FR2814589A1 - CARCASS CONTACTOR FOR A MOTOR VEHICLE STARTER AND STARTER PROVIDED WITH SUCH A CONTACTOR - Google Patents

Abstract

The contactor for a motor vehicle starter, of the type comprising a carcass (1) of material allowing a passage of magnetic flux and comprising a perforated bottom for the passage of a movable core, a shoulder for support of a fixed core and a portion cylindrical axially oriented, called crimping portion, extending axially beyond the shoulder for fixing by crimping a cover characterized in that the carcass (1) is made in three parts, namely a bottom (12 ) of transverse orientation, an external tube (13) of axial orientation having the crimping portion (13 ') and an internal tube (14) of axial orientation housed inside the external tube (13) and in this that the outer tube (13) is fixed on the bottom (12) and extends, in a direction opposite to the bottom (12), in axial projection relative to the inner tube (14) having the shoulder (14 ').

Description

"Carcass contactor for motor vehicle starter and starter

  provided with such a contactor "The invention relates to a carcass contactor for a motor vehicle starter and to a starter provided with such a contactor. As is known, a contactor for a motor vehicle starter, comprises a movable contact capable of '' be moved in translation between a rest position, in which the contact is in abutment against a fixed conductive element connected to a pole ground of the vehicle, and an active position, in which the movable contact establishes the electrical connection between a terminal current input and a starter electric motor supply terminal. In the active position, the electric motor shaft rotates a starter with a pinion, which meshes with a starter ring, linked in

  rotation of the vehicle engine, to start said engine.

  The input and output terminals are carried by a support block

  hollow form forming a cover made of insulating material.

  The contactor comprises a winding with at least one winding to control the displacement of a movable core of the contactor, displacement which has the consequence, on the one hand, of causing the end of travel to supply the electric motor of the starter and, d on the other hand, to cause, via a pivoting fork coupled to the mobile core and coming into engagement with the starter, the displacement of the starter pinion for its engagement with the

toothed starting crown.

  Figure 1 shows such a contactor. In this figure for simplicity, only the main elements belonging to the state of the art have been referenced. Thus, this contactor comprises a carcass 1 made of magnetic material, conventionally made of solid or sintered soft iron. This visible carcass alone in FIG. 2 forms a cylindrical casing 1 closed in leaktight manner by the cover 6. The annular winding 4 with one or two windings is mounted in this casing 1, which, in combination with the cover 6, protects the inside of the contactor vis-à-vis external aggressions and which ensures a return to ground. The annular winding 4, when it is traversed by an excitation current, causes an axial magnetic flux in the contactor, in particular thanks to a polar mass 2 forming a fixed core and mounted at one of the axial ends of the winding 4. The winding 4 is then capable of causing the axial displacement of the movable core 3 of any magnetic material

like the fixed core 2.

  The movable core 3 is thus capable of sliding between a rear rest position in which it projects axially through a first axial end of the carcass of the contactor, and an active front position in which, under the effect of the induced magnetic field by the winding 4, it is almost entirely received inside the

winding 4.

  The first axial end is formed by the bottom, the central hole in the carcass 1, which comprises a tubular part 1b of axial orientation which connects to the external periphery of the bottom.

transverse orientation.

  A helical compression spring resiliently recalls the movable core towards its rest position by resting on the external rear face of the bottom facing away from the winding 4. This bottom also serves, thanks to its central opening, to support for a guide tube also carried by the support for the coil 4. The guide tube is by its internal periphery in intimate contact with the external periphery of the movable core 3 of cylindrical shape. This core is provided centrally with a blind hole for housing an actuating rod and a tooth-to-tooth spring acting between the mobile core 3 and a head of the rod projecting from the mobile core to carry a hinge pin. for the starter fork engaged with the

launcher of it.

  Carcass 1 is closed at its second opposite axial end

at the bottom there by the cover 6.

  The support block 6 comprises a cylindrical annular skirt, which allows its centering and its fixing to the second open end of the

  carcass 1, and a transverse bottom which axially closes the contactor.

  Advantageously, the support is made of plastic.

  The terminals are substantially diametrically opposite on the bottom of the cover 6, on either side of the axis of axial symmetry of the

contactor.

