EP0913847B1 - Starter contactor having an improved movable contact and vehicle starter equipped with such contactor - Google Patents

Description

The present invention relates to a contactor for starter for a combustion engine of a motor vehicle.

The invention relates more particularly to a starter contactor of the type in which a moving contact in plate shape is crossed in the center by a control rod on which the movable contact is slidably mounted between a advanced rest position to which he is reminded elastically, by means acting on the central part of the back side of the moving contact that surround a hole for the passage of the control rod, and in which the contact mobile is in axial support, by its front face against the means stoppers integral with the control rod, and a position of contact in which the two opposite transverse ends of the front face of the movable contact plate cooperate with fixed contact terminals of the contactor.

In order to ensure a good quality of contact and good conduction of electricity, the mobile contact is realized in copper and it comes, according to a known design, under the shape of a thick plate cut into substantially rectangle.

The presence of the central hole for the passage of the stem of control particularly reduces the section of the plate mobile contact in its central part.

This weakening by reduction of the section is harmful because the latter must be sufficient, on the one hand, to allow the passage of the intensity of the current required starter without voltage drop or overheating and, on the other hand, to resist the bending stress that results from the action of the return spring, also called spring compensation or contact spring, which acts on its face when the contact is closed, that is when the movable contact plate is in its retracted position of contact.

In order to have a sufficient section, it is known to increase the thickness of the movable contact plate. This last being usually cut from a sheet or plate of thick copper, the increase in thickness applies to the whole plate and so it is unnecessarily appealing to a excessive amount of copper unnecessarily increasing the weight and therefore the cost of this piece.

Another solution is to increase locally the lateral width of the contact plate, particularly in its central part around the hole for the passage of the stem of ordered. However, the overall size in width of the mobile contact plate is increased, which is detrimental to the installation of the control terminal of the contactor and different electrical connections located in the radial plane plate, thus leading to an overall increase in outer diameter of the contactor cover.

According to another aspect of the known design of a contactor, the mounting of the compensation spring, one of which rear end bears against a radial support collar achieved came of matter with the control rod and plate mobile contact is ensured by means of a support washer in steel which is secured axially to the control rod by complementary fixing means.

These complementary fixing means are constituted by a claw fixing washer which is force-fitted on a free end of the sliding control rod and which immobilizes the thrust washer in axial support against a radial shoulder of the control rod.

In addition to their complexity, these means of assembly and fixation have the disadvantage of creating particles of insulating material, resulting from the forced fitting of the washer claw attachment, which may subsequently pollute the area in which the fixed contact elements are located and mobile.

These particles are deposited in particular on fixed contact elements and cause discontinuities that interfere with the proper functioning of the whole starter and can prevent it from being energized.

The object of the invention is to propose an improvement to the design of a contactor of the type mentioned previously that helps to remedy the disadvantages that have just been mentioned.

For this purpose, the invention proposes a contactor for starter for a motor vehicle of the type in which a plate-shaped mobile contact is traversed at its center by a control rod on which the movable contact is mounted sliding between an advanced position of rest towards which he is resiliently biased by means acting on the part central of the back side of the moving contact that surround a hole for the passage of the control rod, and in which the mobile contact is axially supported by its front face against stop means integral with the control rod, and a retracted position of contact in which both ends opposite sides of the front face of the movable plate of contact cooperate with fixed contact terminals of the contactor, the movable contact plate being delimited by two opposite side edges each of which, at least in the vicinity of the central part, is extended by a lateral cheek of orientation axial so that, at least in its central part, the mobile contact has, in axial section, a profile substantially U-shaped, said movable contact plate being of generally rectangular shape with its two edges lateral sections of greater length which each extend a lateral cheek of axial orientation, characterized in that the control rod has at least one groove which extends axially in its cylindrical wall over a longer length to the stroke of the moving contact between its advanced positions of rest and retracted contact, and the central part of the plate movable contact has a bearing lug which extends radially from the hole for the passage of the stem of command and which is deformed radially when mounting the plate on the stem so as to be slidably received in the groove to cooperate with an axial end face of stop of the groove to determine the advanced position of rest mobile contact.

So the particular shape of the moving contact increases considerably its rigidity and thus reduces the thickness of the copper foil in which the plate mobile is cut and folded, while having a section of copper sufficient for the passage of the current. FR 2 538 037 shows a contactor according to the preamble of claim 1.

