FR3042326A1 - ROTATING ELECTRICAL MACHINE WITH ROTOR COMPRISING CLAY-SHAPED POLES - Google Patents

Abstract

The invention relates to a starter (1) provided with a launcher comprising a pinion body (47) movable in translation relative to the drive shaft and a pinion mounted in translation on said pinion body (47). so that the pinion is movable in translation relative to the drive shaft between a rest position and an engaged position. The starter contactor comprises a contactor having a contact plate (33) adapted to be between a deactivated position in which said contact plate (33) is remote from the contact terminals (35a, 35b) and an activated position in which said plate contact (33) is in contact with the two contact terminals (35a, 35b) for supplying an electric motor (7). The contactor further comprises a second core (75) movable in translation in said protective case (21, 39) which interferes with the movement between the activated and deactivated positions of the contact plate (33) and a second excitation unit (73) adapted to hold the second movable core (75) so that it can block the movement of the deactivated position to the activated position of the contact plate.

Description

ROTATING ELECTRIC MACHINE WITH A ROTOR COMPRISING

POLES IN THE FORM OF CLAW

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a starter for a motor vehicle. The invention finds a particularly advantageous application in the field of restarters for a motor vehicle.

BACKGROUND TECHNOLOGY

Motor vehicles comprising a heat engine also include a starting means of this engine, called starter. The starter is connected to a power source from which an electric motor of the starter drives via a pinion a ring of the engine in a certain direction of rotation, called positive in the following description and thus causes its startup which implies that in particular said ring continues its rotation in the positive direction of rotation. During this starting, a starter of the starter allows the translation of the pinion until the pinion is supported on the ring so that the teeth of the pinion meshing the ring during the rotation of the electric motor. In the starters, the translation of the pinion of the crown involves the rotation of the pinion by the electric motor so that the pinion drives the crown in the positive direction. Furthermore, after starting the heat engine, the crown which continues to rotate in the positive direction does not cause the starter gear. Indeed, a free wheel is interposed between the pinion and a shaft of the electric motor and the crown rotates faster than the starter gear.

When stopping the heat engine, the heat engine goes through a phase well known to those skilled in the art called rocking in which its ring rotates in an opposite direction said negative opposite to said direction of positive rotation.

Compared to conventional starters described above, restarters also known as restarter according to an Anglo-Saxon term well known to those skilled in the art are also intended to restart the engine in this swing phase. This restart is performed by driving the motor ring in the positive direction of rotation. To obtain this training it is necessary that the pinion engrains the crown.

However, this meshing is complicated by the fact that the crown can rotate in the negative direction of rotation. Indeed, when the ring rotates in this direction of negative rotation the freewheel is inoperative and the starter gear is instead driven by the crown of the engine.

In order to improve this meshing it is known to use so-called "active engagement" systems according to which, to facilitate meshing of the pinion in the crown, the launcher comprising the pinion is divided into two subassemblies.

A first subassembly comprising the free wheel mounted on a launcher shaft and the pinion body, said freewheel being interposed between the pinion body and the launcher shaft.

A second subassembly comprising the pinion which is mounted in translation on said pinion body by means of an elastic thrust device adapted to push the pinion relative to the pinion body against the ring gear. This elastic thrust device comprises, for example a spring.

According to these types of launcher, when the front face of the pinion is in tooth tooth position against the crown, only the second set is translated to engage in the ring gear. Thus, when the pinion enters the ring, the mass moved for the meshing is lower than when the pinion is secured to the first subassembly. Thus, there is a greater acceleration of the pinion entering the crown which allows the pinion to enter the crown more easily than when the pinion is secured to the first subassembly. Thus the speed of translational movement of the pinion is increased and it meshes the crown more quickly. In fact, it prevents the pinion comes out of the crown when it does not penetrate enough into the crown. Indeed, when the pinion is secured to the first subassembly, if the first tooth penetrating into the crown has not penetrate sufficiently and is only in contact against a tooth surface of the crown risk due to the high speed of rotation of the crown relative to that of the pinion be ejected from the crown causing deterioration of the tooth of the pinion or the crown.

Because of the accelerated penetration of the pinion in the ring, it is thus possible to address the negative rotational speeds of the crown much larger.

This being so, due to the high negative rotational speeds, a high torque is applied during the meshing pinion so that a milling of the pinion is possible. This milling is in particular due to the relative speed of the pinion relative to that of the crown while the freewheel device is inoperative.

There is therefore a need to improve the restarters equipped with active commitment and to improve their durability including decreasing the occurrence of milling.