  The terminals each include a contact head arranged inside the contactor, against the transverse bottom of the support block 6, and a connection stud partly threaded and which extends axially through the transverse bottom so as to lead to the outside the contactor. The first terminal is intended to be connected to the positive terminal (not shown) of a vehicle storage battery via a switch usually actuated by the ignition key or by any other means. The second terminal is designed to receive a cable

  power supply (not shown) of the electric starter motor.

  The support block 6 is fixed, by sealed crimping, to the second end of the carcass 1. To do this this carcass 1 has at its second end, constituted by the free end of its tubular part 1b, a transverse shoulder lc for support of the fixed core 2, a cylindrical centering portion of the fixed core 2 and a cylindrical portion Id of small thickness, called crimping portion, intended for fixing by crimping the cover 6. More precisely, the end of the portion Id is folded down in 6a (Figure 1) inwardly in contact with an outer portion of frustoconical shape of the cover 6 for clamping the fixed core 2 between the shoulder lc and the free end of the cover 6. The portion id of axial orientation s 'extends axially, in the opposite direction to the bottom la,

beyond the shoulder lc.

  A movable contact 5, consisting of a plate, is capable of being moved axially inside the space delimited by the annular wall and the bottom of the cover 6, between a rear rest position in which it is supported. against the fixed core 2 and an active front position in which the movable contact 5 bears simultaneously against the heads of the terminals so as to establish between these two terminals an electrical connection which makes it possible to supply the starter motor with electric current from vehicle storage battery. The axial movement of the movable contact 5 is controlled by a control rod, which is axially guided, and whose movements

  are controlled by the moving core 3.

  In known manner, the movable contact 5 is slidably mounted on

the control rod.

  The control rod drives the movable contact from its rest position to its active position by means of a contact spring which bears on one side against a shoulder of the control rod

  and on the other side against the rear transverse face of the movable contact 5.

  A return spring allows to bring back the control rod and

  the movable contact 5 in the rest position.

  The return spring bears against the bottom of a cylindrical housing arranged in the center of the transverse bottom of the cover 6 and it biases axially a metal washer (not visible) which is pressed against a second shoulder of the control rod and against the front transverse face of the movable contact, which also cooperates with the terminals. In the rest position, the movable contact in one embodiment comes into contact with the fixed core 2, advantageously provided

i have protuberances for this purpose.

  It is advantageous to use electronic circuits for controlling the power supply of the contactor winding. Such electronic circuits make it possible to have perfect control of the displacement of the movable core of the contactor. Thus, the contactor is here electronic and includes a printed circuit board carrying electronic components and which extends in a transverse plane and axially between the fixed core 2 and a transverse wall belonging to a sealing partition as described in the EP documents. A 0 751 545 and application FR 99 09977 filed on 07/30/1999. Advantageously, the sealing partition is made by molding in plastic material, thus allowing a forced insertion into the cover 6 advantageously made of the same material. The seal is obtained by the

material deformation.

  Thus, the control rod, which connects the movable magnetic core 3 to the movable contact 5, axially passes axially through an axial barrel

  tubular bulkhead.

  The axial shaft is stepped in diameter and has a front section and

  rear as described in application FR 99 09977.

  The rear axial annular section is intended to be received inside the bore of the fixed core with which it cooperates in sealed manner. A metal connection can be inserted in the bulkhead. The metal connection ensures electrical contact between the

  fixed core 2 and the movable contact 5 when it is in the rest position.

  This connection comprises a tongue which protrudes axially s towards the front of the partition and which is folded radially so as to extend along the front transverse face of the partition to ensure electrical contact with the movable contact 5 when the latter is in the rest position. This tongue is secured to a washer-shaped base axially traversed by the rear axial annular section of the barrel of the partition. The base ensures electrical contact with the fixed core 2. For this purpose the barrel has a hole for the passage of the tongue. This hole is formed in the shoulder produced by the change in diameter between the rear and front sections of the barrel of the partition. For more than

  details please refer to said request FR 99 09977.

  The movable contact in the rest position is therefore, according to the embodiments, in contact either with the fixed core, in particular when there is no electronic card inside the contactor, or with a sealing partition directly or indirectly through

  of a part in electrical contact with the fixed core.