• chaque joue latérale s'étend transversalement jusqu'aux deux extrémités transversales opposées du bord latéral qu'elle prolonge ;
• la hauteur axiale de chaque joue latérale est décroissante à partir de la partie centrale de la plaque mobile de contact ;
• chacune des deux joues latérales s'étend axialement vers l'arrière ;
• chacune des deux joues latérales s'étend axialement vers l'avant ;
• la largeur latérale de la plaque mobile de contact est constante ;
• la largeur latérale de la plaque mobile de contact est réduite au voisinage de ses extrémités transversales opposées ;
• le contact mobile est une plaque en tôle dont le contour et le trou central sont réalisés par découpe et dont les joues latérales sont rabattues axialement par pliage ;
• la partie centrale de la plaque mobile de contact comporte deux ergots diamétralement opposés dont chacun est reçu dans l'une de deux rainures axiales diamétralement opposées ;
• la tige de commande est réalisée par moulage, et les rainures sont réalisées venues de matière par moulage.

According to other features of the invention:

• each lateral cheek extends transversely to the two opposite transverse ends of the lateral edge which it extends;
• the axial height of each lateral cheek is decreasing from the central part of the movable contact plate;
• each of the two lateral cheeks extends axially towards the rear;
• each of the two lateral cheeks extends axially forwardly;
• the lateral width of the movable contact plate is constant;
• the lateral width of the movable contact plate is reduced in the vicinity of its opposite transverse ends;
• the movable contact is a sheet metal plate whose contour and the central hole are made by cutting and whose side cheeks are folded axially by folding;
• the central part of the movable contact plate has two diametrically opposed lugs each of which is received in one of two diametrically opposite axial grooves;
• the control rod is made by molding, and the grooves are made integrally by molding.

The invention also relates to a vehicle starter automobile characterized in that it comprises a contactor according to the teachings of the invention.

• la figure 1 est une vue en coupe axiale d'un contacteur de démarreur équipé d'un contact mobile réalisé selon l'état de la technique ;
• la figure 2 est une vue en section axiale, selon la ligne 2-2 de la figure 3, d'un contact mobile réalisé conformément aux enseignements de l'invention illustré avant son montage sur la tige de commande ;
• la figure 3 est une vue latérale de gauche du contact mobile de la figure 2 ;
• la figure 4 est une vue en perspective, avec un arrachement partiel, du contact mobile illustré aux figures 2 et 3 ;
• la figure 5 est une vue en perspective de l'extrémité axiale avant d'une tige de commande réalisée conformément aux enseignements de l'invention et destinée à être équipée du contact mobile illustré aux figures 2 à 4 ;
• la figure 6 est une vue en section axiale qui illustre le contact mobile de la figure 4 en cours de montage sur l'extrémité avant de la tige de commande de la figure 5 ; et
• la figure 7 est une vue similaire à celle de la figure 6 qui illustre le contact mobile en position assemblée sur la tige de commande.

Other features 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 an axial sectional view of a starter contactor equipped with a movable contact made according to the state of the art;
• Figure 2 is an axial sectional view along the line 2-2 of Figure 3, a movable contact made according to the teachings of the invention illustrated before mounting on the control rod;
• Figure 3 is a left side view of the movable contact of Figure 2;
• Figure 4 is a perspective view, with a partial cutaway, of the movable contact illustrated in Figures 2 and 3;
• Figure 5 is a perspective view of the front axial end of a control rod made according to the teachings of the invention and intended to be equipped with the movable contact illustrated in Figures 2 to 4;
• Figure 6 is an axial sectional view which illustrates the movable contact of Figure 4 being mounted on the front end of the control rod of Figure 5; and
• Figure 7 is a view similar to that of Figure 6 which illustrates the movable contact in assembled position on the control rod.

In the following description, components identical, similar or similar will be designated by the same reference numbers.

The contactor 10, partially illustrated in FIG. comprises a housing 12, of general axis X-X, inside which an inductor winding 14 is intended to cause, with the aid of a polar mass 16, an axial magnetic field capable of axially moving a movable core 18 between a position back rest, shown in Figure 1, and a position Advanced control or contact that is axially shifted to the right, considering Figure 1.

The open front axial end 20 of the housing is closed by a cover 22 made of insulating material, one wall transverse 24 of radial orientation carries an input terminal 26 connected to a battery (not shown) of the vehicle automobile and a power terminal 28 connected to the engine electric vehicle (not shown) of the starter of the vehicle equipped with contactor 10.

