EP0859394B1 - Starter contactor for motor vehicule having perfectionate protection means of electronic circuit - Google Patents

Description

The invention relates to a contactor for a starter of motor vehicle comprising improved means of protection of an electronic circuit.

The invention relates more particularly to a contactor, of the type comprising a movable magnetic core which moves axially in the center of a winding and acts on a rod of which a front end controls the movements of a contact plate capable of electrically connecting two contactor terminals, of the type in which the control rod extends axially forward through an orifice of a fixed transverse core of the contactor which is arranged axially in front of the winding, of the type in which the contact plate is received inside a cover arranged at the front of the winding, and of the type in which an electronic circuit is arranged in the cover, between the fixed magnetic core and a bulkhead separation which is crossed by the control rod.

It is known to use electronic circuits for control of the contactor winding supply. Such electronic circuits allow for perfect control displacement of the movable core of the contactor, displacement which on the one hand, to cause the meshing of a starter gear with a gear ring of a motor motor vehicle thermal, and secondly to cause the starter electric motor supply to drive in rotation the heat engine.

It was first proposed to arrange the circuit electronics outside the contactor but it's quickly appeared preferable to integrate it inside the front cover of the contactor so as to reduce the total size thereof.

However, electronic circuits are very sensitive to dust, humidity, and particles that can create electrical connections between different tracks of the circuit.

In contactors according to the state of the art, the electronic card is arranged in a compartment of the cover which is delimited, at the rear of it, by a partition of separation. However, this compartment is not waterproof because that the contact plate displacement control rod passes axially through this compartment at its center.

In this way, since the control rod must ability to slide axially through two axial ports respectively arranged in the fixed magnetic core in the partition, it is necessary to provide a clearance radial between the rod and these orifices. So during displacements of the rod, dust or moisture are likely to enter the compartment in which the electronic circuit is arranged. The document EP 0 751 545 describes a contactor according to the preamble of claim 1.

In order to provide a solution to this problem, the invention provides a contactor, of the type comprising a core moving magnetic which moves axially in the center of a winding (12) and which acts on a rod which controls the displacements of a contact plate capable of connecting electrically two contactor terminals, of the type in which the control rod extends axially forward through a orifice of a fixed transverse core of the contactor which is arranged axially in front of the winding, of the type in which the plate contact is received inside a cover arranged at the front of the winding, and of the type in which an electronic circuit is arranged in the cover, between the fixed magnetic core and a partition which is crossed by the control rod, characterized in that the partition wall has a transverse wall and an axial shaft in which the rod slides control, and in that the barrel opens forward forwards from the transverse wall, and backwards, behind the core transverse fixed.

• la cloison de séparation délimite dans le capot un compartiment avant, dans lequel sont agencées les bornes et la plaque de contact, et un compartiment arrière étanche, dans lequel est agencé le circuit électronique ;
• le fût axial de la cloison de séparation comporte une extrémité axiale arrière qui est engagée de manière étanche dans l'orifice du noyau magnétique fixe ;
• l'extrémité axiale arrière du fût de la cloison comporte un collet radial interne qui délimite un face transversale sensiblement annulaire qui est en appui axialement vers l'arrière contre une face avant du noyau magnétique fixe lorsque l'extrémité arrière du fût est reçue dans l'orifice du noyau magnétique fixe ;
• le fût axial de la cloison de séparation comporte une extrémité axiale avant qui s'étend au-delà de la paroi transversale et qui forme un surface d'appui pour la plaque de contact ;
• le fût axial comporte un alésage central qui comporte un segment arrière dans lequel est guidé un tronçon arrière de la tige de commande, et un segment avant de diamètre élargi ;
• la plaque de contact est montée coulissante sur un tronçon intermédiaire de la tige de commande, un ressort hélicoïdal de compression est interposé entre un collet radial externe, agencé à l'arrière du tronçon intermédiaire, et la plaque de contact pour solliciter cette dernière vers une positon avancée, et le ressort, qui est enroulé autour du tronçon intermédiaire, est reçu avec ce dernier dans le segment avant élargi du fût axial lorsque la tige de commande occupe une position reculée de repos ;
• la paroi transversale de la cloison de séparation comporte des nervures de rigidification ;
• le capot comporte une face transversale qui est tournée vers l'arrière, qui est agencée à la limite des deux compartiments du capot, et contre laquelle la paroi transversale de la cloison est en appui axialement vers l'avant par un bord périphérique ;
• le compartiment arrière du capot dans lequel est reçu le circuit électronique est sensiblement de forme annulaire, autour du fût axial de la cloison de séparation.