  It follows from the above that the thicknesses of the bottom 1a and of the tubular part 1b of the carcass 1 are determined according to the needs of the passage of the magnetic flux. In practice to avoid too great a current consumption and a too large copper volume at the level of the coil 4, it is necessary not to over saturate the magnetic circuit, therefore to have a flux passage section

sufficiently large magnetic.

  The bottom 1a thus has a relatively large thickness of the order of 3 to 6 mm. The thickness of the tubular part 1b is smaller because the cross section of the magnetic flux is distributed over a larger circumference. This thickness is of the order of 2 to 4 mm. These thicknesses correspond to a manufacture of the carcass by

deep drawing of a sheet.

  The crimping portion 1d usually has a thickness of 0.4mm to 1mm; the tubular portion 1b having internally three different diameters for in particular forming the shoulder lc at the

  favor a change in diameter.

  The carcass 1 is produced in a first step by stamping, then in a second operation is the object of resumption of machining operations and finally undergoes in a third step a surface treatment to achieve protection against corrosion and give a good appearance to this carcass visible from the outside especially when the

  starter is mounted on vehicle.

  Machining resumption operations are necessary because, on the one hand, the carcass 1 must be cut to length, and on the other hand, the internal staggered diameters of the tubular part 1b

  for forming the shoulder lc and the crimping portion ld.

  The surface treatment must be a good conductor of electricity because the external face of the bottom 1a (the rear face) is used for the return to ground of the winding 4, which performs a function of maintaining the movable contact after the closure of the latter when the electric motor of the starter turns, and in the case of an electronic contactor for return to ground of the electronic circuit. For the record, it should be noted that the bottom is used for fixing the

  contactor on the starter housing.

  These three stages require heavy investments, in particular with regard to the deep drawing operation and are rarely carried out in the same geographical location, taking into account

especially their difference.

  It is therefore an object of the invention to achieve more

simple and economical the carcass.

  According to the invention, a contactor provided with a magnetic material carcass of the above-mentioned type is characterized in that the carcass is produced in three parts, namely a first piece of transverse orientation, called bottom, constituting the bottom with holes, a axial orientation external tube having the crimping portion and an axial orientation internal tube housed inside the external tube and in that the external tube is fixed on the bottom and extends, in a direction opposite to the bottom, in

  axial projection relative to the inner tube having the shoulder.

  Advantageously, the internal tube is in contact with the bottom and

with the outer tube.

  Thanks to the invention, each of the elementary components does not

  requires only simple and inexpensive means of production.

  Compared to a solution by deep drawing of a sheet, requiring a particular metallurgical quality of the sheet, the

cost of the material.

  Compared to a solution for obtaining the carcass by

  s extrusion reduces investment.

  In addition, the thickness of the bottom can easily be increased.

  The outer tube advantageously undergoes the surface treatment operation in advance. The inner tube is protected and does not need surface treatment as it is surrounded by the longer outer tube. This internal tube o10 is housed for fixing in the internal tube advantageously by fitting. The bottom does not need to undergo an aesthetic surface treatment because it is less visible than the external tube rendered aesthetic, in particular in terms of color and appearance, by its surface treatment which is also well suited to corrosion resistance. This surface treatment of the outer tube does not have to take into account a good conduction of the electricity produced by the protected inner tube, so that one has a greater number of choices as regards the

  surface treatment of the outer tube.

  In addition, since the base is in contact with the starter housing, carrying the electric motor and the contactor, it is possible to dispense with a surface treatment of the base since the risk of corrosion is low since the starter housing is in aluminum alloy. In the case where the starter is subjected to a more aggressive environment from the point of view of corrosion and / or protection is required, the

  nature of the treatment that is best suited without aesthetic concern.

  Of course the thickness of the inner tube increased by the thickness of the outer tube is chosen to correspond to the thickness of the tubular part of FIG. 2 and the thickness of the outer tube

  corresponds to the thickness of the crimping portion of Figure 2.

  This outer tube, thinner than the inner tube, is cut to the desired length to have the desired length for the portion

crimping.

  This arrangement facilitates standardization of the internal tube because the contactor can be electronic or not, which influences the length of the cover and of the crimping portion. The outer tube is therefore a piece of adaptation to this variation in length and more or less exceeds the inner tube to vary the length of the crimping portion according to the applications, which makes it possible to reduce the number of pieces of

reference to store.

  The internal tube reinforces the cross section of the magnetic flux

and conducts electricity.