The terminals 26 and 28 each comprise a head of terminal 30, 32 which is arranged inside the cover 22 of the contactor.

The heads 30, 32 constitute two fixed contacts which are intended to be electrically connected by a movable contact 34 which, according to the known design illustrated in Figure 1, is made in the form of a thick rectangular plate in copper, that is to say of electrically conductive material.

The movable contact 34 is arranged, according to its greatest length, transversely inside the contactor 10 and more particularly inside the hood 22.

The movable contact 30 is arranged axially between the front transverse face 36 of the polar mass 16 and the heads fixed contacts 30 and 32.

The movable contact 34 is likely to be moved axially in the contactor 10 between a first position said recess of rest, in which the electrical circuit between terminals 26 and 28 are open, which is shown in the figure 1 and in which the contact 34 bears axially against the front axial face 36 of the polar mass 16, and a position advanced contact, in which the electrical circuit is closed, which is shifted axially to the right considering FIG. 1 and in which the contact 34 bears axially, by the opposite transverse end portions 35 of its face transversal front, against the heads of terminals 30 and 32 of way to connect them electrically.

Thus, the contactor 10 can control the power supply motor starter motor provided by the vehicle battery.

For this purpose, the displacements of the movable contact 34 to inside the contactor 10 are controlled via of an axial control rod 38 which is likely to be moved axially from back to front in contactor 10 by the mobile core 18.

The rod 38 has a rear guide portion 40 which passes axially through the polar mass 16, in which it is guided in sliding, and whose rear axial end 42 is controlled by the mobile core 18.

The rear guide portion 40 extends axially forwardly by a central section 44, of larger diameter, on which the movable contact 34 is slidably mounted and which is delimited axially towards the rear by an external radial collar 46 of larger diameter.

Beyond the central section 44, the control rod 38 ends with a free end front stretch 48 more small diameter that is delimited, compared to the central section 44, by a shoulder 51.

The central section 44 is thus delimited axially by two radial shoulder surfaces 49 and 51.

The movable contact 34 has a hole or orifice central circular 50 to allow its sliding assembly, between an advanced rest position, illustrated in Figure 1, and an active retracted position on the cylindrical central section 44 of the control rod 38.

To determine the advanced rest position of the contact 34, there is provided a thrust washer 52 which is engaged on the free end section 48 of the stem of command 38 on which it is held in support against the radial shoulder 51 by a claw washer 53 which is force-fitted on the free end section before 48.

A helical compression spring 54, also called compensating spring or contact spring, is arranged around the central portion 44 of the control rod 38 between the shoulder radial front 49 of collar 46 and the central part of the face rear 33 of the movable contact plate 34 surrounding the hole central 50, so as to permanently solicit contact mobile 34 axially towards its rest position, advanced by relative to the rod 38, in which it is in axial support against the stop means constituted by the washer 52.

According to a known design, when the mobile core 18 is commanded to his front position, he drives with him the control rod 38 against the applied return force to the moving equipment by a return spring 55 which is a helical compression spring which is arranged axially at the front of the control rod 38 and which bears axially on the one hand against the front transverse face of the washer to claws 53 and, secondly, against a portion vis-à-vis the inside rear face of the transverse wall 24 of the cover 22.

The compensation spring 54 causes the displacement axial direction of the movable contact 34 relative to the contactor 10 towards its closed circuit position in which the movable contact 34 is in axial support, by its parts 35, against the two heads of terminals 30, 32.

The control rod 38 then continues its displacement axial direction forward under the action of the mobile core 18, which causes the axial compression of the spring 54 of the movable contact 34 because the movable contact 34 is immobilized in support axially against terminals 26 and 28.

The movable contact 34 then moves axially through relative to the control rod 38 of its advanced rest position towards an active backward position, contrary to the jurisdiction of compensation 54.

We will now describe the design according to the invention of the movable contact plate 34 and its associated rod of control 38 with reference to FIGS. 2-7.

As can be seen in particular in Figures 2 to 4, the movable plate 34 of contact is a plate of general shape rectangle made by cutting and folding in a sheet of thin copper, that is to say in a copper foil of significantly reduced thickness compared to that according to the state of the technique illustrated in FIG.

The main part, here rectangular in outline, of the movable contact plate 34 is delimited laterally by two parallel and opposite lateral edges 60 which determine the width of the movable contact plate 34, and by two edges transversal parallel and opposite 62 that determine the transverse length of the plate 34.

