FR2770334A1 - STARTER CONTACTOR COMPRISING AN IMPROVED MOBILE CONTACT AND MOTOR VEHICLE STARTER PROVIDED WITH SUCH A CONTACTOR - Google Patents

Abstract

The invention provides a contactor of the type in which a movable plate-shaped contact (34) is crossed at its center (50) by a control rod on which it is slidably mounted, characterized in that the movable contact plate ( 34) is delimited by two opposite lateral edges (60) each of which, at least in the vicinity of the central part, is extended by a lateral cheek (64) of axial orientation so that, at least in its central part, the contact mobile (34) has, in axial section, a U-shaped profile.

Description

The present invention relates to a starter switch

  for a combustion engine of a motor vehicle.

  The invention relates more particularly to a starter contactor of the type in which a movable plate-shaped contact is traversed in the center by a control rod on which the movable contact is slidably mounted between an advanced rest position towards which it is resiliently returned , by means acting on the central part of the rear face of the movable contact which surrounds a hole for the passage of the control rod, and in which the movable contact is in axial support, by its front face, against stop means integral with the control rod, and a contact position in which the two opposite transverse ends of the front face of the movable contact plate cooperate with terminals

contactor fixed contacts.

  To ensure good quality of contact and good conduction of electricity, the movable contact is made of copper and it is, according to a known design, in the form of a plate

  thick cut substantially in the shape of a rectangle.

  The presence of the central hole for the passage of the control rod particularly reduces the section of the movable plate of

contact in its central part.

  This weakening by reduction of the cross-section is harmful because the latter must be sufficient on the one hand to allow the passage of the intensity of the current necessary for the starter without drop in voltage or excessive heating and, on the other hand, to resist the bending stress resulting from the action of the return spring, also called a compensation spring or contact spring, which acts on its rear face when the contact is closed, that is to say when the plate

  contact mobile is in its remote contact position.

  In order to have a sufficient section, it is known to increase the thickness of the movable contact plate. Since the latter is generally cut from a thick copper sheet or plate, the increase in thickness applies to the entire plate and an excessive amount of copper is therefore unnecessarily used.

  unnecessarily increasing the weight and therefore the cost of this part.

  Another solution consists in locally increasing the lateral width of the contact plate, in particular in its central part around the hole for the passage of the control rod. However, the overall overall width of the movable contact plate is increased, which affects the installation of the contactor control terminal and the various electrical connections located in the radial plane of the plate, thus leading to an increase. overall

  outside diameter of the contactor cover.

  According to another aspect of the known design of a contactor, the mounting of the compensation spring, one rear end of which bears against a radial support collar produced integrally with the control rod and the movable contact plate, is ensured by means of a steel support washer which is made axially integral with the control rod by complementary fixing means. These complementary fixing means consist of a claw fixing washer which is force fitted onto a free end of the sliding control rod and which immobilizes the is stop washer in axial support against a radial shoulder of the rod

control.

  In addition to their complexity, these assembly and fixing means have the drawback of creating particles of insulating material, resulting from the forced mounting of the claw fixing washer, which may later pollute the area in which the

  fixed and mobile contact elements.

  These particles are deposited in particular on the fixed contact elements and cause electrical discontinuities which disturb the proper functioning of the starter assembly and which 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 above which allows

  to remedy the drawbacks which have just been mentioned.

  To this end, the invention proposes a starter switch for a motor vehicle of the type in which a movable contact in the form of a plate is crossed in its center by a control rod on which the movable contact is mounted to slide between an advanced rest position towards which it is recalled elastically, by means acting on the central part of the rear face of the movable contact which surrounds a hole for the passage of the control rod, and in which the movable contact is in axial support, by its front face , against abutment means integral with the control rod, and a retracted contact position in which the two opposite transverse ends of the front face of the movable contact plate cooperate with fixed contact terminals of the contactor, characterized in that the movable contact plate is delimited by two opposite lateral edges each of which, at least in the vicinity of the central part, is extended by a side cheek of axial orientation so that, at least in its central part, the movable contact has, in axial section, a substantially C-shaped profile so as to considerably increase its rigidity and thus make it possible to reduce the thickness of the copper sheet in which the movable plate is cut and folded, while having a copper section

  lo sufficient for current flow.

