METHOD OF MANAGING AN AUTOMOTIVE ALTERNATOR AND SYSTEM

Abstract

The method and management system of an automotive alternator for a vehicle equipped with an internal combustion engine (ICE) are described, the alternator (1) being controlled by the ECU (23), the ECU being capable of promoting the mechanical coupling of the alternator to the timing belt (5) and electrical coupling with said battery (20), and the ECU receiving signals from the battery charge sensor (22) in order to: - determine the battery charge level, between: BC1 (corresponding to a fully charged condition); BC2 (corresponding to a working charge level); and BC3 (corresponding to a low charge); and act on the alternator in such a way that: - at level BC1, the alternator (1) is kept electrically and mechanically uncoupled; - at level BC3, the alternator (1) is kept electrically and mechanically coupled;and - at level BC2, the alternator (1) will be mechanically engaged when the vehicle's travel speed exceeds a predetermined value (VLim) and when the engine (MCI) is disengaged for a gear change, and the alternator (1) is electrically engaged when the vehicle is being driven in cut-off mode.;

Description

METHOD OF MANAGING AN AUTOMOTIVE ALTERNATOR AND SYSTEM

[001] The present invention relates to a method and / or system for managing an automotive alternator and, more specifically, to a method for managing an alternator suitable for being electrically and / or mechanically coupled and decoupled to an internal combustion engine (ICE), or the like. More particularly, the present invention is intended to manage the selective coupling or decoupling of the alternator based on battery conditions combined with vehicle driving conditions. STATE OF THE ART

[002] Vehicle electrical power generation systems, as known in the technical field, generally comprise an electrical machine responsible for producing electrical energy, driven by the vehicle's engine at the moment of ignition. This is done via a timing belt. The alternator powers all electrical devices during vehicle operation and recharges the battery; its name refers to the type of current produced. This device operates on the principle of electromagnetic induction: Electric current flows through the rotor, creating a magnetic field that induces the movement of electrons in the stator coils, resulting in alternating current.Since cars operate on direct current, automotive alternators also include two fundamental components: the rectifier plate, which transforms alternating current into direct current, and the voltage regulator, responsible for controlling the voltage produced.

[003] However, despite the widespread use of these electric motors in vehicles, they contribute to fuel consumption and carbon dioxide (CO2) emissions, as they represent a significant source of mechanical energy consumption from the crankshaft. Since the engine's mechanical energy is derived from the thermal energy generated by fuel combustion, the alternator acts as a load on the system. When the battery is under load, fuel consumption increases to compensate for the energy used by the alternator. Furthermore, even with the battery at an adequate charge level, the alternator continues to consume mechanical energy from the crankshaft. ML / a / ZUZJ / UUUIO» c* ccc σ « based on the need to electrically power vehicular systems, which are increasingly complex and therefore consume more and more electrical energy.

[004] Fuel consumption and carbon dioxide emissions are direct indicators of a vehicle's energy efficiency. Burning fuel, especially fossil fuels, produces high concentrations of carbon dioxide (CO₂). High levels of carbon dioxide emissions into the atmosphere contribute to harmful environmental effects, such as the greenhouse effect and subsequent global warming, which increases the likelihood of natural disasters (e.g., tsunamis) and climate change that impacts daily life. Furthermore, fuel consumption is linked to emissions of carbon monoxide (CO) and hydrocarbons (HC), which are known to be harmful to human health.

[005] To minimize the negative impact of alternators on vehicle fuel consumption, several devices have been devised and implemented. Typically, these projects focus on increasing alternator efficiency (electrical or mechanical) and enabling strategic alternator operation based on the battery's electrical energy demand. Among the most recent developments are so-called intelligent alternators (IAs), designed to minimize the effect of the alternator's mechanical load on the crankshaft by using data collected from the vehicle itself (e.g., the ECU). Alternators equipped with internal control systems include those described in documents DE 19638872 and US 7816893. These documents outline strategies for electrically disconnecting the alternator under specific conditions in relation to the vehicle's electrical load.This electrical disconnection occurs when the battery has a sufficient charge level to power the vehicle's electrical system, or when the alternator's operating conditions are inadequate, among other situations. Electrical reconnection takes place when the battery reaches a minimum charge level and needs to be recharged. In this way, during periods of alternator electrical disconnection, the mechanical load on the crankshaft is minimized. > ai c* ccc σ «

[006] The invention described in US patent 10247265, authored by the present inventor, discloses an alternator (E / MS) suitable for being coupled to and / or decoupled from the crankshaft of a vehicle engine (an internal combustion engine, or similar), wherein the mechanical coupling or decoupling is selectively performed in a stage distinct from the electrical connection or disconnection. The advantages of the described alternator include a reduction in the step generated when the electrical and mechanical coupling compete, as well as a reduction in fuel consumption and, consequently, in the amount of emissions from the vehicle engine.