Furthermore, it is known to use a restart which comprises a launcher comprising two subassemblies as described above as well as a first and a second activation system. The first activation system is linked to the movement of the pinion while the second activation system is linked to the power supply of the electric motor. There is no interaction between these two activation systems that are functionally and organically independent. Such a restarter equipped with the so-called "tandem" system is described in the patent US8302497B2 published in its version issued on November 6, 2012.

It is also known to use an activation system called "split solenoid" comprising two mobile cores interacting and respectively related to the movement of the pinion and the power supply of the electric motor. But this system may have problems of durability because the wear of the pinion is very important.

These two systems "split solenoid" and "tandem" although aiming for the same objectives, are radically different as well on the point of architecture as the means set up.

There is therefore a need for a starter having optimized characteristics, costs and durability.

OBJECT OF THE INVENTION The invention aims to remedy these drawbacks effectively by proposing a starter for an internal combustion engine comprising: an electric motor; a drive shaft driven in rotation by said electric motor; a launcher comprising a first subassembly mounted on said drive shaft comprising a gear body movable in translation relative to the drive shaft between a start position and an end position and a second subassembly comprising a pinion; mounted in translation on said pinion body so that the pinion is movable in translation relative to the drive shaft between a rest position and an engaged position; a mechanical connection element, called a fork to move the pinion body between its starting position and its end position; and a contactor provided with a protective casing comprising: a first core movable in translation in said protective casing, said first movable core being connected to the movement of the pinion via said mechanical connecting element (15); a first excitation assembly adapted to move and hold said first movable core in a position in which, via the mechanical connecting element, the pinion body takes said end position, at least two contact terminals, one of the two contact terminals being adapted to be electrically connected to a power source, the other being electrically connected to the electric motor

According to a general characteristic, the contactor further comprises: a contact plate situated inside said housing able to be moved between a deactivated position in which said contact plate is moved away from the contact terminals and an activated position in which said contact plate is in contact with the two contact terminals for supplying said electric motor; a second movable core in translation in said protective case which interferes with the movement between the activated and deactivated positions of the contact plate; a second excitation unit able to hold the second mobile core so that it can block the movement of the deactivated position towards the activated position of the contact plate.

This blocks the movement of the second core and thus the displacement of the plate and thus the power supply of the electric motor.

A starter is thereby obtained which, for a negative rotational speed of the pinion with respect to the ring of the given thermal engine, greatly reduces the impact torque on engagement. We obtain a starter whose noise is reduced.

According to other characteristics taken individually or in combination: the launcher further comprises elastic means interposed between the pinion and the pinion body, said elastic means being compressed when the pinion is in the rest position and the pinion body is in start position.

Further, when the pinion is in the tooth position relative to the drive shaft, and the pinion body is between a tooth start position and an end position, the spring is dimensioned, so that during their decompression, the elastic means push the pinion to said engaged position. This results in a translation of the pinion relative to the effective pinion body with increased acceleration. the elastic means comprise a crushing spring. It is a simple, robust and affordable way of doing things. the pinion comprises a stop for coming into contact with the pinion body during the compression of the spring of said elastic means before the turns of said spring are joined. This improves the durability of the spring. - The launcher further comprises a freewheel device interposed between the drive shaft and the first subassembly comprising the body of the pinion. The freewheel device prevents the drive of the electric motor when the pinion is meshing with the crown. - The second movable core is movable in translation between a locking position and a contact position, the contact plate being adapted to move from the deactivated position to the activated position only if the second movable core is in the contact position. the second excitation unit is able to hold the second mobile core so as to block its displacement. the second mobile core is linked to the displacement of the contact plate. the second mobile core comprises a portion of reduced section on which the plate is mounted. the second mobile core is of generally cylindrical shape. - The starter further comprises a fixed core mechanically linked to said housing, the first movable core is adapted to move in translation relative to said housing between a rest position and a magnetized position in which it comes into contact with said fixed core. Thus, the first movable core reaches the magnetized position when in contact with the fixed core. the magnetized position according to which the first movable core comes into contact with said fixed core corresponds to the position of the first movable core according to which, via the mechanical connecting element, the pinion body takes said end position. - The starter further comprises a so-called control rod movably connected to said plate and in that said first movable core drives the rod so that it pushes the contact plate. The use of a control rod allows a simple movement of the contact plate. said first movable core drives the rod so that it pushes the contact plate towards the contact terminals when the first movable core moves from the rest position to the magnetized position. - The contact plate is pushed by the rod and reaches the contact position only if the second excitation unit does not maintain the second movable core, said second movable core preventing the passage of the deactivated position to the activated position of the plate contact when maintained. said second core moves in translation along an axis parallel to the axis passing through one of said two contact terminals. The plate thus comprises a first and second zone to be in contact with the first and second terminals respectively and another zone in contact with the second mobile core. This makes it possible to further improve the reliability of the solenoid split system by dissociating the terminal portion of the second core for reasons of wear. The plate can not reach the two contact terminals when the second mobile core is in the blocking position.

