EP2286492A1

EP2286492A1 - Brush holder device, and use thereof for producing a motor vehicle starter

Info

Publication number: EP2286492A1
Application number: EP09731475A
Authority: EP
Inventors: Maximilien Gentil
Original assignee: Valeo Equipements Electriques Moteur SAS
Current assignee: Valeo Equipements Electriques Moteur SAS
Priority date: 2008-06-06
Filing date: 2009-06-03
Publication date: 2011-02-23
Anticipated expiration: 2029-06-03
Also published as: BRPI0911800A2; RU2010153251A; FR2932318B1; EP2286492B1; FR2932318A1; CN102057543B; CN102057543A; WO2010001006A1; KR20110033120A; ES2428330T3

Abstract

The brush holder device according to the invention comprises a plate bearing a brush holder assembly. According to the invention, each of the brush holders receives, on the outer end thereof opposite the end thereof whereat a brush that the brush holder receives is placed in electrical contact with a collector, a bushing (6) made of a dielectric material and comprising a means for supporting a conductive element (5) for electrically connecting the brush to at least one separate brush, of a similar polarity, received in an equivalent brush holder remotely attached onto the plate. The bushing carries out a function of electrically and mechanically insulating the brushes and brush holders opposite a protective casing surrounding the assembly formed by the brush mounting, the brush holders, and the brushes. The bushing also carries out a function of electrically and mechanically insulating the brushes and brush holders opposite the bridge between brushes, and a mechanical function for supporting said bridge between brushes.

Description

BROKEN HOLDER DEVICE AND ITS APPLICATION TO THE

REALIZATION OF A STARTER FOR

MOTOR VEHICLE

The present invention relates to the field of starters for a motor vehicle. The invention relates to a brush-holder device and a nozzle fitted to brush holders included in such a brush-holder device.

Conventionally, a motor starter brush holder is mounted on the starter rotor shaft so as to cooperate with an electrical collector integral with the rotor shaft.

In the brush holder devices for a vehicle starter, it is known to increase the number of brushes for high power starters, in order to reduce the electrical contact resistance or to limit the individual wear of the brushes and thus prolong the duration starter life. Usually, the brushes, generally even in number, are housed in respective brush holders which are arranged on a brush support plate of the brush holder device. With the increase in the number of brushes, there then arises the problem of the electrical connections of these brushes respectively, on the one hand, to the rotor supply circuit (for brushes of positive polarity for example), and, on the other hand on the other hand, to the vehicle ground (for brushes of negative polarity, for example). Indeed, the space devoted to these elements being reduced to a minimum, it is important first of all that the electrical insulation, between them, brushes of different polarities is optimal, as well as the electrical insulation of each of the brushes with its environment, so as to avoid the risk of short-circuiting and untimely generation of arcing. This point is even more important that such brushes are often, typically for reasons of wear distribution, arranged on the brush support plate alternating their polarities. It is also important that the electrical connection of each of the brushes allows the passage of currents possibly high, as well to improve the starter performance as to decrease warming and increase the life of the starter. Braids, cords or rings or sectors of copper rings are generally used to make these connections.

Conventionally, the brushes are each placed in a brush holder fixed on one side of the brush support plate, and the central part of the latter comprises an orifice through which the assembly formed by this plate, brush holders and brushes is mounted around the starter rotor shaft. By convention, the following will be referred to in the following as the front face of the brush support plate on which the brush holders are fixed, and the rear face of the opposite face of this plate. In some cases, the support plate of brooms, conventionally a disc, has a set of through holes and has, on its rear face, a housing for receiving a braid, a ring or a sector of copper ring to which the brushes are individually electrically connected and which electrically interconnects all or part of the brushes of the same polarity. One or more inter-brush electric bridges are thus produced, which simplifies the connection of the brushes thus electrically connected to each other with the corresponding electrical circuit. Such an arrangement however results in a certain complexity in the production of the support plate of brushes, which increases the cost. It also induces additional space in the rear face of this plate, which may be incompatible with specific constraints of space in the space allocated to the starter, which is increasingly reduced on motor vehicles.