[007] Thus, despite the advantages derived from the work of the aforementioned intelligent alternators, as well as from the alternator with distinct electrical and mechanical coupling, subsequent studies led to the development of new management strategies for a vehicle alternator, so that such advantages can be increased even further. OBJECTIVES OF THE INVENTION

[008] Thus, a first objective of the present invention is a method for managing an alternator, suitable for being coupled or uncoupled from the crankshaft of a vehicle engine, in order to reduce its load and, consequently, significantly reduce the step, in addition to providing a reduction in fuel consumption, the level of carbon dioxide (CO₂) emissions and also other emissions of polluting gases such as carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxides (NOx).

[009] Another objective of the present invention is a method for managing an alternator intended to promote selective coupling and decoupling of the alternator, based on the battery charge and the vehicle's driving mode, in combination. SUMMARY OF THE INVENTION

[010] These and other objectives are achieved and satisfied from a method for the management of an automotive alternator comprising the stages of: > ai c. ccc σ « - Determine the battery charge level, between: BC1 (corresponding to a fully charged battery condition); BC2 (corresponding to a working battery charge level); and BC3 (corresponding to a low battery charge); And given that: - at level BC1, keep the alternator electrically and mechanically decoupled; - at level BC3, keep the alternator electrically and mechanically coupled, and - at level BC2, mechanically engage the alternator when the vehicle's travel speed exceeds a predetermined VLim value and when the MCI engine is disengaged for a gear change; and electrically engage the alternator when the vehicle is being driven in cut-off mode.

[011] In addition, the method also includes the step of mechanically and electrically decoupling the alternator when the engine rotational speed is below a predetermined limit value RLim.

[012] Similarly, the objectives are also achieved and satisfied from an automotive alternator management system, comprising a vehicle equipped with an internal combustion engine, in which the crankshaft rotation is transmitted to the alternator via a toothed belt, and given that said vehicle further comprises a battery for powering the vehicle's electrical system, and a battery charge sensor, the alternator is controlled by an ECU, said ECU being capable of promoting the mechanical coupling of the alternator to said toothed belt through actuation of the pulley, and electrical coupling to said battery, and given that the ECU receives signals from the battery charge sensor to: - Determine the battery charge level, between: BC1 (corresponding to a fully charged battery condition); BC2 (corresponding to a working battery charge level); and BC3 (corresponding to a low battery charge); and operate the alternator so that: - at level BC1, the alternator will remain electrically and mechanically decoupled; - at level BC3, the alternator will remain electrically and mechanically connected, and > ai c* ccc σ « - At level BC2, the alternator will be mechanically engaged when the vehicle's travel speed exceeds a predetermined VLim value and when the internal combustion engine is disengaged for a gear change; and the alternator is electrically engaged when the vehicle is being driven in cut-off mode.

[013] In addition, the system also comprises mechanically and electrically decoupling the alternator when the engine rotational speed is below a predetermined limit value RLim. BRIEF DESCRIPTION OF THE DRAWINGS

[014] The present invention will be better understood in light of the detailed description of a preferred embodiment of the invention, which is supported and illustrated by the accompanying figures, which are provided for illustration and guidance but do not limit the scope of the invention, in which: - Figure 1 is a schematic view of the mechanical coupling between the alternator pulley and the crankshaft pulley; - Figure 2 is a schematic view of the power and control systems of an alternator; - Figure 3 refers to a graph illustrating the operating parameters of an internal combustion engine (ICE), as a function of the driving time of a vehicle equipped with a manual transmission, and indicates the battery charging possibilities, and - Figure 4 refers to a graph illustrating the operating parameters of an MCI, as a function of the driving time of a vehicle equipped with an automatic or automated transmission, and indicates the battery charging possibilities. DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

