FR3083572A1 - CRANKSHAFT TARGET WITH NUT TOOTH AND METHOD FOR SYNCHRONIZING AN INTERNAL COMBUSTION ENGINE - Google Patents

Abstract

The subject of the present invention is a target (1) intended to be mounted on a crankshaft associated with a thermal combustion engine, the target (1) comprising teeth (# 1 to # 60) regularly distributed and of a height predetermined at its periphery. At least one so-called reference tooth (# 60) of the target (1) has at least one longitudinal notch (5) extending in said at least one reference tooth (# 60) over at least a major part of the height of said at least one reference tooth (# 60) and separating said at least one reference tooth (# 60) into at least two portions (# 60_1, # 60_2). The object of the invention is to eliminate the absence of teeth which causes inaccuracy in the rotational position of the motor.

Description

The present invention relates to a target intended to be mounted on a crankshaft associated with a thermal combustion engine, the target comprising regularly distributed teeth and of a predetermined height at its periphery. The present invention also relates to a method of determining an angular position of a crankshaft associated with an internal combustion engine and a method of synchronizing an internal combustion engine.

The synchronization of an internal combustion engine consists in precisely identifying the position of the moving parts of the engine assembly and associated elements that are each piston housed in an engine cylinder, the crankshaft and the camshaft in charge of intake and exhaust into the combustion chamber taking into account the type of two-stroke or four-stroke engine in order to allow the engine control electronics to manage the engine with the accuracy and precision required for its optimal functioning.

Therefore, an internal combustion engine must be "phased" in order to determine and optimize the best time to burn fuel in the cylinder, hence, among other things, an optimization of emissions and fuel consumption .

Phasing is generally carried out by combining two pieces of information from sensors associated respectively with a crankshaft and a camshaft.

The internal combustion engine comprises at least one cylinder comprising a piston movable between a top dead center and a bottom dead center, a movement of the piston causing, on the one hand, a crankshaft carrying at least one crankshaft target comprising several teeth and, on the other hand, at least one camshaft carrying a camshaft target. It is between the crankshaft and the camshaft that the phasing is carried out, the camshaft target making one revolution for two turns of said at least one crankshaft target for a four-stroke engine.

The target on the crankshaft has teeth at its periphery and the succession of teeth has an asymmetry which makes it possible to know the position of the engine to within 360 °. This asymmetry is generally called signature or interval sometimes mentioned under the Anglo-Saxon name of "gap" or long tooth.

In FIG. 1, a portion of teeth # 1 to # 60 consecutive from a target 1a is shown. Teeth # 1 to # 58 are shown distributed over a straight portion while this portion is curved and corresponds to the diameter of target 1 a at the base of the teeth, teeth # 1 to # 58 being spaced by the same interval 7 In this figure, however, a greater spacing 10 is provided between two consecutive teeth # 58 and # 1 obtained by the removal of two teeth, this spacing 10 forming a long tooth.

The sensor is shown at a distance from the target 1a and detects the sequential passage of teeth # 1 to # 58 of the target 1a then in rotation. The sensor 8 transmits this information to the engine management computer, in charge in particular of injecting fuel into the engine, in order to be able to determine the position of the engine. The computer, when it sees the long tooth, knows the position of the engine to within 360 °.

The role of the crankshaft sensors is to determine the rotation speed and the position of the crankshaft. Most often, they are mounted near the flywheel which serves as a rotary target or supports the rotary target 1a, advantageously in the form of a disc.

The rotation of the target disk causes changes in the magnetic flux. The various voltage signals produced by the magnetic fields are sent to the engine management computer. From the signals sent, it calculates the rotation speed and the position of the crankshaft to obtain the basic data necessary for determining the injection point and adjusting the ignition advance point.

The additional information of the camshaft which follows a revolution of 720 °, makes it possible to determine a correct synchronization phasing, that is to say, with certainty, in the combustion cycle, where each cylinder is placed. . The sequence of signals received by the camshaft sensor is not regular, but follows a known profile.

The synchronization method consists, at each long tooth interval, of comparing the information received by the camshaft sensor with the theoretical information, stored in the computer. If this information is similar, the long tooth interval is recognized and the position of the motor as well.

Usually, the crankshaft targets have 36 or 60 teeth, regularly spaced, in which one or two teeth have been removed consecutively in order to create an asymmetry in the succession of teeth. This allows setting a reference for the position of the motor.

