EP2160510A1

EP2160510A1 - Starter device for a combustion engine, particularly of a motor vehicle

Info

Publication number: EP2160510A1
Application number: EP08806008A
Authority: EP
Inventors: Julien Quincerot; Karine Stofleth; Jean-Marc Dubus; Arnaud De Vries; Michaël Chemin
Original assignee: Valeo Equipements Electriques Moteur SAS
Current assignee: Valeo Equipements Electriques Moteur SAS
Priority date: 2007-06-29
Filing date: 2008-06-16
Publication date: 2010-03-10
Also published as: JP2010531953A; US8770163B2; FR2918127A1; WO2009004240A1; US20100257951A1; FR2918127B1

Abstract

The invention relates to a starter device (10) for a combustion engine (1), particularly of a motor vehicle, comprising: - a rotary electrical machine (11) comprising a drive member (12), - a belt (13) collaborating with the drive member of the rotary electrical machine and with the combustion engine in order that the latter can be started using the belt rotationally driven by the electrical machine in a first direction (A), - a tensioner (15) pressing against a length (16) of the belt that runs between the electrical machine and the combustion engine, it being possible, as the rotary electrical machine rotates in a second direction (B) the opposite of the first, for the tensioner to be brought from a stopped position into a position for beginning to start the combustion engine, the movement from the stopped position to the position for beginning to start being accompanied by a lengthening of said length of belt and/or by an increase in the tension in this length of belt.

Description

Starting device for a heat engine, particularly a motor vehicle

The invention relates to a starting device for a heat engine, particularly a motor vehicle.

Typically, the designation "Stop & Start" refers to a technology allowing the automatic stopping and restarting of a motor vehicle engine in situations in which the vehicle is stationary, engine running, for example at a traffic light. red, in a traffic jam ...

It is known to use, to restart the engine, a reversible alternator ensuring, in addition to the alternator function providing electrical energy to cover the needs of the vehicle, the starting function of the engine.

This reversible alternator is, in some cases, located at a facade of the engine, facade on which extends a crankshaft pulley mounted on the engine. A belt is provided, on the one hand, to drive the alternator and, where appropriate one or more accessories, when the heat engine is in operation, and secondly, to transmit a torque delivered by the reversible alternator to the crankshaft pulley during the restart phases. In this type of technology, it is important to ensure good slip control between the belt and pulleys on the front of the engine, in particular to allow correct transmission of the alternator torque to the crankshaft pulley.

Indeed a slip of the belt on some pulleys can make it impossible to restart the engine. The present invention aims to improve the conditions for starting the heat engine, in particular by controlling the slippage between the belt and some pulleys on the front of the engine during a restart.

The invention thus relates to a device for starting a heat engine, especially a motor vehicle, comprising:

a rotary electric machine comprising a drive member,

a transmission member, in particular a belt or a chain, cooperating with the driving member of the rotating electrical machine and with the heat engine to cause it to be started using the driven transmission member; rotating in a first direction (A) by the electric machine,

- A control system for controlling the rotation of the electric machine in the first direction (A) to start the engine and, in a pre-start phase, in a second direction opposite to the first

According to one aspect of the invention, the starting device comprises:

a rotary electric machine comprising a drive member,

a transmission member, in particular a belt, cooperating with the drive member of the rotating electrical machine and with the heat engine to cause the latter to start using the belt rotated in a first direction; by the electric machine,

- A tensioner resting on a strand of the belt extending between the electric machine and the heat engine, the tensioner can be brought, during a rotation of the rotating electrical machine in a second direction opposite to the first, from a position stopping at a starting position of starting of the heat engine, the transition from the stop position to the starting start position accompanied by an elongation of said strand and / or an increase in the voltage in this strand. Thanks to the invention, because of an elongation of said strand and / or an increase in the tension in the belt strand which serves to transmit the torque of the electric machine to the engine (said strand being a hard strand when starting the engine), the slipping of the belt is reduced, which allows a reliable restart of the engine.