[015] According to Figures 1 and 2 attached hereto, 1 denotes an alternator, which comprises, in a known manner, a load 2 in which there is a rotor (not visible) and a stator (not visible) whose relative rotary motion gives rise to the generation of an electromagnetic field for the production of electrical energy. In particular, alternator 1 is an alternator (E / MS) with a mechanical coupling system and selective electrical connection (conforming to US 10247265). In general, alternator 1 is an alternator > ϊ< c N C* ccc σ « suitable for being coupled and / or uncoupled from the drive system of a vehicle, as well as electrically connected / disconnected from the electrical system of a vehicle, independently of each other. In particular, and as is clear to technicians in the sector, the advantages of the aforementioned alternator materialize when the mechanical coupling precedes the electrical connection.

[016] While the stator is mounted in a fixed manner with respect to the load 2, the rotor occupies a central position of the alternator 1 and is supported, with free rotation, around a shaft 3, which projects beyond the volume delimited by said load 2 and which is intended to receive the torque necessary to provide the relative rotational movement between rotor and stator, through the pulley 4. Also known, a belt 5, usually a toothed belt, engages both the pulley 4 and the pulley 6 of the crankshaft 7. Also known, said belt 5 may be engaged with other mechanical devices such as, for example, a tensioner 8 intended to keep the belt 5 tensioned within specific operating parameters, as well as directional pulleys, in the form of idler pulleys (not polished).Likewise, pulley 6 of the crankshaft 7 is also responsible for driving other vehicle devices such as, for example, pulley 28 of the hydraulic steering pump, via belt 29, or pulley 9 of the air conditioning.

[017] With regard to the electrical connections of the system (see figure 2), the alternator 1 is electrically connected in parallel with the battery 20 and both are connected to power the electrical loads 21 of the vehicle, such as air conditioning, radio, internal and external lights, etc.

[018] In one embodiment, the battery 20 is still connected to a battery charge status sensor 22, which has the ability to assess the electrical charge stored in the battery cells and provide an indicative signal of this charge to the Control Unit or ECU 23, via a data line 24.

[019] Generally speaking, the charge of battery 20 is determined by means of battery charge determination or detection systems and / or devices. By way of illustration, but not limitation, the detection or determination of the charge of battery 20 > K c N C* ccc σ « can be made from devices or systems such as those taught in document WO 2017 / 027950 of the present applicant, or in documents US 8536872 or US 6674266, among others.

[020] In the particular case of alternator 1 being the alternator (E / MO), according to US patent 10247265, the mechanical coupling between shaft 3 and pulley 4 is carried out and mediated by means of an electromagnetic clutch 10, suitable for coupling and uncoupling shaft 3 in relation to pulley 4. In this case, the ECU 23 is connected to alternator 1, through data line 25A, and the clutch 10 through data line 25B, so that it can control the electrical behavior (connection or disconnection) of alternator 1 and the mechanical behavior of pulley 4, respectively. More specifically, the alternator 1 comprises, in addition to the electrical connection with the battery 20 and with the electrical loads 21 of the vehicle, also a logic connector (not illustrated) that interconnects the voltage regulator (not illustrated) of the alternator 1 with the ECU 23 through line 25A.Note that, according to the logical communication infrastructure of the vehicle in which the system is installed, lines 24 and / or 25A, 25B can be independent lines, as well as being part of a CAN network, or an Ethernet network, or another, previously existing in the vehicle.

[021] Figure 3 is a flow diagram illustrating the method, according to the invention, wherein the coupling and / or uncoupling of the alternator 1 is a function of the battery charge 20, in combination with the vehicle driving conditions.

[022] More specifically, the method of the present invention analyzes and combines battery charging conditions with vehicle driving to indicate an opportune moment for the alternator to engage or disengage. The primary focus of the method is to reduce fuel consumption and, consequently, vehicle emissions. However, with an appropriate strategy, as described, it is also possible to enhance the vehicle's driving feel by selecting the optimal moments to engage and disengage the alternator. In this way, it is possible to control the alternator's engagement to avoid the jerk inherent in the sudden increase in load on the crankshaft of the vehicle's internal combustion engine. Specifically, this jerk can be defined as > κ c N C* ccc σ « as a sudden reduction in the vehicle's travel speed, due to the sudden increase in load on the crankshaft.