On each front of a received crankshaft target tooth, the engine position is increased by 6 °. Between the teeth, the engine click position is predicted using the instantaneous speed and the speed gradient determined at the same position on the previous cylinder, or even at 720 ° crankshaft angle before.

The teeth and the hollows between the teeth forming the intervals are identified by the sensor, but, depending on the technology used, only one type of brow is precise. This is called the active front which will be used to determine the position of the motor.

A big disadvantage is that if there is noise or interference with the sensor signal, additional or missing teeth may appear.

These edges disturb the calculation of the position of the motor and generate an inaccuracy in this determination. The combustion parameters are therefore no longer optimally sequenced and can generate pollution.

The position of the motor is precisely determined when the sensor sends the information "active edge of the target received". For a classic crankshaft target of 60 minus 2 teeth, i.e. 60 teeth with a large gap between two consecutive teeth resulting from two missing teeth, the position is precise in steps of 6 °, and 18 ° in the signature. Between the positions, the position is estimated. The estimate in the long tooth is less precise.

The problem underlying the present invention is, for a target carried by a crankshaft and whose signature is followed by a sensor in order to measure the rotation of the crankshaft, to carry out a signature on the target which can guarantee a measurement of the rotation as precise as possible, an absence of one or two teeth as proposed by the state of the art resulting in inaccuracy of the measurement.

To this end, the present invention relates to a target intended to be mounted on a crankshaft associated with a thermal combustion engine, the target comprising regularly distributed teeth and of a predetermined height at its periphery, remarkable in that at least one said target reference tooth comprises at least one longitudinal notch extending in said at least one reference tooth over at least a major part of the height of said at least one reference tooth and separating said at least one reference tooth in at least two portions.

The adjustment of an internal combustion engine requires an angular resolution on the rotation of the crankshaft of the order of 1 ° therefore much lower than that obtained by the signal from a sensor associated with a target of the prior art which is 6 ° for two missing teeth.

The invention consists in removing the long tooth so as to no longer have interpolation zones of imprecise position with an angle of 18 ° of crankshaft rotation during a revolution of the crankshaft target followed by the sensor.

The invention consists in making one or two notches in consecutive teeth in order to create asymmetry on the crankshaft target. For example, without being limiting, it can be a notch of 1 ° of crankshaft angle centered on a target tooth which extends over 3 ° of crankshaft.

When the engine is synchronized, the rotation speed is relatively low, around 300 rpm for a conventional starter, less than 1,000 rpm when the engine is started by an electric motor.

At this speed, the notch will be seen by the sensor and the computer will be able to see that the angle of the tooth before the notch is 1 °, that of 1 °, the notch being 1 ° , these angles being different from the 3 ° of the other teeth.

At low speed, the cut will be recognized. This recognition will be used to synchronize the target. At each revolution, if the notch is recognized, the synchronization is confirmed.

The solution eliminates the need for a long tooth on the crankshaft target, so as to improve the accuracy of determining the engine position. The improvement will be all the more significant as the number of cylinders of the engine will be important, for example 6 or 8, because the interval zone will coincide with zones where the relative precision of the rotation of the engine required is important, for example for injection or ignition.

Such a detection accuracy of the notched tooth leads to a precision on the angular position of the crankshaft and to better synchronization of the engine, resulting in more efficient combustion in the engine by implementing better adjustments.

Advantageously, said at least two portions are equal, a width of each portion being twice the width of the notch.

Advantageously, the target comprises a single median longitudinal notch surrounded by two equal target portions, the single median notch extending to the base of said at least one reference tooth by separating the two equal target portions.

The invention relates to a method for determining an angular position of a crankshaft associated with an internal combustion engine comprising at least one cylinder comprising a piston movable between a top dead center and a bottom dead center, a movement of the piston causing a crankshaft carrying at least one crankshaft target comprising several teeth, the target having at least one so-called reference singularity, a passage of which in front of a sensor is detected, remarkable in that it implements such a device for determining the angular position.

The invention also relates to a method of synchronizing an internal combustion engine comprising at least one cylinder comprising a piston movable between a top dead center and a bottom dead center, a movement of the piston causing, on the one hand, a crankshaft bearing at least one crankshaft target comprising several teeth and, on the other hand, at least one camshaft carrying a camshaft target, a synchronization phasing between said at least one crankshaft target and the shaft target cams being produced, remarkable in that a determination of the angular position of the crankshaft is carried out in accordance with such a method of determining an angular position, the synchronization taking place at low engine speed of less than 1,000 rpm and being checked at each crankshaft revolution.

