EP1404968A1

EP1404968A1 - Starter for a motor vehicle

Info

Publication number: EP1404968A1
Application number: EP02764970A
Authority: EP
Inventors: Gérard Vilou; Chantal Bocquet; Olivier Chane-Waye; Pascal Jacquin
Original assignee: Valeo Equipements Electriques Moteur SAS
Current assignee: Valeo Equipements Electriques Moteur SAS
Priority date: 2001-07-10
Filing date: 2002-07-10
Publication date: 2004-04-07
Anticipated expiration: 2022-07-10
Also published as: US20040020315A1; DE60220052T2; EP1404968B1; KR20030029164A; PL359762A1; CN1277051C; BR0205724A; ATE362048T1; FR2827342A1; WO2003006824A1; DE60220052D1; MXPA03002051A; JP2005509104A; FR2827342B1; CN1464943A

Abstract

The starter for a motor vehicle comprises a starting drive mechanism (12) and a pinion gear (1), an electric motor (M) provided with a shaft (101) which can drive the shaft (100) of a starting drive mechanism, an electromagnetic contactor extending in a parallel manner with respect to the electric motor (M) above said motor and comprising a moveable core (2d), a fork (13) which is hingedly mounted on the upper end thereof to said moveable core (2b), the driver (12) comprising a groove for receiving the lower end of the fork (13), said groove being defined by two flanks (121,122) while the starting drive mechanism is rotationally fixed by cooperating means between the fork (13) and the driver (12) so that it can pass from the rest position to an engaged position with the flywheel ring gear.

Description

STARTER FOR MOTOR VEHICLE

Field of the invention

The present invention relates to starters for motor vehicles.

STATE OF THE ART Such a starter is shown in FIG. 1 and comprises an electric motor M mounted inside a first metal cylinder head, an electromagnetic contactor 2 extending parallel to the electric motor M and comprising a coil 2a mounted at the interior of a second metal cylinder head. The two cylinder heads are fixed, here by means of tie rods, on a support 4 with interposition here of a support plate 28 of a planetary gear reducer. The support 4 is a molded part based on aluminum, which is intended to be fixed on the casing of the internal combustion engine of the motor vehicle hereinafter called the heat engine. The support 4 ensures the return to ground and has a front end in the form of a warhead open locally for the passage of the starting crown C of the vehicle's heat engine. This warhead is connected to a fixing and centering zone respectively of the electric motor M, of the contactor 2 and of the support 4 on the casing of the heat engine. The warhead has at the front (left part of the figure) a support sleeve for a bearing inside which is rotatably mounted the front end of a launcher shaft 100 locally locally at its outer periphery clean splines engaging with complementary grooves formed at the internal periphery of a trainer 12 belonging to a launcher 102 also comprising a pinion 1 connected by a coupling device 14, here freewheeling, to the trainer. The shaft 100 is coaxial with the shaft 101 of the electric motor M belonging to the armature of this motor with the interposition here of a reduction gear with planetary gear between the two shafts.

The aforementioned support plate 28 carries a plastic part in the form of an internally toothed crown and belonging to the aforementioned gear reducer, the input pinion of which is integral with the front end of the shaft of the electric motor. The planet carrier of the gear unit is integral with the rear end of the shaft 100. The rear end of the shaft 101 is mounted for rotation inside a bearing carried by a part, called the rear bearing, closing the first cylinder head. This first cylinder head internally carries an inductor, here with magnets, surrounding, with the presence of an air gap, the armature of the electric motor comprising a rotor in the form of a sheet pack fixed on the shaft of the electric motor knurled to this effect.

This package of sheets has axial grooves for the accommodation of electrically conductive elements in the form of bars arranged in networks connected to the electrically conductive blades of a collector carried by the rear end of the shaft 101. Brushes, mounted at the interior of cages carried by the rear bearing, are intended to cooperate with the blades of the collector, here of the frontal type.

A series of these brushes is connected to ground via the first cylinder head and the support 4. A second series of these brushes is connected to a connector for receiving a cable connecting the connector to a first contact terminal of the contactor 2 secured to 'a cover of electrically insulating material closing the open rear end of the second cylinder head having at its front end a bottom with holes for the passage of an internally hollow movable core 2b. The cover also carries a second contact terminal and at least one connection for the electrical supply of the winding 2a. A fixed core 2d is installed for attachment to the rear end of the second cylinder head and partially penetrates inside a support 2c of the winding 2a. The support 2c has a U-shaped cross-section and therefore constitutes a pad for guiding the core 2b. A first shouldered rod passes through the fixed core 2d and carries a contact plate intended to come to bear on the two aforementioned contact terminals having contact pads for this purpose.

The second terminal is connected to the positive terminal of the battery. The winding 2a is connected to this positive terminal of the battery via a start switch operated by the ignition key or any other device. This coil 2a is connected to ground via the second cylinder head and the support 4. The first rod and the contact plate belong to a movable contact 3, which in its rest position, is held pressed by a cutting spring 19 against the fixed core. The cut-off spring acts between the contact plate and the cover provided with a cut-out spring receiving housing. Another spring, said contact spring 21, of greater stiffness than that of the cut-off spring, is installed axially between the other face of the contact pad and a shoulder of the rod, passing through the fixed core 2d to present an end. . The movable core 2b penetrates inside the second cylinder head and into the winding 2a. This movable core 2b extends in axial projection relative to the front end, and the second cylinder head. The movable core 2b is subjected to the action of a return spring 18 acting between the bottom of the second cylinder head and a shoulder integral with the movable core provided centrally with a blind hole for the axial sliding mounting of a second rod shouldered at its rear end for spring action, said tooth to tooth spring 5, acting between said shoulder and the bottom of the movable core. The teeth against teeth spring has a greater stiffness than that of the return spring 18 and less than that of the springs associated with the movable contact 3.

The front end of the second rod carries an axis for articulation of the upper end of an operating lever 13 of the pinion launcher 102. This lever 13 is mounted, at an intermediate pivot point 11 carried by a protuberance secured to the support plate 28 called the base plate. This intermediate point 11 has an axial clearance called the JC cutting clearance which makes it possible to electrically disconnect the electric motor from the starter in the event that the pinion 1 remains meshed in the starting crown C. For starter models not having a base plate, this intermediate point 11 may be carried for example by the support 4 of the starter. The lower end of the operating lever comprises two arms or branches mounted in an annular groove produced in the driver 12 so that the operating lever is in the form of a fork.

More precisely, the groove of the coach is delimited by an annular bottom of axial orientation and by two annular sides of transverse orientation perpendicular to the shaft 100.

The axial distance between the two sides depends on the thickness of the arms, usually called fingers, of the fork so that these can penetrate at least mounting clearance in the groove to be able to move the driver axially when the contactor is electrically powered.

As shown in Figure 1, the switch 2, the electric motor M and the launcher are in their rest position. In this position the winding 2a and the electric motor M are not supplied electrically; the aforementioned start switch being open. The pinion 1 is at an axial distance from the starter ring C of the heat engine, the movable contact 3 is at a distance from the contact terminals in the form of studs, while the core 2b is at an axial distance from the rod of the movable contact.

When the switch is closed using the ignition key, the coil 2a is electrically powered and a magnetic field is created so that the movable core 2b moves axially towards the fixed core 2d and the movable contact and moves, via the operating fork, the starter and the pinion 1 in the direction of the crown C. The pinion 1 can penetrate between the teeth of the crown C so that it is in the engagement position with the crown C. The movement of the pinion 1 is limited by cooperation of the pinion 1 with a working stop 6 secured to the shaft 100. The movement of the movable core continuing, the latter comes into abutment against the rod of the movable contact thanks to a washer that carries at the rear the movable core 2b for this purpose. The cut-off spring is then compressed until the movable contact closes by contact of its plate with the contact terminals. The electric circuit of the electric motor M is then closed so that the latter drives the shaft 100 in rotation and therefore the pinion 1 via the driver and the helical splines intervening between the driver and the shaft 100. The magnetic circuit closes completely after the electrical circuit, the movable core 2b coming into contact with the fixed core 2d after compression of the contact spring. The freewheel is blocked when the electric motor is running, the internal combustion engine not yet being started.

It may happen that the pinion abuts against the crown C without meshing with the latter. In this case, the 5-tooth spring against teeth is compressed until the movable contact is closed and the electric motor is supplied, which then rotates the shaft 100 with penetration of the pinion teeth 1 into the teeth of the crown C. When the internal combustion engine has started, the freewheel allows the pinion to rotate relative to the shaft 100 and therefore to spare the motor M. The movable core 2b and the tooth against tooth spring 5 increase the radial size of the contactor, which must be powerful .

This mode of penetration of the pinion 1 of the launcher 102 has the following drawbacks:

- the kinematics, which is an intrinsic characteristic of the starter, expresses the advance of the launcher in millimeters between the moment when the ignition key is turned until the moment when the electric motor is energized. This kinematics must be greater than the distance that exists at rest between the launcher and the crown C otherwise the electric motor could be energized before the pinion 1 of the launcher has penetrated into the crown C of the heat engine, thus causing the milling of this same crown by the launcher. This kinematics depends on the power of the solenoid, comprising the coil 2a, on the mass of the launcher 102, on the stiffness of the various springs present in the system, on the viscosity of the greases, on the friction existing between the various moving elements and on the temperature. The kinematics is difficult to optimize given the large number of parameters which influence it.