[023] Therefore, and initially, it is necessary to establish some operating levels of the battery (20), which: - BC1: corresponding to a fully charged battery condition - for example, such a full charge level can be defined as a battery charge exceeding 99% of the total battery charge; - BC2: corresponding to a working battery charge level, i.e., a charge sufficient for the vehicle to be driven without risk of compromising the operation of the electrical system, even in vehicles with several active electrical accessories, in case of the alternator being unavailable - for example, this working charge level can be set from a battery charge between 99% and 75% of the total battery charge; and - BC3: corresponding to a low battery charge, i.e., a battery charge level insufficient to maintain normal vehicle operation for an estimated period of time - For example, this low charge level can be set from a battery charge below 75% of the total battery charge.

[024] It is imperative to emphasize that the battery charge percentages that define the BC1, BC2, and BC3 charge levels are merely illustrative and not limiting. As any industry technician will infer, the battery charge percentage values ​​can vary depending on the total battery charge, the quantity and type of equipment that must be powered by the vehicle's power system, among other factors.

[025] In this way, the system initially tests the battery's charging condition to define the behavior of the E / MS 1 alternator during vehicle driving.

[026] Thus, when sensor 22 detects that the battery's state of charge is at level BC1, i.e., indicating that battery 20 is fully charged, it is not necessary to activate alternator 1. In this situation, pulley 4 is mechanically uncoupled from alternator 1, thus reducing the load on crankshaft 7. > ai c* ccc σ «

[027] In the diametrically opposite condition, i.e., with battery 20 storing little charge (level BC3), the system understands that it is imperative to replenish the battery's charge. Therefore, alternator 1 is engaged both mechanically and electrically, regardless of the vehicle's operating conditions. This behavior is selected to prevent the battery from compromising the power supply to the vehicle's electrical systems. This condition is maintained until the battery charge reaches at least level BC2. Specifically, the graph in Figure 3B shows that, as the battery charge level (red curve) falls below the operating range (BC2), the alternator remains engaged (blue curve at level 1), both mechanically and electrically, until the battery charge returns to that operating range.

[028] Finally, as soon as the charging sensor 22 indicates a charging condition within the BC2 level, this allows the system to appropriately manage the operation of alternator 1 in order to reconcile battery recharging with fuel savings and the reduction of pollutant emissions.

[029] To this end, and as particularly illustrated in Figure 3, which illustrates an example of the parameters controlled by the present system as a function of a journey made by a vehicle, it is possible to define the operational conditions of the present invention.

[030] At time t = 0, the vehicle is disconnected and alternator 1 is disengaged, both electrically and mechanically, from the crankshaft 7. The engine is then started (increase in revolutions according to the gray curve in the graph). Starting is facilitated because the starter motor (not illustrated) does not need to turn the alternator.

[031] After the engine starts and before first gear is engaged, the alternator remains mechanically disengaged from the crankshaft. The driver begins moving the vehicle with the alternator still disengaged—see in particular the black curve illustrating the vehicle's speed. The speed increases and the gears shift consecutively until the vehicle reaches a limit speed VLim, which is indicated in Figure 3 > N CNC* ccc σ « exemplifying as 40 Km / h. From this moment, the system remains waiting for the next gear change, in which an opportunity is configured to perform the mechanical coupling of the alternator 1. During the period of time in which the driver presses the clutch pedal (vehicle disengaged), and makes the change from a current gear to a consecutive one (this period of a few seconds), the system detects such condition and takes advantage of the opportunity to perform the mechanical coupling of the alternator 1 - the curve in blue indicates the condition of mechanical coupling of the alternator, being level 1 for coupled and level 0 for uncoupled.

[032] Note that the limiting speed (VLim) is preferably a value that varies depending on the battery's state of health (SoH) and / or state of charge (SoC). Thus, higher battery charge values ​​allow coupling to be postponed, which is reflected in coupling at higher VLim speeds; on the other hand, a battery with some usage time (reduced charge storage capacity) requires more frequent coupling, which is reflected in a reduction in the limiting speed (VLim).

