each of the layers being arranged on one face of the metal plate 121.

In FIG. 13, when the fusing element melts, the support of the fixing lugs 32 on the metal plate 121 by means of the fusing element 122 is not stable so that the support does not compensate plus the forces 63 and F2 which prevail and cause the tilting of the broom.

FIG. 14 illustrates a brush holder according to a second embodiment of the invention. This second embodiment differs from the first embodiment in that the two brush body 39 with brushes 13.1, 13.3, on which the forces of the second spring 40 are exerted, each comprise a groove 42 for receiving the second spring 40, the two grooves 42 facing the axis X and being arranged on the internal periphery of their respective cage body.

FIG. 15 illustrates a brush holder according to a third embodiment of the invention. According to this third embodiment, it is a spring of the X-axis spiral spring type. This spring may comprise two ends, a first end bearing on the support plate 12 and a second bearing on the body 39 of the brush cage 13.1, 13.2, 13.3, 13.4, the second spring 40 being mounted prestressed so as to exert a force on the support plate 12 and the cage body 39.

This spring thus exerts forces directly on the body 39 of the brush cage 13.1, 13.2, 13.3, 13.4. For example, in the radial direction in the direction of the external periphery towards the center of the support plate 12.

For this, the cage body 39 with brush 13.1, and 13.3 on which the forces of the second spring 40 are exerted each comprise a groove 62 for receiving the second spring 40, the grooves being disposed on the side opposite the axis X la outer periphery of their respective cage body 39.

FIG. 16 illustrates in more detail the spring of the spiral spring type of axis X. of the third embodiment of the invention. This one has two ends 40.1 and 40.2. The end 40.1 will be housed in the groove 62 while the end 40.2 is for example received in a hole arranged in the support plate 12. One could also provide for the end 40.2, a pin on the plate 12.

Claims (14)

1. Brush holder (10) for a motor vehicle starter (201), the brush holder (10) being provided with an X axis and comprising: a support plate (12) comprising a metal plate (121) having a first polarity; -a brush (15.1, 15.2, 15.3, 15.4) having a second polarity different from the first polarity; -a broom cage (13.1, 13.2, 13.3, 13.4) fixed on the support plate (12), the broom cage (13.1, 13.2, 13.3, 13.4) comprising a cage body (39) receiving the broom (15.1 , 15.2, 15.3, 15.4), a first spring (35) capable of acting on the brush (15.1, 15.2, 15.3, 15.4) to make it slide in the cage body (39); a melting element (122) which is interposed between the brush cage (13.1, 13.2, 13.3, 13.4) and the metal plate (121); characterized in that the brush holder (10) further comprises a second spring (40) configured so that the brush cage (13.1, 13.2, 13.3, 13.4) tilts relative to the support plate (12) under the action the first spring (35) and the second spring (40) when the fusing element (122) melts. 2. Brush holder (10) for a starter motor (201) according to claim 1, characterized in that the second spring (40) exerts forces directly on the body (39) of the brush cage (13.1, 13.2, 13.3 13.4). 3. Brush holder (10) for a starter motor (201) according to claim 1 or 2, characterized in that the second spring (40) exerts forces in the radial direction in the direction of the center towards the external periphery of the plate support (12). 4. Brush holder (10) for a motor vehicle starter (201) according to claim 1 or 2, characterized in that the second spring (40) exerts forces in the radial direction in the direction of the external periphery towards the center of the support plate (12). 5. Brush holder (10) for a starter (201) of a motor vehicle according to any one of claims 1 to 3, characterized in that the second spring (40) comprises two ends, a first end bearing on the support plate (12) and a second bearing on the body (39) of the broom (13.1, 13.2, 13.3, 13.4), the second spring (40) being pre-tensioned so as to exert a force on the support plate ( 12) and the cage body (39). 6. Brush holder (10) for a motor vehicle starter (201) according to the preceding claim, characterized in that the second spring (40) is of the X axis spiral spring type. 7. Brush holder (10) for a motor vehicle starter (201) according to any one of claims 1 to 4, characterized in that the brush holder (10) comprises, in addition to the brush cage (13.1, 13.2, 13.3 , 13.4) said first broom cage (13.1, 13.2, 13.3, 13.4), a second broom cage (13.1, 13.2, 13.3, 13.4) comprising a cage body (39) and in that the second spring (40) comprises two ends, a first end exerting a first force on the body (39) of the first broom cage (13.1, 13.2, 13.3, 13.4) and a second end exerting a second force on the body (39) of the second cage with broom (13.1, 13.2, 13.3, 13.4). 8. Brush holder (10) for a motor vehicle starter (201) according to claim 7 when dependent on claim 3, characterized in that the two cage body (39) with brush (13.1, 13.2, 13.3, 13.4) on which exert the forces of the second spring (40) each include a groove (41) to receive the second spring (40), the two grooves facing the axis X and being arranged on the outer periphery of their body (39 ) of respective cage. 9. Brush holder (10) for a motor vehicle starter (201) according to claim 7 when dependent on claim 3, characterized in that the two brush body bodies (39) (13.1, 13.2, 13.3, 13.4) on which exert the forces of the second spring (40) each include a groove (42) for receiving the second spring (40), the two grooves (42) facing the axis X and being arranged on the inner periphery of their respective cage body. 10. Brush holder (10) for a motor vehicle starter (201) according to any one of claims 7 to 9, characterized in that the second spring (40) is of the C spring type. 11. Brush holder (10) for a starter motor (201) according to any one of claims 7 to 9, characterized in that the second spring (40) is of the O-spring type. 12. Brush holder (10) for a starter motor (201) according to one of claims 7 to 11, characterized in that it comprises, in addition to the brush (15.1, 15.2, 15.3, 15.4) said first brush (15.1 , 15.2, 15.3, 15.4), a second brush (15.1, 15.2, 15.3, 15.4) for the second brush cage, said second brush (15.1, 15.2, 15.3, 15.4) having the second polarity and in that the second spring (40) being conductive, it serves as an electrical conductor between the second brush (15.1, 15.2, 15.3, 15.4) and the first brush (15.1, 15.2, 15.3, 15.4). 13. Brush holder (10) for a starter motor (201) according to one of the preceding claims, characterized in that the fusing element (122) comprises a layer overmolded on the metal plate (121) of the plate support (12) and which in the initial state keeps the cage in position relative to the support plate (12). 14. Motor vehicle starter (201) comprising a brush holder (10) according to one of the preceding claims.