  The means of production can be brought together in the same geographical location, which reduces the additional costs of transport and

production management.

  In addition, no resumption of machining operation is necessary since the inner tube has the shoulder and the outer tube the crimping portion. No deep drawing of parts is necessary. Advantageously, the external tube covers at least partially the external periphery of the bottom, which thus may not be visible and serves as

centering device on the outer tube.

  This arrangement facilitates the fixing of the external tube with the bottom

  because it allows prior centering of these parts.

  The first part constituting the bottom consists in an embodiment in a simple washer. As a variant, the background is rectangular, square or polygonal. This is made possible because one can easily give a complementary shape to the relevant end of the outer tube or even to the entire outer tube. The internal tube easily having a shape complementary to that of the external tube, it follows that the section of the tubes can be circular, rectangular, square,

polygonal or other.

  The attachment of the outer tube with its bottom is advantageously carried out inside the outer tube and therefore of the carcass

  to protect this binding and for aesthetic reasons.

  In one embodiment, the bottom and the outer tube are assembled, that is to say fixed to each other, by indirect heat supply, in particular by laser welding or by electron beam allowing very high heating. localized does not affect the outer periphery of the outer tube when this welding is carried out inside the carcass. In addition, no addition of metal is necessary and a solid, tight fixing is obtained with good continuity of the magnetic circuit and without

protrusion of the weld bead.

  This welding is advantageously carried out from inside the tube

  external with an oblique shot directed towards the external periphery of the bottom.

  The invention also provides a starter in accordance with

teachings of the invention.

  Other characteristics and advantages of the invention will appear

  on reading the following detailed description for understanding

  which should be attached to the accompanying drawings in which: - Figure 1 shows a contactor according to the prior art which is illustrated in axial section - Figure 2 is an axial sectional view of the carcass of Figure 1; - Figure 3 is an axial sectional view of the carcass according to the invention; - Figure 4 is an enlarged view of insert IV of the

  Figure 3 before mounting the inner tube.

  The cylindrical carcass of Figure 3 is intended to replace the

  carcass of FIGS. 1 and 2. This carcass, of axis of axial symmetry A-

  A, therefore authorizes a passage of the magnetic flux like that of FIG. 1 and comprises parts made of magnetic material each of form

simple and economical.

  More precisely according to the invention the carcass 1 is made in three parts, namely a first part 12 of transverse orientation, called bottom, constituting the perforated bottom, an external tube 13 of axial orientation having the crimping portion 13 'and a internal tube 14, of axial orientation, housed inside the external tube 13. This internal tube 14 has the shoulder 14 'for the fixed core 2 and is here in contact with the bottom 12 and with the external tube 13 of thinner than the inner tube 14. The thickness of the bottom 12 and therefore of the first part is

  greater than that of tubes 13,14.

  These three parts 12,13,14 are here made of sheet steel based on mild steel.

  In this figure the tubes 13,14 are of constant thickness and have a

circular section.

  The outer tube 13 is fixed to the bottom 12 and extends in axial projection relative to the inner tube 14 having the shoulder 14 'and this in

opposite direction to the bottom 12.

  The bottom 12 replaces the bottom 1a in FIG. 1 and is therefore perforated here centrally for the passage of the movable core 3. This bottom 12 at the same

  thickness as the bottom 1a and here consists of a simple washer 12.

  The sum of the thicknesses of the tubes 13 and 14 is equal to

  the thickness of the tubular part 1b of FIG. 2.

  The thickness of the outer tube 13 is equal to that of the portion Id

  to be able to carry out the crimping.

  The internal diameter of the inner tube 14 is equal to that of the tubular part 1b. This tube 14 is supported on the bottom 12 by its first axial end. Its second axial end constitutes the shoulder 14 ′ for axial support of the fixed core 2. The length of this tube 14 is therefore determined accordingly. Here the outer tube 13 has a first end 13 ', which extends, in a direction opposite to the bottom 12, in axial projection relative to the shoulder 14' and the tube 14 to form the cylindrical crimping portion 13 '. The tube 14 is also in contact by its external periphery with the internal periphery of the external tube 13 and is intended to provide an electrical connection between the bottom 12 and the fixed core 2. The tube 14 is protected by the external tube

13 longer.