According to one embodiment, the wafer comprises on its edge an open hole on the U-shaped edge to insert an end of the second core. - The starter further comprises a carcass in which rotates the drive shaft, said pinion in its engaged position being located inside said carcass. - The starter further comprises a carcass in which rotates the drive shaft, said pinion in its engaged position being located outside said carcass. The proposed solution can be applied to a starter with an outgoing gear or a starter having a non-outgoing gear. The invention will be better understood on reading the description which follows and the examination of the figures which accompany it. These figures are given for illustrative but not limiting of the invention.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 is a longitudinal sectional view of the starter according to one embodiment of the present invention;

Figure 2 is a view of an idle curve of a heat engine;

FIG. 3 is a view of a curve of the torques at the engagement of the pinion; and

Figure 4 is a longitudinal sectional view of the starter according to another embodiment of the present invention.

Identical, similar or similar elements retain the same reference from one figure to another. An axial forward-to-back orientation corresponding to a left-to-right orientation according to FIG. 1 will be used.

DESCRIPTION OF EXAMPLES OF EMBODIMENT OF THE INVENTION

FIG. 1 represents a diagram of a starter 1, for example a restarter.

The starter 1 comprises a launcher 3 on which is mounted a pinion 5 intended to engage a ring gear of a motor to be started, said ring gear 13. The pinion 5 is rotated by an electric motor 7 arranged in a cylinder head 9. The electric motor 7 comprises a shaft 10. The driving of the launcher 3 is achieved via a reducing ring 11 disposed at the end of the cylinder head 9. An axis X is defined as the axis of rotation of the electric motor 7. According to an example embodiment, this axis also corresponds to the axis in which is moved the pinion by the launcher. The forward and reverse directions in the remainder of the description are defined with respect to the direction of this axis. More specifically, the front of the starter is located when one follows the X axis to the left of the starter according to Figures 1 and 4 while the rear of the starter is located when one follows the X axis towards the right of the starter according to Figures 1 and 4. The X axis is also called the axis of the electric motor.

The starter 1 also comprises a contactor 100 able to act on the launcher 3 via a fork or pivoting lever 15.

This contactor 100 is provided with a mobile core 17, a fixed core 19 and a metal tank 21 in which an excitation assembly 16 is arranged. This excitation assembly 16 comprises a call coil 25 and a holding coil 23. The call coil 25 and the holding coil 23 are mounted on an insulating annular support 27. This support 27 and the rear end of the tank 21 are centrally provided with a passage for the mobile core 17. An axis Y is defined as the axis in which the movable core 17 moves under the action of the excitation assembly 16. The axis Y is also called the axis of the contactor 100.

One end of the movable core 17 is connected to the pivoting fork or lever 15. The other end of the movable core 17 is intended to act on a front end of a control rod 29 by pushing through a central hole 31 of the fixed core 19 in which the front portion of the control rod 29 is slidably mounted.

The control rod 29 carries a contact plate 33. The contact plate 33 extends transversely with respect to the rod 29 to cooperate with two electrical terminals 35a, 35b of an electrical power circuit and establish an electrical contact therebetween. when the contact plate is in an activated position. One of the terminals 35a is intended to be connected to a positive terminal of the battery, the other terminal 35b being intended to be connected via a cable to the brushes of the electric motor 7 of positive polarity.

The two terminals 35a, 35b are fixed and carried by a cover 39 of electrically insulating material ensuring the closing of the rear of the tank 21. Thus, the cover 39 with the tank 21 form a protective casing of the contactor 100. Fixing the cover 39 is made by folding the material of the free end of the tank 21 on the cover 39. The plate 33 is adapted to translate relative to the cover 39 along the Y axis between an activated position according to which it is in position. contact with the two electrical terminals 35a, 35b and a deactivated position in which said contact plate 33 is remote from the contact terminals 35a, 35b. The two electrical terminals 35a 35b are also called contact terminals because they allow electrical contact with the contact plate 33 for the supply of the electric motor 7.

The control rod 29 further carries a compression spring 37 along the Y axis arranged between a shoulder 41 of the control rod 29 and a face of the contact plate 33. The contactor 100 also comprises a return spring 43 arranged between the cover 39 and a stop of the control rod 29.

The launcher 3 comprises a first subassembly mounted on a drive shaft 45 connected in rotation with the shaft 10 of the rotor of the electric motor 7. This first subassembly comprises a pinion body 47 movable in translation relative to the shaft 45 between a start position and an end position.

