FR2827341A1 - Automobile starter motor, spigot once meshed with engine crown wheel is stopped from rotating, by a friction, cooperating shape or toothed blocking system - Google Patents

Abstract

A rotation blocking part (21) belongs to a blocking system intervening between a drive (12) and fork or support (4). The blocking system may be of the friction, cooperating shape, or toothed type. At the moment the fork contactor has an electrical supply the fork cooperates with a side (121) of the forks reception throat. The side has circumferential undulations and the fork has fingers with complementary undulation to those on the side. Automobile starter having a gear spigot, fitted with a drive and pinion (1), designed to move from a retracted position to an advance position meshing with the engines crown wheel. The starter has a motor (M) with shaft (101) driving the spigot shaft (100), with complementary helicoidal threads locally intervening between the internal periphery of the drive and the external periphery of the shaft. An electromagnetic contactor (2) extends parallel to and above the motor, and has a movable core (20b). A fork is hinge mounted at the upper end of the core and at an intermediate point on a support between the motor and contactor. The drive has a reception throat, for the lower end of the fork, delimited by two sides (121,122) and in which is a device to slowly rotate the motor. The spigot is fitted with a device to stop its rotation at the moment it passes from its rest position to its meshing position with the engine crown wheel.

Description

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The present invention relates to starters for motor vehicles.
Such a starter is shown in FIG. 1 and comprises an electric motor M mounted inside a first metal yoke, an electromagnetic contactor 2 extending parallel to the electric motor M and comprising a winding 2a mounted inside the first metal yoke. a second metal head.

 The two yokes are fixed, here using tie rods, on a support 4 with interposition here of a support plate. The support 4 is an aluminum-based casting, which is intended to be fixed to the casing of the internal combustion engine of the motor vehicle, hereinafter referred to as the heat engine. The support 4 ensures the return to earth and has a front end shaped warhead open locally for the passage of the starter ring C of the engine of the vehicle. This warhead is connected to a fastening and centering area respectively of the electric motor M, the switch 2 and the support 4 on the housing of the engine.

 The warhead has at the front a support sleeve of a bearing inside which is rotatably mounted the front end of a launcher shaft 100 locally having at its outer periphery clean grooves to engage with complementary splines formed at the inner periphery of a driver 12 belonging to a launcher also having a pinion 1 connected by a coupling device 14, here freewheeling, to the driver.

 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 gear reducer epicyclic train between the two shafts.

 The aforesaid support plate carries a plastic part in the form of ring gear internally and belonging to the aforesaid gear reducer, the input gear of which is secured to the front end of the shaft of the electric motor.

 The planet carrier of the gearbox is secured to the rear end of the shaft 100.

 The rear end of the shaft 101 is rotatably mounted within a bearing carried by a part, said rear bearing, closing the first yoke. This first yoke 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 packet of sheets fixed on the shaft of the electric motor knurled at this effect.

 This bundle of plates is provided with axial grooves for the accommodation of electrically conductive elements in the form of bars arranged in networks

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 connected to the electrically conductive blades of a collector carried by the rear end of the shaft 101.

 Brushes, mounted inside cages carried by the rear bearing, are intended to cooperate with the blades of the collector.

 A series of these brushes is connected to ground via the first yoke 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 secured to a hood electrically insulating material closing the open rear end of the second yoke having at its front end a perforated bottom for the passage of a movable core 2b. The cover also carries a second contact terminal and at least one connection for the power supply of the winding 2a.

 A fixed core 2d is implanted to attach to the rear end of the second yoke and penetrates partly inside a support 2c of the winding 2a. The support 2c has a U-shaped section and therefore constitutes a pad for guiding the core 2b. A first stepped rod passes through the fixed core 2d and carries a contact plate intended to bear on the two 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 winding 2a is connected to ground via the second yoke and the support 4.

 The first rod and the contact plate belong to a movable contact 3 which, in its rest position, is kept pressed by a breaking spring against the fixed core. The cutoff spring acts between the contact pad and the cover having a receiving housing of the breaking spring.

 Another spring, said contact spring, of greater stiffness than that of the breaking spring, is implanted axially between the other face of the contact plate and a shoulder of the rod, passing through the fixed core 2d to present an end.

 The movable core 2b penetrates inside the second yoke and in the winding 2a. This movable core 2b extends in axial projection with respect to the front end, and the second cylinder head. The movable core 2b is subjected to the action of a return spring acting between the bottom of the second yoke and a shoulder secured to the movable core centrally provided with a hole for the axial sliding assembly of a second rod stepped to its rear end for action

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 a spring, said spring teeth against teeth, acting between said shoulder and the bottom of the movable core. The spring teeth against teeth has a stiffness stronger than that of the return spring and lower than that of the springs associated with the moving contact 3.