This way of causing an elongation of said strand and / or an increase of the tension in the belt strand by using the tensioner and by previously rotating the electric machine, at a certain angle, in a direction opposite to the direction for starting, is particularly simple, and in particular does not require additional equipment.

Preferably, the tensioner is arranged so that, once the engine has started, said strand of the belt takes a shorter length than in the starting position start.

Advantageously, the device comprises a roller in contact with said strand of the belt, this roller being arranged to be moved when the tensioner is brought from the stop position to the starting start position, in particular with a view to extending said strand of belt and / or increase the tension in this strand.

In an exemplary implementation of the invention, the tensioner is arranged so that the length of said strand gradually decreases between the start of start and the actual start of the engine.

Advantageously, the tensioner is arranged so as to be able to relax during the transition from the stop position to the starting start position, and to retract between the start of start and the actual start of the engine.

If necessary, the tensioner comprises a hydraulic damping member, having a differential hydraulic leak, the hydraulic leak being faster when the tensioner relaxes than when it retracts.

The invention can thus make it possible, by virtue of the prior rotation of the electric machine in the opposite direction, to increase the stroking stroke of the tensioner. This has the effect, during the actual starting phase immediately following the rotation in the opposite direction, because of the increase in the return stroke of the tensioner and a greater resistance of this tensioner, to ensure a sufficient time for starting the heat engine, before the hard strand finds a length exposing the belt at risk of slippage.

In another embodiment of the invention, the tensioner, for example of the mechanical type, is arranged to remain locked in the starting start position at least until the engine has actually started.

In other words, the length of the hard strand is constant during the start-up phase.

The risk of slipping of the belt is reduced by an increase in tension in the hard strand.

For example, the tensioner comprises a spring, in particular a spring spiral, helical or flat.

The device may, if desired, comprise a locking element of the tensioner in the starting start position, this element comprising at least: a clutch, an electromagnet and a ratchet wheel, an electric motor with a screw without end...

According to one aspect of the invention, the control system is arranged to control a reverse rotation of the electric machine, in the second direction, to move the crankshaft pulley of the engine in a position limiting the resistive torque of the engine during the passage the first compression.

Preferably, the device comprises a control system of the rotating electrical machine arranged to selectively control the rotation of the electric machine in the first and second directions. The control system comprises for example at least one switch arranged to selectively connect position sensors of a rotor of the electric machine to arm controls of an inverter.

The control system may comprise, if desired, at least one microcontroller or an ASIC. The rotary electrical machine is for example a synchronous machine, in particular polyphase. If necessary, the electric machine is of the reversible type, being in particular an alternator-starter.

Alternatively, the rotating electrical machine is a belt starter.

The invention also relates to a rotating electrical machine, in particular an alternator-starter for a motor vehicle, arranged to start a heat engine, the electric machine being associated with a control system for controlling the rotation of the electric machine in a first direction. to start the engine and, in a pre-start phase, in a second direction opposite to the first. The invention also relates to a method for starting a heat engine, particularly a motor vehicle, using a rotary electric machine, which is arranged to start the heat engine via the rotation in a first direction of a transmission member, particularly a belt, connecting the electric machine to the heat engine, a tensioner being provided to press a strand of the transmission member extending between the electric machine and the heat engine, the method comprising the following steps :

- Pre-rotate the belt in a second direction opposite to the first one, the tensioner then moving from a stop position to a starting start position,

- then turn the belt in the first direction to start the engine.

The device according to the invention may comprise one or more tensioners. The invention will be better understood on reading the following detailed description, non-limiting examples of implementation of the invention, and on examining the appended drawing, in which:

FIG. 1 represents, schematically and partially, a facade of a motor vehicle engine and a starting device according to the invention, FIGS. 2A to 2E illustrate different phases of operation of the starting device of FIG. 1, FIGS. 3A to 3D correspond to curves representing different physical characteristics for the operating phases of FIGS. 2A to 2E,

FIGS. 4 and 5 show, schematically and partially, two examples of the control system of the device of FIG. 1, and

- Figure 6 shows, schematically and partially, a starting device according to another embodiment of the invention.