  According to other characteristics of the invention - the movable contact plate is of generally rectangular shape with its two lateral edges of greater length which each extend by a side cheek of axial orientation; 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 decreases 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 forward; 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 outline and central hole are made by cutting and whose side cheeks are folded axially by folding; the control rod has at least one groove which extends axially in its cylindrical wall over a length greater than the stroke of the movable contact between its advanced rest and retracted contact positions, and the central part of the movable contact plate comprises a support lug which extends radially from the hole for the passage of the control rod and which is deformed radially when the plate is mounted on the rod so as to be received in sliding in the groove to cooperate with an axial end face of abutment of the groove for determining the advanced position of rest of the movable contact; - The central part of the movable contact plate has two diametrically opposite lugs, each of which is received in one of two diametrically opposite axial grooves; - The control rod is produced by molding, and the grooves are produced integrally by molding. The invention also relates to a motor vehicle starter, characterized in that it comprises a contactor conforming to

teachings of the invention.

  Other characteristics and advantages of the invention

  will appear on reading the following detailed description for the

  understanding of which reference will be made to the accompanying drawings in which: - Figure 1 is an axial sectional view of a starter switch equipped with a movable contact made according to the prior art; - Figure 2 is an axial sectional view, along line 2- 2 of Figure 3, of a movable contact made in accordance with 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 produced in accordance with the teachings of the invention and intended to be equipped with the contact

  mobile illustrated in Figures 2 to 4; -

  - Figure 6 is an axial section view which illustrates the movable contact of Figure 4 during mounting 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 the assembled position on the control rod.

  In the following description, identical components,

  Similar or analogous will be designated by the same reference numbers. The contactor 10, partially illustrated in FIG. 1, comprises a housing 12, of general axis XX, inside which an inductor winding 14 is intended to cause, by means of a polar mass 16, a magnetic field axial capable of moving axially a movable core 18 between a rear rest position, shown in FIG. 1, and an advanced control or contact position which is offset

  axially 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, a transverse wall 24 of radial orientation carries an input terminal 26 connected to a battery (not shown) of the motor vehicle and a terminal power supply 28 connected to the electric motor (not shown) of the vehicle starter

lo fitted with contactor 10.

  The terminals 26 and 28 each have a terminal head 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 FIG. 1, is produced in the form of a thick rectangular copper plate, that is i.e. in material

conductor of electricity.

  The movable contact 34 is arranged, along its greatest length, transversely inside the contactor 10 and more

  particularly inside the cover 22.

  The movable contact 30 is arranged axially between the front transverse face 36 of the pole piece 16 and the contact heads

fixed 30 and 32.

  The movable contact 34 is capable of being moved axially in the contactor 10 between a first remote position called rest, in which the electrical circuit between the terminals 26 and 28 is open, which is shown in FIG. 1 and in which the contact 34 is in axial abutment against the front axial face 36 of the pole piece 16, and an advanced contact position, in which the electrical circuit is closed, which is offset axially to the right when considering FIG. 1 and in which the contact 34 comes to bear axially, by the opposite transverse end portions 35 of its front transverse face, against the heads of the terminals 30 and 32 so as to connect them electrically. Thus, the contactor 10 can control the supply of the starter motor with electric current supplied by the vehicle battery. To this end, the movements of the movable contact 34 inside the contactor 10 are controlled by means of an axial control rod 38 which is capable of being moved axially,

  from back to front, in the contactor 10 by the movable core 18.

  The rod 38 comprises a rear guide section 40 which passes axially through the pole piece 16, in which it is guided in sliding, and whose rear axial end 42 is controlled by the

movable core 18.

  The rear guide section 40 is extended axially forwards by a central section 44, of larger diameter, on which the movable contact 34 is slidably mounted and which is axially delimited.

  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 section 48 of smaller diameter which is delimited, with respect to the central section 44, by a shoulder 51. The central section 44 is thus delimited axially in pairs

  radial shoulder surfaces 49 and 51.

  The movable contact 34 has a circular central hole or orifice 50 to allow its sliding mounting, between an advanced rest position, illustrated in FIG. 1, and an active back position,

  on the central cylindrical section 44 of the control rod 38.

  In order to determine the advanced rest position of the contact 34, a stop washer 52 is provided which is engaged on the free end section 48 of the control rod 38 on which it is held in abutment 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 a compensation or contact spring, is arranged around the central section 44 of the control rod 38 between the front radial shoulder 49 of the collar 46 and the central part of the rear face 33 of the movable contact plate 34 which surrounds the central hole 50, so as to permanently urge the movable contact 34 axially towards its rest position, advanced 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 movable core 18 is controlled towards its front position, it drives with it the control rod 38 against the return force applied to the movable assembly 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 claw washer 53 and, on the other hand, against a portion in vis-à-vis the rear inner face of the transverse wall 24

cover 22.