 The front end of the second rod carries an axis for the hinge assembly of the upper end of an operating lever 13 of the pinion launcher 1. This lever 13 is mounted at an intermediate point, hinged on the support 4. The lower end of the operating lever comprises two branches mounted in an annular groove formed in the driver 12 so that the operating lever is fork-shaped.

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

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

 In FIG. 1, the contactor 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 electrically powered; the aforementioned switch being open. The pinion 1 is at axial distance from the start ring C of the heat engine, the movable contact 3 is remote from the contact terminals in the form of pads, while the core 2b is at axial distance from the rod of the movable contact.

 When the switch is closed by means of the ignition key, the winding 2a is electrically powered and a magnetic field is created so that the mobile core 2b moves axially toward the fixed core 2d and the movable contact and moves, by means of the operating fork, the launcher and the pinion 1 towards the ring gear C. The pinion 1 can penetrate between the teeth of the ring gear C so that it is in the meshing position with the crown C.

The movement of the pinion 1 is limited by cooperation of the pinion 1 with a working abutment 6 integral with the shaft 100. The movement of the movable core continuing, it abuts against the rod of the movable contact with a washer that carries the mobile core 2b for this purpose. The cutoff spring is then compressed until closing of the movable contact by contacting its plate with the contact terminals.

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 The electrical circuit of the electric motor M is then closed so that it rotates the shaft 100 and thus the pinion 1 via the driver and the helical splines intervening between the driver and the shaft 100. The magnetic circuit is closed 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 engine has not yet started.

 It may happen that the pinion abuts against the crown C without meshing with it. In this case, the spring 5 teeth against teeth is compressed until closing of the movable contact and supply of the electric motor which then drives in rotation the shaft 100 with penetration of the teeth of the pinion 1 in the teeth of the crown C. When the engine has started, the freewheel allows the pinion to rotate relative to the shaft 100 and thus spare the engine M.

 The movable core 2b and the spring against teeth 5 increase the radial size of the contactor, which must be powerful. The weight of the contactor is not negligible.

 To overcome these disadvantages, and to increase the vibration resistance of the contactor, it has been proposed, as soon as the contactor coil is energized by means of the switch, to provide the contactor with means which, in a first phase, provide the low speed rotation of the electric motor of the starter and in a second phase the direct power supply of the electric motor barely power. This is achieved using two sets of fixed contacts and the wafer of the moving contact.

 During the passage from the first series of contacts to the second series of fixed contacts the supply of the electric motor is cut off so that the attraction force to the plunger must be significant.

 The arrangement uses springs of different stiffness acting on both sides of the contact plate.

 In US-A-4 418 289, the same means as in FR-A-2 174 421 with two contact series are also provided. Nevertheless, the electric motor continues to run at a slow speed when switching from one series of contacts to another. For this it uses two contact plates.

 These solutions are satisfactory, however, the Applicant wondered if it was not yet possible to further reduce the electromagnetic power of the contactor.

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 According to the invention a starter of the type indicated above is characterized in that the launcher is provided with means for locking it in rotation during its passage from its rest position to its meshing position with the starter ring.

 In one embodiment of the rotational locking means intervene between the launcher and the fork.

 These means comprise for example Wolf teeth, alternatively it is a friction means with a high coefficient of friction.

 In a variant, the means for locking in rotation intervene between the launcher and the support. They intervene for example between a cylindrical outer face skirt of the coach and the support. It may be the outer cage of the freewheel or the skirt having internally one of the frustoconical surfaces of a conical clutch.

 A ratchet and ratchet device can be envisaged.

 Thanks to these provisions the radial size of the contactor is further reduced.

 In all cases, the fork is a follower fork and the rotational locking means associated with the slow speed of rotation of the electric motor in a first phase - after catching the games - further reduce the electromagnetic power of the contactor.

 The mobile core is simplified.

 This contactor is not dimensioned according to the mechanical characteristics and the weight of the launcher.

 Thanks to the invention the weight of the launcher can be decreased so that it can include a coupling device to conical clutch as described for example in the document FR 01 08607 filed June 29, 2001.

 The angle of inclination of the grooves can be between 180 and 280.

 Alternatively it may be more important for example 45. The operation of the starter is therefore reliable.