- The stiffness of the tooth against tooth spring 5 must be sufficient to push the starter pinion 102 into the crown C of a sufficient length when the pinion 1 is no longer in a tooth against tooth position. In return, this stiffness should not be too high because it is a component of the dimensioning of the power of the solenoid 2a. The more the tooth against tooth spring 5 has a greater stiffness, the more the solenoid must create a strong electromagnetic field. The larger the solenoid 2a, the larger the magnetic field it has to create. The power of the solenoid thus depends on the mass of the launcher 102 and the stiffness of the tooth against tooth spring 5. The more powerful the solenoid, the lower the kinematics. Indeed, a powerful solenoid is able to overcome the force of the tooth-to-tooth spring so as to make the power contact while the launcher will not have practically moved because of its inertia. The dimensioning of the solenoid is therefore not easy and takes a significant development time. It is also necessary to adapt the solenoid to the launchers that it must set in motion which results in a lack of standardization.

- The power required to set in motion the smallest launcher is such that the volume of the solenoid 2a is large. In general, the diameter of the solenoids is close to 50mm for a length set at most on that of the starter.

- in tooth-to-tooth position, the electric motor is switched on before the starter pinion 1 has penetrated into the crown C. If the surface conditions of the crown C for starting the heat engine or the pinion 1 are degraded, if the stiffness of the tooth against tooth spring is too low, if the electric motor has too much acceleration at the start, which is often the case for starters without a reduction gear, there is a risk of not seeing the launcher penetrate sufficiently into the crown C and thus of rotating the pinion 1 in front of the crown C at high speed, that is to say causing a milling of this crown by the pinion 1 of the launcher thus causing irreversible deterioration.

- When the launcher comes into abutment against the crown C by being launched by the fork 13 moved by the movable core 2b, the latter has a significant speed and the impact is strong. This generates noise and causes deterioration of the contact surfaces. This deterioration at startup can be a cause of milling.

Document FR A 2,174,421 discloses a double contact solution in order to generate a pre-rotation of the electric motor. The system has a solenoid and comprises a coil electrically connected, on the one hand, to the switch actuated by the ignition key and to a fixed contact positioned on the fixed core of the solenoid and, on the other hand, via the contact plate of the movable contact to a second fixed contact, arranged diametrically opposite the first contact on the fixed core and itself electrically connected directly to the electric motor. In the nominal rest position, the contact plate rests on the two aforementioned contacts so that when the switch is closed by actuating the ignition key, the electric motor is energized by passing a current through the contacts via the plate and an electrical resistance. The electric motor starts a pre-rotation at low speed while the moving core is set in motion under the action of the magnetic field created by the coil. After engagement of the pinion in the crown C, the movable core, during its displacement, comes into contact with a spring, an independent part and distant from the movable core of a length calculated so that there is contact between the two parts only when the pinion meshes with the crown. The contact plate, secured to the action of the spring, sets in motion and disconnects from the first two contacts, cutting off the power to the electric motor. At the end of translation of the movable core, the plate comes into contact with two other contacts which allow the closing of the power circuit and supply the electric motor under full load. The disadvantages of this principle are of two types. First, the interruption of the electrical supply to the electric motor when the contact pad moves, then the level of the current (around 70A) which passes through the first two contacts, the coil and the switch actuated by the ignition key to pre-rotate the electric motor. This intensity value is not acceptable at the level of the switch, in fact, the maximum authorized value is of the order of 50A.

US patent A 4,418,289 shows a double-stage contactor solution similar to the solution of document FR A 2,174,421. This solution is two contact pads coming into contact with two contact series. The electrical diagram is identical except that the resistive coil is in this case a pure resistance placed outside the solenoid. The two pads are not brought back simultaneously during deactivation by the ignition key of the contactor solenoid.

US patent A 5,814,896 presents a solution where the contactor is coaxial with the starter body and is placed at the rear of the device. The double contact system is provided by a single-contact plate placed on a movable axis secured to the movable core, which is actuated by a cable running the entire length of the electric motor and connected to the launcher. The second contact is made by a movable contact connected to a spring type "clothespin" whose other end is connected to the movable axis. This contact comes into contact with the battery terminal in the same way as the contact plate. The disadvantage of this solution consists in the sequential breaking of the two power circuits.

Document US A 2,342,632 discloses a starter in which the rotation pinion pinion is provided for advancing it towards the starter ring of the heat engine by screwing the driver onto the helical teeth carried by the shaft which carries the starter pinion. Locking in rotation is achieved by a needle operated by a solenoid perpendicular to the driver. This embodiment is bulky radially.

These solutions are satisfactory, however the applicant has wondered whether it is not yet possible to further reduce the electromagnetic power of the contactor in order to further reduce its external diameter.

Subject of the invention

In order to overcome these drawbacks, the invention provides a starter for a motor vehicle with an internal combustion engine and an engine starting ring gear. thermal comprising a launcher, equipped with a driver and a pinion, suitable for passing from a retracted position of rest to an advanced position of engagement with the starting crown of the thermal engine of the motor vehicle, an electric motor provided with '' a shaft suitable for driving a launcher shaft associated with the launcher, complementary helical splines intervening locally between the internal periphery of the trainer and the external periphery of the launcher shaft, an electromagnetic contactor extending parallel to the electric motor at -above it and comprising a movable core, a fork mounted with articulation at its upper end on the movable core and at an intermediate point on a support of the electric motor and the contactor, in which the driver comprises a receiving groove of the lower end of the range delimited by two sides and in which means are provided for making turn the electric motor at slow speed in a first phase then at full power, characterized in that the starter is locked in rotation by means of cooperation between the fork and the trainer for its passage from its rest position to its position d with the starter ring.

Thus, by blocking the launcher in rotation and these means, the power of the electromagnetic contactor and its radial size can be further reduced, thanks to an energy supply from the electric motor.

In addition, it takes advantage of the existing space between the sides of the groove, which does not increase the axial size beyond measure. In addition, the fork becomes a mainly following fork. According to other characteristics of the invention: - said means are means for locking in rotation with cooperation of shapes.

- Said means are friction locking means of rotation.

- during the electrical supply of the contactor, the fork cooperates with the flank, called the front flank of the groove for receiving the fork; said front being provided with circumferential undulations. - The fork has branches with corrugations of a shape complementary to those of the front flank.

- Said means are of the wolf tooth type.

- The front flank of the receiving groove of the fork has notches and bumps, while the fork has projecting fingers cooperating with the notches for locking the launcher in rotation - The front side of the fork receiving groove cooperates with a ring of the fork slidably mounted axially on the barrel of the coach.

- The ring is articulated on the body of the fork and is actuated by the body of the fork. - The fork has at its end, which cooperates with the groove of the coach, at least one shoe, which cooperates with a flange located at the periphery of the coach when the launcher meshes with the starting crown of the motor vehicle engine. .

- Said means are disengageable. - The support has a front sheet metal part generally in the shape of a warhead.

- the front part is connected to a fixing and centering flange.

the sheet metal support is obtained by deformation of material, such as a stamping, and the flange is in one piece with the front part.

- The electric motor and the contactor each comprise a cylinder head secured to the other cylinder head.

- the two cylinder heads belong to the same part.

- the one or both cylinder heads are closed on the side opposite the support by a common part forming the rear bearing of the electric motor.

- The means provided to rotate the electric motor in pre-rotation then at full power, include two plates carried by the movable core, the first plate, used during pre-rotation, is connected to two contacts, the first contact is connected to the resistive coil, the second contact is connected to the positive terminal of the battery, then at full power, the second wafer is connected to two contacts, the third contact is connected to the resistive coil and to the electric motor, the fourth contact is connected to the positive terminal of the battery.

- A contact plate is allowed to switch around the second fixed contact to cooperate with another fixed contact axially offset and connected to the positive terminal of the battery to power the electric motor. - The movable axis comprises a strip provided with a local allowance which drives the contact plates when the movable axis returns after opening the control circuit.

- The electromagnetic contactor comprises, at least one plate capable of evolving in rotation around the movable axis for the pre-rotation then at full power of the electric motor. - the wafer comprises two electrically connected pads, a first pad continuously electrically connected with a contact connected to the battery voltage, a second pad connected to a contact when the motor is pre-rotated, this second pad then coming in contact with a third contact, after rotation of said wafer, to provide full power to the starter, the second and third contacts being interconnected by the resistive pre-rotation coil, the contact being connected to the electric motor.

- the starter pinion is connected to the driver by a coupling device with a conical clutch. - The cylinder head (s) are added by crimping on the support.

- Pre-rotation is carried out by supplying sufficient electric current to the electric motor via the call coil without using a resistive element such as a resistive pre-rotation coil. In this case, the fork is used to block the launcher in rotation and advantageously to help the launcher to move towards the starter ring of the heat engine.

Brief description of the drawings

The description which follows illustrates the invention with reference to the appended drawings in which: FIG. 1 is a view in axial section of a starter of the prior art; FIG. 2 is a diagram of the supply circuit of the electric motor of the starter according to the invention; - Figure 3 is a view similar to Figure 1 for a first embodiment of the invention; Figure 4 is a view similar to Figure 3 for a second embodiment of the invention; Figure 5 is a perspective view of the starter support of Figures 3 and 4;

- Figure 6 is a perspective view of a single cylinder head fitted to the starters of Figures 3 and 4; Figures 7a, 7b are perspective views, from different angles, of a starter equipped with a support and a single cylinder head of Figure 6; Figures 8 and 9 are partial sectional views showing the assembly of the support or the rear bearing with the single cylinder head for two embodiments; Figure 10 is a local view of the rear bearing assembled with the single cylinder head for a third example of assembly of the rear bearing with the single assembly cylinder head of Figure 6; Figure 11 is a partial view in axial section of the embodiment of Figure 10; Figure 12 is a sectional view along line 12-12 of Figure 10; Figure 13 is a view similar to Figure 10 for a fourth mode of assembly of the rear bearing with the single cylinder head; Figure 14 is a partial view in axial section for a fifth mode of assembly of the rear bearing with the single cylinder head; - Figures 15 and 16 are views similar to Figure 13 for a sixth and seventh mode of assembly of the single cylinder head with the rear bearing; Figure 17 is a sectional view for an eighth method of assembling the single cylinder head with the rear bearing; - Figure 18 is a top view of Figure 17; Figure 19 is an axial sectional view for a ninth method of assembling the rear bearing with the single cylinder head; Figures 20,21, 23 are views similar to Figure 19 for respectively a tenth, eleventh and twelfth mode of assembly of the single cylinder head with the rear bearing; Figures 22 and 24 are views along the arrows 22 and 24 of Figure 23; FIG. 25 is a schematic view of an embodiment of a starter launcher associated with the contactor according to the invention; - Figures 26 and 27 are two views in axial section of two alternative embodiments of Figure 25; Figure 28 is a front view of the elastic washer fitted to the launchers of Figures 26 and 27. Figures 29 and 30 each illustrate in perspective an embodiment of the fork according to the invention. Figures 31 and 32 each illustrate a perspective view of an embodiment of the coach comprising means for locking in rotation.