In order to allow its sliding guidance on the section 44 of the control rod 38, the main part of the control plate 34 has of course a central hole 50 whose diameter corresponds substantially to that of the diameter outside the central section 44 of the control rod 38.

In accordance with the teachings of the invention, and in to strengthen the movable contact plate 34 in its part center and to have a sufficient section for the passage of the current, each of the two lateral edges 60 is extended axially, here to the rear, by a lateral cheek 64.

The two cheeks 64 are made of material by folding with the rectangular main part of the plate 34.

In the example shown in the figures, both cheeks 64 are identical and each has its maximum height H in its central part, that is to say in the vicinity of the hole central 50 so as to give the mobile contact plate 34 a section, transverse along the Y-Y axis, U-shaped.

In the example illustrated in the figures, the height H each cheek 64 decreases gradually since the game centrally towards the transverse end edges 62. effect, the bending moments of the efforts applied to the moving plate 34 decrease gradually according to the direction transversal from the central part with the hole 50, and it is therefore not necessary that the wings 64 be a significant height near the ends 62.

According to another aspect of the invention, the Thin copper foil design of the contact tab 34 allows to realize the latter with means, realized come from matter by cutting and folding, for its axial retention relative to the control rod 38 so as to suppress the thrust washer 52 and the claw washer 53 according to the state of the technique.

As can be seen in Figures 2 to 4, two tabs or lugs 66, diametrically opposite, are cut simultaneously with the central hole 50 and they extend radially towards the center.

Each lug 66 is delimited by an end edge free 68, parallel to the edges 62 of the contact plate 34, and it extends transversely outwards to its crease of base 70 which is located radially outwards by relative to the contour of the hole 50 so as to have pins 66 of sufficient length which are delimited laterally by cutting slots 72 parallel to the side edges 60.

As can be seen in particular in Figures 2, 4 and 6, the lugs 66 are bent axially towards the rear, forming a acute angle α which determines a transverse distance D1 between their edges 68 which is greater than the initial distance D0 between these edges after the initial cutting operation (shown in dashed lines in Figure 3).

As can be seen in Figures 5 to 7, the section central 44 of the guide rod 38 according to the invention comprises two axial grooves 74 which are diametrically opposed and which emerge radially outward into the surface outer cylindrical 45 of the section 44.

The width of the axial grooves 74 is slightly greater than the width of the lugs or tabs 66 so that each of these pins can be received in axial sliding in a corresponding groove 74.

The depth of the grooves 74 is a depth stepped.

For this purpose, each groove 74 comprises a section main rear 76 of great depth, that is to say that the distance D2 separating the opposite bottoms of these sections 76 is the lower and it is slightly lower than the distance D0 previously mentioned.

The axial length L of the section 76 of great depth grooves 74 is at least equal to the axial stroke of the contact mobile 34 between its advanced and retreated positions.

Each groove 74 opens axially forward in the shoulder 51 by a lower section 78 of lower height so that the distance D3 separating the bottoms of the sections 78 slightly less than the distance D1 mentioned previously.

Due to the geometric arrangement and choice of dimensions D1 and D3, one understands, more particularly in considering Figure 6, that it is possible to engage axially the movable contact plate 34 on the central section 44 of the control rod 38, from right to left considering FIG. 6, since the pins 66 folded axially can penetrate axially into the grooves 74 by the front sections 78.

Diagram 6 also shows schematically two tooling elements to ensure in one operation mounting and retaining the movable plate of contact 34 on the control rod 38.

These tooling elements comprise a rear element 80 which is essentially an element of axial support towards the left against which the control rod 38 is supported by its flange 46, and a front element 82 for placing and deformation of the movable contact plate 34.

Indeed, from the position illustrated in the figure 6 on which the movable contact plate 34 has already been engaged in the grooves 74 with guidance of its movement of sliding by receiving the cylindrical section 44 through the hole 50, the assembly operation continues by acting axially, from right to left considering the figure 6, on the front transverse face 35 of the plate 34 by through element 82.

This axial action has the effect, because of the support free end edges 68 of the lugs 66 against the face rear 84 of the segments 76 of the grooves 74, to cause a progressive deformation of the pins 66, that is to say that last are brought back into the general plane of the movable plate contact 34 to occupy their original position again, that is to say after cutting and before folding, as they are represented in Figure 7.