 The means for slow speed rotation comprises two series of contacts and at least one electrically conductive contact pad connected to the simplified mobile core.

 In one embodiment, two electrically conductive contact pads are provided, each pad cooperating with a series of contacts.

 The first wafer cooperates with a first contact series, one of which is connected to an electrical resistance and the other of which is connected to the electric motor.

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 With this arrangement the motor runs at a slow speed from the closing of the switch constituted by the first plate and the first series of contacts.

 With the movement of the movable core continuing, the second contact pad comes into contact with the second contact series, one of which is connected to the electric motor and the other to the positive terminal of the battery so that the electric motor rotates. full power.

 In a variant, only one plate is provided. It is mounted in a tilting manner. A single contact connected to the electric motor is provided. The wafer in a first phase is perpendicular to the movable core and moves in contact with a contact connected to the resistor until it comes into contact with the contact connected to the positive terminal of the battery via the start switch.

 In a variant, the two series of contacts are angularly offset and helical ramps intervene between the movable core and the wafer in order to turn the wafer so that it can pass from the first to the second series of contacts.

 Thanks to the invention, it reduces the radial size of the support and the cylinder head associated with the movable contactor.

 As a result, the two yokes can belong to the same room or be integral with each other.

 The support can be obtained by deformation of material being for example stamped sheet.

 It then comprises a fixing and centering flange instead of the deeper fixing zone of FIG.

 The rear bearing of the electric motor is advantageously the closure 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 removed.

 Thanks to the invention, it reduces the number of components of the starter, and also reduces the size including radial, and the mass thereof. The number of springs of the contactor is decreased, these acting axially in the same direction.

 The solution is simple and economical.

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 The following description illustrates the invention with reference to the accompanying 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 power 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 yoke equipping the starters of Figures 3 and 4; Figures 6 and 7 are perspective views, at different angles, of a starter equipped with a support and a single yoke respectively Figures 5 and 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 yoke for a third example of assembly of the rear bearing with the single assembly head of Figure 10; - Figure 11 is an axial sectional view of the embodiment of Figure 10; - Figure 12 is a sectional view along the line 11-11 of Figure 10; FIG. 13 is a view similar to FIG. 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 yoke; FIGS. 15 and 16 are views similar to FIG. 13 for a sixth and seventh mode of assembly of the single yoke with the rear bearing; FIG. 17 is a sectional view for an eighth method of assembling the single yoke with the rear bearing; FIG. 18 is a view from above of FIG. 17;

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FIG. 19 is a view in axial section for a ninth mode of assembly of the rear bearing with the single cylinder head; - Figures 20,21, 23 are views similar to Figure 19 for respectively a tenth, eleventh and a twelfth mode of assembly of the single yoke with the rear bearing; FIGS. 22 and 24 are views according to the arrows 22 and 24 of FIG.
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 embodiments of Figure 25; - Figure 28 is a front view of the spring washer equipping the launchers of Figures 26 and 27.

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

 In these figures, the starter comprises, as in FIG. 1, a support 4 which comprises, first fixing and centering means of the electromagnetic contactor, second fixing and centering means of the electric motor M extending parallel to the contactor and below this one. The support 4 also comprises third means for fixing and centering the starter on the casing of the engine of the motor vehicle so that the pinion 1 of the launcher meshes reliably with the starter ring C.

The support 4 is metallic and ensures the return to ground. It is economical because it is here obtained by deformation of matter.

 The electric motor M has a constitution similar to that of Figure 1 except for the assembly of the brushes and the collector blade.

 Here the brushes are carried internally by the metal cylinder head of the electric motor and the collector is of axial orientation. Four brooms are provided here. Two brushes, called negative brushes, are connected to ground via the yoke 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 are shown schematically at 27 a broom-cage assembly.

 Here the shaft 101 of the electric motor is also the shaft 100 of the launcher and therefore carries the working stopper 6.

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 The rear bearing 26 is made of plastic and, according to one characteristic, is also the rear bearing of the contactor. The yokes of the contactor 2 and the electric motor M are integral with each other. Advantageously, the two yokes belong to one and the same continuous part 25.

 The connection cable between the contactor and the positive brushes is removed as described below. The starter is thus less expensive because it has fewer components.

 The fork 13 is, as in FIG. 1, hingedly mounted at an intermediate point on the support 4. The fork 13 is hingedly mounted at its upper end directly on the movable core 20b of the contactor 2 and penetrates at its lower end. as in FIG. 1, in a groove of the driver 12 belonging to the pinion launcher 12.