The launcher 3 also comprises a second subassembly comprising the pinion 5 mounted in translation on said pinion body 47 so that the pinion 5 is movable in translation relative to the drive shaft 45 between a rest position and a position meshed. In the engaged position the pinion 5 is moved sufficiently towards the front of the starter as indicated by the arrow 49 to come to the level of the crown 13 and thus intermesh therein.

Furthermore, the launcher 3 may comprise a freewheel device 51 interposed between the drive shaft 45 and the first subassembly comprising the body of the pinion. For example, the freewheel 51 comprises a bell 53, a roller 55 and a track (not referenced in FIG. 1). The bell 53 and the roller 55 are rotatably connected to the drive shaft 45, while the track is rotatably connected to the body 47 of the pinion.

The fork 15 comprises a first end 15a attached to the movable core 17 of the contactor 100. The connection between the fork 15 and the movable core 17 can be done by any suitable means to transmit the force between the fork 15 and the movable core 17 as per example a hitch pin.

The second end 15c of the fork 15 comes into contact with the launcher 3 to allow the axial displacement of the pinion 5. The contact is made for example at the bell of the freewheel device 51 of the launcher 3 configured to receive the end 15c of the fork 15 over the entire displacement of the launcher 3. Indeed, the point of contact between the end 15c of the fork 15 and the bell 53 of the freewheel device 51 varies during the tilting of the fork 15 causing the axial displacement of the launcher 3.

The fork 15 also comprises a central portion 15b comprising a pivot point 57 intended to come against a support element 59. The support element 59 is for example fixed on the yoke 9 of the starter 1 or on the reducing ring 11 In the absence of power supply of the contactor 100, a return spring 61 forces the mobile core 17 into a rest position in which the gap 63, that is to say the distance between the fixed part 19 of the core magnetic and the movable core 17, is maximum.

As shown in FIG. 1, the mobile core 17 is initially in a so-called rest position, in which the core 17 is remote from the fixed core 19. The plate 33 is then in a deactivated position in which the plate 33 is remote from the contact terminals 35a, 35b.

In the rest position of the movable core 17, the fork 15 is generally not in contact with the support element 59. The fork 15 is for example made of rigid plastic such as a thermoplastic (PA66 GF30).

Following a request from the engine computer (not shown), the coils 25 and 23 of the first excitation element 16 are electrically activated and then create a magnetic field. This magnetic field allows the axial displacement of the mobile core 17 towards the fixed core 19, as shown in Figure 1 by the arrow 65. In other words, the supply of the first excitation element 16 of the contactor 100 causes the moving core 17 to move in the gap 63 as indicated by the arrow 65.

Then, the rear end of the movable core 17 then comes into contact with the front end of the control rod 29 and then axially moves the rod 29 through the hole 31 towards the rear of the switch 100 until said movable core 17 bears against the fixed core 19 in a so-called magnetized position.

In the so-called magnetized position, the movable core 17 acts on the fork by means of a connecting rod 69 so that the fork 15 moves firstly to contact with the bearing element 59 which corresponds to the beginning of the engagement of the fork 15 with the support element 59. It is advantageous that until the engagement of the fork with the support element 59 and in particular during the passage of the position of rest in the magnetized position the mobile core 17 accelerates without resistance since the launcher 3 has remained motionless.

In a second step, the pivot point 57 of the fork comes into contact with the support element 59 which causes the fork 15 to tilt around the pivot point 57 and moves the launcher 3 axially along the axis X as indicated by the arrow 49. This axial displacement of the launcher 3 causes the movement of the pinion 5 to the ring gear 13 of the engine to be started.

More specifically, the end 15c of the fork acts on the bell 53 of the freewheel, which causes the pinion body to move relative to the drive shaft 45. In this way, the pinion body 47 is moves in translation relative to the drive shaft 45 from a start position to a fine position in which it comes closer to the pinion 5 to cause its movement. For this purpose for example, the connection between the pinion body and the drive shaft is a slide connection.

Elastic means 71 are interposed between the pinion 5 and the pinion body 47. The elastic means act on the pinion 5 to cause its displacement. When the pinion body 47 reaches the end position while the pinion 5 is still in the rest position, for example if the pinion 5 comes into tooth against tooth contact with the motor ring 13, then the elastic means are compressed. They therefore exert an axial force on the pinion which is displaced relative to the drive shaft 45 from its rest position to its engaged position and this as soon as a firing window is present.