FIG. 1 shows a front facade of a motor vehicle engine 1, on which a crankshaft pulley 2 can be rotated by the engine when it is in operation.

A starting device 10 for starting the heat engine 1 is mounted at the front of the engine.

This device 10 comprises: an alternator / starter 11 comprising a drive member formed, in the example in question, by a pulley 12,

a belt 13 cooperating with the pulley 12 of the rotary electric machine 11 and with the heat engine 1 to cause the latter to start using the belt 13 rotated in a first direction A by the electric machine 11 ,

- A tensioner 15, of hydraulic type, bearing on a strand 16 of the belt 13 extending between the electric machine 11 and the heat engine 1, the tensioner 15 can be brought, during a rotation of the rotating electrical machine in a second direction B opposite to the first direction A, from a stop position to a starting start position of the heat engine 1, the transition from the stop position to the starting start position accompanied by a elongation of said strand 16 and / or an increase of the tension in this strand 16.

In the example considered, the tensioner 15 presses on the belt strand 16 via a roller 18 rotatably mounted on a support 19, which is fixed on the one hand pivotally on a fixed point 20 of the facade, and on the other hand also part so pivoting at one end of a hydraulic damping member 21 of the tensioner 15.

The hydraulic member 21 is surrounded by a spring 22, in particular helical, and can relax or retract depending on the force experienced by the tensioner 15. This hydraulic member 21 has a differential hydraulic leak, the hydraulic leak is faster when the hydraulic member 21 relaxes only when it retracts, in the damping phase.

When the hydraulic member 21 relaxes or retracts, the roller 18 moves and the length of the belt strand 16 varies. In normal operation, the tensioner 15 makes it possible to control the average tension, in particular by keeping it substantially constant, within the strand 16.

For example, the length of the strand 16 decreases gradually between the starting start position and the actual start of the engine. The belt 13 also serves, via a belt strand, to drive an accessory pulley 26, associated for example with an air conditioner compressor, not shown.

The rotation of the alternator-starter 11 is controlled by a control system 28 shown very schematically in FIG. 2A, arranged to selectively control the rotation of the alternator-starter 11 according to the first directions A and the second direction B.

As illustrated in FIG. 4, the control system 28 may comprise, for example, a position detector 30 formed by three Hall effect sensors 31 to 33 making it possible to detect the position of a rotor of the alternator-starter 11. The sensors 31 to 33 are for example separated from each other by an electrical angle of 120 °.

The sensor 31, respectively 32 and 33, is associated with an arm U, respectively V and W, of an inverter of the electric machine 11.

The control system 28 further comprises three switches 34 to 36 each associated with a sensor 31 to 33. The switch 34 for example is arranged to selectively connect the sensor 31 to the arms U or V of the inverter.

In order to turn the electrical machine 11 along the direction B prior to the actual starting of the heat engine 1, the control system 28 acts on the switches 34 to 36 so that the sensor 31 is assigned to the arm W, the sensor 32 on the arm U and the sensor 33 on the arm

V (see switching switches shown in dotted lines).

It is thus possible to perform a reverse rotation of the electric machine 11, along the direction B, with an optimal advance. In a variant, as illustrated in FIG. 5, the control system 28 comprises a microcontroller or an ASIC (Application Specified Integrated Circuit) 38 interposed between the sensors 31 to 33 and the inverter 39.

Of course, the number of phases of the electric machine 11 may be greater than three, being for example equal to seven for a heptaphase machine. Reference will now be made with reference to FIGS. 2A to 2E and 3A to 3D, different phases of operation of the starting device 10.