 The starter of Figures 3 and 4 has a radially smaller size than that of Figure 1 while being more economical. The number of its components is reduced.

 The mass is reduced compared to that of FIG. 1, in particular because of the reduction in the electromagnetic power requirement of its contactor 2.

 The movable core 20b of the contactor is simplified because it comprises a simple rod 20b light and directly connected to the fork 13. The number of springs is also decreased and the number of rods.

 According to a characteristic of the invention, the fork 13 exerts a very weak force on the driver 12 of the launcher when the switch 2 is actuated so that the fork 13 follows the movement of the launcher when it moves axially from its position 2-inactive rest-switch-in its advanced position meshing with the starter ring C of the internal combustion engine, the pinion 1 then being in contact with the working stopper 6. During this axial displacement, the driver 12 the launcher is locked in rotation according to another feature of the invention.

 The rotational locking is disengageable when the pinion 1 abuts against the starter ring as described below.

 Means are provided for, following a start command by closing the start switch, rotating the electric motor at a slow speed before turning it to full power.

 Thanks to the rotational locking of the launcher and these means, it is possible to reduce the electromagnetic power and the radial size of the contactor, thanks to a contribution

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 of electric motor energy, while having a greater tilt range of the helical splines intervening between the launcher shaft and the coach.

 The size and weight of the launcher have no impact on the sizing of the contactor so that one can choose without stress the launcher, which can be lighter or heavier.

 Here the angle of the grooves referenced at 9 in Figure 25 is between 180 and 250.

 Of course, this angle can be increased to have inclinations of the order of 450 or more, for example 600.

 The invention offers the possibility of replacing the freewheel of FIG. 1 by a conical clutch coupling device described hereinafter in FIGS. 25 to 28.

 This device reduces the weight of the launcher, as well as the number of these components and the axial size of the launcher.

 The fork 13 becomes a follower fork.

 Because of the reduction in the radial size of the launcher, the two yokes can be secured to one another by being advantageously in one piece.

 The support 4 can be simplified.

 The means for rotating at low speed the electric motor and then at full power comprise two series of contact and at least one electrically conductive contact pad.

 Each series of contact comprises a contact connected to the positive brushes of the electric motor and the other connected respectively to a resistor, advantageously wound, and to the positive terminal of the battery via the start switch.

 The rotational locking of the launcher is achieved by cooperation of shapes, friction, using magnets or by any other means.

 In Figure 2 there is shown the electric circuit of the starter.

 It comprises a call winding 37, a holding coil 36, a resistor R, two electrically conductive contact pads 30, a first contact series 34, 33, a second series of contacts 31, 32, the electric motor M and the start switch 35 connected to the positive terminal of the battery; the electric motor M and the winding 37 being connected to ground.

 The plates 30, 3 are carried by the movable core 20d of FIG.

 Note that a Wolf-tooth system exists between the fingers of the fork 13 and the driver 12.

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 More precisely, the fingers of the fork are received in a groove of the driver 12 delimited by the flanks 121, 122.

 In the rest state the fingers of the fork 13 are supported on the smooth rear flank 122 of the receiving groove. The fingers of the fork are corrugated as visible in 22. The front flank 121 has circumferential corrugations 21 of shape complementary to those of the fork.

 Thus, according to the invention, the launcher is equipped with means 21 for locking it in rotation during its displacement from its rest position (FIG. 3) to its meshing position with the starter ring C.

 Rotational locking means 20 intervene here between the launcher and the fork 13.

 These means comprise the complementary corrugations 21,22 forming the teeth of Wolf.

 A gap exists between these teeth for the rest position (Figure 3).

 The starter of Figures 2 and 3 operates as follows.

 When the ignition key is actuated, the switch 35 of FIG. 2 closes so that the winding 20a, consisting of the call winding 37 and the holding coil 36 connected in series with the electric motor M, is energized. .

 As a result, the movable core 20b moves toward the fixed core 20d. The fork 13, hingedly mounted on the projecting front end of the core 20b, is moved and tilts around its point of articulation on the support 4.

 The teeth 21,22 are then engaged, after catching a game, so that the driver 12 is locked in rotation by cooperation of forms between the teeth 21,22.

 Then the wafer 30 comes into contact with the contacts 33,34 so that the electric motor M rotates at low speed because of the presence of the resistor R then fed electrically.

 The coach advances because, on the one hand, the presence of the helical splines, visible in FIG. 25, between the driver and the launcher shaft 100 and, on the other hand, its rotational locking for the fork.