According to other characteristics of the invention:

• the partition delimits in the cover a front compartment, in which the terminals and the contact plate are arranged, and a sealed rear compartment, in which the electronic circuit is arranged;
• the axial shaft of the partition has a rear axial end which is sealingly engaged in the orifice of the fixed magnetic core;
• the rear axial end of the barrel of the partition has an internal radial collar which delimits a substantially annular transverse face which bears axially towards the rear against a front face of the fixed magnetic core when the rear end of the barrel is received in the orifice of the fixed magnetic core;
• the axial shaft of the partition wall has a front axial end which extends beyond the transverse wall and which forms a bearing surface for the contact plate;
• the axial shaft has a central bore which includes a rear segment in which a rear section of the control rod is guided, and a front segment of enlarged diameter;
• the contact plate is slidably mounted on an intermediate section of the control rod, a helical compression spring is interposed between an external radial collar, arranged at the rear of the intermediate section, and the contact plate to urge the latter towards a advanced position, and the spring, which is wound around the intermediate section, is received with the latter in the enlarged front segment of the axial shaft when the control rod occupies a retracted position of rest;
• the transverse wall of the partition wall has stiffening ribs;
• the cover has a transverse face which is turned towards the rear, which is arranged at the limit of the two compartments of the cover, and against which the transverse wall of the partition bears axially forwards by a peripheral edge;
• the rear compartment of the cover in which the electronic circuit is received is substantially annular in shape, around the axial shaft of the partition.

• la figure 1 est une vue partielle en coupe axiale d'un contacteur de démarreur conforme aux enseignements de l'invention ;
• la figure 2 est une vue schématique en perspective éclatée illustrant le capot avant et la cloison de séparation d'un contacteur selon l'invention ; et
• la figure 2 est une vue agrandie en coupe axiale de la cloison de séparation selon l'invention.

Other characteristics and advantages of the invention will appear on reading the detailed description which follows for the understanding of which reference will be made to the appended drawings in which:

• Figure 1 is a partial view in axial section of a starter switch according to the teachings of the invention;
• Figure 2 is a schematic exploded perspective view illustrating the front cover and the partition of a contactor according to the invention; and
• Figure 2 is an enlarged view in axial section of the partition according to the invention.

FIG. 1 shows a contactor 10 for an electric starter for a motor vehicle.

Contactor 10 includes an inductor winding annular 12 of axis A1 which is arranged in a housing 14 substantially cylindrical and which is wound on a body of coil 16.

A mobile magnetic core 18, substantially cylindrical, can slide axially in the center of the winding 12 between a remote rest position, which is shown in Figure 1, and an active forward position (not shown) in which the movable core 18 has moved towards the left considering figure 1 under the effect of a field magnetic created by the coil 12 traversed by a current electric. The field lines created by the winding 14 are close again thanks to the presence of a fixed magnetic core 46 which is arranged transversely at the front of the winding 12.

In a known manner, by moving towards its position active, the mobile magnetic core 18 causes the meshing a starter pinion (not shown) with a crown gear of a heat engine (not shown) of the vehicle.

Simultaneously, the movable core 18 causes the axial displacement of an axial rod 20 of the contactor 10 which controls the axial movement of a contact plate 22 from a retracted position of rest, shown in FIG. 1, to an active forward position (not shown) in which the contact plate 22 bears axially towards the front against the heads 24, 26 of two terminals 28, 30 one of which is connected to a vehicle storage battery and the other is connected to an electric starter motor. So, in the active position, the contact plate 22 causes the starter motor power supply which is then likely to cause the combustion engine to rotate vehicle to allow it to start.