In step 2A, the tensioner 15 is in the off position and has a length L1.

In step 2B, the alternator-starter 11 is driven by the control system 28 so as to perform a prior rotation in the direction of the arrow B.

This reverse rotation has the effect of allowing the belt strand 16 to lengthen and the tensioner 15 to relax. The tensioner 15 then has a length L2 greater than L1. Strand 16 is a 'soft' strand in this step 2B.

In step 2C, immediately after step 2B, the alternator-starter 11 is controlled to rotate along the arrow A, in order to transmit a sufficient torque (via the strand 16 which is then a hard strand) to the engine 1 to start it.

With the prior rotation in the opposite direction along the arrow B, it is possible to increase the travel, relaxation, of the tensioner 15. This has the effect, during the actual start phase, because of the increase of the return stroke of the tensioner 15 and a greater resistance of this tensioner

15, to ensure sufficient time for starting the heat engine 1. During this step 2C, the length L3 of the tensioner 15 decreases from L2 to L1.

In step 2D, the engine 1 has started.

In step 2E, the alternator-starter 11 driven by the heat engine 1 operates as an alternator, ensuring electric power generation. During this alternator operation, the belt strand 16 has a length L5 greater than L1.

The graphs of FIGS. 3A to 3D respectively illustrate the evolution of the torque of the electric machine 11, the speed of rotation of the electric machine 11, the mechanical tension in the belt strand 16 and the hydraulic stroke connected to the hydraulic member 21 of the tensioner 15, for the succession of phases 2A to 2E.

FIG. 6 shows a starting device 40 according to another embodiment of the invention.

This device 40, like the device 10 previously described, comprises a belt 13 arranged to transmit a torque from an electric machine 11 equipped with a pulley 12, to a heat engine 1 on its crankshaft pulley 2.

The belt 13 drives accessory pulleys 42.

The device 40 comprises a tensioner 44 provided with a roller 18 in contact with the strand 16 of the belt 13.

The tensioner 44 can be brought, during a reverse rotation of the rotating electrical machine along arrow B, from a stop position (position a in FIG. 6) to a start-up position of the engine (position b). in Figure 6), the transition from the stop position to the starting start position accompanied by an elongation of said strand and an increase in the mechanical tension in this strand.

The tensioner 44, of the mechanical type, is arranged to remain locked in the starting start position until the engine has actually started. The tensioner 40 comprises, in the example considered, a spring 46, for example spiral type. The device 40 may comprise a locking element of the tensioner 44 in the starting start position, this element comprising at least: a clutch, an electromagnet and a ratchet wheel, an electric motor with a worm ... Of course, the invention is not limited to the implementation examples which have just been described.

For example, the electric machine 11 may be a machine other than an alternator-starter (claw machine).

This machine 11 may for example be a synchronous machine with magnets, double excited wound rotor, an asynchronous machine, variable reluctance, or a DC machine.

Claims

claims

1. Starting device (10) for a motor vehicle engine (1), comprising:

a rotating electrical machine (11) comprising a drive member (12), a transmission member comprising a belt (13) or a chain, cooperating with the drive member of the rotating electrical machine and with the thermal engine for causing it to start using the transmission member rotated in a first direction (A) by the electric machine; - a control system for controlling the rotation of the electric machine according to the first direction (A) to start the engine and, in a phase prior to a starting phase to start the engine, in a second direction opposite the first, characterized in that it comprises a tensioner (15) in support on a strand (16) of the transmission member extending between the electric machine and the heat engine, the tensioner being able to be brought, during a rotation of the rotating electrical machine according to the second direction (B) op placed at the first, from a stop position to a starting position of the starting engine, the transition from the stop position to the starting start position accompanied by an elongation of said strand and / or an increase in the tension in this strand.

2. Device according to the preceding claim, characterized in that the tensioner (15) is arranged so that, once the engine has started, said strand (16) of the transmission member takes a longer length. weak than in the starting start position.