  The compensation spring 54 causes the movable contact 34 to move axially relative to the contactor 10 to its closed circuit position in which the movable contact 34 is in axial support, by

  its parts 35, against the two terminal heads 30, 32.

  The control rod 38 then continues its axial displacement lo forwards under the action of the movable core 18, which causes the axial compression of the spring 54 of the movable contact 34 because the movable contact 34 is immobilized in abutment axially against terminals

26 and 28.

  The movable contact 34 then moves axially relative to the control rod 38 from its advanced rest position towards a

  retracted position active, against compensation spring 54.

  We will now describe the design according to the invention of the movable contact plate 34 and its associated control rod 38 in

reference to Figures 2 to 7.

  As can be seen in particular in Figures 2 to 4, the movable contact plate 34 is a plate of generally rectangular shape

  produced by cutting and folding in a thin copper sheet, that is to say

  say in a copper sheet of thickness significantly reduced by

  compared to that according to the state of the art illustrated in FIG. 1.

  The main part, here of rectangular contour, 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 parallel and opposite transverse edges 62

  which 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 naturally includes a central hole 50 whose diameter corresponds substantially to that of the outside diameter of the section

  central 44 of the control rod 38.

  In accordance with the teachings of the invention, and in order to reinforce the movable contact plate 34 in its central part and to have a sufficient section for the passage of the current, each of the two lateral edges 60 is extended axially, here towards the rear, by

a side cheek 64.

  The two cheeks 64 are produced integrally by folding

  with the rectangular main part of the plate 34.

  In the example illustrated in the figures, the two cheeks 64 are identical and each has its maximum height H in its central part, that is to say in the vicinity of the central hole 50 so as to give the movable contact plate 34 a section, transverse along the axis YY, U-shaped. In the example illustrated in the figures, the height H of each of the cheeks 64 decreases progressively from the central part in the direction of the transverse end edges 62. In Indeed, the bending moments of the forces applied to the movable plate 34 gradually decrease in the transverse direction starting from the central part comprising the hole 50, and it is therefore not necessary for the wings 64 to be of a significant height in the vicinity

ends 62.

  In accordance with another aspect of the invention, the thin copper foil design of the contact tab 34 makes it possible to produce the latter with means, produced integrally by cutting and folding, for its axial retention relative to the rod 38 to remove the thrust washer 52 and the claw washer 53

according to the state of the art.

  As can be seen in Figures 2 to 4, two tongues or pins 66, diametrically opposed, are cut simultaneously

  with the central hole 50 and they extend radially towards the center.

  Each lug 66 is delimited by a free end edge 68, parallel to the edges 62 of the contact plate 34, and it extends transversely outwards to its base fold 70 which is located radially towards the outside relative to the contour of the hole 50 so as to have lugs 66 of sufficient length which are delimited laterally by cutting slots 72 parallel to the lateral edges 60. As can be seen in particular in FIGS. 2, 4 and 6, the pins 66 are folded axially towards the rear, forming an acute angle a which determines a transverse distance D1 between their edges 68 which is greater than the initial distance DO between these edges at the end of

  the initial cutting operation (shown in dotted lines in Figure 3).

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

section 44.

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

correspondent 74.

  The depth of the grooves 74 is a stepped depth.

  To this end, each groove 74 has a rear main section 76 of great depth, that is to say that the distance D2 l0 separating the opposite bottoms from these sections 76 is the smallest and it

  is slightly less than the distance DO mentioned above.

  The axial length L of the very deep section 76 of the grooves 74 is at least equal to the axial stroke of the movable contact 34

  between its forward and backward positions.

  Each groove 74 opens axially forwards into the shoulder 51 by a front section 78 of smaller height so that the distance D3 separating the bottoms of the sections 78 is

  slightly less than the distance D1 mentioned above.

  Because of the geometrical arrangement and the choice of dimensions D1 and D3, it is understood, more particularly [especially considering FIG. 6, that it is possible to axially engage the movable contact plate 34 on the central section 44 of the control rod 38, from right to left considering Figure 6, because the pins 66 axially folded can penetrate axially into the grooves 74 by the

front sections 78.

  FIG. 6 also shows diagrammatically two tooling elements making it possible, in a single operation, to assemble and retain the movable contact plate 34 on the rod.

command 38.

  These tooling elements comprise a rear element 80 which is essentially an axial support element to the left against which the control rod 38 is supported by its flange 46, and a front element 82 for positioning and deforming the plate

contact mobile 34.

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

  the plate 34 via the element 82.