 During this movement the fork becomes a fork following.

 The movement of the core 20b continues, the plate 3 comes into contact with the contacts 31,32 so that the electric motor M is powered at full power.

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 If before gearing with the crown C, the pinion abuts against the crown C, there is a friction between the pinion 1 and the starter ring which will blow the teeth, so that the pinion 1 moves relative to the starter ring and enters the teeth of the crown to mesh with it. The movement is at low speed due to the slow speed rotation of the electric motor.

 Because the fork 13 is a follower fork, the contact between the starter ring and the pinion is made under low pressure so that the wear is reduced.

 The contactor 2 thus becomes a small dimension piece, its specification being independent of the size of the launcher.

 Note that the fork 13 is in two parts, namely a rigid portion hingedly mounted on the movable core 20b and on the support, and a more elastic inner portion including the fingers with the corrugations so that the teeth 21,22 can jump in particular when the pinion comes into contact with the starter ring without meshing with it.

 The rotational locking means are therefore of the disengageable type, the launcher being movable in translation and fixed in rotation during the aforesaid movement, while the launcher shaft 100 is rotatable and fixed in translation, which allows the launcher to rotate. advance axially via the aforementioned helical grooves.

 The core 20b is stepped in diameter and has a larger diameter portion protruding outside the winding 20a.

 A return spring 20e acts between the winding support and a shoulder of the front portion of the core 20b. This spring replaces the return spring of Figure 1.

 The first portion of larger diameter penetrates inside the winding and is extended by a second portion of smaller diameter around which is mounted a spring 20f bearing on the change in diameter between the first and second portions of the movable core and on the first electrically conductive contact pad 30 axially fixed on an attached stop 39, 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 spring 20g bearing on the abutment 39 and the second plate 3 fixed axially on an end stop 38 attached to the rear end of the movable core. The electrically conductive pads can therefore move relative to the core 20b.

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 Thus when the plate 30 is in contact with the contacts 33, 34 the core 20b moves axially by compressing the spring 20f. It is the same for the plate 3, the spring 20g being compressed. After opening of the contact 35, the springs 20g, 20f and 20e 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 31. Similarly, the contact 32 belongs to an electrical track connected to the positive brushes of the electric motor M.

 The contact 33 also belongs to an electrical track connected to the positive brushes, the contact 34 is connected to the resistor.

 The connection terminal of the electric motor of 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 electric tracks are obtained by the overmoulding technique.

 The rear bearing has a receiving sleeve of the rear end of the shaft 101. This sleeve internally carries a bearing in which is mounted rotatably the rear end of the shaft 101. The resistance R, for example aluminum, is wound and is connected to the contact 31 and the positive terminal of the battery.

 In Figure 3 the resistor is wound around the winding 20a.

 In FIG. 4, the resistor carries the reference 200b and is wound next to the attraction winding 200a of the mobile core 20b.

 In this case, the second portion of the movable core 20b is longer without spring, while the first portion of this core is shorter.

 The third portion is surrounded by the spring 20f acting on the wafer 300 which is here unique, a third spring 200g acts between the outer periphery of the wafer and the support of the coil 200a. A single contact 32 is provided. The outer periphery of the wafer 300 is connected to an electrical track 340 in connection with the resistor 200b.

 The track 340 is located in the upper part of the contactor 2.

 An elastically deformable pad (not visible) is interposed radially between the track 340 and the plate 300.

 When the wafer 300 comes into contact with the contact 32, the wafer 300 switches around the fixed contact 32 to come into contact with the contact 231.

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 offset axially in the direction opposite to the support 4 relative to the contact 32 and replacing the contact 31 of Figure 3. After contact of the wafer 300 with the fixed contact 231, the electric motor is powered at full power and without cut-off thanks to the pad which always remains in electrical contact with track 340.

The hole formed in the wafer for the passage of the third portion of the core 20b is of course oblong.

 In a variant, the track 340 and the pad are replaced by an electric wire connected to the resistor 200b.

 Alternatively the resistor 200b is connected to a flexible auxiliary blade, for example C-shaped.

 Thus the wafer comes into contact with the auxiliary blade and the contact 32, then tilts to bear on the contact 231 without cutting because of the presence of the elastically deformable auxiliary blade.

 As a variant, helical ramp means intervene between the outer periphery of the third portion and the inner periphery of the wafer.

 The tracks 31, 231, 32 belong to the plastic rear bearing 26 which closes the cylinder head 25 forming a single cylinder head for the contactor 2 and the electric motor M.