  The outer tube 13 is cut to length to have the same axial length as that of the carcass of Figures 1,2 and therefore to have the same axial position for the free ends of the portions of

crimping Id, 13 '.

  This external tube 13 is intended, via the internal periphery of its cylindrical crimping portion 13 ', to serve as a centering device for the fixed core. This arrangement simplifies the carcass, which thus has only two inside diameters and does not require additional machining operations. The length of the portion 13 ′ is therefore greater than the portion lb. Of course the external diameter of the

  fixed core is increased in this case.

  The outer tube 13 surrounds and therefore at least partially covers the bottom 12. Here the tube 13 is in contact by the inner periphery of its other axial end 13 "with the outer periphery of the bottom 12 so that the bottom 12 is hidden by the tube 13, which undergoes a surface treatment in advance to give it an aesthetic appearance and to resist corrosion. The possibilities of choice of this treatment in quality and cost are much greater than those of the carcass of FIG. 2 because this treatment does not have to be a good conductor of electricity. The bottom may not undergo a surface treatment because it is intended to come into contact with the casing of the starter based on aluminum and little prone to corrosion. However, under severe climatic conditions of use, the bottom may undergo a treatment of

  surface that is best suited without aesthetic concern.

  The tube 14 does not need surface treatment because it is housed

in tube 13.

  No post-assembly treatment 12,13,14

is not necessary.

  This assembly is carried out by first fixing the end 13 "of the external tube to the bottom 12, then simply by fitting the tube 14 into

  the outer tube 13 until abutment of the tube 14 against the bottom 12.

  This fitting is advantageously carried out with tightening, here a slight tightening because after crimping the cover 6 the tube 14 is tightened axially between the bottom and the free end of the cover 6 which contributes to preventing it from turning. The tightening value therefore depends on the applications. The tube 14 is therefore housed for fixing in the tube 13 so as not to get lost and to constitute a manipulable and transportable carcass.

  before mounting the other components of the contactor.

  The fixing of the tube 13 with the bottom 12 is facilitated by the adjacent 13 "end of the tube 13 covering at least partially the periphery

external of the bottom 12.

  In the case where dimensions do not arise, the diameter of the bottom 1 and of the end 13 ′ can be slightly increased to form a shoulder in the tube 13 at the change in diameter between the end 13 "and the main part of the tube 13. In this case, the end 13" can be extended and folded down in contact with the rear face of the bottom in contact with its front face with said shoulder. The fixing between the parts 12, 13 is therefore carried out in an embodiment by crimping. If necessary, at least one welding point can be made between the rear face of the bottom 12 and the folded part of the end 13 "to avoid any relative rotation between

parts 12.13.

  In Figure 3 the attachment is made from the inside of the outer tube 13 and therefore of the carcass at the outer periphery of the front face of the bottom 12 in particular for an aesthetic appearance and protect the attachment against external aggressions. In this figure we only increase

  not the bulk and the tubes 13,14 have a simple shape.

  The fixing is carried out locally by indirect heat input 10 here by an own laser type welding or by electron beam. The energy densities used in this type of welding are very high so that the surface treatments are destroyed in the welding zone and do not interfere with the welding. The heating is very localized and does not affect the surface treatments of the rest of the part concerned in particular of the external periphery of the external tube 13, which

  thus retains its aesthetic appearance.

  Said welding is carried out from the inside of the external tube 13 and therefore from the carcass at the level of the external periphery of the front face of the bottom 12 and of the adjacent internal periphery of the end 13 "of the

  tube 13 with an oblique shot along arrow F in FIG. 4.

  The internal tube 14 consists of a tube section or, as a variant, of a rolled and welded or rolled and stapled sleeve. This tube serves to reinforce the cross section of the magnetic flux also passing

from the bottom 12.

  The outer tube 13 also consists of a section of tube or

  alternatively in a rolled and welded socket or rolled and stapled.

  The contactor equipped with the carcass according to the invention is mounted in the embodiment shown on a motor vehicle starter. Of course, the present invention is not limited to the examples of embodiments described. Thus it is possible to further increase the thickness of the bottom 12, which can easily have a thickness of 1.3 to 2 times the sum of the thicknesses of the tubes 13,14. Other fixing means can be envisaged for the tubes 13, 14. For example, the tube 14 can be fixed by oblique shot welding to the bottom 12 in the same way as the tube 13. In general, it is sought to make the tube 14 captive to constitute a manipulable carcass and

transportable.