  This axial action has the effect, due to the support of the free end edges 68 of the lugs 66 against the rear face 84 of the sections 76 of the grooves 74, to cause a progressive deformation of the lugs 66, that is to say say that the latter are brought back into the general plane of the movable contact plate 34 to again occupy their initial position, that is to say after cutting and before folding, as they

are shown in Figure 7.

  o10 In this position, the pins 66 extend radially inwards in the very deep sections 76 of the axial grooves 74 and the distance DO, greater than D2 and less than D3, is such that the movable contact plate 34 can slide axially in the grooves 74 while being retained axially forwards due to the abutment of the front faces of the lugs 66 against the front face 86

sections 76 of grooves 74.

  These are the faces 86 which then constitute the abutment means which retain the movable contact plate 34 axially forwards.

  which determine the rest position of the latter relative to the axis X-

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

compression spring 54.

  According to another variant, the initial folding of the tongues can be carried out in the other direction, that is to say that they then initially protrude axially forwards beyond the face 35, which however requires to use another design of a bending tool of suitable shape to allow the lugs 66 to be straightened and

  return to the plane of the movable contact plate 34.

  Nor is it necessary for the movable contact plate 34 to be of constant width, its width being able to be reduced in the vicinity of the opposite transverse ends 62 because the material is only necessary to ensure punctual contact with the heads 30 and 32 and the bending moments are weak near these areas of

contact with the terminals.

Claims (13)

  1. Starter contactor (10) for a motor vehicle of the type in which a movable contact (34) in the form of a plate is crossed in its center by a control rod (38, 44) on which the movable contact (34) is mounted sliding between an advanced rest position towards which it is resiliently recalled, by means (54) acting on the central part (33) of the rear face of the movable contact (34) which surround a hole (50) for the passage of the control rod (38, 44), and in which the movable contact (34) is in axial support, by its front face, against abutment means integral with the control rod (38), and a retracted position of contact in which the two opposite transverse ends (35) of the front face of the movable contact plate (34) cooperate with fixed contact terminals (26, 28, 30, 32) of the contactor (10), characterized in that the plate contact mobile (34) is delimited by two opposite lateral edges (60) of which c each, at least in the vicinity of the central part, is extended by a side cheek (64) of axial orientation so that, at least in its central part, the movable contact (34) has, in axial section, a profile in U shape. 2. Contactor according to claim 1, characterized in that the movable contact plate (34) is of generally rectangular shape with its two lateral edges (60) of greater length which are   each extend by a side cheek (64) of axial orientation.   3. Contactor according to one of claims 1 or 2,   characterized in that each lateral cheek (64) extends transversely to the two opposite transverse ends (62) of the lateral edge (60) which it extends; 4. Contactor according to claim 3, characterized in that the axial height (H) of each lateral cheek (64) is decreasing at   from the central part of the movable contact plate (34).   5. Contactor according to any one of the claims   previous, characterized in that each of the two side cheeks   (64) extends axially towards the rear.   6. Contactor according to any one of claims 1 to 4,   characterized in that each of the two side cheeks (64) extends axially forward.   7. Contactor according to any one of the claims   previous, characterized in that the lateral width of the plate   contact mobile (34) is constant.   8. Contactor according to any one of claims 1 to 6,   characterized in that the lateral width of the movable contact plate (34) is reduced in the vicinity of its opposite transverse ends (62).   9. Contactor according to any one of the claims   above, characterized in that the movable contact is a sheet metal plate 10 whose outline and central hole (50) are produced by cutting and   whose side cheeks (64) are folded axially by folding.   10. Contactor according to any one of the claims   previous, characterized 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) greater than the stroke of the movable contact (34 ) between its advanced rest and retracted contact positions, and in that the central part of the movable contact plate (34) comprises a lug (66) which extends radially from the hole (50) for the passage of the control rod and which is deformed radially during assembly of the movable contact plate (34) on the control rod (38) so as to be received in sliding in the groove (74, 76) to cooperate with an axial end face (86) of abutment of the groove (74, 76) for determining the advanced position of rest of the movable contact (34).   11. Contactor according to claim 10, characterized in that the central part of the movable contact plate (34) comprises two diametrically opposed lugs (66) each of which is received in one of   two diametrically opposite axial grooves (74, 76).   12. Contactor according to one of claims 10 or 11,   characterized in that the control rod (38) is made by molding, and in that the grooves (74, 76, 78) are made from material by molding.   13. Motor vehicle starter, characterized in that it   comprises a contactor (10) according to any one of claims previous.