 The tracks 31, 231, 32 are obtained by the overmolding technique.

As best seen in Figure 4, the rear bearing 26 has a sleeve internally bearing a bearing for rotatably mounting the rear end of the shaft 101.

 The rear bearing 26 is attached by clipping 29 on the yoke 25 and closes it on the side opposite the support 4. For example the yoke 25 has holes and the bearing 26 of the elastically deformable tongues each carrying a lug with a ramp.

 When we put the tongues of the bearing 26 in the cylinder head, they retract downwards thanks to the ramps protruding lugs. When the lugs arrive in front of the holes, the tabs unfold and the lugs fit into the holes. Several pins and holes are provided.

 The yoke 25 has the shape shown in FIG. 6 and has two receiving recesses respectively of the electric motor M and the contactor 2.

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

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

 In a variant, the two yokes 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 anti-corrosion surface treatment being optionally performed.

 For example, pre-coated sheets may be used. The support 4 is made by stamping and comprises a front portion 43 in the form of a rib with a sleeve 42 internally bearing a support bearing of the front end of the launcher. The nose 43 has an opening 44 for the passage of the starter ring.

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

 The simple-shaped flange replaces the more complex attachment zone of FIG. 1. Rigidizing ribs 47 are present between the flange 45 and the nose 43.

 41 hollow studs are made for fixing and centering of the support on the housing of the engine of the vehicle and thus constitute the aforementioned third fastening and centering means.

 46 is a spherical cap for creating a clearance from the front end of the movable core 20b of the contactor 2 whose number of springs is reduced compared to that of Figure 1. The fixed core 20d, 200d is also simplified since it consists of a simple plate without frustoconical portion as in Figure 1. It is the same for the mobile core 20b.

 A support washer is provided for the support of the return spring 20e.

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

 Alternatively the ogive 43 is pressed sheet metal and the flange 43 aluminum.

 The flange 25 may be stamped to form hollow fitting means for penetration of tabs from the cylinder head and formation of centering means.

 Here the yoke 25 is fixed by crimping on the support 4 as visible for example in Figures 8 to 24.

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

These solutions are economical because it avoids having recourse as in Figure 1 to an expensive screwdriver investment point of view if one wants to take into account precise screwing parameters.

In addition, this type of screw or tie assembly is cumbersome and poses additional constraints in the automation of assembly stations (distribution of long or small parts, little space for the passage of the heads of the screwdrivers). Moreover, the cycle time of a screwing operation is traditionally long.

In Figures 8 to 24 we do not find these disadvantages.

In these figures is deformed a portion of the cylinder head 25 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 traversed axially by tabs of the cylinder head whose free ends are folded in contact with the support or the bearing.

Reference 28 in Figure 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 are bent the slats 71, 72 obtained by cutting into the cylinder head 25.

The nozzles are supported on the lateral edges of the recesses thus performing an angular indexing and a stop in rotation.

In FIG. 9 the two beaks meet to form a band of material 73 which is deformed in the cavity 70.

In Figures 10 to 12 there is formed such a web of material 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 means of recesses 74, 75 facing each other. Axial and radial fixation is thus obtained without the need for casing.

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

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 In FIG. 13, there is shown a local deformation of material using a cylindrical punch showing a deformation of penetrating material, for example in the recess 270.

 As an alternative to FIG. 15, only one recess 470 is provided, the upper part of FIG. 10, that is to say the recess 74 being eliminated. In a variant of FIG. 16, the recess 470 of FIG. 15 is open and two tabs 471, 472 are formed, the reference 473 being a solid part.

 Alternatively instead of crossing a hole, the axial tabs pass through a recess 76 in the form of a notch and the precut side edges 77 'of the tabs for example of the yoke 25 are folded in contact with the side edges of the notches made in the support or the landing.

 Alternatively the side edges 77 'consist of protuberances connected to one another by a removal of material and the protuberances are crushed.

 Alternatively Figure 19 is a casing. The bearing 26 has for example bearing protrusions 79 for the lower face of the yoke 25.

 The piece 26 has a flange 78 folded radially by crimping or folding in contact with the upper face of the yoke 25.

 As a variant in FIG. 1, the flange is deformed axially in contact with the upper face of the yoke 25. As a variant of FIG. 21, it is formed with the aid of a punch a cutout in the flange with an inclined flap 278 folded in contact the upper face of the breech.