The object of the invention is to propose a device making it possible to set up such inter-brush bridges in a simple, inexpensive and applicable manner regardless of the configuration of the starter and the brush support plate in order to achieve a standardization generating additional savings in the manufacture of brush devices. According to a first aspect, the invention relates to a brush holder device for a motor vehicle starter comprising a plate supporting a set of brush holders. According to the invention, each of the brush holders accommodates, at its outer end opposite its end, through which a broom which it receives is placed in electrical contact with a collector, a tip made of a dielectric material and comprising means for maintaining a conductive element for electrically connecting the blade with at least one separate brush, of similar polarity, received in a similar brush holder fixed remote on the plate.

This tip fulfills a shutter function of one end of the corresponding brush holder which is fixed on a support plate brushes.

The holding means are advantageously arranged in such a way that the inter-brush bridge is on the same side of the brush support plate as that on which the brush holders are fixed, that is to say, to use the denomination mentioned above, on the side of the front of this deck. In addition, these holding means are advantageously configured, according to the invention, to hold the inter-island bridge at least in its part closest to the outer edge of the brush support plate.

By convention, the term "lower" will be used hereinafter to denote the portion of the inter-brush bridge closest to the support plate of brushes and brushes, and "superior" to that part of this bridge furthest from said platen and said brushes. Similarly, for the sake of clarity, the invention will be described in the following in one of its preferred embodiments, but not limiting, in which the brush support plate is conventionally in the form of a disk.

It should be noted that, particularly in this case, the inter-brush bridge may be in the form of a ring, a ring sector, or a set of ring sectors of a material driver (by example of copper) electrically interconnecting all the brushes of the same polarity or only a part of them. More generally, the inter-brush bridge may be in the form of a continuous conductive element interconnecting all the brushes of the same polarity, or a set of elementary sectors electrically connecting together all or part of the brushes of the same polarity.

According to one of its features, the tip is made of a dielectric material, for example a polymeric material.

According to a complementary feature, the end closed by the tip is the end of the receiving housing of the brush in the brush holder opposite to the end of the same housing by which the blade can come into contact with a manifold. More specifically, the tip seals the end of the brush receiving housing closest to a protective housing, or cylinder head, surrounding the assembly consisting of the support plate brushes, brush holders and brushes. Thus, for example, when the brush support plate is in the form of a disk whose central portion is pierced with an orifice to allow passage of a starter rotor shaft, the different brush holders are arranged radially. on this disc, and the tip closes the end located on the outer side thereof, periphery of the assembly.

The tip then performs an additional function of electrical insulation between the different brushes and their environment, specifically between the different brushes and the aforementioned protective housing. To this function is also added a function of mechanical insulation between the brush and the protective housing, the nozzle according to the invention preventing, by its presence, any dust from the wear of the brush to come into contact of the casing that they would then risk to pollute or on which they could constitute sites of priming of possible electric arcs.

According to another characteristic, the holding means that comprises the endpiece comprise at least one tongue that isolates electrically and mechanically while holding the interbalais bridge element inserted into this endpiece. More specifically, the tip according to the invention comprises a substantially U-shaped part of which a branch is formed by this isolation tab.

According to another of the features of the invention, another of the branches of this U carries out the electrical isolation between the inter-brush bridge and a protective casing of the assembly formed by the support plate of brushes, the brush holders and the brushes, or, more generally, between the inter-brush bridge and the external environment of the brush holder and its support plate.

According to different embodiments in the implementation of the invention, the branches of this U can be configured in such a way that, when the end piece is put in place at the end of a brush holder and when the Brush support plate is placed around a rotor shaft, they are located in a plane substantially perpendicular to the axis of this shaft or in a plane substantially parallel thereto.

The tip of the brush holder device according to the invention as it has just been defined in its principle thus fulfills:

a function of electrical and mechanical isolation of the brushes and brush holders vis-à-vis a protective casing of the assembly formed by the support plate of brushes, the brush holders and the brushes,

a function of electrical and mechanical insulation of the brush holders with respect to the inter-brush bridge, each of the brushes of the same polarity being electrically connected to the inter-brush bridge by appropriate means such as braids of conducting wires, for example,

a mechanical function for maintaining this inter-brush bridge.

The tip of the brush holder device according to the invention is particularly suitable for the equipment brush holder very simple shapes, such as for example made by folding thin sheets, which allows significant cost reductions compared to brush holders made by molding plastics.