In other words, the pinion can have two positions relative to the pinion body, an uncompressed position and a compressed position. In the initial state, relative to the drive shaft 45, the pinion 5 is in the rest position and the pinion body is in the start position. The pinion is then in an uncompressed position relative to the pinion body. In the intermediate state, with respect to the drive shaft, the pinion 5 is in the rest position and the pinion body is in the end position. The pinion is then in a compressed position relative to the pinion body. In the final state, relative to the drive shaft 45, the pinion 5 is in the engaged position and the pinion body is in the end position. The pinion is then in an uncompressed position relative to the pinion body. The intermediate state is a transient state that corresponds to the position of the pinion relative to the pinion body before the action of the elastic means. For example, the elastic means 71 comprise a crushing spring. This spring can be oriented along the X axis.

In the case of a ring 13 which has a positive or negative rotation speed, the pinion will be able to be inserted as soon as a firing window arises.

According to one embodiment, the connection between the pinion body 47 and the drive shaft 45 is a helical connection which allows the translation while causing a rotation of the body of the pinion 47 relative to the drive shaft 45 Thus, in the case of a zero ring gear 13, due to this rotation of the pinion body 47 caused by the helical linkage, it is possible to insert into the engaged position without the electric motor 7 being in rotation.

According to one embodiment, a tooth-tooth spring 67 is mounted on the connecting rod 69, said spring acting between the movable core 17 and said connecting rod 69. Where appropriate, when the pinion 5 comes into contact with the tooth against the tooth with the motor ring 13 this also causes the compression of the tooth-tooth spring 67. It can thus be seen that the spring teeth against teeth 67 is able to be compressed in the event of non direct penetration of the pinion 5 of the launcher into the crown of the heat engine 13 .

In order to limit the power of the first excitation element 16, the support element 59 is a flexible element, that is to say an element whose modulus of elasticity is less than the modulus of elasticity of the tooth spring -dent 67, for example a modulus of elasticity in compression less than 1000 MPa.

According to one embodiment, the flexible element 59 also has a modulus of elasticity lower than that of the fork.

Furthermore, in the case where there is a spring 67 tooth tooth, said tooth tooth spring 67 may also have a modulus of elasticity lower than that of the fork. The spring 67 tooth tooth is compressed so before deformation of the fork 15. The flexible element is for example made of elastomer or rubber or in a mixture of elastomer and rubber. Indeed, the use of a flexible support element that will compress before the compression of the tooth-tooth spring 67 can change the angle of the fork 15 and reduce the stroke of the movable core 17 during the tooth contact against tooth between the pinion 5 and the motor ring 13.

It should be noted that instead of using a support element 59 which is flexible, it is also possible to place the flexible element at the pivot point 57 of the fork 15 or an intermediate element disposed between the fork 15 and the support element 59. The support element 59 is integral with the cylinder head 9 or with an element attached to the cylinder head 9, such as, for example, a casing 87 of the starter 1 or the reducing ring 11.

According to Figure 1, the contact plate 33 is shown in its deactivated position. The displacement of the rod 29 has the effect of moving as shown in Figure 1 by an arrow 85, the plate 33 to a position, called pre-engagement. In this position the plate 33 is in contact with the terminal 35b but is kept at a distance from the other terminal 35a. In this pre-engagement position, the pinion 5 via the launcher 3 and the fork 15 can be in the engaged position. However, the electric motor 7 is not running yet. Indeed, the rotation of the motor is consecutive to its supply that occurs when the plate 33 is in contact with the two contact terminals 35a and 35b.

In other words, to allow contact between the two contact terminals 35a and 35b via the contact plate 33 and thus allow the motor to start, it is not only the mobile core 17, the control rod 29 and the plate 33 which intervene.

According to the invention a micro-solenoid 72 is integrated in one of the terminals, for example the terminal 35a. According to another embodiment, the micro-solenoid 72 is connected in parallel with the terminal 35b, between a wall of the cover and the contact zone of the terminal 35a. In particular, the contact zone is located between the terminal 35b and the second core of the micro-solenoide in the same plane. In addition, the terminal 35a comprises a remote portion to be in contact with the wafer and a cylindrical portion to be connected to the electric motor of the starter. This micro-solenoid 72 comprises a second excitation unit for example, a coil 73 fixed relative to the cover 39 and a second core 75 movable in translation relative to the cover 39. The core 75 is positioned in the opening delimited by the coil 73. The core 75 is movable between a locking position in which one end of the core 75 protrudes from the terminal 35a so as to prevent electrical contact between the plate 33 and the terminal 35a; and a contact position in which the core 75 allows electrical contact between the plate 33 and the terminal 35a. An axis Z is defined as the axis in which the movable core 75 moves under the action of the excitation assembly 73. In other words, the second mobile core 75 is movable relative to the cover 39 in translation. between a locking position and a contact position, the contact plate 33 being adapted to move from the deactivated position to the activated position only if the second movable core 75 is in the contact position.

