FR3068393A1 - INHIBITION OF INJECTION FOR TOO SHORT STARTER ACTIVATION - Google Patents

Abstract

A method for controlling the start-up and injection of a combustion engine of a motor vehicle, the motor vehicle comprising: - a combustion engine (10) comprising a fuel injection system (20), - an engine starter ( 30), - a management system, the method comprising the steps of: - measuring, during activation of the starter (30), a rotation speed of the engine (10), - confirming (300) the activation of the starter ( 30) if the rotational speed of the motor (10) is greater than a start rotation threshold, - determining (400) an activation duration (110) of the starter (30) after activation of the starter (30) confirmed, - deactivating (500) the fuel injection system (20) if the duration of activation of the starter (110) is less than a time threshold of activation of the starter (111), so as to prevent an injection of fuel (21).

Description

INHIBITION OF INJECTION FOR ACTIVATIONS OF TOO SHORT STARTERS [0001] The present invention relates generally to a method for managing the starting and injection of a combustion engine mounted on a motor vehicle in order to avoid entry into resonance of the engine and of the double damping flywheel, and a starting and injection management system implementing such a method.

It is known in the prior art injection management methods. The document EP2230393 describes a method for detecting the entry into resonance of an engine which detects the start of resonance and reduces its amplitude by managing the injection.

On the other hand, this system has the particular disadvantage of not proposing a preventive strategy for the motor to enter into resonance, before the motor enters into resonance.

An object of the present invention is to respond to the drawbacks of the document of the prior art mentioned above and in particular, first of all, to propose a preventive strategy for controlling the starter and the injection, in order to prevent the motor and / or the double shock-absorbing flywheel from resonating in the event of too short activation of the starter.

[0005] For this, a first aspect of the invention relates to a method for managing the starting and injection of a combustion engine of a motor vehicle, the motor vehicle comprising:

- a combustion engine comprising a fuel injection system and an engine speed sensor,

- a motor starter,

- a management system, the method implemented by the management system comprising the steps

-2 consisting of:

- measure the engine speed when the starter is activated using the engine speed sensor,

- confirm activation of the starter if the engine rotation speed is greater than a starting rotation threshold,

- determine a starter activation time once the starter activation has been confirmed,

- deactivate the fuel injection system if the starter activation time is less than a starter activation time threshold, so as to prevent fuel injection and resonance of the engine when starting.

This makes it possible to propose a start-up and injection management method preventing the injection of fuel into the engine and thus preventing it from entering into resonance, so as not to damage it. Indeed, the engine can enter into resonance in the event of too short activation of the starter, for example if a vehicle user turns a non-impulse ignition key for too short a time, accustomed to this by the fear of activation too the starter may damage it. The motor thus enters into resonance and can be damaged, either by vibrations and jolts causing for example a reverse rotation of the motor, or by vibrations and jolts causing very large oscillations, which can be coupled to vibrations and jolts. a double damping flywheel of the vehicle, connected to the engine. Activation of the key too short does not then start the engine enough for it to exceed the resonance speed of the double damping flywheel or its own resonance speed.

This also allows the suppression of noise accompanying vibrations and jolts which annoy the user and which may raise doubts about the reliability of the vehicle at start-up, allowing the vehicle to move upmarket.

Advantageously, the vehicle also comprises an intelligent service unit, and the step of confirming the activation of the starter comprises the sub-steps consisting in:

- recover raw information on the activation of the starter from the smart service box,

- compare the engine speed with the starting rotation threshold,

- confirm the activation of the starter if the raw information on the activation of the starter indicates an activation of the starter and if the engine rotation speed is higher than the starting rotation threshold.

This makes it possible to propose a start-up and injection management method with great robustness by confirming the relevant information for effective management.

Advantageously, the method further comprises the step consisting in:

- determine the starting rotation threshold by setting a value by calibration.

This makes it possible to propose a method with a possibility of calibration in order to refine the adjustment of the rotation threshold.

Advantageously, the engine further includes a cooling water temperature sensor, and the method further comprises the step of:

- determine the starting rotation threshold as a function of the cooling water temperature, in order to take into account the engine thermal losses during starting.

This allows to propose a method taking into account the thermal losses at startup and thus a method more suited to the operation of the vehicle, taking into account the possibilities of hot or cold starting of the engine.