  As a variant, the tube 13 is fixed by axial welding, for example by indirect heat input such as laser type welding or by electron beam, at the rear face of the bottom 12 between the external and internal peripheries respectively. of the bottom 12 and of the adjacent end 3 "of the tube 13. This type of welding can be carried out radially between two transverse faces respectively of the bottom 12 and of the adjacent end 13" of the tube 13. In this case the bottom has 0 advantageously a plug shape with a shouldered head delimiting the transverse face concerned from the bottom and a body penetrating into the tube 13 while being in contact with a portion of the internal periphery of the end 13 "whose end edge constitutes the other transverse face As a variant, the radial welding is carried out between the edge of the end 13 "and the external periphery of the front face of the bottom 12 so that the external tube 13 does not cover the fo nd 12. In this variant the external diameters of the external tube 13 and of the bottom 12 are equal. Advantageously in all cases the weld beads are continuous for good sealing of the bottom, good continuity of the magnetic circuit and good joining between the parts. It is preferable to use a weld without addition of metal to preserve the dimensions of the carcass and avoid a protuberance of the weld. Welding of the laser or electron beam type, in general

  by indirect heat, is well suited for this purpose.

  As a variant, the internal tube 14 may advantageously have in advance a change in diameter at the shoulder 14 ′ for centering the fixed core 2 as in FIG. 1 so that the fixed core 2 in FIG. 1 is not not changed. When space conditions, in particular axial, do not arise, the outer tube 13 can cover the outer periphery of the bottom 12 and extend in axial projection relative to the rear face of the bottom 12. The fixing between the bottom 12 and the outer tube 13 is then produced by welding the inside of the tube 13 with an oblique shot as in FIG. 3 in this case between the outer periphery of the rear face of the bottom 12 and the adjacent inner periphery of

the 13 "end.

Claims (10)

  1- Contactor for a motor vehicle starter, of the type comprising a carcass (1) of material allowing a passage of magnetic flux and comprising a perforated bottom for the passage of a movable core (3), a shoulder for bearing a core fixed (2) and a cylindrical portion of axial orientation, called crimping portion, extending in a direction opposite the bottom, axially beyond the shoulder for 0 fixing by crimping of a cover (6) characterized in that the carcass (1) is made in three pieces, namely a first piece (12) of transverse orientation, called bottom, constituting the perforated bottom, an external tube (13) of axial orientation having the crimping portion (13 ') and an internal tube (14) of axial orientation housed inside the external tube (13) and in that the external tube (13) is fixed on the bottom (12) and extends, in opposite direction at the bottom (12), projecting axially with respect to   to the internal tube (14) having the shoulder (14 ').   2- Contactor according to claim 1, characterized in that the   inner tube (14) is housed for fixing in the outer tube assembly (13) - bottom (12).   3- Contactor according to claim 1 or 2, characterized in that   the inner tube (14) is tightly fitted into the outer tube (13).   4- Contactor according to any one of the claims   previous, characterized in that the inner tube (14) is in contact   with the bottom (12) and with the outer tube (13).   - Contactor according to any one of the claims   previous, characterized in that the outer tube (13) covers at   less partially the outer periphery of the bottom (12).   6- Contactor according to any one of the claims   above, characterized in that the bottom (12) and the outer tube (13) are fixed to each other by indirect heat input such as welding   of the laser or electron beam type.   7- Contactor according to any one of claims   previous, characterized in that the bottom (12) and the outer tube (13)   are attached to each other from inside the outer tube (13).   8- Contactor according to the preceding claim, characterized in that the fixing is carried out by welding of the laser or beam type   of electrons with an oblique shot directed towards the external periphery of the bottom (12).   9- Contactor according to any one of claims   previous, characterized in that the outer tube (13) has a   surface treatment against corrosion and aesthetics.   - Contactor according to any one of the claims   previous, characterized in that the outer tube (13) is thinner than the inner tube (14).   11- Contactor according to any one of claims   previous, characterized in that the thickness of the bottom (12) is   greater than that of the internal (14) and external (13) tubes.   12- Motor vehicle starter, characterized in that it   comprises a contactor according to any one of the claims preceding.