The contact plate 33 is attached to the core 75 so that when moving the contact plate 33 from the activated position to the deactivated position in which the plate 33 is moved away from the contact terminals 35a, 35b, the contact plate 33 drives the core 75 to its blocking position. For this purpose, as is clearly visible in FIG. 1, the plate 33 is mounted via an opening on a portion 77 of reduced section of the core 75. This portion is delimited axially by a head 78 of the core 75 located on the core side. fixed 19 and an intermediate shoulder 79 located between the two end heads 78, 81 of the core 75. The plate 33 has an opening having a diameter substantially equal to the diameter of the portion of reduced section 77, but less than the diameter of the end head 78 and the intermediate shoulder 79. This shoulder 79 is defined by a diameter difference of the core 75.

The manufacture may for example be made by inserting the portion 79 still free of the head 78 in the opening of the contact plate 33, then the end of the portion 79 is deformed by crushing forming the head 78.

According to another embodiment, the head 78 and the opening of the plate are formed so as to be mounted by bayonet. In other words, the head 78 is for example rectangular and the opening is also rectangular so as to be able to mount the head then the portion 79 of the core 75 in the plate through the opening and then turned at 90 ° the core 75 by 90 ° to the plate so that the rectangle-shaped head can not pass through the rectangle-shaped opening.

According to another embodiment of manufacture, the head 78 is a washer attached to the portion 79, for example by tight fitting, welding bonding.

According to another embodiment, the wafer comprises on its edge an open hole on the U-shaped wafer to insert the reduced section 77 of the second core located. Thus the editing is simpler.

When the micro-solenoid 72 is not powered. The movable core 75 is held in the blocking position by the contact plate 33 which pulls on the head 78 of the core 75 while the opposite head 81 bears against one end of the coil 73.

The contactor 100 further comprises a magnet 83 positioned at the bottom of the cover 39 to ensure retention of the core 75 of the micro-solenoid 72 when the latter is in the contact position, in order to minimize the risk of rebounds of the core 75. The force of the return spring 43 is strong enough to detach the core 75 from the magnet 83 when powering down the call coils and holding the element 16.

When the contact plate 33 pushes the core 75 towards its contact position and the coil of the solenoid microphone 72 is turned off the core 75 moves from its blocking position to its contact position. The core 75 can finish its course by being attracted by the magnet 83 or by means of the plate that pushes it or a compressed elastic element in the initial position of the core.

To maintain the plate at a distance from the other terminal 35a, the micro-solenoid 72 has been pre-fed, so that the core 75 can withstand the force applied by the plate 33 resting against the intermediate shoulder 79. , thanks to the second excitation unit and despite the force applied by the plate, the core 75 is held in the locking position and its displacement to its contact position is prevented. The return spring 43 and the crushing spring 37 are otherwise compressed.

When a start request is requested by the engine computer, the supply of the micro-solenoid 72 is cut off, so that the core 75 no longer resists the force applied by the plate 33 and then goes into the contact position. The contact plate 33 can switch to the activated position and then makes contact with the two terminals 35a, 35b, which provides power to the electric motor of the starter.

Note that there is preferably a clearance between the head 78 of the core 75 turned towards the fixed core 19 and a face of the plate 33 when the core 75 is in the contact position. This prevents the head 78 of the core comes into contact with the plate 33 when the core 75 is in the contact position.

There is also a clearance between the intermediate shoulder 79 of the core 75 of the micro-solenoid 72 and a face of the contact plate 33 facing said intermediate shoulder 79. This makes it possible to avoid any rebound of the core 75 when this last pass from the blocking position to the contact position causes a shock between the plate 33 and the intermediate shoulder 79.

When the coils 25 and 23 are de-energized, the mobile core 17 is no longer attracted towards the fixed core 19, which causes the mobile core 17 to return to the so-called rest position via the action of the return spring. 61 positioned between the tank 21 and an end of the movable core 17. The axial compression spring 37 and the return spring 43 are decompressed by pushing on the control rod 29, which has the effect of moving the contact plate away 33 of the terminals 35a, 35b. The core 75 then separates from the magnet 83 and is driven by the contact plate 33 to its blocking position. The displacement of the core 75 is limited by the head 81 which abuts against the coil 73. The contact plate 33 then moves from the activated position to the deactivated position.

Figure 2 shows the idle curve of a heat engine. The curve 210 is that of the rotational speed of the crown of the engine as a function of time. This curve is represented in an orthonormal coordinate system comprising an abscissa axis 202 and an ordinate axis 201. The unit of the axis 202 is the seconds, while that of the axis 201 is expressed in revolutions per minute. Note that this idle curve can be divided into several sequences represented by the terminals 205, 206 and 207 on the axis 202.