Advantageously, the management system includes a counter, and the step of determining the activation time includes the steps consisting in:

- increment the activation time using the counter when the starter activation is confirmed.

This makes it possible to propose a method with an incrementation of the duration of activation of the starter, in order to build reliable information of the duration of activation and thus have an effective method without being too sensitive, in particular avoiding false negatives, that is to say by avoiding unnecessarily deactivating the injection if it turns out that there will be no problem of resonance entry.

Advantageously, the engine further comprises a cooling water temperature sensor, the method further comprises the step of:

- determine the activation threshold of the starter as a function of the cooling water temperature in order to take into account the thermal losses of the engine when starting.

This makes it possible to propose an efficient process, suitable for hot and cold starting, in order to take into account the needs of the user and the conditions of effective use of the vehicle.

Advantageously, the vehicle further comprises an intelligent service box, the method further comprises the steps consisting in:

- recover raw information on the activation of the starter from the smart service box,

- detect a falling edge of the raw information passing from an activation of the starter to a deactivation of the starter, and in which the step of deactivation of the fuel injection system is

-5 realized when the falling edge of raw information is detected.

This makes it possible to propose a method with a detection of the instant when the starter is deactivated and to check at this instant whether the activation duration is long enough in order to usefully deactivate the injection system.

Advantageously, the step of deactivating the fuel injection system consists in cutting off the fuel injection if the fuel injection has already taken place or in inhibiting a fuel injection authorization if the injection of fuel has not yet occurred.

This makes it possible to propose a method cutting the injection or inhibiting the injection authorization in order to protect the engine and / or the double damping flywheel, without hampering the management of the injection which depends in particular on the position. combustion engine pistons.

Advantageously, the vehicle further comprises an intelligent service box, the method further comprises the step of

- recover raw information on the activation of the starter from the intelligent service unit, and in which the step of deactivation of the fuel injection system is carried out when the raw information indicates that the starter is no longer activated, and the engine rotation speed is lower than the starting rotation threshold during a time starting rotation threshold.

This makes it possible to propose an adapted and effective method, in which the deactivation of the injection system is limited to the protection of the engine and / or of the double damping flywheel, without being too often triggered so as not to hinder use. of the vehicle.

Advantageously, the motor vehicle further comprises a double damping flywheel.

This allows to propose a process that protects both the

-6motor than the double damping flywheel, for which the resonance regimes can come to disturb each other.

It should be noted that the steps of the method are provided with reference letters for the sake of clarity and ease of understanding only, without the alphanumeric order being necessarily respected. In other words, the steps can be executed without any other order than that necessary for the proper execution of the process.

A second aspect of the present invention relates to a start-up and injection management system implementing the start-up and injection management method according to the first aspect.

This allows to propose a management system implementing the method so as to provide preventive protection of the engine and / or the double flywheel in the event of too short activation of the starter.

A third aspect of the present invention relates to a motor vehicle comprising the management system according to the second aspect.

This makes it possible to propose a vehicle provided with a management system making it possible to protect the engine and / or the double damping flywheel in a preventive and simple manner in the event of too short activation of the starter.

Other characteristics and advantages of the present invention will appear more clearly on reading the following detailed description of an embodiment of the invention given by way of non-limiting example and illustrated by the accompanying drawings, wherein :

FIG. 1 represents a part of the method according to a first embodiment of the present invention, comprising a step of confirming activation of a motor vehicle starter, FIG. 2 represents the first embodiment of the method of starting management and injection according to the present invention,

FIG. 3 represents a second embodiment of the method according to the present invention.

Figure 1 shows a part of the method according to a first embodiment according to the present invention, comprising a step of confirming activation of a motor vehicle starter.

The start-up and injection management method of a combustion engine of a motor vehicle makes it possible to prevent and avoid a resonance entry of the engine at start-up. The motor vehicle comprises a combustion engine 10 comprising a fuel injection system 20 and an engine speed sensor 22, which can be installed for example on a crankshaft of the engine, as well as a starter 30, a system 40, an intelligent service unit recovering signals emitted by the vehicle's electrical components and a cooling water temperature sensor 50.

The start-up and injection management process includes the following:

- measure a speed of rotation 100 of the motor 10 using the motor rotation sensor 22,

- confirm the activation 300 of the starter 30 if the rotation speed 100 of the motor 10 is greater than a starting rotation threshold 101.