 As a variant, an inclined lug 378 (FIGS. 22 to 24) is folded in contact with the upper face of the yoke 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 freewheel. This free wheel uses a large number of components due in particular to the presence of rollers each subjected to the action of a spring.

 Alternatively (Figures 25 to 28) with the invention it is possible to use a light launcher, less bulky and reduced number of components.

 In these figures there is provided a conical clutch coupling device 7 (Figure 25) for coupling the pinion 1 to the driver 12. The conical clutch 7 comprises 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 complementary shape

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 at the first surface 8 and integral with the driver 12. The coupling device comprises, on the one hand, a hollow-shaped coupling piece having a bottom extended by an annular skirt directed axially towards one of the pinion elements 1-trainer 12 and, on the other hand, resilient means 10 axially acting on a first abutment integral with the coupling piece for action on a second abutment 4'solidaire one of the elements pinion 1-coach 12. The elastic means 10 are carried by the skirt 1b (Figure 26), 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 8.8 'surface carried internally by the skirt.

 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 the second surface 8, 8 'carried by the skirt 1b, 12b is longer axially 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 with respect 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 bearing the second abutment 4' for axially compressing implantation of elastic means with axial action 10 between this second abutment 4 'and a first abutment carried by the free end of the skirt of the coupling piece.

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

 The elastic means with axial action here have a shape of circlips and are received in a groove made at the inner periphery of the free end of the skirt.

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 These resilient means have alternately claws for engaging resiliently with the inner periphery of the free end of the skirt of the coupling piece as described in the document FR 01 08607 cited above for more details.

 In FIG. 28 the elastic means with axial action 10 comprise tongues 1 Ob that are deformable axially and extend circumferentially.

 The tabs 10b are axially arched 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 tongues are connected to the inner periphery of the washer 10a in favor of rooting zones 1 Od. The tabs 10b consist of annular sector-shaped arms extending circumferentially cantilevered on either side of a rooting zone 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 1 Ob.

 Alternatively the first stop is formed by a circlip or a snap ring mounted in a groove formed at the inner periphery of the free end of the skirt. The elastic means 10 may then consist of at least one Belleville washer or at least one corrugated washer see in a frustoconical coil spring bearing against the circlip or the ring for action on the coach (Figure 26) or on the pinion (figure 27) for controlled tightening of surfaces 8,8 '.

 In another embodiment, the first abutment 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 frustoconical.
Advantageously for evacuation of dust and separation of surfaces 8, 8 'one of the first and second friction surfaces

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8, 8' présente pour contact avec l'autre surface des rainures et l'une au moins une première et seconde surface de frottement 8, 8' est en variante constituée par une garniture de frottement.

8, 8 'for the contact with the other surface of the grooves and at least one first and second friction surface 8, 8' is alternatively constituted by a friction lining.

In Figure 26 the pinion 1 is integral with the generally bell-shaped coupling piece and the coupling piece is fixed on the pinion.

In Figure 27 the structures were inverted so that the coupling piece is secured to the launcher 2 which therefore has an outer skirt 12 b of cylindrical shape at its outer periphery.

As a result, the trainer is in an embodiment obtained by molding being for example plastic. In this case the corrugations 21 are easily obtained by molding. FIG. 25 shows the decomposition of the forces when the pinion 1 is in contact with the working abutment 6.

More precisely, the initial pressure of the elastic means between the stops produces a frictional torque between the driver and the pinion, which is always, by construction, greater than the torque required 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 work stop, 6 at the beginning of the driving 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 one another with a blockage This blockage of movement between the pinion and the driver depends in particular on the angles and diameters of the frustoconical friction surfaces.

As can be seen in FIG. 25, during the drive 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 converted by the helical spline device 9 intervening between the driver 2 and the shaft 100-creates an axial force Fa.

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 This force Fa is itself decomposed at the frustoconical friction surfaces to create a normal contact force Fc, which generates a tangential force Ft to 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.

 In order for the pinion to behave 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 grooves 9, the average radius of these splines and the coefficient of sliding between the output shaft 100 and the driver.

 The coefficient of proportionality between F 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, 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 f'c 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 mean radius of the grooves, the cone angle of the surfaces 8, 81 and the coefficient of friction thereof.

All this influences the choice of materials of the coach, the skirt and the pinion.

 When the engine of the vehicle to start the pinion 1 rotates faster than the output shaft 100 which allows the unscrewing of the launcher on the shaft 100. The previously transmitted axial force disappears and there remains only the low residual torque 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

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 relative movement between the surfaces 8,8 '. The average contact diameter between the two surfaces 8, 8 'is therefore also a friction diameter in the event of overspeed.

