WO2010089113A1

WO2010089113A1 - Jump start system for a vehicle

Info

Publication number: WO2010089113A1
Application number: PCT/EP2010/000687
Authority: WO
Inventors: Heinz Wenzl; Hans-Peter Beck; André HAUBROCK
Original assignee: Heinz Wenzl; Hans-Peter Beck; Haubrock Andre
Priority date: 2009-02-04
Filing date: 2010-02-04
Publication date: 2010-08-12
Also published as: EP2394050A1; DE102009007545A1

Abstract

At least one internal jump start accumulator (2) having a predeterminable nominal voltage is provided in a jump start system (10) for a vehicle, wherein the internal jump start accumulator (2) can be or is connected in parallel to the starter battery (12) of the vehicle for supporting the power requirement during the starting process. The jump start system (10) is automatically connected depending on an analysis result of the starting process. In a method for a jump start in a vehicle, the onboard power supply system voltage is measured when a or the jump start system is being connected to the onboard power supply system of a vehicle, a control logic (1) of the jump start system is supplied with power, the point in time for connecting the voltage of the jump start accumulator (2) is calculated from the onboard power supply system voltage measured during connection, reduced by a voltage jump of n volt, and the power supply is interrupted as soon as the onboard power supply system voltage exceeds a presettable voltage (U2).

Description

START-UP SYSTEM FOR A VEHICLE

The invention relates to a starting aid system for a vehicle, comprising at least one power switch, in particular semiconductor switch, and a method for jump starting in a vehicle.

In the breakdown statistics of the ADAC are unwilling to start batteries all winter on the front rank. Almost 850,000 times last year ADAC road watch drivers had to jump-start because of discharged or defective batteries - and not only in older cars. Usually used are relatively large and heavy starting aids, which are equipped with a lead acid battery. For mobile use, these devices are therefore limited. In addition, this type of jumpers usually can not be quickly recharged via the electrical system of a vehicle.

In the prior art, for example, a portable multi-purpose starter device from DE 20 2007 004 272 U1 is known. This has a housing for receiving a rechargeable battery, wherein in the housing electrical connection elements for connecting the battery are provided with provided in the housing electrical components.

From DE 299 09 348 U1 a portable battery energy storage with an integrated inverter and a network-independent recharging device, which can be recharged by means of solar and / or wind generators known.

DE 199 51 094 C2 discloses a method and a device for securing a network containing a battery against reverse polarity, short circuit and / or overvoltage, whereby a reduced current flow from a jump start point to the battery detected and only in the case of compliance with predetermined limits, a direct connection of the Fremdstartstützpunktes to the battery and the electrical system is made. DE 100 49 321 A1 discloses a device for external power supply in a motor vehicle for powering electrical consumers, which are internally connected to a power storage of a motor vehicle electrical system, wherein an inductive receiving device in the vehicle and an inductively from the outside inductively coupling means are provided ,

Another system for jump-starting is known from US 6,212,054 B1. This system can detect a wrong connection and thereby avoid the danger of battery exploding due to pole reversal. The system includes a switch that turns the power on and off. The system automatically detects a wrong polarity of the connected cables via its terminals and disconnects them from the power supply, if a wrong polarity is detected. Furthermore, the terminals are also de-energized when the cables are disconnected from them.

In all these products and methods, a second energy storage is connected, the nominal voltage or operating voltage of the on-board network corresponds to avoid the problem when connecting parallel voltage sources with different voltage.

In addition start-up systems that are additionally connected in case of failure of the starting function of an internal combustion engine, fixed-mounted starting systems for improving the starting power are known in which in addition to the on-board battery, a second energy storage, i.a. a high-performance memory based on double-layer capacitors is used. These starting systems, e.g. described in US 5,818,115, DE 10 2004 016 292 A1, DE 196 01 241 A1 and DE 41 35 025 A1, also have in common that the additional energy storage has the same rated voltage as the memory still required for the energy supply of the electrical system.

DE 10 2004 032 197 A1 and DE 196 01 241 A1 and DE 197 09 298 A1 disclose a starting system, in contrast to a start-up aid system, in which the energy store used primarily for the starting process has a higher voltage. The performance of the second, for the Onboard energy storage responsible is either not used during the boot process or only to the extent that allows the performance of a DC / DC converter for voltage adjustment, or it is only possible when the voltage of the memory with high rated voltage to the voltage level of the second Energy storage drops. Also in EP 1 424 494 A1, which describes a hybrid drive system for the common application of drive torque from two different memories with very different nominal voltage, the power of the two memories is not connected in parallel, as long as the voltages are different, but over one, the Power limiting DC / DC adjuster, which causes additional costs and additional weight.

The question of how the maximum power of a second energy storage, which would flow at about 50% of its nominal voltage, can be used for the starting process to support the already existing electrical system and starter battery, is not solved in any of these prior art documents.

When a vehicle is started, currents of several hundred amps flow, for example, over 1,000 A for large diesel cars and over 2,000 A for truck engines and other large engines. Immediately at the beginning of the starting process when the starter motor is stationary, the starter battery supplies a battery current which is essentially limited by the ohmic winding resistance of the starter motor, which is several times the internal resistance of a new battery, until countervoltage builds up due to the rotation of the starter motor and the battery current significantly reduced. The resulting current is approximately 30 - 50% of the peak current. The compression processes in the internal combustion engine result in large power fluctuations. Typically, a boot does not take longer than about one second. The required amount of charge is often well below about 1,000 As and the amount of energy depending on the voltage significantly below 10,000 Ws. The in the first about 0.1 seconds, so at the beginning of the starting process required peak current can often also from an aged battery or a battery be delivered with very low capacity or state of charge. The afterwards for On the other hand, current flowing for about 1 to 2 seconds can no longer be supplied by an aged or heavily discharged battery, especially not when the temperature of the battery and / or the motor is very low.