The step of confirming the activation 300 of the starter 30 includes the substeps consisting of:

- recover 310 raw information 130 on the activation of the starter 30, such as coming from the intelligent service box,

- compare 320 the speed of rotation 100 of the motor 10 with the starting rotation threshold 101,

- confirm 330 the activation 300 of the starter 30 if the raw information 130 on the activation of the starter 30 indicates an activation of the starter 30 and if the rotation speed 100 of the motor 10 is greater than the starting rotation threshold 101.

In other words, according to an advantageous example, the confirmation of the activation 300 of the starter comprises the substeps 310, 320 and 330.

It is also possible to provide a switch for implementing a boolean 103 and thus choose between a starting rotation threshold 101 depending on a function 104 taking into account a temperature value 51 given by the temperature sensor of cooling water 50 of the engine 10 and a fixed starting rotation threshold 102, fixed by calibration. Function 104 makes it possible to determine the starting rotation threshold 101 using the cooling water temperature value 51, such as for example using a correspondence table between water temperature values cooling 51 and starting rotation threshold values 101. The correspondence of the table can be adjusted by calibration.

Thus, the method further comprises the step of: - determining the starting rotation threshold 101 as a function of the cooling water temperature 51, in order to take into account the thermal losses of the engine 10 when starting .

The logical comparison operations are carried out by operators such as the logical operator> denoted 1000 in FIG. 1 and the logical operator & also called logical operator AND, denoted 1001 in FIG. 1.

FIG. 2 represents the first embodiment of the start-up and injection management method according to the present invention.

As explained above, the raw information 130 on the activation of the starter 30 is recovered. It is then necessary to detect a falling edge 135 of this raw information 130 in order to detect the instant t when the starter 30 is deactivated.

In addition, the management system 40 includes the counter 41, thus making it possible to increment 410 the activation time 110 using the

Counter 9 when the activation of the starter 30 is confirmed 300. In other words, the activation time 110 is updated or incremented by a counter step or time 41 as long as the activation of the starter 30 is confirmed , using the increment function 410. When the activation 300 is not confirmed, the NOT operator also noted 420 does not increment the activation duration 300. The determination function 400 makes it possible to determine the activation time 110 of the starter 30 once it has been activated and once the confirmation 300 of its activation has been made.

The start-up and injection management method thus also comprises the steps consisting in:

- determine 400 the activation time 110 of the starter 30 once the activation of the starter 30 is confirmed,

deactivating 500 the fuel injection system 20 if the duration of activation of the starter 110 is less than a time threshold for activation of the starter 111, so as to prevent a fuel injection 21 and an entry into resonance of the engine 10 at startup in the event of too short activation of starter 30.

The activation time 110 of the starter 30 is compared to the activation threshold of the starter 111 thanks to the logical operator <also noted 1002. The logical operator <noted 1002 sends a true or positive signal or 1 for example to another logical operator &, also noted 1003, if the activation time 110 is less than the activation threshold of the starter 111. The logical operator & noted 1003 processes the signals coming from the logical operator <noted 1002 and from the falling edge detection 135 of the raw information 130 of activation of the starter 30, and deactivates 500 the fuel injection 20 if the two values are true or positive or equal to 1. The management system 40 implements the process described in figure 2.

Figure 3 shows a second embodiment of the method according to the present invention.

- 10 In this second embodiment, the deactivation conditions 500 of the injection system 20 of the first embodiment 499, illustrated by FIGS. 1 and 2 are repeated. Deactivation 500 is also possible under other conditions described below, using the logical operator OR, also noted 1004.

The raw information 130 of activation of the starter 30 is recovered and if the starter 30 is deactivated, a positive or true information or 1 is sent by the operator NOT, also noted 1007 to the operator &, also called 1005.

In addition, if the speed of rotation 100 of the motor 10 is less than the starting rotation threshold 101, as defined above as a function of the temperature of the cooling water 51 measured by the sensor 50 using of the function 104, and this during a delay defined using the counter 41 below a time threshold for starting rotation 106, then a positive or true information or 1 is sent to the operator &, noted 1005. The logical operator <also noted 1008 compares the speed of rotation value 100 of the motor 10 to the starting rotation threshold 101 and sends a positive or true signal or 1 if the speed of rotation value 100 of the motor 10 is less than the rotation threshold 101, the signal being sent to the logical operator 1006. The signal is negative, false or 0 in the other case. The logic operator 1006 is in charge of comparing the delay during which the rotation speed 100 of the motor 10 is less than the starting rotation threshold 101 and the starting rotation time threshold 106 defined by calibration.