At high speed, the magnetic field induced by the sensor magnet may not vary significantly enough when passing through the notch and therefore cannot detect it. On the other hand, the active fronts of the target will all be well detected at their correct position, the fronts being advantageously 60 in number.

The crankshaft target synchronization algorithm to take into account the possibility of seeing or not seeing the notch, at the predetermined position.

If the cut is detected at a position other than the predetermined one, it means that missing or additional teeth have been detected: the target can possibly be resynchronized.

Advantageously, when the synchronization is shifted or lost for an engine speed greater than 1,000 revolutions / minute, combustion in the engine is temporarily inhibited so that the engine speed drops below 1,000 revolutions / minute, in which case a new synchronization is carried out.

It is also possible to envisage a solution in degraded mode, for example by detecting the top dead centers of the engine according to the speed of rotation of the engine or only based on the target of the camshaft. A new low speed synchronization is preferable.

The invention finally relates to a motor vehicle comprising an internal combustion engine provided with at least one camshaft and associated with a crankshaft, remarkable in that it comprises such a device for determining an angular position of a crankshaft an internal combustion engine.

Other characteristics, aims and advantages of the present invention will appear on reading the detailed description which follows and with regard to the appended drawings given by way of nonlimiting examples and in which:

- Figure 1 is a schematic representation of a side view of a portion of teeth of a crankshaft target moving past a sensor for a determination of the angular position of the crankshaft according to the prior art, the teeth being shown aligned on a straight line and a signature being produced by the removal of two teeth,

- Figure 2 is a schematic representation of a side view of a portion of teeth of a crankshaft target as shown in Figure 1 with illustration of the measurement interval,

- Figure 3 is a schematic representation of a side view of a portion of teeth of a crankshaft target according to an embodiment of the present invention running past a sensor for a determination of the angular position of the crankshaft, the teeth being shown aligned on the same straight line and a signature being produced by a notched tooth,

- Figure 4 is a schematic representation of a side view of a portion of teeth of a crankshaft target as shown in Figure 3 with illustration of the measurement interval,

- Figures 5 and 6 show the signal, emitted by a sensor of a device for determining an angular position of a crankshaft of an internal combustion engine, of detection of the teeth of a crankshaft target according to a mode of the present invention, this for low and high engine speeds respectively, for the figures of 280 revolutions per minute and above 1000 revolutions per minute, the notched tooth being detected for a low speed but not being for a high diet,

- Figure 7 shows an engine speed of rotation, during a combustion cycle, the position of a top dead center of compression being identifiable by reaching a minimum of this speed of rotation. In FIG. 2 which shows a target 1a of a crankshaft conforming to the state of the art, the teeth # 1 to # 60 bear their assigned number in the non-limiting succession of 60 teeth, the teeth # 59 and # 60 being the teeth missing to complete the signature.

The measuring fronts of teeth # 1 to # 60 are the falling fronts. In an known manner, an interval ratio RI is defined according to the following equation:

RI = (ln-1 * ln-1) / (ln-2 * In)

With: In = tooth reference n, ln-1 = tooth reference n-1, ln-2 = tooth reference n-2, as explained below.

By calculating the interval ratio RI for various teeth we get:

RI = 1 for a regular tooth,

RI = 9 for two missing teeth on tooth 2,

RI = 4 for a missing tooth on tooth 2.

It is defined for the interval report RI a calibrated threshold C_CRK_GAP_VLD so as to be robust to the strong variations of speed which can intervene. It can be calibrated here, for example 3, for 2 missing teeth. Thus the detection of the long tooth is done when the interval ratio RI is greater than 3 at the level of tooth 2. The reference I2 is the distance between, on the one hand, the falling edge of tooth # 58 preceding the two missing teeth # 59 and # 60 and, on the other hand, the falling edge of tooth # 1 along the two missing teeth # 59 and # 60. Reference 11 is the distance between, on the one hand, the descending front of the penultimate tooth # 57 preceding the two missing teeth # 59 and # 60 and, on the other hand, the descending front of tooth # 58 preceding the two missing teeth # 59 and # 60. The reference I3 is the distance between, on the one hand, the falling edge of tooth # 1 following the two missing teeth # 59 and # 60 and, on the other hand, the falling edge of tooth # 2 next.