 Thanks to the invention and the rotational locking of the driver promotes the movement of the launcher by reducing the risk of jamming at the flutes. In connection with the previous figures we arrive at the most compact solution possible with a significant reduction in the number of components and weight. The solution is simple and economical.

 Of course, the present invention is not limited to the described embodiments. In particular, the variant support is of the type of FIG. 1 and the two yokes can be distinct. A gear reducer is alternatively interposed between the two shafts and / or a cable is provided between the motor M and the contactor as in Figure 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 alternative brushes are axially oriented as in FIG.

Claims (21)

 1. Starter for a motor vehicle having a launcher with a driver (12) and a pinion (1) adapted to move from a retracted rest position to an advanced meshing position with the starter ring (C). ) of the engine of the motor vehicle, an electric motor (M) having a shaft (101) adapted to drive a starter shaft (100), complementary helical splines (9) intervening locally between the inner periphery of the driver (12) and the outer periphery of the launcher shaft (100), an electromagnetic contactor (2) extending parallel to the electric motor (M) above it and having a movable core (20 d), a fork (13) hingedly mounted at its upper end on the movable core (20b) and at an intermediate point on a support (4) of the electric motor (M) and the contactor (2), wherein the driver (12) ) has an end receiving groove lower end of the fork (13) delimited by two sides (121, 122) and in which means are provided for rotating the electric motor at low speed in a first phase and then barely power, characterized in that launcher is provided with means ( 21) for its rotational locking during its passage from its rest position to its meshing position with the starter ring. 2. Starter according to claim 1, characterized in that said means (21) belong to rotational locking means (20) intervening between the driver (12) and the fork (13). 3. Starter according to claim 1, characterized in that said means (21) belong to rotational locking means intervening between the driver (12) and the support (4). 4. Starter according to claim 2 or 3, characterized in that the rotation locking means are cooperating forms. 5. Starter according to claim 2 or 3, characterized in that the rotation locking means are friction type. <Desc / Clms Page number 24> 6. Starter according to claim 4, characterized in that the rotational locking means are of the Wolf teeth type. 7. Starter according to claim 6, characterized in that during the power supply of the switch the fork cooperates with the flank (121), said front flank of the receiving groove of the fork (13) and in that the flank front (121) is circumferentially corrugated (21). 8. Starter according to claim 7, characterized in that the fork (13) has fingers with corrugations of complementary shape to those of the leading edge. 9. Starter according to claim 8, characterized in that the fork (13) comprises a rigid portion hingedly mounted on the movable core (20b) and a more resilient portion comprising the corrugations. 10. Starter according to one of claims 1 to 9, characterized in that the locking means in rotation are disengageable. 11. Starter according to one of claims 1 to 10 characterized in that the support (4) comprises a front portion (43) generally sheet-shaped warhead. 12. Starter according to claim 11, characterized in that the front portion is connected to a flange (45) for fixing and centering. 13. Starter according to claim 12, characterized in that the support (4) sheet metal is obtained by deformation of material, such as stamping, and in that the flange (45) is in one piece with the part before. (43). 14. Starter according to one of claims 1 to 13, characterized in that the electric motor (M) and the switch (2) each comprise a yoke integral with the other yoke. 15. Starter according to claim 14, characterized in that the two yokes belong to the same part (25). 16. Starter according to claim 14 or 15, characterized in that the or both yokes are closed on the side opposite the support by a common part (26) forming the rear bearing of the electric motor (M). 17. Starter according to claim 16, characterized in that the electrical part carries at least one electrical connecting track between a <Desc / Clms Page number 25>  contact (32) of the contactor (2) and the positive brushes that the electric motor comprises.  18. Starter according to one of claims 1 to 17, characterized in that the means for rotating the electric motor (M) at low speed comprise an electrical resistance connected to the positive terminal of the vehicle battery and a second fixed contact intended to be connected via a contact pad and to another fixed contact connected to the brushes of the electric motor. 19. A starter according to claim 18, characterized in that the contact plate (300) is allowed to switch around the second fixed contact to cooperate with another fixed contact offset axially and connected to the positive terminal of the battery for powering the engine. electric at full power. 20. Starter according to one of claims 1 to 19 characterized in that the pinion (1) of the launcher is connected to the driver by a coupling device with conical clutch. 21. Starter according to one of claims 1 to 20 taken in combination with claim 14 or 15, characterized in that the yoke or heads are reported by crimping on the support (4).