FIG. 33 is a view of a starter comprising a device for blocking the rotation of its driver associated with a ring. - Figure 34 is a partial sectional view of a relay comprising a tilting plate.

Figures 35 and 36 are two views, respectively in axial section and from the front, showing a relay comprising a turntable. - Figure 37 is a full sectional view of an electromagnetic contactor according to an embodiment of the invention.

Figures 38a to 38c show exemplary embodiments of the rotation locking means.

Figures 39 and 40 illustrate, respectively in axial section and schematically, other embodiments of the pre-rotation according to the invention.

Description of preferred embodiments

In the figures illustrated, the common elements will be assigned the same reference signs and the front-rear direction corresponds to the direction going from the left part to the right part of FIGS. 1, 3 and 4.

In FIGS. 3 and 4, the starter comprises, as in FIG. 1, a support 4 which comprises, first means for fixing and centering the electromagnetic contactor, second means for fixing and centering the electric motor M extending parallel to and below the contactor. The support 4 also comprises third means for fixing and centering the starter on the casing of the thermal engine of the motor vehicle so that the pinion 1 of the launcher reliably meshes with the starting ring C of the thermal engine; said crown here belonging to a flywheel integral in rigid or elastic rotation with the crankshaft of the heat engine or internal combustion engine.

The support 4 is metallic and ensures the return to ground. It is economical because it is here obtained by deformation of material, for example by stamping. The electric motor M has a constitution similar to that of FIG. 1 except as regards the mounting of the brushes and the blade collector. Here the brushes are radially oriented and are carried internally by the metal cylinder head 25 of the electric motor and the collector is axially oriented. Four brushes are provided here. Two brushes, called negative brushes, are connected to earth via the cylinder head 25 and the support 4. Two brushes, called positive brushes, are connected to the positive terminal of the battery via the contactor 2.

These figures show schematically at 27 a brush-cage assembly.

Here the shaft 101 of the electric motor also constitutes the shaft 100 of the launcher and therefore carries the working stop 6. The rear bearing 26 is made of plastic and, according to one characteristic, also constitutes the rear bearing of the contactor. The cylinder heads of the contactor 2 and of the electric motor M are integral with one another. Advantageously, the two cylinder heads belong to one and the same continuous part 25 as visible in FIG. 6. The connection cable between the contactor and the positive brushes is eliminated as described below. The starter is thus less expensive because it has fewer components.

The fork 13 is, as in FIG. 1, articulated at an intermediate point 11 on the support 4. The fork 13 is articulated at its upper end directly on the movable core 2b of the contactor 2 and penetrates at its lower end , as in FIG. 1, in a groove in the driver 12 belonging to the pinion launcher 102.

According to a characteristic of the invention, a starter of the above-mentioned type is characterized in that the driver 12 is provided with means for locking it in rotation during its passage from its rest position to its engagement position with the start-up crown.

According to a first embodiment, as shown in Figures 3 and 4, the rotation lock is achieved by a fork 13 preferably made of rigid material. A rotation blocking device therefore intervenes between the launcher and the fork.

Thus according to the invention the launcher is locked in rotation by means of cooperation between the fork 13 and the coach 12 for its passage from its rest position (Figures 3 and 4) to its engagement position, via its pinion, with the starter ring.

These cooperation means, which in FIGS. 3 and 4 are rotationally locking means with cooperation of shapes, are located at the level of the fingers situated at the base of the fork 13 and at the level of the rear face of the driver 12 More precisely, the branches or arms of the fork are received in a groove of the driver 12 delimited by the sides 121, 122, respectively front and rear, transverse with respect to the axis of the shaft 101. In the state the fingers of the fork 13 rest on the smooth rear side 122 of the receiving groove. The branches of the fork are wavy for finger formation as visible at 22. The front flank 121 has, for reception of the fingers 22, circumferential undulations 21 as shown in Figures 3 and 38c. As a variant, the front flank 121 may have other means for cooperation of shapes, for example in the form of saw teeth (FIG. 38a), in wolf teeth (FIG. 38b) or wavy (FIG. 38c); the branches of the fork having means complementary to those of the sidewall 121. In general, the fork cooperates with the sidewall 121 and has branches with corrugations of shape complementary to that of the sidewall 121. In another embodiment, the rotation locking means may consist of plane frictions arranged, on the one hand, on the coach and, on the other hand, on the fork.

As a variant, as illustrated in FIGS. 31 and 32, the circumferential corrugations 21 are formed by notches 320 and bumps 321. The notches 320 are of shapes complementary to those of the fingers 22 of the branches 293 of the fork 13 as shown in FIG. 31 The protruding fingers 22 penetrate into the notches 320.

FIG. 33 illustrates a variant of the device for locking the launcher in rotation. In this embodiment, the internal periphery of the fork has a ring and the fingers 22 of the fork 13 are offset on the ring 15 mounted to slide axially on the tubular portion in the shape of a barrel of the driver. This ring 15 is hingedly mounted on the internal end of the rod-shaped body 292 the fork by means of a pivoting means 291 comprising for example a pivot carried by the rod 292 and received in a yoke of the ring 15. The ring 15 is actuated by the body 292 of the fork for its axial displacement on the barrel of the coach. As a variant, the pivoting means comprises a clearance JC (not shown) performing the above-described cut-off clearance function.

In this embodiment, the fork 13 therefore does not have an arm but a rod 292 comprising at its lower end the means 291 for pivoting with the ring 15.

This embodiment of the rotation blocking device carried by a ring 15 has the advantage of having a perfect connection between the ring 15 and the trainer throughout the translation of the launcher which is not the case with the fork which pivots around its axis thus favoring the teeth of the fork to come out of the notches of the trainer.

As a variant, it is possible to envisage a ratchet and ratchet wheel device.

In general, the rotation of the launcher is blocked by friction, using magnets, by cooperation of shapes or by any other means.

Obviously, the forms which cooperate with each other are not limited to the embodiments described above.

Thus, according to the invention the rotation blocking of the launcher consists of means which cooperate rigidly with each other. In fact, the rotation blocking device (wolf teeth, friction, magnets, etc.), the fork and the rod of the movable axis are parts made from rigid materials which cannot exhibit material deformation under the effect of the force exerted by the attraction of the mobile core.

An advantage according to the invention is to provide a rotation lock with a reduced number of components, these components being mainly components known in the field of starters, in particular the fork, the movable axis and the groove of the driver in which comes to lodge the fingers of the fork.

Thus, in a simple and economical manner, a rotation lock is produced which makes it possible to obtain an electromagnetic contactor of reduced size, in particular as regards the movable core, since the force which makes it possible to advance the Forward launcher is provided by the electric motor in its prerotation regime.

The force exerted by the fork on the launcher is very reduced. It will be appreciated that the mobile core is simplified.

In order to put the electric motor M in pre-rotation before applying full power to it, the relay constituted by the electromagnetic contactor must include a device which allows, on the one hand, to implement the pre-rotation of the electric motor under low power, then apply full power to the same motor and, on the other hand, when opening the ignition key, simultaneously deactivate full power and pre-rotation of the electric motor. It is important to be able to deactivate these two operating modes simultaneously, in particular in the case where the pinion remains blocked in the starting gear. In this case, the device according to the invention must make it possible, by means of the JC cutting set, to disconnect the full power simultaneously with the pre-rotation in order to completely deactivate the electric motor M.

In a first embodiment, the means for rotating the electric motor at slow speed and then at full power comprise two contact plates mounted on a movable axis integral with the movable core and two pairs of contacts

In Figure 2 there is shown schematically the electric circuit of the starter. This comprises a holding coil 37, a call winding 36, a call and pre-rotation coil 39, two electrically conductive contact pads P1 and P2 intended to come into contact with a first series of contacts respectively. comprising two contacts C1 and C2 and with a second series of contacts comprising two contacts C3 and C4, the electric motor M and the start switch 35 electrically connected to the positive terminal of the battery. The electric motor M and the holding coil 37 are electrically connected to ground, while the contacts C2 and C4 are electrically connected, respectively by lines 33, 34, to the positive terminal of the battery. The call coils 36 and holding coils 37 surround the movable core 2b. Advantageously, the pre-rotation coil 39 also surrounds the movable core

2b. This pre-rotation coil 39 is advantageously electrically connected to the contact C1 of the first series of contacts and to the electric motor M, while contact C3 is electrically connected to the electric motor. The plates P1 and P2 are carried by the movable core 2b of FIG. 3. In this FIG. 3 the coil 2a comprises the coils 37 and 36 of FIG. 2 mounted in series with the coil 39 in the form of an electrical resistance.

Thanks to this arrangement, the switch 35 being closed, the motor rotates at slow speed as soon as the first switch consisting of the first plate P1 and the first series of contacts C1, C2 is closed.

The movement of the movable core continues, the second contact pad P2 comes into contact with the second series of contacts C3, C4 one of which is electrically connected to the electric motor and the other electrically to the positive terminal of the battery so the electric motor is running at full power.