This interval ratio is 1 for two consecutive so-called regular teeth not separated by a large interval but separated by an interval referenced 7 in Figures 1 and 2. This interval ratio is 9 for two separated teeth # 58 and # 1 by a large interval in Figure 1 made with two teeth # 59 and # 60 missing. This interval ratio is 4 for two teeth separated by a large interval made with a missing tooth, which is not shown in Figure 2.

The reference 12a indicates the detection point at the end of the measurement interval starting at the falling edge of tooth # 56 arranged two teeth before the long interval and the falling front of tooth # 2 following tooth # 1 posterior to the long interval achieved. by removing the two teeth # 59 and # 60. The following table shows the calculation of an RI report with falling edges of 6, "tooth number" being the tooth number.

Tooth number 56 57 58 1 2 3 4 Tooth size 6 6 6 18 6 6 6 IR report 1 1 0.33333 9 0.33333 1

When the calculated interval ratio RI is greater than the calibrated threshold, for example being greater than 3, the tooth on which this ratio has been calculated is determined to be tooth # 2.

Referring to Figures 3 and 4, the present invention relates to a target 1, advantageously circular, intended to be mounted on a crankshaft associated with a thermal combustion engine. Target 1 has teeth # 1 to # 60 regularly distributed and of a predetermined height at its periphery, like a target 1 of the state of the art.

In Figures 3 and 4 only a portion of the teeth of target 1 is shown with teeth # 1 to # 60 arranged in a rectilinear fashion, which is not the case on target 1 for which teeth # 1 to # 60 extend around the circular periphery of target 1.

According to the invention, at least one so-called reference tooth # 60 of target 1 has at least one longitudinal notch 5 extending in said at least one reference tooth # 60 over at least a major part of the height of said au at least one reference tooth # 60 and separating said at least one reference tooth # 60 into at least two portions # 60_1, # 60_2.

In FIG. 4 which relates to a crankshaft target 1 according to an embodiment of the present invention with a notched reference tooth # 60 serving as a signature, the teeth # 1 to # 60 bear their assigned number in the succession not limiting of 60 teeth, tooth # 60 being the tooth provided with a notch 5 and separated into two portions # 60_1 and # 60_2 to make the signature.

The measuring fronts of teeth # 1 to # 60 are the falling fronts. In FIG. 4, the falling edges of two teeth # 58 and # 59 preceding the notched reference tooth # 60 and of the two teeth # 1 and # 2 following the notched reference tooth # 60 are referenced 6, the falling edge of a first portion # 60_1 of the notched tooth # 60 is referenced 4 and the falling edge of a second portion # 60_2 of the notched tooth # 60 is referenced 2.

We always define an interval ratio RI according to the following equation:

RI = (ln-1 * ln-1) / (ln-2 * In)

By calculating the interval ratio RI for various teeth we get:

RI = (6.6 / 6.6) = 1 for teeth # 2 to # 59,

RI = (6.6 / 4.6) = 1.5 for tooth # 60_1,

RI = (4.4 / 2.6) = 1.33 for tooth # 60_2,

RI = (2.2 / 4.6) = 0.1666 for tooth # 1.

A calibrated threshold C_CRK_GAP_VLD is defined so as to be robust to the strong variations in speed which may occur. The threshold is calibrated here at for example 0.4. Thus the detection of the long tooth is done when the interval ratio RI is greater than 0.4 at the level of tooth 1. The reference I5 is the distance between, on the one hand, the falling edge 4 of the first half -portion # 60_1 of the notched tooth # 60 and, on the other hand, the falling edge 2 of the second half-portion # 60_2 of the notched tooth # 60. The reference I4 is the distance between, on the one hand, the falling edge 6 of the last tooth # 59 preceding the notched tooth # 60 and, on the other hand, the falling edge 4 of the first half-portion # 60_1 of the notched tooth # 60. The reference I3 is the distance between, on the one hand, the falling edge 2 of the second half-portion # 60_2 of the notched tooth # 60 and, on the other hand, the falling edge 6 of the tooth # 1 along the tooth notched # 60. This interval ratio is 1 for two consecutive so-called regular teeth not separated by the signature. This interval ratio is 1.5 for the first half portion # 60_1 of the notched tooth # 60. This interval ratio is 1.33 for the second demiportion # 60_2 of the notched tooth # 60. The reference 12 indicates the detection point at the end of the measurement interval between the falling edge 6 of tooth # 58 penultimate tooth preceding the notched tooth # 60 and the falling edge of tooth # 1 following the notched tooth # 60 .