Before terminal 205, the sequence is that of a motor idle. This sequence is characterized by an idle speed represented by the terminal 208 on the axis 201 around which the speed of rotation of the motor ring oscillates.

Between the terminal 205 and the terminal 206, this oscillation continues, but at the same time the average rotational speed falls sharply. This is a slowdown sequence of the engine.

Between terminal 206 and terminal 207, the swing sequence is reached. During this sequence the rotational speed of the motor becomes negative. Until now the speed of rotation of the motor was positive, it corresponded to a rotation of the ring in the positive direction mentioned above. A negative rotation speed corresponds to a rotation of the motor in the negative direction opposite to the positive direction. It can thus be seen that during this swing sequence the speed of rotation of the heat engine ring changes sign several times, it becomes negative then becomes positive again and finally negative.

During the first passage in negative speed of the sway sequence, we see that the curve 210 passes through two thresholds represented by the lines 203 and 204. The threshold 203 corresponds to the most negative speed addressable with a monobloc gear while the threshold 204 corresponds to the most negative speed addressable with a sprocket in two parts also called "active engagement" according to an Anglo-Saxon term well known to those skilled in the art. For example, the threshold 203 corresponds to -100 rpm, while the threshold 204 corresponds to -200 rpm. From terminal 207, the motor is stopped and the rotational speed of the engine is zero.

In the magnetized position of the movable core 17, it is possible in particular, in the case of a zero, positive or negative rotation speed which corresponds to the sequences 205, 206 or 207 described in FIG. 2, to engrain the ring gear 13 without the motor electrical 7 is operated using the device illustrated in Figure 1.

FIG. 3 illustrates several points representing the shock torque at the engagement of the pinion 5 in the ring 13 as a function of the negative rotation speed of the ring gear. The points are represented in an orthonormal coordinate system, each point corresponding to an engagement occurrence. The orthonormal coordinate system comprises an abscissa axis 402 expressed in revolutions per minute and an ordinate axis 401 expressed in N.meters. 5 groups of points 403, 404, 405, 406 and 407 are represented therein. The 3 groups 403, 404 and 405 correspond to couples of shocks with a conventional starter or a restarter while the groups 406 and 407 correspond to pairs of shocks with restarter according to the invention illustrated in FIG.

As can be seen in FIG. 3, in group 405 the engagement occurrences all occur at the negative rotational speed of the crown of -75 rpm. Those in the 404 group operate at the negative rotational speed of the crown of -100 rpm. Finally those of the 403 group are held at the negative rotation speed of -150 rpm. As can be seen in groups 403, 404 and 405, the greater the negative rotational speed (in absolute value) the greater the average value of engagement torque at engagement increases. This becomes critical with the occurrences for which the shock torque at engagement becomes too high, which strongly impacts the durability of the starter, indeed the shock propagates from the pinion to the electric motor, which can deteriorate the different parts between these two elements, in particular the free wheel and the gearbox.

Furthermore, given the threshold 203, it appears that the groups 404 and 405 are addressable with a one-piece gear or with a two-part gear. On the other hand, the 403 group with a speed of -150 rpm can only be reached with a two-part gear. Note that the two-part gear does not reduce the shock torque on engagement, on the contrary, it increases even as the negative speeds addressable are more important.

The groups 406 and 407 correspond to those obtained with a starter according to the invention provided with a contactor 100. It appears for the same negative speed of rotation the shock torque at the engagement of the pinion 5 in the ring 13 is greatly reduced as can be seen when comparing groups 404 and 407.

It appears for the same shock torque when the pinion 5 is engaged in the maximum average ring gear 13, the addressable negative rotation speed can be greatly increased (doubled) as can be seen when comparing the groups 404 and 406. It is even possible to obtain a shock torque when the pinion 5 is engaged in the smaller ring 13 with a higher negative rotational speed (in absolute value), as can be seen by comparing the groups 403 and 406. is possible from the principle of the switch 100 which allows to decouple the meshing of the ring 13 of the actuation of the electric motor 7 in combination with the active engagement as shown in Figure 1.

FIG. 4 illustrates a starter according to one embodiment of the invention. Each of the references of FIG. 1 are taken again and correspond to the same element in FIG. 4. The starter of FIG. 4 differs from that of FIG. 1 from the positioning of the carcass 87 with respect to the pinion 5. More specifically in Figure 1, the pinion is in its engaged position located inside the carcass 87 in which rotates the drive shaft. On the contrary, in Figure 4 the pinion is in its engaged position located outside of the carcass 87 in which rotates the drive shaft.