If the operator &, denoted 1005 receives two positive or true information or 1, then the fuel injection 21 is deactivated 500, by means of the logical operator OR, denoted 1004. The management system 40 implements the method described in FIG. 3.

Therefore, the method further comprises the step of

- recover the raw information 130 on the activation of the starter 30, such as coming from the intelligent service unit, and in which the step of deactivation of the fuel injection system 20 is carried out when

- the raw information 130 indicates that the starter 30 is no longer activated, and when

the rotation speed 100 of the motor 10 is lower than the starting rotation threshold 101 during a starting rotation time threshold 106.

It will be understood that various modifications and / or 10 improvements obvious to those skilled in the art can be made to the various embodiments of the invention described in the present description.

Claims (10)

1. Method for managing the starting and injection of a combustion engine of a motor vehicle, the motor vehicle comprising: - a combustion engine (10) comprising a fuel injection system (20) and an engine speed sensor (22), - a motor starter (30), - a management system (40), the method implemented by the management system (40) comprising the steps consisting in: - when the starter (30) is activated, measure a rotation speed (100) of the motor (10) using the motor rotation speed sensor (22), - confirm (300) the activation of the starter (30) if the rotation speed (100) of the motor (10) is greater than a starting rotation threshold (101), - determine (400) an activation time (110) of the starter (30) once the activation of the starter (30) is confirmed, - deactivate (500) the fuel injection system (20) if the duration of activation of the starter (110) is less than a time threshold for activation of the starter (111), so as to prevent fuel injection ( 21) and a motor resonance input (10) at start-up. 2. Method according to the preceding claim, the vehicle further comprising an intelligent service box, in which the step of confirming (300) the activation of the starter (30) comprises the sub-steps consisting in: - recover (310) raw information (130) on the activation of the starter (30) from the intelligent service unit, - compare (320) the rotation speed (100) of the motor (10) with the starting rotation threshold (101), - confirm (330) the activation of the starter (30) if the raw information (130) on the activation of the starter (30) indicates an activation of the starter (30) and if - 13the rotation speed (100) of the motor (10) is greater than the starting rotation threshold (101). 3. Method according to one of the preceding claims, the engine (10) further comprising a cooling water temperature sensor (50), the method further comprising the step of: - determine the starting rotation threshold (101) as a function of the cooling water temperature (51), in order to take into account the thermal losses of the engine (10) at start-up. 4. Method according to one of the preceding claims, the engine (10) further comprising a cooling water temperature sensor (50), the method further comprising the step of: - determine the activation threshold of the starter (111) as a function of the cooling water temperature (51) in order to take into account the thermal losses of the engine (10) at start-up. 5. Method according to one of the preceding claims, the vehicle further comprising an intelligent service box, the method further comprising the steps of: - recover raw information (130) on the activation of the starter (30) coming from the intelligent service box, - detecting a falling edge (135) of the raw information (130) passing from an activation of the starter (30) to a deactivation of the starter (30), and in which the step of deactivation of the fuel injection system (20) is performed when the falling edge (135) of the raw information (130) is detected. 6. Method according to one of the preceding claims, in which the step of deactivating the fuel injection system (20) consists in cutting off the fuel injection (21) if the fuel injection (21) has already occurred or to inhibit a fuel injection authorization if the fuel injection (21) has not yet taken place. 7. Method according to any one of the preceding claims, the vehicle further comprising an intelligent service box, the method further comprising the step of: - recovering raw information (130) on the activation of the starter (30) coming from the intelligent service unit, and in which the step of deactivation of the fuel injection system (20) is carried out when the raw information ( 130) indicates that the starter (30) is no longer activated, and the rotation speed (100) of the motor (10) is lower than the starting rotation threshold (101) during a starting rotation time threshold (106) . 8. Method according to any one of the preceding claims, in which the motor vehicle further comprises a double damping flywheel. 9. Start-up and injection management system implementing the method according to one of the preceding claims. 10. Motor vehicle comprising the management system according to the preceding claim. 1/2