Clearances J1 and J2 are calculated so that the first contact of the wafer P1 with the contacts C1, C2 takes place when the breaking clearance JC is taken up by the movable core and the second contact of the wafer P2 with the contacts C3 , C4 takes place when the movable core is located with respect to the fixed pinion 2d (FIG. 3) almost at zero gap, which ensures good penetration of the pinion in the starting ring gear.

The return of the wafers during the opening of the control circuit of the motor M and of the relay constituted by the electromagnetic contactor must take place simultaneously so as not to leave the armature energized, even with a low intensity. For this, as shown in Figure 37, a clip is used for the first contact pad. This clip is produced by producing in the movable axis 40, by means of a removal of material in this axis, a strip 23 provided with a local allowance. When the movable axis advances, the contact plate P1 comes into contact with the contacts C1 and C2. It locks while the movable axis continues its axial stroke backwards. The excess thickness of the strip 23 arrives at the level of the plate P1. The strip 23 is lowered, leaving passage to the plate P1 which then crosses the extra thickness here located in the middle of the tongue, then rises again afterwards. The clip is then in position to operate. On the return, that is to say when the movable axis is moving forward, the excess thickness abuts against the plate P1. The axial effort required to bend again the strip 23 being greater than the force provided by the contact spring 20 of the plate, said plate is forced to follow the movement of the movable axis towards the front and therefore disconnects electrically from the contacts C1 and C2. The plate then abuts against the fixed core 2d of the solenoid and, the force exerted by the return spring 17, 18 of the movable core being greater than the disengaging force, the strip is lowered and the excess thickness returns to the other side of the insert in its nominal rest position. Advantageously, this clip makes it possible to electrically disconnect the electric motor, in particular at a slow pre-rotation speed, in the case where the pinion remains blocked in the starting ring gear C of the internal combustion engine. This is possible thanks to the JC cutting set which allows the movable axis to move forward even if the pinion remains geared in the starting gear.

FIG. 3 illustrates a starter comprising a contactor provided with two contact pads P1 and P2 as described above. In this embodiment, the mobile core 2b is stage in diameter and has a portion of larger diameter projecting outside the coil 2a. This core, like that of FIG. 37, is simplified compared to that of FIG. 1 and consists of a simple economic stepped rod of reduced radial size guided by the support 2c of the coil 2a forming a solenoid.

A return spring 18 acts between the winding support and a shoulder of the front part of the core 2b. This spring replaces the return spring 18 of FIG. 1. The first portion of larger diameter penetrates inside the coil 2a and is extended by a second portion of smaller diameter around which is mounted a spring 20 of contact of plate P1 resting on the change in diameter between the first and second portions of the movable core and on the first electrically conductive contact plate P1 wedged axially on an attached stop 54, such as a circlip, mounted at the rear end of the second portion extended by a third portion, of smaller diameter than the second portion, around which is mounted a contact spring 21 bearing on the stop 54 and on the second plate P2 axially wedged on an end stop 38 relative to the rear end of the movable core. The electrically conductive plates can therefore move relatively relative to the core 2b. In particular, the plate P1, wedged axially against the stop 54, is pushed rearward under the action of the spring 20 which is wedged axially forward against a shoulder of the movable core. So, when the movable core moves backwards, the plate P1 moves backwards, under the effect of the contact spring 20, until it comes into abutment against the contacts C1 and C2. A recess 60 is provided in the fixed core 2d to allow the passage of the contact spring 20 of the first plate P1.

Thus when the plate P1 is in contact with the contacts C1, C2 the core 2b moves axially by compressing the spring 20. It is the same for the plate P2, the contact spring 21 being compressed under the action of the displacement towards the back of the floor movable core. After opening the switch 35 associated with the ignition key, the springs 21, 20 and 18 exert a permanent action.

The screw 131 is connected to the positive terminal of the battery and is in electrical connection with an electrical track having a perpendicular return constituting the contact C2. Likewise, contact C1 belongs to an electric track connected to the positive brushes of the electric motor M.

Note the presence (not visible) of a screw located in the same horizontal plane as the screw 131 connected on the one hand to the switch (ignition key) and on the other hand to the winding of the contactor. The contact C3 also belongs to an electric track connected to the positive brushes, the contact C2 is electrically connected, on the one hand, to an electrical resistance to make the electric motor turn at low speed at first and, on the other hand, to contact C4 connected to the positive terminal of the battery.

FIG. 37 illustrates with greater precision a complete relay integrating an electromagnetic contactor comprising two plates. In this embodiment, two contact plates P1 and P2 are fixed on a movable plastic pin 40 on which they can move in translation. This movable axis 40 and for example fixed by clipping or gluing or welding on the movable core 2b. This movable core can have a cylindrical or square section. In the case of a square section, the movable core is produced economically from a stack of sheets. Springs 20 and 21 hold the plates against shoulders made in the axis. The plates have cylindrical central openings with a diameter equivalent to that of the shoulders to make mounting possible. Then they are fixed by deformation of the opening which reduces along an axis the diameter making the opening oblong. Flats in the axis allow this deformation. The movable axis is integral with the movable core and the assembly can move in translation along the longitudinal axis of the contactor forming a relay. A core return spring 18 is positioned at the front between a shoulder secured to the movable core 2b and a washer 2'd secured to the winding support 2a. It allows the movable core to be brought back to its rest position and to be kept in this position after the relay control circuit has been cut. The fork is positioned between two sides of the movable core. It is, at rest, resting on one of the flanks and distant from the second flank by a distance called the JC cutting set.

Positioned between the fork and the washer 2'd, the lever spring 17 makes it possible, on the one hand to bring the fork back to its rest position after cutting the control circuit, and on the other hand to keep the starter in the rest. The springs 17 and 18 are dissociated because the spring 17 has a greater stiffness because the launcher can exert a strong thrust on the fork during sudden decelerations of the vehicle. It is impossible to put a stiffness on the spring 18 equivalent to that of the spring 17 because the winding is not dimensioned, at the start, to counter the axial force created by the spring 17 on the fork. The springs 17, 18 allow, as mentioned above, an unlocking of the PL plate

As can be seen in FIG. 29, the fork 13, here in rigid plastic material in a metallic variant, below its axis of rotation 11, separates into two branches 293 like a fork. The two ends of this fork have fingers 22 which have a particular shape, here cylindrical, and which can be inserted in the complementary shape 21 located on the external face of the coach. These forms, arranged on the trainer, can be compared to notches whose purpose is, when the fork is fitted into the trainer, to block the launcher in rotation. On the other hand, if the pitcher has the necessary torque, the trainer can jump the notches by rolling the fork back.

In FIG. 37, as mentioned above, a strip 23 provided with an additional thickness is created on the movable axis in order to fulfill a clip function with the plate P1 which will make it possible to bring back at the same time, during the opening of the circuit. two P1 and P2 plates. The double contact is made, firstly by contact of the plate P1 with the contacts C1 and C2, and secondly by contact of the plate P2 with the contacts C3 and C4. The springs 20 and 21 respectively serving as compression springs for the pads to ensure good contact.

Contact C4 is connected to the battery terminal and is connected to contact C2 via an electrical connection 29 of the wired type. The contact C1 is electrically connected to the resistive pre-rotation coil by an electrical connection means 30. The contact C1 is electrically connected to the contact C3 by an electrical connection means 32. The contact C3 is also connected to the electric motor by a connecting means 49.

The contacts C1 and C2 are electrically connected to a resistive coil for pre-rotation of a resistance close to 150 mohms in order to limit the passage of current to a value between 50 and 80A, thereby ensuring sufficient pre-rotation of the electric motor.

This resistive pre-rotation coil is placed on top of the other two coils that are conventionally encountered in all contactors, namely the call 36 and holding 37 coils.

In a second embodiment visible in FIG. 34, a single plate PO is used as well as a single pair of contacts C5 and C6 which are axially offset relative to each other along the axis of the relay. Contact C5 pre-rotates the electric motor M and contact C6 supplies the same motor at full power. Contact C6 and connected to the battery. In an exemplary embodiment, the resistive pre-rotation coil 39 is connected to C6 via an electrical connection 48, for example of the wired type. Advantageously, the contact C5 is connected directly to the electric motor by an electrical connection means 49. This embodiment has the advantage of not using external connection terminals and an external connection wire. This avoids sealing problems at the external terminals and also helps to reduce the size of the starter as well as its cost and weight.

The contact plate in a first phase is perpendicular to the movable core and moves in contact with a contact connected to the resistor until it comes to the contact of the contact connected to the positive terminal of the battery via the start switch.

The resistive coil 39, here also serving as a call coil, is electrically connected to the contact plate PO by an electrical connection means 31 which is for example welded to the plate PO. This connecting means 31 can consist of a wire coming directly from the winding 39. As a variant, this connecting means 31 can consist of a spring plated on the circumference of the plate PO. When the winding 39 of the solenoid is energized, the movable core 2b is attracted and the movable axis 40 is set in motion. The contact plate PO comes into contact with the contact C5, thus closing the armature supply circuit under low current in order to perform a pre-rotation of the electric motor. The movable core 2b continues its course and the movable axis 40, via the contact spring 16 of the wafer, presses on the wafer PO which pivots around the contact C5. When the movable core 2b is almost at the end of its travel, the plate PO comes into contact with the contact C6, closing the power circuit and short-circuiting the pre-rotation circuit. The same clipping system as that used in the previous solution thanks to a strip (not shown) makes it possible to open the two power circuits simultaneously when the movable core returns to its rest position.

FIG. 4 illustrates a starter comprising a contactor provided with a pivoting PO contact plate as described above. In this embodiment, the pre-rotation resistance is here in the form of a resistive coil 39 wound next to the winding 2a of attraction of the movable core 2b.