Since the brushes have shapes and sizes that can be selected from one motor vehicle starter model to another, and the same applies to the brush holders, it follows that the nozzle of the device according to the invention can be realized in the form of a standard model used profitably on different types of motor vehicle starter. In preferred embodiments, the inter-brush bridge holding function is performed by a part of the tip different from that which is at the end of the brush holder and which ensures the electrical insulation of the brushes with regard to their environment. Since the shapes making it possible to ensure these different functions are thus distinct in each endpiece, the invention therefore makes it possible to reduce the variants of embodiments of the brush holder assemblies. This allows a further reduction in costs by standardizing the manufacture of assemblies receiving brushes and inter-brush bridges. In addition, made in a dielectric material and ensuring, as previously indicated, an electrical insulation function, the tip of the device according to the invention allows the manufacture of the brush holder and that of the support plate brushes in any material, for example folded sheet, which leads to a further reduction in cost.

Other characteristics and advantages of the invention will emerge on reading the description which follows, illustrated by the following figures in which:

FIGS. 1A and 1B are diagrammatic perspective views of first and second embodiments of a brush holder device according to the invention each formed of a support plate for brushes on which are fixed six brush holders provided with each of a mouthpiece according to the invention, FIG. 2 is a schematic perspective view of a first embodiment of a nozzle according to the invention included in a brush holder device according to the first embodiment, and

- Figure 3 is a schematic perspective view of a second embodiment of a nozzle according to the invention included in a brush holder device according to the second embodiment.

Figures 1A and 1B show the brush holder device according to first and second embodiments, respectively.

As shown in Figures 1A, 1B, the brush holder is shown mounted on a manifold 7 of the starter. The manifold 7 is provided to be fixedly mounted on a rotor shaft (not shown) of the starter. The rotor shaft is normally engaged in a through hole 2 shown in FIGS. 1A, 1B.

The brush holder device comprises a brush support plate 1 made in the form of a disk drilled at its center at the through orifice 2. The plate 1 supports six brushes each inserted in a suitable housing provided in a holder. 3. Brushes and brush holders are regularly distributed radially on the plate 1, and each of the brush holder 3 is open at its end closest to the orifice 2 to allow the electrical contact of the broom that hosts with the starter manifold.

For the sake of cost reduction, each of the brush holders is made by folding a plate of thin sheet so as to form substantially an omega whose end branches are fixed on the plate 1. Such an embodiment brings an additional advantage in that such a brush holder has a greater resistance to high temperatures, which is particularly advantageous especially for starters called to be frequently solicited during operation of the vehicle. In Figures 1A and 1B there is also partially shown a protective housing or yoke 4 surrounding the brush holder device comprising the brush support plate 1, the brush holder 3 and the brushes.

In the examples illustrated in FIGS. 1A and 1B, an inter-brushing electrical bridge 5 interconnects all the brushes placed on the brush support plate 1. This inter-brush bridge, which is made of a material having a high electrical conductivity (preferably, but not exclusively, copper), here takes the form of a rigid ring of a height of the order of a few millimeters electrically connecting between them all the brooms. However, it should be noted that such an inter-island bridge may take any form and electrically connect together all or part of the brushes placed on the plate 1.

According to the particular embodiments illustrated in FIGS. 1A and 1B, the ring forming the inter-brush bridge 5 is deformed into two diametrically opposite zones (marks 50 in FIGS. 1A and 1B). These deformations are advantageously placed opposite two diametrically opposite orifices, designated by the marks 100 in FIG. These orifices are formed in the support plate brush 1 to allow the passage of tie rods (not shown in the figures) which are used for mechanical assembly of the starter.

A tip according to the invention, designated by the reference 6, closes one of the ends of each of the brush holders 3. More specifically, the tip 6 closes the peripheral end of the receiving housing of the blade in the holder. broom, that is to say the one that is furthest from the through hole 2 through which the plate 1 allows passage of the starter rotor shaft. It thus constitutes a mechanical separation between the blade placed in the brush holder 3 and the protective casing 4. More generally, it mechanically separates the blade from its external environment at its end opposite the end intended to come into electrical contact with the blade. the starter manifold. The tip 6 according to the invention is preferably made of a dielectric material. It isolates well Also electrically the brush, including the protective casing 4. In an effort to reduce cost, it is for example made by injection / molding a plastic material for example based on polyamide.

Two embodiments of the nozzle according to the invention corresponding to the first and second embodiments of the brush holder device according to the invention are shown in detail in FIGS. 3 and 4, respectively.