3. Device according to one of the preceding claims, characterized in that it comprises a roller (18) in contact with said strand of the transmission member, and in that the roller is arranged to be moved when the tensioner is brought from the stop position to the starting start position.

4. Device according to any one of the preceding claims, characterized in that the tensioner (15) is arranged in such a way that the length of said strand gradually decreases between the start of start and the actual start of the engine.

5. Device according to the preceding claim, characterized in that the tensioner (15) is arranged to be able to relax during the transition from the stop position to the starting position start, and retract between the beginning of start and effective start of the engine.

6. Device according to the preceding claim, characterized in that the tensioner comprises a hydraulic damping member (21) having a differential hydraulic leak, the hydraulic leak is faster when the tensioner relaxes when it retracts. .

7. Device according to any one of claims 1 to 3, characterized in that the tensioner (44) is arranged to remain locked in the starting start position at least until the engine has actually started.

8. Device according to the preceding claim, characterized in that the tensioner (44) is of the mechanical type.

9. Device according to the preceding claim, characterized in that the tensioner (44) comprises a spring (46), in particular a spiral type spring, helical or flat.

10. Device according to any one of claims 7 to 9, characterized in that it comprises a locking element of the tensioner in the starting start position, this element comprising at least: a clutch, an electromagnet and a wheel Rochet, an electric motor with a worm.

11. Device according to any one of the preceding claims, characterized in that the control system (28) is arranged to control a reverse rotation of the electric machine, in the second direction, to move the crankshaft pulley of the engine in a position limiting the resistive torque of the engine during the passage of the first compression.

12. Device according to any one of the preceding claims, characterized in that the control system (28) of the rotating electrical machine (11) is arranged to selectively control the rotation of the electric machine in the first and second direction.

13. Device according to the preceding claim, characterized in that the control system comprises at least one switch (34; 35; 36) arranged for selectively connecting position sensors (31; 32; 33) of a rotor of the electric machine with arm controls (U; V; W) of an inverter.

14. Device according to claim 11, characterized in that the control system comprises at least one microcontroller (38) or an ASIC.

15. Device according to any one of the preceding claims, characterized in that the rotating electrical machine (11) is a synchronous machine.

16. Device according to any one of the preceding claims, characterized in that the electric machine (11) is an alternator-starter.

17. A device for starting a thermal engine, a motor vehicle, comprising: a rotary electric machine comprising a driving member;

a transmission member, comprising a belt, cooperating with the drive member of the rotating electrical machine and with the heat engine to cause the latter to start using the transmission member driven in rotation according to a first sense by the electric machine,

a tensioner resting on a strand of the transmission member extending between the electric machine and the heat engine, the tensioner being able to be brought, during a rotation of the rotating electrical machine in a second direction opposite to the first, from a stopping position to a start-up position of the engine, the transition from the stopping position to the starting start position accompanied by an elongation of said strand and / or an increase in the tension in this strand

18. A rotating electric machine (11), forming an alternator-starter for a motor vehicle, arranged to start a heat engine, the electric machine being associated with a control system for controlling the rotation of the electric machine in a first direction to start the engine. thermal engine and, in a phase prior to a starting phase for starting the heat engine, in a second direction opposite to the first, characterized in that the steering system comprises at least one switch (34; 35; 36) arranged to selectively connect position sensors (31; 32; 33) of a rotor of the electric machine to arm controls (U; V; W) of an inverter.

19. A method for starting a motor vehicle engine, using a rotary electric machine (11), which is arranged to start the engine by rotating in a first direction of a transmission member, comprising a belt, connecting the electric machine to the heat engine, a tensioner (15) being provided to press a strand of the transmission member extending between the electric machine and the heat engine, the method comprising the following steps:

- Beforehand rotate the transmission member in a second direction opposite to the first, the tensioner then moving from a stop position to a starting start position, - then rotate the transmission member in the first direction to start the engine.