In this embodiment, the resistive coil 39 surrounds the first portion of large diameter of the movable core while the second section of smaller diameter of the movable core is surrounded by the winding 2a for holding and calling. In another embodiment, the reverse configuration can be carried out.

The second portion of the movable core 2b is longer, having no spring, while the first portion of this core is shorter and is surrounded by a return spring 18. The third portion is surrounded by a spring 16 acting on the plate PO which is unique here, a third spring 24 (visible in Figure 34) acts between the outer periphery of the plate and the fixed core 2d of the coil 2a.

In a third embodiment visible in FIGS. 35 and 36, a contact plate P3 is mounted on a movable axis 40 integral with the movable core and comprising at its external periphery helical grooves 50 cooperating with complementary helical grooves produced at the internal periphery of the P3 brochure. The axis 40 carries in radial projection a stop 53 for the plate P3.

At rest, the contact plate P3 is held pressed against a shoulder 51 of the body of the solenoid 2a by an elastic washer 52 secured to the movable axis 40. The plate P3 has a special shape as can be seen in FIG. 36. It comprises two circular sectors of which one, of greater circumferential extent, is intended to cooperate with the contact C7 and the other with the contact C8 or C9 axially of the same height. Contacts C7 and C9 are diametrically opposite

When the movable core advances, the plate driven by the movable axis and held by the stop 53, follows the translational movement towards the rear. It abuts on the first contact C7, which is connected to the vehicle battery, and on the contact C8, itself electrically connected to C9 by the resistive prerotation coil 39 thus closing the first power contact since the contact C9 is connected directly to the electric motor. The movable core continues to advance, and as the plate P3 is blocked - axially, it starts to rotate on itself thanks to the aforementioned grooves and comes into contact C7 and C9 while remaining in contact with C8 via the coil 39 pre-rotation so as not to create a current break. In this position, the resistive coil 39 is short-circuited, which makes it possible to directly supply the electric motor M of the starter at full power.

The contact crushing force is produced by the axial thrust force of the movable core and reflected by the splines.

When the movable core returns, the movable axis pulls with it the wafer which suddenly withdraws from the contacts C7 and C9, thus opening the power circuit without closing the first circuit between C7 and C8. The electric motor M is thus cut off from any electrical supply. The plate then comes into abutment against the shoulder 51 of the body of the solenoid. Being blocked in translation, the plate P3 starts to rotate under the pressure of the elastic washer 52 which forces the plate P3 to return to its initial position by screwing onto the helical teeth 50.

To facilitate the rotation of the plate P3 and to avoid possible jamming of this plate in the grooves of the movable axis given the small thickness of the plate and therefore of the tooth, it is possible to envisage a plastic sleeve coming resume on the grooves of the movable axis and itself comprising grooves.

In Figures 29 and 30 is shown a preferred embodiment of the fork 13 according to the invention. This fork has an axis of rotation 11 carried for example by the support 4 of the starter. Under the effect of the action of the electromagnetic contactor, the fork 13 rocks in rotation around this axis 11. This fork comprises a rod-shaped body 292 making a rigid connection between the axis of rotation 11 and two arms or branch 293. These two arms are advantageously circular in shape. These two arms each carry a tooth 22, in the shape of a finger, oriented towards the front. The tooth has forwardly a shape 295 preferably circular capable of cooperating with the notches 320 shown in Figures 31 and 32. The teeth or fingers 22 are in the form of a cylindrical stud. The lower part of the arms 293 is advantageously provided with pads 290. These pads are in the form of a protuberance oriented forward as for the teeth 22, that is to say oriented towards the launcher. The most advanced front end portion of the shoe 296 can be flat as shown in FIGS. 29 to 31. In another embodiment, this end portion of the shoe can be curved. As a variant, the fork may have only one shoe 290. At its upper end, the fork 13 has two ears 297, perpendicular to the main axis of the fork carried by the two branches 298 used for the articulation assembly with the mobile axis 40 secured to the mobile core of the contactor. These two ears 297 serve as a support for the return spring 17 of the fork 13.

Figure 30 shows us the fork 13 associated with the movable axis 40 integral with the movable core 2b, here of generally rectangular section. The movable axle assembly

40-movable core has at its front end an H shape perpendicular to the axis of the mobile axis 40-mobile core assembly and delimiting a recess 300 intended to receive the two branches 298 of the fork 13 for its articulation mounting. This recess 300 has an axial length greater than the thickness of the arms 298 of the fork so as to leave a clearance JC, which plays the role of cutting clearance in the event of pinion blockage in the starter ring gear. The branches of the H of the front end of the movable axis 40- movable core assembly extend in projection to define in particular a rear shoulder 301 with rear face 301.

According to one embodiment, the rear face 301 of the rear shoulder of the recess 300 constitutes the front stop of the return spring 18 of the movable core and the rear face 302 of the ears 297 of the fork 13 constitutes the front stop of the spring recall 17 of the fork.

In the preceding figures, the launcher comprises, as in FIG. 1, a driver coupled by a freewheel coupling device to the pinion 1.

Advantageously, the weight of the launcher can be further reduced by the use of a coupling device with a conical clutch as described for example in the document FR 01 08607 filed on June 29, 2001. This coupling device, more economical and lighter than that of the freewheeling type will be described below in FIGS. 25 to 28.

This device makes it possible to reduce the weight of the launcher, as well as the number of these components and the axial size of the launcher.

In all cases, the fork 13 becomes a mainly follower fork. Due to the reduction in the radial size of the launcher, the two cylinder heads can be integral with one another, advantageously being in one piece 25 (FIG. 5).

The support 4 can be simplified.

Alternatively (Figures 25 to 28) thanks to the invention it is possible to use in the aforementioned manner a light launcher, less bulky and with a reduced number of components. In these figures, a coupling device with a conical clutch 7 (FIG. 25) is provided for coupling the pinion 1 to the driver 12. The conical clutch 7 comprises (FIGS. 26 and 27) a first frustoconical friction surface 8, said first surface, integral with the pinion 1 and a second frustoconical friction surface 8 ′, said second surface, of shape complementary to the first surface 8 and integral with the driver 12. The coupling device comprises, on the one hand, a hollow coupling piece having a bottom extended by an annular skirt directed axially towards one of the pinion elements 1 - driver 12 and, on the other hand, elastic means 10 with axial action bearing on a first stop secured to the coupling piece for action on a second stop 4 'secured to one of the pinion elements 1 - driver 12. The elastic means 10 are carried by the skirt 1b (figure 26) or 12b (figure 27) of the coupling piece. This skirt, on the one hand, internally carries one of the first and second surfaces 8, 8 ′ and, on the other hand, is, via the bottom of the coupling piece, secured to one of the pinion elements 1 - launcher 12, which is associated with the surface 8, 8 ′ carried internally by the skirt, more precisely by the internal periphery thereof. Here, the contact diameter of the first surface 8 with the second surface 8 'is greater than the diameter of the head circle of the teeth of the pinion. In these figures the first or second surface 8, 8 'carried by the skirt 1b, 12b is axially longer than the other second or first surface 8', 8. The elastic means 10 are carried by the free end of the skirt 1b, 12b and extend in axial projection relative to said other second or first surface 8 ', 8.

The axial end of larger diameter of said other surface 8 ', 8 is delimited by a transverse shoulder carrying the second stop 4' for implantation under axial compression of elastic means with axial action 10 between this second stop 4 'and a first stop carried by the free end of the skirt of the coupling piece.

The transverse shoulder is extended at its internal periphery by an annular bearing 4 "generally of axial orientation delimiting with said shoulder a removal of material to accommodate at least partially the elastic means with axial action 10.

The elastic means with axial action here have the form of a circlip and are received in a groove produced at the internal periphery of the free end of the skirt. These elastic means alternatively have claws intended to come into resilient engagement with the internal periphery of the free end of the skirt of the coupling piece as described in the aforementioned document FR 01 08607 to which reference will be made for more details.

In FIG. 28, the elastic means with axial action 10 comprise tongues 10b which are axially deformable and which extend circumferentially. The tongues 10b are bent axially and comprise a washer 10a. In FIG. 28, the elastic means with axial action 10 comprise a washer 10a surrounding the elastic tongues 10b. These elastic tabs are connected to the internal periphery of the washer 10a in favor of rooting zones 10d. The tongues 10b consist of arms in the form of an annular sector extending circumferentially in overhang on either side of a zone d 'rooting 10d. The washer 10a has a radial slot 10g symmetrically affecting one of the two rooting zones 10d; four arms 10b being provided at the rate of two arms per zone 10b.

As a variant, the first stop is formed by means of a circlip or a stop ring mounted in a groove produced at the internal periphery of the free end of the skirt. The elastic means 10 can then consist of at least one Belleville washer or at least one corrugated washer or even a frustoconical coil spring bearing on the circlip or the ring for action on the trainer (Figure 26) or on the pinion (figure 27) for controlled tightening of surfaces 8,8 '. In another embodiment, the first stop is attached to the free end of the skirt.

In all cases the elastic means with axial action comprise an elastic washer.

In these figures the free end of the skirt consists of a tubular extension.

In Figure 26 the skirt of the coupling piece is of frustoconical shape.

Advantageously for dust evacuation and detachment of the surfaces 8,8 'one of the first and second friction surfaces 8,8' has for contact with the other surface of the grooves and one at least a first and second friction surface 8.8 'is alternatively constituted by a friction lining.

In FIG. 26 the pinion 1 is in one piece with the coupling part generally in the shape of a bell and this coupling part is fixed to the pinion.

In Figure 27 the structures have been inverted so that the coupling piece is integral with the launcher 12 which therefore has an outer skirt 12 b of cylindrical shape at its outer periphery.