In general, as shown in FIGS. 2 and 3, a nozzle according to the invention comprises a body 60 forming a housing 61 whose shape and dimensions are substantially identical to the shapes and dimensions of the cross-section of the brush holder 3 in its shape. end to which the tip is placed, so that the body 60 can be simply nested around this end. A channel 62 extends inside the housing 61, in the same direction as the edges 610 of the latter, over a length of a few millimeters. When the tip 6 according to the invention is put in place at the end of the brush holder 3, this channel accommodates a portion of a spring (not shown in the figures) placed at the rear of the blade, spring intended for guarantee, by its compression by the brush, the maintenance of the electrical contact between the latter and the collector of the starter. At its base 63, the body 60 of the tip 6 is substantially planar so as to bear on the front face of the brush support plate 1, on which the brush holders 3 are fixed.

One or the other of the first and second embodiments of the invention corresponding to FIGS. 1A, 2 and 1B, 3 is chosen as a function of the starter application envisaged. According to the embodiment chosen, the shape of the tip 6 at the end of the body 60 opposite its base 63, and the shape of the inter-brush bridge 5 are different, as is clear from the figures. Regarding the tip 6, it comprises, at the end of the body

60 opposed to its base 63, a substantially forming part U which is oriented differently depending on whether it is the first or the second embodiment. The branches of this U form the holding means mentioned above intended to retain all or part of the inter-brush bridge 5.

According to the embodiment shown in FIGS. 1A and 2, the branches of this U extend substantially parallel to the body 60 of the end piece 6. In other words, once the end piece 6 has been put in place at end of the brush holder 3 fixed on the plate 1 and the brush holder device mounted in the starter, the branches of this U are disposed substantially perpendicular to the rotor shaft of the starter. In other words again, according to the embodiment more specifically illustrated by FIGS. 1A and 2, once the tip 6 has been put in place at the end of the brush holder 3 fixed on the plate 1 and the door device -balais mounted in the starter, the branches of this U are disposed substantially perpendicular to the axis of the through orifice 2.

According to the second embodiment more specifically illustrated in FIG. 3, the end piece 6 is configured such that the legs of this U then extend substantially parallel to the axis of the through orifice 2 when the endpiece 6 is placed at the end of the brush holder 3 fixed to the plate 1 and that the brush holder device is mounted in the starter.

Whatever the embodiment chosen, the inter-brush bridge 5 or the inter-brush bridge element is inserted into the groove formed by the U-shaped part of the tip 6. The branches of this U form a tongue, respectively. 64 and a tongue 65 extending from the body 60 of the tip 6 substantially over the entire width thereof, tabs which are interconnected by a tongue 66 of the same width which constitutes the bottom of the U. The bridge inter-brush, which is here in the form of a flat conductive ring, is thus maintained on at least three sides of its periphery, including at least, whatever the variant chosen, its nearest part of the outer edge of the plate 1 and its lower part. This allows both to ensure a correct and reliable maintenance over time of this inter-brush bridge, and to fulfill a guiding function during the establishment thereof.

Indeed, according to the embodiment illustrated by Figures 1 A and 2, more specifically adapted to the case where the inter-brush bridge is in the form of a ring or flat ring portions whose dimension in the direction Longitudinal collector is greater than its dimension in the transverse direction of the collector, it is sufficient, once the tips placed at the ends of each of the brush holder 3, to bring the inter-brush bridge in the upper part of the front face of the assembly formed by the plate 1, the brush holders 3 and the brushes and insert substantially parallel to the axis of the orifice 2 between the two tongues 64 and 65, which then constitute in its regard cooperating jaws .

Advantageously, the space separating the tabs 64 and 65, occupied by the bottom 66, is very slightly less than the thickness of the ring or the ring portions forming the inter-brush bridge, so that the elasticity natural material constituting the tip 6 allows a slight compression of this bridge on the three sides of its periphery by which it is in contact with the tip 6, thereby contributing to its maintenance while allowing a very simple implementation and fast.

According to the embodiment illustrated by FIGS. 1 B and 3, more specifically adapted to the case where the inter-brush bridge is in the form of a ring or a set of flat ring sectors whose transverse dimension is greater than the longitudinal dimension, the inter-brush bridge 5 is advantageously inserted substantially perpendicular to the axis of the orifice 2 (thus radially) between the tongues 64 and 65. In this case, for easy installation, it will be advantage of setting up only part of the end pieces 6 on the brush holders 3, then inserting the inter-brush bridge, and finally to put in place place the remaining bits to put said bridge in slight compression at its outer periphery to contribute to a more reliable maintenance.