[033] At this particular moment, which in combination with others defines the essential characteristics of the invention, the mechanical engagement is not perceived by the vehicle driver since it occurs with the engine disengaged from the drivetrain. The vehicle maintains a regular motion, due to inertia, and the alternator's engagement is directed solely to the engine, but is not detectable by the vehicle or the driver.

[034] Once this mechanical coupling of the alternator has been made, the system awaits a second opportunity to finally make the electrical connection of the alternator. According to the invention, this opportunity occurs when the vehicle is being driven at a cut-off point (rotation of the internal combustion engine maintained by the drivetrain and without using the accelerator pedal), that is, with the vehicle moving downhill (acceleration defined exclusively by a component of the weight force), with the engine running (some gear engaged and with the clutch and accelerator pedal not actuated), as well as with the engine rotating at a certain speed (in > s N CNC* ccc σ « rpm) above a certain limit. For example, and in the graph in figure 3, this limit is set at 1200 rpm.

[035] Thus, when the cut-off condition is detected, the system takes advantage of the opportunity to make the electrical connection of alternator 1, that is, the rotation of the alternator is carried out by the displacement of the geared vehicle (sequence: wheel, gearbox, engine, alternator) so that the mechanical energy transformed into electrical energy by the alternator comes exclusively from the industrial displacement of the vehicle.

[036] As is clear to a technician in the field, this condition allows battery 20 to be charged at zero fuel cost and with zero emissions, since fuel injection is deactivated in the cut-off condition. In the graph in Figure 3, the red curve indicates the periods of time when the alternator is charging the battery (level 1), and the periods when battery 20 is not being charged (level 0).

[037] On the other hand, this method of battery charging is maintained as long as the cutoff condition persists. The rotational speed limit that defines the cutoff condition depends primarily on alternator 1, that is, its minimum rotational speed that results in significant electrical power production, as well as the characteristics of the internal combustion engine (ICE) that allow it to operate at a specific rotational speed without fuel injection. In other words, for the other vehicle systems to be fully functional (such as the water pump, oil pump, air conditioning, etc.), the engine must be at a given rotational speed, which, in this case, must be maintained by the vehicle's movement.

[038] Thus, once the engine speed falls below this functional limit (RLim), the system provides for the alternator's decoupling, both mechanically and electrically. In the graph in Figure 3, it is possible to identify this moment (with t at approximately 120 s), when the vehicle speed reduces from approximately 50 km / h to a complete stop. At a point on this curve, around 20 km / h, the engine speed falls below the minimum rotation limit (RLim), > nc NC* ccc σ « therefore, the total decoupling of the alternator is promoted 1. As the vehicle resumes operation, the alternator re-couples, first mechanically and then electrically, provided that the above conditions are met.

[039] For vehicles equipped with automated transmission, the operation of the proposed system is exactly the same, since each gear change is performed after the driver indicates, via the gear lever, that a gear change should be made. Alternatively, vehicles with an automated transmission system can follow the engagement procedure as described below for vehicles with automatic transmission, since, in these automated systems, the clutch is actuated by an actuator controlled by the TCU, and not by the driver.

[040] In the case of an engine with automatic transmission, the engagement and disengagement conditions follow exactly the same parameters indicated above. The essential difference, in this case, lies in the fact that the TCU is the entity that manages each gear change and, therefore, there must be communication (not illustrated) between the proposed system (i.e., between the processor responsible for managing the current system) and the TCU, via a CAN network, or similar, so that the system of the invention informs the TCU about the need to engage, and the TCU informs the system that the vehicle is disengaged.

[041] Alternatively, Figure 4 illustrates a diversified operating possibility for the invention system, namely, through mechanical and electrical coupling at consecutive instants. This is possible, provided that the conditions for both mechanical and electrical coupling are met (as indicated above), and with a delay in the TCU shift time, if necessary, since automatic gear changes can require an excessively short time, preventing or compromising the mechanical and / or electrical coupling of the alternator, as is known.

[042] Alternatively, and even more advantageously for both automatic and automated-transmission vehicles, the mechanical and electrical couplings can > κ c N C* ccc σ « to be carried out (alternator coupling conditions checked) already within the cut-off condition and in sequence, for example, with a time interval between each coupling of a few tenths of a second. In this situation, and as the TCU itself controls the shift inclination (moment and opening time), it is possible to condense the mechanical and electrical couplings in time, within the cut-off condition, in order to reduce the rotational load of the alternator on the crankshaft (7) to the maximum.