As a result, the coach is in an embodiment obtained by molding, for example being made of plastic. In this case the corrugations 21 are easily obtained by molding from the front flank 121. In FIG. 25 we see the decomposition of the forces when the pinion 1 is in contact with the working stop 6. More precisely, the initial pressure of the elastic means between the stops produces a friction torque between the driver and the pinion which is always, by construction, greater than the torque necessary for screwing and advancing the launcher on the shaft 100. This condition allows the self-priming movement of the launcher between its rest position and its advanced position against the working stop, 6 at the start of the drive phase of the vehicle engine via the starter ring. When the pinion reaches the stop 6 there is compression of the surfaces 8, 8 'against each other with a blocking. This blocking of movement between the pinion and the driver depends in particular on the angles and the diameters of the friction surfaces. truncated. As can be seen in FIG. 25, during the driving of the internal combustion engine of the motor vehicle by the electric motor of the starter the torque Cd - generated by the starter at the output shaft 100 carrying the driver 12 and transformed by the helical spline device 9 intervening between the driver 2 and the shaft 100 - creates an axial force Fa.

This force Fa is itself decomposed at the frustoconical friction surfaces to create a normal contact force Fc, which generates a tangential force Ft at the frustoconical surfaces 8,8 'as a function of the coefficient of friction between these surfaces. The value of this force Ft multiplied by the average contact radius of the frustoconical friction surfaces determines the torque Ce transmitted by the conical clutch 7.

For the pinion to be driven normally without slipping, the relation Ce> Cd must always remain true. All this depends on the applications because the coefficient of proportionality between Cd and Fa depends on the angle of inclination of the splines 9, the mean radius of these splines and the coefficient of slip between the output shaft 100 and the driver. The coefficient of proportionality between Fa and Fc depends on the angle of the cone between the two frustoconical friction surfaces.

The value of Ft is related to Fc and to the coefficient of friction fc between the two materials of the frustoconical friction surfaces of the clutch 7. To avoid any jamming one will make sure of the tangent relation (a)> fc, in which a is the value of the half-angle at the top of the cone of contact between the frustoconical friction surfaces and fc the coefficient of adhesion. All these values are calculated according to mechanics formulas known per se and depend on the applications.

These formulas involve the coefficient of friction between the splines of the shaft and the driver, the average radius of the splines, the angle of the cone of the surfaces 8,8 'and the coefficient of friction of these. All this influences the choice of materials for the driver, the skirt and the pinion.

When the vehicle engine has started, the pinion 1 rotates faster than the output shaft 100 which allows the starter to be unscrewed on the shaft 100. The axial force previously transmitted disappears and only the residual torque remains low due to the elastic means 10 which is transmitted to the electric motor of the starter. During this short overspeed phase the clutch behaves like a freewheel device with a relative movement between the surfaces 8,8 '. The mean contact diameter between the two surfaces 8,8 'is therefore also a friction diameter in the event of overspeed.

Figures 31 and 32 illustrate a conical clutch launcher having provided with rotation locking means according to the invention.

In all cases the launcher has a trainer provided with a groove for receiving the fork. In the figures, the trainer 12 comprises a front flange of transverse orientation, advantageously of annular shape, perforated centrally for passage of the launcher shaft 100 associated with the launcher. This flange is extended towards the rear by a barrel-shaped tubular portion surrounding the shaft 100 and having locally at its internal periphery the helical grooves, better visible in FIG. 25, for cooperation with the complementary helical grooves formed locally at the outer periphery of the shaft 100. The tubular portion carries, for example axially secured, a washer, not referenced in FIGS. 3 and 4, the front face of which constitutes the side 122 of the groove for receiving the lower end of the fork 13. The other side 121 of this annular groove is formed by the rear face of the front flange of the coach. As a variant, the sidewall 122 and its associated washer came from molding with the driver (FIG. 27). The bottom of the groove is axially oriented and has an annular shape. This bottom belongs to the tubular portion on which the arms of the fork overlap or the ring 15 of the fork slides. In Figure 27 the front flange is extended forward at its outer periphery by the skirt 12b. In figure 26 the flange is massive and is extended forward by the range 4 ". In the freewheel variants the flange is extended at its outer periphery towards the front by a cylindrical skirt internally constituting a track for the rollers of the freewheel.

The starter of FIGS. 2, 3 and 37 comprising a contactor provided with two contact pads P1 and P2 operates in the following manner.

- when the ignition key is actuated, constituting the switch 35 in FIG. 2, the winding 2a, composed of the call winding 36 and the holding winding 37 mounted in series with the electric motor M, is supplied creating a weak magnetic field sufficient to overcome the force exerted by the return spring 18. As a result, the movable core 2b moves towards the fixed core 2d while first compressing the return spring 18 of the core and the return spring 17 of fork 13.

- the movable core catches up with the cutting clearance JC by compressing the return spring 18. During the phase of catching up with the cutting clearance, the fork 13 remains immobile because it is held in place by the fork return spring 17, the stiffness of this fork return spring 17 being greater than that of the return spring 18 of the core. The fork 13, mounted with articulation on the projecting front end of the core 2b, moves and rocks around its articulation point 11 carried for example by the support 4.

By moving backwards, the movable core moves the first contact pad P1 against the first series of contact C1, C2 which has the effect of energizing the coil 39 for calling and pre-rotating the relay creating additional efforts to attract the mobile core.

This coil 39 for calling and pre-rotation has an electrical resistance which limits the current flowing in the electric motor to a value preferably between 40 and 80 amps. This additional pre-rotation coil 39 is wound, for example, around the other two call and maintenance coils 36 in the contactor. Thus, means are provided for, following a start command by closing the start switch, turning the electric motor at low speed before making it run at full power.

- During the rotation of the armature during pre-rotation, the movable core comes to pull the fork 13 which pivots around its axis to come into contact with the external face of the trainer provided with notches. - Under the effect of the rotation of the armature shaft 100, the launcher 102, blocked in rotation by the teeth or fingers 22 of the fork inserted in the notches 320 of the trainer, starts translational movement. This translation is effected by means of the helical grooves carried by the armature shaft 102 which act as a worm. Preferably the angle of the helical grooves, referenced at 9 in Figure 25, is between 18 ° and 25 °. Of course, this angle can be increased to have inclinations of the order of 45 °.

Thanks to the rotation lock of the launcher and these means, the electromagnetic power and the radial size of the contactor can be reduced, thanks to an energy supply from the electric motor.

The size and the weight of the launcher have a smaller impact on the dimensioning of the contactor, compared to a traditional contactor, so that one can choose with less constraints the launcher, which can be lighter or heavier.

- the fork, always attracted by the moving core, follows the progress of the launcher and therefore remains in contact with the trainer, always blocking it in rotation. The fork is follower and does not contribute to moving the launcher forward.

As a variant, the fork, in addition to its role of blocking the launcher in rotation, can also participate in the forward movement of the launcher by providing force at the level of its fingers resulting from the displacement of the movable core towards the rear.

- the pinion then reaches the level of the crown C of the heat engine.

- if the pinion via its teeth can penetrate directly into the crown C, more precisely into the teeth thereof, to mesh with the crown C, then the launcher continues its progression until the movable core comes into abutment against the fixed core.

- the pinion can also be in tooth-to-tooth position against the crown. In this case, the pinion is locked in translation and in rotation. In this position, the armature provides a torque proportional to the low intensity current. because the starter is still in the pre-rotation phase. Thus, the electric motor exerts a torque on the pinion and the launcher through the grooves carried by the armature shaft 100. Being blocked in translation, the coach will rotate so as to push the fork 13 towards the rear which is no longer able to block the driver in rotation. The fork can be pushed back because the coil 2a of the contactor has a force less than the force exerted by the notches on the fork. When the pinion, when turning, finds an opening in the crown of the motor, it enters there pushed by the axial force of the fork generated by the attraction of the mobile core by the solenoid 2a.

The value of the intensity to be passed through the first power circuit is dimensioned so that the pinion enters rotation in tooth / tooth phase, that is to say that the armature has the torque necessary for the pinion to make skip the notches and push the fork back. The value of this intensity is a function of the angle of the helical grooves, the shape of the notches and the dimensioning of the solenoid 2a.

Thus, if before meshing with the crown C, the pinion abuts against the crown C, the pinion starts to exert a torque on the notches such that the teeth 22 will jump notches by making the fork move back 13. The pinion can then turn and enter the crown. The movement takes place at low speed due to the slow speed rotation of the electric motor. Wear is thus reduced due to the low impact produced by the pinion when it comes into contact with the crown thanks to its low axial speed.

The means of cooperation between the launcher and the fork, which in the illustrated figures form means for locking in rotation, are therefore of the disengageable type; the launcher being mobile in translation and fixed in rotation during the aforementioned movement, while the launcher shaft 100 is mobile in rotation and fixed in translation which allows the launcher to advance axially via the above-mentioned helical grooves.

The contactor 2 thus becomes a part of reduced size and its specification becomes independent of the dimensioning of the launcher. - Once the pinion 1 has successfully entered the ring C under the effect of the armature rotation, it continues its forward movement under the effect of the rotation of the armature.

- at the level of the relay, the movable core comes into abutment against the fixed core, which has the effect, on the one hand, of closing the power contact between C3 and C4 via the second plate and, on the other hand, to disengage the fork from the pitches of the launcher. The pinion can reach the end of the stroke against the shaft stop while being released from the fork. The rotation lock is thus disengageable when the pinion 1 abuts against the starter ring.

- the power contact C3 and C4 being closed by means of the second plate, the armature of the electric motor is then supplied at full power. It can therefore drive the crown C to start the engine.

- during decompression of the heat engine during the start-up phase, the crown C becomes driving relative to the starter pinion. This phase is called freewheeling phase during which the pinion tends to screw back on the helical teeth which has the effect of moving it back.