The following table shows the calculation of an IR report with different falling edges 6, 4 and 2.

Tooth number 57 58 59 60-1 602 1 2 Tooth size 6 6 6 4 2 6 6 IR report 1 1 1.5 1.333333 0.166667 3

When the calculated RI interval ratio is less than the calibrated threshold, for example by being less than 0.4, the tooth on which this ratio has been calculated is determined to be tooth # 1.

Preferably, the notched tooth # 60 is only provided with a notch 5 separating the notched tooth # 60 in a first portion # 60_1 and a second portion # 60_2 equal. A width of each portion # 60_1, # 60_2 can be equal to twice the width of the notch 5, the width of the notch 5 being advantageously 1 ° of crankshaft rotation.

The target 1 of the crankshaft can comprise a single median longitudinal notch 5 surrounded by two equal portions # 60_1, # 60_2 of target 1, the single median notch 5 extending to the base of said at least one reference tooth # 60 by separating the two equal portions # 60_1, # 60_2 of target 1.

The invention also relates to a device for determining an angular position of a crankshaft of an internal combustion engine, the determination device comprising a target 1 mounted on and integral in rotation with the crankshaft. A sensor 8 is placed near the target 1 and detects a sequential passage of each tooth # 1 to # 60 of the target 1 during the rotation of the crankshaft. The determination device comprises means for processing signals emitted by the sensor 8 to establish the angular position of the crankshaft and a target 1 as previously described with said at least one reference tooth # 60 provided with said at least one notch 5.

Preferably, the sensor 8 is a variable reluctance sensor comprising a magnet. The size of the magnet can preferably be greater than the width of the notch 5, said at least one reference tooth # 60.

The invention relates to a method for determining an angular position of a crankshaft associated with an internal combustion engine comprising at least one cylinder comprising a piston movable between a top dead center and a bottom dead center, a movement of the piston causing a crankshaft carrying at least one crankshaft target 1 comprising several teeth # 1 to # 60. The target 1 having at least one so-called reference singularity, a passage in front of a sensor 8 of which is detected.

The determination method implements such an angular position determination device for its step of determining the angular position measured by detection by the sensor 8 of the passage of the notched tooth # 60.

The invention also relates to a method of synchronizing an internal combustion engine comprising at least one cylinder comprising a piston movable between a top dead center and a bottom dead center, a movement of the piston driving a crankshaft carrying at least one target 1 of crankshaft with several teeth # 1 to # 60.

The piston also drives at least one camshaft carrying a camshaft target, a synchronization phasing between said at least one crankshaft target 1 and the camshaft target being produced. The camshaft target can make one revolution for two turns of said at least one crankshaft target 1.

A determination of the angular position of the crankshaft is carried out in accordance with a method of determining an angular position as previously carried out, the synchronization taking place at low engine speed of less than 1000 rpm.

Such a target 1 with a notched tooth # 60 is particularly well suited to a synchronization made at start-up. Such a synchronization method is very precise and can be very advantageously implemented for a motor vehicle equipped with an automatic stop and restart system, in which case synchronization can be carried out at each stop and restart.

Such a notched tooth # 60 can no longer be detected by the sensor 8 at high speed, for example from a speed greater than 1000 revolutions per minute.

For example, Figures 5 and 6, while referring to Figures 3 and 4, show the signal S from the sensor 8 associated with the crankshaft target 1 having a notched tooth # 60, the teeth # 1 to # 60 of the target 1 scrolling past the sensor 8, this respectively for an engine speed of 280 revolutions / minute in the figures and 1000 revolutions / minute in FIG. 6.

It is visible in FIG. 5, for the two signal curves S of sensor 8 that the signal is representative of the detection of the notched tooth # 60 visible in the surrounded part of the signal. In FIG. 6, the signal from the sensor 8 no longer makes it possible to detect the passage of the notched tooth # 60 in front of the sensor 8, as shown by the surrounded part.

It is however then possible to follow a top dead center of compression of a piston by a curve of speed of rotation of the engine, the passage of such a top dead center being detectable by a drop in speed of rotation of the engine reaching a value minimal. It is thus then taken as a reference point, in particular for fuel injection operations and the like, not the neutral position, the actual position of which is not known with sufficient precision, but the position of the engine in which the speed of rotation of the motor goes through a relative minimum.