In this position, the lugs 66 extend radially inwards in the large reaches depth 76 of the axial grooves 74 and the distance D0, greater than D2 and less than D3, is such that the plate movable contact 34 can slide axially in the grooves 74 while being held axially forward because of the coming in support of the front faces of the lugs 66 against the face before 86 of the segments 76 of the grooves 74.

It is the faces 86 which then constitute the means stoppers which retain axially forwardly the movable plate 34 and which determine the rest position of this last in relation to the X-X axis.

As a variant, not shown in the figures, the lateral wings 74 can be oriented axially towards the front, that is to say in the direction of the return spring 55 and this in order to reduce the overall width of the plate of mobile contact 34 which, in the embodiment illustrated on the figures, depends on the outer diameter of the spring of compression 54.

According to another variant, the initial folding of tongues can be done in the other direction, that is to say that they then initially protrude axially forward beyond the 35 face, which requires however to appeal to another design of a folding tool of suitable shape to allow to straighten the pins 66 and bring them back into the plane of the movable contact plate 34.

It is also not necessary that the movable plate contact 34 is of constant width, its width being reduced in the vicinity of opposite transverse ends because the material is only necessary to ensure contact punctual with heads 30 and 32 and bending moments are low in the vicinity of these contact areas with the terminals.

Claims (11)

1. A starter contactor (10) for a motor vehicle, of the type in which a moving contact (34) in the form of a plate has, passing through its centre, a control rod (38, 44) on which the moving contact (34) is mounted for sliding movement between a forward rest position, towards which it is resiliently biased by means (54) acting on the central portion (33) of the rear face of the moving contact (34), which surrounds a hole (50) for the passage through it of the control rod (38, 44), and in which position the moving contact (34) is in axial engagement through its front face against abutment means fixed with respect to the control rod (38), and a retracted contact position, in which the two opposed transverse ends (35) of the front face of the moving contact plate (34) are in cooperation with fixed contact terminals (26, 28, 30, 32) of the contactor (10), the moving contact plate (34) being delimited by two opposed side edges (60), each of which, at least in the vicinity of the central portion, is extended in length by an axially oriented side portion (64), in such a way that, at least in its central portion, the moving contact (34) has a V-shaped profile in axial cross section, the said moving contact plate (34) being of a generally rectangular form, and having each of its two side edges (60), being those of greater length, each of which is extended by an axially oriented side portion (64), characterised in that the control rod (38) has at least one groove (74) which extends axially in its cylindrical wall (44, 45) over a length (L) which is greater than the travel of the moving contact (34) between its forward rest position and its retracted contact position, and in that the central portion of the moving contact plate (34) includes an engagement lug (66) which extends radially and axially from the hole (50) through which the control rod passes, and which is deformed radially during fitting of the moving contact plate (34) on the control rod (38), so as to be received in sliding relationship in the groove (74, 76), whereby to cooperate with an axial terminal engagement face of the groove (74, 76), so as to determine the advanced rest position of the moving contact (34).
2. A contactor according to Claim 1, characterised in that each side portion (64) extends transversely as far as two opposed transverse ends (62) of the side edge (60) of which it is an extension.
3. A contactor according to Claim 2, characterised in that the axial height (H) of each side portion (64) is of decreasing value away from the central portion of the moving contact plate (34).
4. A contactor according to any one of the preceding Claims, characterised in that each of the two side portions (64) extends axially towards the rear.
5. A contactor according to any one of Claims 1 to 3, characterised in that each of the two side portions (64) extends axially towards the front.
6. A contactor according to any one of the preceding Claims, characterised in that the lateral width of the moving contact plate (34) is constant.
7. A contactor according to any one of Claims 1 to 5, characterised in that the lateral width of the moving contact plate (34) is reduced in the vicinity of its opposed transverse ends (62).
8. A contactor according to any one of the preceding Claims, characterised in that the moving contact is a plate of sheet steel, the contour and the central hole (50) of which are formed by stamping out, with its side portions (64) being deflected axially by bending.
9. A contactor according to Claim 1, characterised in that the central portion of the moving contact plate (34) includes two diametrically opposed lugs (66) each of which is received in one of two diametrically opposed axial grooves (74, 76).
10. A contactor according to Claim 1 or Claim 9, characterised in that the control rod (38) is of moulded construction, and in that the grooves (74, 76, 78) are formed integrally by moulding.
11. A motor vehicle starter, characterised in that it includes a contactor (10) according to any one of the preceding Claims.

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