[043] As a result of both the system and the method now proposed by the present invention, it is possible to obtain a reduction in fuel consumption and, therefore, in emissions of polluting gases, of the order of 3 to 4% with respect to a vehicle whose alternator is of a conventional type (always mechanically and electrically coupled to the vehicle), according to the tests already carried out by the inventor.

[044] This advantage stems, among other things, from the following features of the proposed system.

[045] Initially, it is possible to start the vehicle without the alternator connected, as well as to begin moving the vehicle without the alternator connected. This scenario reduces the mechanical load on the engine, reducing the need for injected fuel.

[046] Shifting the battery charging periods to the vehicle's cut-off condition leads to battery charging without any fuel consumption, simply by taking advantage of the geography of the displacement terrain.

[047] Establishing the three battery charge levels (BC1, BC2, and BC3), along with their specific operating procedures, allows the vehicle to be driven safely without the risk of battery discharge, which could compromise its electrical systems. Note that, with the system of the invention, the electrical power supply to the vehicle's systems is primarily provided by the battery, and no longer by the alternator, as is the case in conventional vehicles.

[048] Another advantage of the proposed system lies in the reduction of the engine load, for example, under conditions of higher power demand. Thus, the alternator can be > ai NCN to σ <c totalmente desacoplado en el caso que conductor indique la realización de una maniobra adelantamiento (acelerador comprimido y eventual reducción marcha).

[049] During periods of slow running (e.g., vehicles at rest or in uncontrolled movement) and with the battery charged within the operating range, the alternator remains decoupled, which means a considerable reduction in fuel consumption (30 to 40%) in this condition.< / c>

Claims

1. A method for managing an automotive alternator, characterized by comprising the steps of: - determining the battery charge level, between: BC1 (corresponding to a fully charged battery condition); BC2 (corresponding to a working battery charge level); and BC3 (corresponding to a low battery charge); and wherein: - at level BC1, keeping the alternator (1) electrically and mechanically disengaged; > 15 κ c N C* ccc σ - at level BC3, keeping the alternator (1) electrically and mechanically engaged, and - at level BC2, mechanically engaging the alternator (1) when the vehicle's travel speed is above a predetermined value (VLim) and when the engine (MCI) is disengaged for a gear change, and electrically engaging the alternator (1) when the vehicle is being driven in cut-off mode.

2. Method, according to claim 1, characterized in further comprising the step of mechanically and electrically decoupling the alternator (1) when the engine rotational speed is below a predetermined limit value RLim.

3. Method, according to claim 1, characterized in that the limiting speed VLim varies depending on the health of the battery and / or the amount of charge of the battery (20).

4. An automotive alternator management system for operationalizing the method defined in claim 1, characterized in comprising a vehicle equipped with an internal combustion engine (ICE), in which the rotation of the crankshaft (7) is transmitted to the alternator (1) via a toothed belt (5), and wherein said vehicle further comprises a battery (20) for powering the vehicle's electrical system, and a battery charge sensor (22), the alternator (1) being controlled by an electronic control unit (ECU) (23), said ECU being suitable for promoting the mechanical coupling of the alternator to said toothed belt (5) via actuation of the pulley (4), and electrical coupling to said battery (20), and wherein the ECU receives signals from the battery charge sensor (22) in order to: - determine the battery charge level, between: BC1 (corresponding to a fully charged battery condition); BC2 (corresponding to a working battery charge level);and BC3 (corresponding to a low battery charge); and act on the alternator so that: - at level BC1, the alternator (1) will remain electrically and mechanically disengaged; > 16 ϊ< c N C» ccc σ - at level BC3, the alternator (1) will remain electrically and mechanically engaged, and - at level BC2, the alternator (1) will be mechanically engaged when the vehicle's travel speed exceeds a predetermined value (VLim) and when the engine (MCI) is disengaged for a gear change, and the alternator (1) is electrically engaged when the vehicle is being driven in cut-off mode.; 5. System, according to claim 4, characterized by the ECU mechanically and electrically decoupling the alternator (1) when the engine rotational speed is below a predetermined limit value RLim.

6. System, according to claim 4, characterized by the limit speed VLim varying according to the health of the battery and / or the amount of charge of the battery (20).

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