This can be done from a calibrated motor, what is the angular difference between the reference position and the position in which the speed of rotation of the motor passes through a relative minimum under predetermined conditions, this angular difference remaining constant while this type of engine.

This is shown in FIG. 7 where the speed of rotation of the motor Vmot is shown in operation of the motor. The top dead center of compression which is identified by a vertical line is reached at the minimum speed of rotation of the engine Vmot for each combustion cycle.

Thus, for another motor of the same type, it suffices to determine under the predetermined operating conditions what is the angular position in which the speed of rotation of the motor passes through a relative minimum in order to deduce therefrom the precise position of the corresponding reference position .

The angular difference between this reference position and its theoretical position then constitutes the correction to be made to the angular measurements carried out. This correction can be specific for each cylinder, in the case of an engine with several cylinders, a correction adapted to each cylinder will be executed for each fuel injection.

When the synchronization is offset or lost for an engine speed greater than 1000 revolutions / minute, as a follow-up of the notched tooth # 60 is not then possible by the sensor 8, combustion in the engine can be temporarily inhibited so that the engine speed drops below 1000 rpm. At such a speed of less than 1000 revolutions / minute, it is possible to carry out a new synchronization.

The invention finally relates to a motor vehicle comprising an internal combustion engine provided with at least one camshaft and associated with a crankshaft, the motor vehicle comprising such a device for determining an angular position of a crankshaft of a internal combustion engine.

Claims (8)

1. Target (1) intended to be mounted on a crankshaft associated with a thermal combustion engine, the target (1) comprising teeth (# 1 to # 60) regularly distributed and of a predetermined height at its periphery, characterized in that at least one so-called reference tooth (# 60) of the target (1) has at least one longitudinal notch (5) extending in said at least one reference tooth (# 60) over at least a major part the height of said at least one reference tooth (# 60) and separating said at least one reference tooth (# 60) into at least two portions (# 60_1, # 60_2). 2. Target (1) according to the preceding claim, in which said at least two portions (# 60_1, # 60_2) are equal, a width of each portion (# 60_1, # 60_2) being twice the width of l 'notch (5). 3. Device for determining an angular position of a crankshaft of an internal combustion engine, the determination device comprising a target (1) mounted on and integral in rotation with the crankshaft, a sensor (8) being arranged nearby of the target (1) and detecting a sequential passage of each tooth (# 1 to # 60) of the target (1) during the rotation of the crankshaft and of the means for processing signals emitted by the sensor (8) to establish the angular position of the crankshaft, characterized in that the target (1) is according to any one of the preceding claims with said at least one reference tooth (# 60) provided with said at least one notch (5). 4. Device according to the preceding claim, wherein the sensor (8) is a variable reluctance sensor (8). 5. Method for determining an angular position of a crankshaft associated with an internal combustion engine comprising at least one cylinder comprising a piston movable between a top dead center and a bottom dead center, a movement of the piston causing a crankshaft carrying the at least one crankshaft target (1) comprising several teeth (# 1 to # 60), the target (1) having at least one so-called reference singularity, a passage of which in front of a sensor (8) is detected, characterized in that it implements a device for determining the angular position according to any one of the two preceding claims. 6. A method of synchronizing an internal combustion engine comprising at least one cylinder comprising a piston movable between a top dead center and a bottom dead center, a movement of the piston causing, on the one hand, a crankshaft carrying at least one target (1) of crankshaft comprising several teeth (# 1 to # 60) and, on the other hand, at least one camshaft carrying a camshaft target, a phasing of synchronization between said at least one target (1) of the crankshaft and the camshaft target being produced, characterized in that a determination of the angular position of the crankshaft is carried out in accordance with a method of determining an angular position according to the preceding claim, the synchronization being carried out at low speed motor less than 5 to 1000 rpm. 7. Synchronization method according to the preceding claim, in which when the synchronization is shifted or lost for an engine speed greater than 1000 revolutions / minute, combustion in the engine is temporarily inhibited so that the engine speed drops below 1000 revolutions / minute, in which case a new 10 synchronization is performed. 8. Motor vehicle comprising an internal combustion engine provided with at least one camshaft and associated with a crankshaft, characterized in that it comprises a device for determining an angular position of a crankshaft of an engine with internal combustion according to any one of claims 3 or 4.