It follows from the foregoing that whatever the configuration of the inter-brush bridge 5 and the tip 6, the latter ensures, by the tabs 64 and 65 that it comprises, a reliable and durable maintenance of said bridge-inter brooms and a quick and easy installation of it. The tabs 64 and 65, as well as the bottom 66 of the U-shaped part of the end piece according to the invention also fulfill the functions of mechanical isolation and electrical insulation for the inter-brush bridge 5 respectively, respectively , brush holders 3 and brushes which are housed therein and the protective casing or cylinder head 4. More generally, the nozzle according to the invention thus provides, by the U-shaped part it comprises, mechanical insulation and electrical inter-brush bridge 5 with regard to all of its environment. The electrical connection between each brush and this bridge is achieved by means of, for example, conductive braids (not shown).

The tip according to the invention further ensures, by its body 60, a mechanical and electrical insulation of the brush holder with which it is associated and the brush that it receives with respect to their external environment, and in particular to the sight of a guard 4.

A tip according to the invention such as the tip 6 can be used to close the end of a brush holder even in the absence of interbalai bridge, the height of the tongues 64 and 65 and the bottom 66 being, whatever either the variant chosen, low (typically of the order of a few millimeters), and the shape 60 of the body of the tip 6 by which the latter is fitted on the end of the brush holder being independent of the shapes of the tongues 64 and 65 and bottom 66.

It follows that the tip according to the invention can be used for any type of platinum brush support and for any type of starter, which allows to reduce the costs by increasing the amounts of makes the standardization and versatility of the starter production chains.

Similarly, such a tip allows the realization of very simple brush holder plates, for example by stamping thin sheet metal plates on which are then fixed the folded sheet plates forming the brush holder, thus allowing additional savings.

It appears however that the invention can not be limited to the embodiments illustrated by the figures and described above, and that it extends to all equivalent forms and all technically operating combinations thereof.

In particular, the shapes and dimensions of the inter-brush bridge 5 are not limited to the shapes and dimensions explained above. The shapes and dimensions delimited by the tabs of the U-shaped portion of the nozzle according to the invention being directly linked, as described above, to the shapes and dimensions of this inter-brush bridge, it is Therefore, the U-shape and dimensions of this part are also not exclusive, and the invention also extends to any shape that simply maintains, at least in its part, the closest to the outer edge. the brush holder plate for a reliable and durable maintenance, all or part of an inter-brush electric bridge.

Claims

1. Brush holder device for a motor vehicle starter comprising a plate supporting a set of brush holders, characterized in that each of said brush holder accommodates, at its outer end opposite its end, through which a broom which it receives is brought into electrical contact with a collector, a tip (6) made of a dielectric material and comprising means for holding a conductive element (5) for electrically connecting said brush with at least one separate brush, of similar polarity, received in a similar brush holder fixed remote on said platen.

2. Device according to claim 1, characterized in that said means for holding said tip are configured to maintain said conductive member on the same side of a support plate of said brush holders as that on which said brush holders are placed on said plate. .

3. Device according to either of claims 1 or 2, characterized in that said tip is made of a dielectric material and in that it comprises a body (60) which closes a broom receiving housing in a brush holder at the end of the latter opposite the end by which said brush received in said brush holder is in electrical contact with a starter manifold.

4. Device according to any one of claims 1 to 3, characterized in that said tip comprises a U-shaped portion of which a branch (64) electrically and mechanically isolates the brush holder that equips said conductive element (5). ), and a branch (65, 66) electrically and mechanically isolating a broom received in said holder broom vis-à-vis a protective housing or cylinder head (4) to be placed around the assembly formed by the support plate brushes, brush holders and brushes of the starter.

5. Device according to claim 4, characterized in that said U-shaped portion of said tip extends substantially parallel to said body (60) of said tip.

6. Tip according to claim 4, characterized in that said U-shaped portion of said tip extends substantially perpendicularly to said body (60) of said tip.

7. brush holder device according to any one of claims 1 to 6, characterized in that each of said brush holder is made in the form of an omega obtained by folding a thin metal sheet.