Claims (18)

1. Starter (1) for an internal combustion engine, which starter comprises: an electric motor (7); a drive shaft (45) driven in rotation by said electric motor (7); a launcher comprising a first subassembly mounted on said drive shaft (45) comprising a pinion body (47) movable in translation relative to the drive shaft between a start position and an end position and a second subassembly comprising a pinion mounted in translation on said pinion body (47) so that the pinion is movable in translation relative to the drive shaft between a rest position and an engaged position; a mechanical connection element, called fork (15) for moving the pinion body between its starting position and its end position; and a contactor (100) provided with a protective casing (21, 39) comprising: a first mobile core (17) in translation in said protective casing (21, 39), said first movable core being connected to the displacement of the pinion (5) via said mechanical connecting element (15), a first excitation assembly (16) able to move and hold said first movable core (17) in a position in which via the pinion body takes the end position of the mechanical connection element, at least two contact terminals (35a, 35b), one of the two contact terminals being able to be electrically connected to a power source, another being electrically connected to the electric motor (7), characterized in that the contactor (100) further comprises: a contact plate (33) located inside said housing (21, 39) able to be moved between a deactivated position in which said plate of c ontact (33) is remote from the contact terminals (35a, 35b) and an activated position in which said contact plate (33) is in contact with the two contact terminals (35a, 35b) for supplying said electric motor (7) a second core (75) movable in translation in said protective case (21, 39) which interferes with the movement between the activated and deactivated positions of the contact plate (33); a second excitation unit (73) capable of holding the second movable core (75) so that it can block the movement of the deactivated position towards the activated position of the contact plate. 2. Starter according to claim 1, characterized in that the launcher further comprises resilient means interposed between the pinion and the pinion body, said elastic means being compressed when the pinion is in the rest position and the body of the pinion is in end position, so that during their decompression elastic means push the pinion to said engaged position. 3. Starter according to claim 2, characterized in that the elastic means comprise a crushing spring. 4. Starter according to claim 2, characterized in that the pinion comprises a stop for coming into contact with the pinion body during compression of the spring of said elastic means before the turns of said spring are contiguous. 5. Starter according to any one of the preceding claims, characterized in that the launcher further comprises a freewheel device (51) interposed between the drive shaft (45) and the first subassembly comprising the body of the pinion. . 6. Starter according to any one of the preceding claims, characterized in that the second movable core (75) is movable in translation between a locking position and a contact position, the contact plate (33) being adapted to move from the deactivated position to the activated position only if the second movable core (75) is in the contact position. 7. Starter according to any one of the preceding claims, characterized in that the second excitation unit (73) is adapted to maintain the second movable core (75) so as to block its displacement. 8. Starter according to any one of the preceding claims, characterized in that the second movable core (75) is connected to the displacement of the contact plate (33). 9. Starter according to any one of the preceding claims, characterized in that the second movable core (75) comprises a portion of reduced section on which is mounted the plate (33). 10. Starter according to any one of the preceding claims, characterized in that the second movable core (75) is of generally cylindrical shape. 11. Starter according to any one of the preceding claims, characterized in that it further comprises a fixed core (19) mechanically connected to said housing (21, 39), the first movable core (17) is able to move in translation with respect to said housing between a rest position and a magnetized position in which it comes into contact with said fixed core (19). 12. Starter according to the preceding claim, characterized in that the magnetized position in which the first movable core (17) comes into contact with said fixed core corresponds to the position of the first movable core (17) according to which by means of the mechanical connecting element (15), the pinion body takes said end position. 13. Starter according to any one of the preceding claims, characterized in that it further comprises a rod (29) said control connected in displacement to said plate (33) and in that said first movable core drives the rod ( 29) so that it pushes the contact plate (33). 14. Starter according to claim 13 when dependent on claim 12, characterized in that said first movable core (17) drives the rod (29) so that it pushes the contact plate (33) towards the contact terminals (35a, 35b) when the first movable core (17) moves from the home position to the magnetized position. 15. Starter according to claim 13 or 14, characterized in that the contact plate is pushed by the rod (29) and reaches the contact position only if the second excitation unit (73) does not maintain the second movable core (75), said second movable core (75) preventing passage from the deactivated position to the activated position of the contact plate (33) when held. 16. Starter according to any one of the preceding claims, characterized in that said second core (75) moves in translation along an axis passing through one of said two contact terminals (35a, 35b). 17. Starter according to any one of the preceding claims, characterized in that it further comprises a carcass (87) in which rotates the drive shaft, said pinion in its engaged position being located inside. of said carcass. 18. Starter according to any one of the preceding claims, characterized in that it further comprises a carcass (87) in which rotates the drive shaft, said pinion in its engaged position being located outside of said carcass.