In known manner, the contact plate 22 and the heads 24, 26 of terminals 28 and 30 are arranged in a cover 32 which closes, at the front, the housing 14 of the contactor 10.

As we can see more particularly on the Figure 2, the contact plate 22 and the terminals 28, 30 are received in a front compartment 34 of the cover 32 which is substantially rectangular in shape, while a rear compartment 36 of cover 32, of cylindrical shape, allows the junction of the cover 32 with the housing 14 of the contactor 10.

In known manner, the contactor 10 comprises a card with printed circuit 38 which extends in a transverse plane and which is received inside the rear compartment 36 of the cover 32. The printed circuit board 38 carries an electronic circuit of control of the power supply to the field winding 12.

In a known manner, the rear compartment 36 is axially delimited inside the cover 32 on the one hand, at the front, by a transverse wall 42 of a partition of separation 44 and on the other hand, at the rear, by the core fixed transverse magnetic 46.

In this way, the front compartment 34 of the cover 32 is axially delimited at the rear by the transverse wall 42 of the partition 44 and, at the front, by a wall transverse front 50 through which extend, axially outwards, the cylindrical body threaded each of the terminals 28, 30.

So the control rod, which connects the core movable magnetic 18 to contact plate 22, crosspiece axially the rear compartment 36 of the cover 32, passing through in particular the fixed transverse magnetic core 46 through an axial orifice 52 thereof.

In accordance with the teachings of the invention, the partition 44 has an axial shaft 54 substantially tubular which allows to make the rear compartment 36 appreciably waterproof compared to the front compartment 34 of the cover 32 and relative to the central bore 56 of the body coil 16 in which the mobile magnetic core 18 moves.

The axial shaft 54 has the shape of a cylindrical tube stepped which delimits an internal bore 59 comprising a segment rear 58 and a front segment 60 of enlarged diameter with respect to rear segment 58.

As can be seen in Figures 1 and 3, the bore internal 59 of the axial shaft 54 opens axially forwards in front of the transverse wall 42, that is to say in the front compartment 34 of cover 32, and towards the rear, in the orifice 52 of the fixed magnetic core 46, so that the internal bore 59 of the barrel 54 forms an axial passage connecting the internal bore 56 of the coil body 16 in the front compartment 34.

For this purpose, the rear axial end 62 of the barrel 54 has an internal radial collar 64 which delimits a face transverse annular 66 turned towards the rear. As we can see in Figure 1, the internal radial collar 64 is intended to be received inside the orifice 52 of the magnetic core transverse fixed 46 while the annular transverse face 66 is intended to bear axially rearwards against a front face 68 of this fixed core 46.

Furthermore, the transverse wall 42 of the partition of partition 44 is intended to bear axially towards the front, by a peripheral edge 70, against a face internal transverse 72 of the cover 32 which is turned towards the rear and which delimits the two front compartments 34 and rear 36 of the cover 32. As can be seen in FIG. 2, the transverse wall 42 has substantially the shape of a rectangle similar to the cross-sectional shape of the front compartment 34, but slightly larger.

Thus, when the cover 32 is fixed on the housing 14 of contactor 10, the partition 44 is tight axially between the cover 32 and the fixed magnetic core 46, itself secured to the housing 14, so that the compartment rear 36 is isolated from the front compartment 34 and from the bore 56 of the coil body 16.

The rear compartment 36, which is traversed axially through the barrel 54, is therefore substantially annular, so that the printed circuit board 38 must also be annular. From this done, it has a central passage for the barrel 54.

As we can see more particularly on the Figure 1, a rear section 74 of the control rod 20 is guided in axial sliding in the rear segment 58 of the internal bore 59 of the axial shaft 54.