- The two pads 290 provided at the base of the fork have the function of avoiding too great a recoil of the launcher during the freewheeling phase during which the pinion tends to be tightened as described above. In the absence of these pads 290, this decline would have the consequence of bringing the notches of the coach into contact with the fingers of the fork, which would cause wear and noise. These pads come (Figure 31) to bear on a flange 310 located on the periphery of the coach. The shape of the arms of the fork which supports these fingers and these pads is such that the pads can only be in contact with the driver when the fork is in the pivoting or maximum rotation position.

After opening the switch using the ignition key, the winding 2a is de-energized, which has the effect of canceling the force of attraction on the mobile core 2b. Fork return spring 17 assisted by springs 18, 20 and 21 pressing respectively on the fork and the movable core 2b forces the movable core to disengage and return to its rest position. The movable axis 40, integral with the core, pulls the wafer P2 with it. The additional thickness of the strip 23 comes into abutment on one face of the plate PL The angle of the slope of this additional thickness is dimensioned (approximately 40 °) so that the force necessary for the strip to collapse is greater than the force of resistance to the contact opening produced between the plate P1 and the contacts C1 and C2. Thus, the plate P1 will follow the movable axis and the two power circuits will open simultaneously. When the plate P1 arrives at the fixed core, it is stopped while the movable axis always moves back. The strip then collapses, the force necessary for this subsidence is provided by the springs 18 and 21. The additional thickness passes on the other side of the plate and the strip returns to its initial position relative to the plate P1.

Thus, the rotation lock of the launcher and the management of the tooth against tooth position are carried out by the notching system arranged on the one hand, on the rear face of the coach and on the other hand, on the front end of the base of the fork. The launcher is returned to its rest position thanks to the fork and the screwing during the freewheeling phase on the splines of the armature shaft. Maintaining in the rest position is achieved by the return spring 17 located between the relay and the fork, as in a traditional device.

The relay is no longer dimensioned to develop a pushing force. It is not very dependent on the mass of the launcher. It is dimensioned to overcome, in the initial position, the force exerted by the return spring 17 on the movable core. Thereafter, the solenoid 2a must have the power necessary to overcome the return springs 18 of the launcher, and crushing 20, 21 of the contact pads in the variants where they are present. The gain in mass of copper, in magnetic materials, in size, in cost and development time are the direct advantages of this undersizing.

It is good to note that the act of turning the armature allows to catch all functional games and when the pinion transmits to the 1 ^st time his marriage to the crown - approach phase - there are no shock as on a conventional starter which requires less mechanical starter. Thus, in accordance with the present invention, the relay constituted by the electromagnetic contactor comprising the call, holding and pre-rotation coils is no longer dimensioned to develop a force for pushing the driver forward for the purposes of the engagement of the pinion in the crown C of the heat engine. Its dimensioning is not very dependent on the mass of the launcher. It is dimensioned only to be able to overcome the force exerted by the return springs on the movable core when the solenoid is energized. It must also be dimensioned to allow the rotation of the starter when the pinion is in tooth-to-tooth position by a rearward movement of the fork which can disengage from the wolf teeth thanks to a slight displacement of the movable core forwards .

The gain in mass of copper, in magnetic materials, in size, in cost and development time are the direct advantages of this undersized contactor according to the present invention. Another advantage of this invention consists in that the starter does not include additional parts for the implementation of a contactor and a driver according to the invention. However, the penetration of the launcher by pre-rotation of the armature may require the installation in the relay of a two-contact switching system, in the case where the intensity of pre-rotation exceeds the limit given by the control system (ignition key), one to let low power through (current limited to 80 amps), the other to let all available power through.

According to another embodiment, a starter devoid of tooth against tooth spring and of pre-rotation device can be envisaged. Thus, as soon as the ignition key is activated, all the power is allocated to the armature. A single contact relay would be sufficient. In this variant embodiment without tooth-to-tooth spring, it is the strong acceleration of the armature at start-up which would cause the launcher to advance by inertia by coming to be screwed onto the helical splines of the armature shaft without locking in rotation by a fork. The tooth against tooth problem would no longer appear thanks to the permanent rotation of the pinion during its forward travel by screwing on the armature shaft. We find in this variant the principle of starting inertia starters.

Figures 39 and 40 illustrate another embodiment of the pre-rotation according to the invention. In this embodiment, as shown in FIG. 40, when the switch 35 is closed, a current is passed through the holding coil 37 and the call coil 36. This current, in particular that passing through the call coil 36, must be sufficient to activate the electric motor M in a pre-rotation movement, that is to say it must be sufficient to allow the electric motor M to overcome the frictional forces which appear during the starting the starter. These friction forces appear for example at the level of the grooves cooperating with the launcher, at the level of the fork pressing against the throat of the trainer and in particular depends on the forms of the means of cooperation between the teeth of the fork and the internal face of the groove of the coach for locking in rotation as described above. As soon as the contact plate PO comes into contact with the power pads C1 and C2, the electric motor is activated at full power and the holding coil remains active while the call coil 36 is short-circuited.

FIG. 39 illustrates a contactor authorizing an effective pre-rotation and which uses only a call coil 36 and holding 37 without using an additional resistive element such as a call and pre-rotation coil 39 as described previously. Such a contactor has the advantage of using only two springs, namely a return spring 18 of the core and a contact spring 20 to guarantee good contact between the contact pad PO and the power pads C1 and C2.

In such a contactor, it is no longer necessary to have a tooth against tooth spring against the crown since this configuration is now managed by the fork and the pre-rotation. In this case, as described above, the pinion is locked in translation and in rotation. In this position, the armature provides a torque proportional to the low intensity current because the starter is still in the pre-rotation phase. Thus, the electric motor exerts a torque on the pinion and the launcher through the grooves carried by the armature shaft 100. Being blocked in translation, the coach will rotate so as to push the fork 13 towards the rear which is no longer able to block the driver in rotation. The fork can be pushed back because the winding 2a of the contactor has a force less than the force exerted by the notches on the fork 13. When the pinion, turning, finds an opening in the crown of the motor, it penetrates there pushed by the 'axial force of the fork generated by the attraction of the mobile core by the solenoid 2a. Similarly, in such a contactor, it is no longer necessary to use a cut-off spring because the movable core 2b has a movable axis 40 which is integral with it in translation (coupled axis) so that it is the spring of reminder 18 which acts as a cut-off spring.

The fork 13 is identical to that described in FIGS. 3, 4, 29 and 30 and allows a rotation lock of a launcher similar to that described in FIGS. 3, 4, 31, 32, 33.

Advantageously, during the pre-rotation, in addition to the function of blocking the launcher in rotation, the fork also helps the launcher to move forward thanks to the force exerted towards the rear by the movable core 2b under the effect of the magnetic field created by the current passing through the solenoid 2a. This promotes the movement of the launcher by reducing the risk of jamming at the grooves.

The connection terminal of the electric motor in Figure 1 is replaced by an internal connection.

This is made possible by the fact that the rear bearing 26 is made of plastic so that the electrical tracks are obtained by the technique of overmolding.

The rear bearing has a sleeve for receiving the rear end of the shaft

101. This sleeve internally carries a bearing in which the rear end of the shaft 101 is rotatably mounted. The resistor 39, for example made of aluminum, is wound and is connected to the contacts C1 and C2. In FIG. 3, the resistance is wound around the windings 36 and 37.

It follows that the two cylinder heads may belong to the same part or be integral with one another. The support 4 can be obtained by deformation of material by being, for example, stamped sheet metal. It then comprises a fixing and centering flange instead of the deeper fixing zone of FIG. 1. The rear bearing of the electric motor advantageously constitutes the closing plate of the contactor. The rear bearing is then, in one embodiment, equipped with one or more electrical tracks, for example by overmolding. This or these tracks connect at least one fixed contact to the electric motor so that the cable of FIG. 1 can be eliminated. The rear bearing 26 is attached by clipping 29 onto the cylinder head 25 and closes the latter on the side opposite to the support 4. For example, the cylinder head 25 has holes and the bearing 26 of the elastically deformable tongues each carrying a lug with a ramp. When the tabs of the bearing 26 are threaded into the cylinder head, they retract downwards thanks to the ramps of the protruding pins. When the pins arrive in front of the holes, the tabs deploy and the pins enter the holes. Several lugs and holes are provided.

The cylinder head 25 has the shape shown in FIG. 6 and has two cavities for receiving the electric motor M and the contactor 2 respectively.

Here the yoke 25 is formed by means of a closed metal strip, for example of generally oval shape, which is deformed using jaws in contact with removable cores delimiting the cavities.

The strip can be opened at the origin and be closed by buttoning as described in document US-A-4 309 815 or by welding. The cylinder head is made of magnetic material, for example sheet metal.

As a variant, the two cylinder heads are fixed to one another, for example by welding.

The support 4 is made of sheet metal and is obtained by deformation of material without recovery operation, only the anticorrosion surface treatment possibly being carried out.

Pre-coated sheets can be used, for example. The support 4 (FIG. 5) is produced by stamping and comprises a front portion 43 in the form of a warhead provided with a sleeve 42 internally carrying a support bearing for the front end of the launcher. The warhead 43 has an opening 44 for the passage of the starting crown.

The warhead is connected at the rear to a fixing flange 45 of transverse orientation, that is to say perpendicular to the axis of rotation X-X of the shaft 100-101.

The simple shape flange replaces the more complex fixing area in Figure 1.

Rigidification ribs 47 are present between the flange 45 and the warhead 43. Hollow studs 41 are made for fixing and centering the support on the casing of the thermal engine of the vehicle and thus constitute the third means of fixing and centering supra.

We see at 46 a spherical cap for creating a clearance by the front end of the movable core 2b of the contactor 2, the number of springs is reduced compared to that of FIG. 1. The fixed core 2d, 2d is also simplified since it consists of a simple plate without frustoconical portion as in the figure

1. It is the same for the mobile core 2b.

A support washer is provided for supporting the return spring 18.

The first means of fixing and centering the support 4 are used for fixing the cylinder head 25.

As a variant, the warhead 43 is made of stamped sheet metal and the flange 43 of aluminum.

The cylinder head 25 can be stamped to form hollow casing means for penetration of lugs from the cylinder head and formation of centering means. Here the cylinder head 25 is fixed by crimping on the support 4 as visible for example in FIGS. 8 to 24.

These embodiments are also applicable to the fixing of the cylinder head to the rear bearing.

These solutions are economical because it avoids having to use, as in FIG. 1, an expensive screwdriver from an investment point of view if one wants to take into account precise tightening parameters.

In addition, this type of screw or tie rod assembly is bulky and poses additional constraints in the automation of assembly stations.

(distribution of long or small parts, little space for the passage of screwdriver heads). In addition, the cycle time for a tightening operation is traditionally long.

In Figures 8 to 24 we do not find these drawbacks. In these figures, a part of the cylinder head 25 is deformed to immobilize the other components so that the size of the starter is reduced. Thus the support 4 or the bearing 26 may have holes axially traversed by lugs of the cylinder head, the free ends of which are folded down in contact with the support or the bearing. The reference 28 in FIG. 3 symbolizes such an assembly.

As a variant (FIG. 8) the support 4 or the bearing 26 have cavities 70 for example in the form of recesses in which the beaks 71, 72 obtained by cutting in the cylinder head are folded down. The beaks are supported on the lateral edges of the recesses thus achieving an angular indexing as well as a stop in rotation. In FIG. 9, the two nozzles meet to form a strip of material 73 deformed in the cavity 70.

In FIGS. 10 to 12, such a strip of material is formed, but the recess 170 extends parallel to the axis X-X of the shaft 101, instead of being perpendicular thereto. The strip 73 is formed by virtue of recesses 74.75 opposite. An axial and radial fixing is thus obtained without the need for fitting.

In FIG. 14, the wall of the part 26 (or in variant 4) is locally deformed in 373 by pushing it back inside the recess 270 using a punch here of prismatic shape in conical or cylindrical variant the structures can be reversed, the cylinder head 25 being locally deformed to penetrate into the recess 70, 170, 270 forming a cavity so that the bearing 26 can be made of plastic.

In FIG. 13, a local deformation of material has been shown using a cylindrical punch showing a deformation of material 273 penetrating for example into the recess 270.

As an alternative to FIG. 15, only one obviously 470 is provided, the upper part of FIG. 10, that is to say the recess 74, being deleted. As a variant in FIG. 16, the recess 470 in FIG. 15 is open and two tongues 471, 472 are formed, the reference 473 being a solid part. As a variant in the figures in FIG. 17, instead of passing through a hole, the axial tabs 77 pass through a notch 76 and the precut lateral edges 77 ′ of the tabs, for example of the yoke 25, are folded down in contact lateral edges of the notches made in the support or the bearing. As a variant, the lateral edges 77 ′ consist of protuberances connected to one another by removal of material and the protuberances are crushed. As a variant in FIG. 19, a casing is produced. The bearing 26 has for example protuberances 79 for supporting the lower face of the cylinder head 25. The part 26 has a flange 78 folded radially by crimping or folding in contact with the upper face of the cylinder head 25.

As a variant (FIG. 20), the flange is deformed axially at 178 in contact with the upper face of the cylinder head 25. As a variant in FIG. 21, it is formed using a punch a cut in the flange with an inclined tab 278 folded in contact with the upper face of the cylinder head.

As a variant, an inclined tab 378 (FIGS. 22 to 24) is folded down in contact with the upper face of the cylinder head 25. All that has just been described is applicable to the flange 45 of the support 4.

The coupling device between the driver 12 and the pinion comprises in an exemplary embodiment a free wheel. This freewheel uses a large number of components due in particular to the presence of rollers each subjected to the action of a spring. The coupling device with conical clutch allows a great simplification in the aforementioned manner.

Thanks to the invention and to the blocking in rotation of the trainer, the movement of the launcher is favored by reducing the risks of jamming in the grooves. In conjunction with the previous figures, the solution is as compact as possible with a significant reduction in the number of components and the weight. The solution is simple and economical.

Of course, the present invention is not limited to the embodiments described. In particular, the alternative support is of the type in FIG. 1 and the two cylinder heads can be separate. As a variant, a gear reducer is interposed between the two shafts and / or a cable is provided between the motor M and the contactor as in FIG. 1.

The inductor of the electric motor M as a variant comprises a winding. Tie rods can connect the support to the rear bearing. The brushes as a variant are of axial orientation as in FIG. 1. Obviously, the embodiments presented above are also suitable for starters with magnet or wound inductors, with direct drive or with internal reducer and with support with warhead or outgoing pinion type.

Claims

claims

1. Starter for a motor vehicle with an internal combustion engine and a starter ring for an internal combustion engine, comprising a launcher, provided with a drive (12) and a pinion (1) capable of passing from a retracted position of rest to an advanced engagement position with the starter ring (C) of the thermal engine of the motor vehicle, an electric motor (M) provided with a shaft (101) suitable for driving a launcher shaft (100) associated with the launcher (12 ), complementary helical grooves (9) acting locally between the internal periphery of the driver (12) and the external periphery of the launcher shaft (100), an electromagnetic contactor (2) extending parallel to the electric motor ( M) above it and comprising a movable core (2d), a fork (13) mounted at articulation at its upper end on the movable core (2b) and at an intermediate point (11) on a support (4 ) of the electric motor (M) and the contactor electromagnetic (2), in which the driver (12) has a groove for receiving the lower end of the fork (13) delimited by two sides (121, 122) and in which means are provided for turning the motor electric at slow speed in a first phase known as pre-rotation, then at full power, characterized in that the launcher is locked in rotation by means of cooperation between the fork (13) and the trainer (12) for its passage from its rest position to its engagement position with the starter ring.

2. Starter according to claim 1, characterized in that the cooperation means are rotationally locking means with cooperation of shapes.

3. Starter according to claim 1, characterized in that the cooperation means are friction type.

4. Starter according to claim 2, characterized in that during the electrical supply of the electromagnetic contactor (2), the fork (13) cooperates with the side (121), said front side of the receiving groove of the fork ( 13) and in that the front flank (121) is provided with circumferential undulations (21).

5. Starter according to claim 4, characterized in that the fork (13) has branches (293) with corrugations of shape complementary to those of the front flank (121).

6. Starter according to claim 2, characterized in that the rotation locking means are of the wolf tooth type.

7. Starter according to claim 2, characterized in that with the flank (121) before the receiving groove of the fork (13) comprises notches (320) and bumps (321) and in that the fork ( 13) has fingers (22) cooperating with the notches (320) for locking the launcher in rotation

8. Starter according to claim 1, characterized in that with the side (121) before the receiving groove of the fork (13) cooperates with a ring (15) slidably mounted axially on the barrel of the coach.

9. Starter according to the preceding claim, characterized in that the ring (15) is hingedly mounted on the body (292) of the fork (13).

10. Starter according to claim 1, characterized in that the fork (13) has at its end which cooperates with the groove of the driver at least one shoe (290) which cooperates with a flange (310) located at the periphery of the trainer when the launcher is engaged in the starter ring of the motor vehicle engine.

11. Starter according to claim 1, characterized in that the cooperation means are disengageable.

12. Starter according to claim 1, characterized in that the support (4) comprises a front part (43) of sheet metal generally in the form of a warhead.

13. Starter according to claim 12, characterized in that the front part is connected to a flange (45) for fixing and centering.

14. Starter according to claim 13, characterized in that the support (4) in sheet metal is obtained by deformation of material, such as a stamping, and in that the flange (45) is in one piece with the part before. (43).

15. Starter according to claim 1, characterized in that the electric motor (M) and the contactor (2) each comprise a cylinder head secured to the other cylinder head.

16. Starter according to claim 15, characterized in that the two cylinder heads belong to the same part (25).

17. Starter according to claim 16, characterized in that the or the two cylinder heads are closed on the side opposite to the support by a common part (26) forming the rear bearing of the electric motor (M).

18. Starter according to claim 1, characterized in that the means provided for rotating the electric motor (M) in pre-rotation then at full power, comprise two plates (P1, P2) carried by the movable core (2b), the first plate (P1) used during the pre-rotation is connected to two contacts (C1, C2), the first contact (C1) is connected to the resistive coil (39), the second contact (C2) is connected to the positive terminal of the battery, then at full power, the second plate (P2) is connected to two contacts (C3, C4), the third contact (C3) is connected to the resistive coil (39) and to the electric motor ( M), the fourth contact (C4) is connected to the positive terminal of the battery.

19. Starter according to claim 1, characterized in that a contact plate (PO) is allowed to switch around the second fixed contact (C5) to cooperate with another fixed contact (C6) offset axially and connected to the positive terminal battery to power the electric motor.

20. Starter according to claim 18 or 19, characterized in that the movable axis (23) comprises a strip (23) provided with a local allowance which drives the contact pads (PO, P1) when returning from the movable axis (40) after opening of the contactor control circuit (2).

21. Starter according to claim 1, characterized in that the electromagnetic contactor (2) comprises, at least plate (P3) able to evolve in rotation around the movable axis (40) for the pre-rotation then at full power of the _. electric motor (M).

22. Starter according to claim 21, characterized in that the plate (P3) comprises 2 pads connected electrically, a first pad continuously connected electrically with a contact (C7) connected to the battery voltage, a second pad connected to a contact (C8) during the pre-rotation of the engine, this second stud then coming into contact with a third contact (C9), after rotation of said wafer (P3), to provide full power to the starter, the second and third contacts (C8, C9) being interconnected by the resistor pre-rotation coil (39), the contact (C9) being connected to the electric motor (M).

23. A starter according to claim 1, characterized in that the pinion (1) of the starter is connected to the driver by a coupling device with conical clutch.