The control rod 20 is extended axially to the front by an intermediate section 76 on which the plate contact 22 is mounted axially movable, and on which it is stressed axially forwards by a compression spring 78. The spring 78 is interposed axially between a collar external radial 80 arranged at the rear of the intermediate section 76 and a rear face 82 of the contact plate 22.

When the control rod 20 is in the position of rest, the rear collar 80, the intermediate section 76 and the compression spring 78 are substantially received in the front segment 60 of the internal bore 59 of the axial shaft 54. In this position, the contact plate 22 is supported by its face rear transverse 82 against an annular transverse face front end 84 of the axial shaft 54.

To limit the bending of the transverse wall 42, this is provided with stiffening ribs 86 which extend in axial planes on each side transverse front and rear of the wall 42.

Claims (10)

1. A contactor of the type comprising a moving magnetic core (18) which is displaced axially at the centre of a winding (12), and which acts on a rod (20) that controls the displacements of a contact plate (22) which is arranged to connect two terminals (28, 30) of the contactor (10) together electrically, of the type in which the control rod (20) extends axially forward through an aperture (52) in a fixed transverse core (46) of the contactor (10) which is arranged axially in front of the winding (12), of the type in which the contact plate (22) is received within a cap (32) which is arranged in front of the winding (12), and of the type in which an electronic circuit (38) is disposed inside the cap (32) between the fixed magnetic core (46) and a separating partition (44) through which the control rod (20) extends,
   characterised in that the separating partition (44) comprises a transverse wall (42) and an axial bush (54) in which the control rod (20) slides, and in that the bush (54) is open forward in front of the transverse wall (42) and open backward behind the fixed transverse core (46).
2. A contactor according to Claim 1, characterised in that the separating partition (44) delimits, within the cap (32), a front compartment (34) in which the terminals (28, 30) and the contact plate (22) are arranged, and a sealed rear compartment (36) in which the electronic circuit (38) is arranged.
3. A contactor according to Claim 2, characterised in that the axial bush (54) of the separating partition (44) has a rear axial end portion (62) which is engaged sealingly in the aperture (52) of the fixed magnetic core (46).
4. A contactor according to Claim 3, characterised in that the rear axial end portion (62) of the bush (54) of the partition (44) comprises an internal radial collar portion (64) which defines a substantially annular transverse face (66) which is in axial rearward abutment against a front face (68) of the fixed magnetic core (46) when the rear end portion (62) of the bush (54) is received in the aperture (52) of the fixed magnetic core (46).
5. A contactor according to any one of the preceding Claims, characterised in that the axial bush (54) of the separating partition (44) has a front axial end portion (84) that extends beyond the transverse wall (42) and defines an abutment surface for the contact plate (22).
6. A contactor according to any one of the preceding Claims, characterised in that the axial bush (54) has a central bore (59) which includes a rear segment (58) in which a rear portion (74) of the control rod (22) is guided, together with a front segment (60) of enlarged diameter.
7. A contactor according to Claim 6, characterised in that the contact plate (22) is mounted for sliding movement on an intermediate portion (76) of the control rod (20), in that a helical compression spring (78) is interposed between, on the one hand, a radially outer collar portion (80) disposed behind the intermediate portion (76), and on the other hand the contact plate (22), whereby to bias the latter towards an advanced position, and in that the spring (78), which is coiled around the intermediate portion (76), is received with the latter in the wide front segment (60) of the axial bush (54) when the control rod (20) occupies a retracted rest position.
8. A contactor according to any one of the preceding Claims, characterised in that the transverse wall (42) of the separating partition (44) has stiffening ribs (86).
9. A contactor to any one of Claims 2 to 8, characterised in that the cap (32) has a transverse face (72) which faces towards the rear and which is disposed at the limit of the two compartments (34, 36) of the cap (32), and against which the transverse wall (42) of the partition (44) is in axial forward abutment through a peripheral edge (70).
10. A contactor according to any one of Claims 2 to 9, characterised in that the rear compartment (36) of the cap (32), in which the electronic circuit (38) is received, is of substantially annular form around the axial bush (54) of the separating partition (44).

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