The requested electric power of the starter depends on the one hand on the design of the internal combustion engine, ie displacement, gasoline / diesel engine, etc., and on the other of the environmental conditions, such as temperature, oil, the previous resting phase, etc., dependent. Furthermore, the electrical resistance between battery and starter terminals must be considered.

These explanations make it clear that when designing a starting aid or starting aid system or starting system, it is not the energy content of the memory that is decisive, but its performance or its high-current behavior. For this reason, it has also been proposed to use instead of batteries as energy storage double-layer capacitors whose performance is very high for a few seconds, and their energy content is low, but still sufficient. A high performance also offers the possibility to bring the memory back to a high state of charge within a few seconds directly after the jump start has taken place in order to have sufficient energy available for subsequent starting operations.

In modern vehicles, a lower limit voltage must not be undershot during the starting process, so that the engine control remains functional. The vehicle electrical system voltage must thus always be above this limit even during the starting process. In addition, the battery for some vehicles before starting for a few seconds, a high power for some startup required functions is taken, such as over 100 A for preheating a diesel engine or about 50 A for the engine control unit and other control units. Before the launch power is released, a startup assistance system must be able to deliver a certain minimum energy without significantly reducing the starting power. It is known that in principle the maximum power that can be delivered by batteries and double-layer capacitors is reached when the internal resistance and the load resistance are equal. However, it should be noted here that, especially with batteries, the internal resistance depends on the current. This means that the higher the current, the lower the internal resistance will be. Furthermore, the internal resistance changes during the startup process. The differences in internal resistance depend on the age of the battery and the importance of diffusion and transport processes. These can significantly increase the internal resistance within one second. In addition, the resistance of the starter motor (load resistance) is significantly influenced by the induced by induction counter tension of the starter motor, which in turn is speed dependent. Furthermore, this is influenced by the fluctuating torque requirement of the internal combustion engine in the compression and expansion phases. It is therefore not possible to operate the battery during startup always at the point of maximum power output. It is also to distinguish between the point of maximum power output at the start of the starting process (breakaway torque) and the maximum power output during the startup process.

At the start of the starting process, the load resistance of the starter at standstill is given by the ohmic resistance of the windings and very low (in the range of about 2 milliohms to 5 milliohms). The usually used in the vehicle battery is thus operated at the start of the boot almost in the short circuit and near the maximum power point and the terminal voltage is well below the rated or operating voltage at about 8 - 10 V. With an optimal power adjustment (internal resistance of Battery equal load resistance (sum of all line resistances, including cable and starter windings)) would be the voltage at a fully charged lead-acid battery with 12 V nominal voltage about 6.5 V.

During the starting process, at the required for the engine start speed of the starter, the reverse voltage generated by induction is converted into a current-dependent or speed-dependent load resistance approx. 10 to 50 milliohms (mΩ) and is thus much higher than at the beginning of the starting process. The maximum power of the battery used could then be removed if the internal resistance of the battery at the respective currents flowing corresponds to the load resistance, that is to say the resistance of the starter during the starting process. The internal resistance of a conventional lead-acid battery with 12 V nominal voltage is significantly lower in design and technology due to the currents flowing during the starting process, so that the battery does not output its maximum power and is significantly oversized and too heavy for the starting process. The use of a smaller battery with higher internal resistance causes it to run in the range of its maximum power output, whereby the maximum power would decrease inversely proportional to the increase of the internal resistance because of the higher internal resistance. However, the voltage at the beginning of the starting process would then drop almost to zero because of the short-circuit-like operation and the minimum voltage required for starting the engine would not be maintained. In addition, during the starting process, the voltage would be approximately 50% of the output voltage. The voltage lower limit for the engine start would then, if at all, only just exceeded. Under these conditions, a battery that is over-dimensioned with regard to the maximum possible power output appears to be the only solution to the aforementioned problem.

However, it would be desirable to provide a lightweight portable startup device that can provide a high starting current for a few seconds, wherein the peak current required within the first approximately 0.1 second need not be fully provided by a start-up aid system, since an existing (lead starter ) Battery can also provide a high current for a short time in the aged state and deep discharge. The possibility of a direct reloading of the auxiliary starting memory after the jump start via the electrical system of the motor vehicle would also be desirable, the charging time should be low. Likewise, it would be desirable to deliver maximum battery power and make the best use of the power delivered. The present invention is therefore an object of the invention to solve the above-mentioned problems and to provide a start-up system that allows a maximum power output of the battery or other energy storage, which flows at about 50% of its nominal voltage, this power can be optimally used and that it can be recharged both via the on-board network and via the public supply network.

The problem is solved for a start-up assistance system according to the preamble of claim 1, characterized in that at least one internal starting aid memory with a predetermined, also provided below and above the nominal or operating voltage of the electrical system voltage rated voltage and the at least one circuit breaker is automatically switched by a control logic , At the same time with the current flow through an intended for starting electric drive and / or upon detection of a voltage drop below a predeterminable, dependent on the rest voltage of the starter battery threshold, the internal starting assistance memory for assisting in the power requirement during the startup to the starter battery is connected in parallel or switched , For a method for starting assistance in a vehicle, the object is achieved in that when connecting one or the jump start system to the electrical system of a vehicle, the vehicle electrical system voltage is measured at rest, a control logic of the starting assistance system is powered, the time for switching on the voltage of the auxiliary starting memory falls below a predeterminable threshold based on the voltage measured during clamping vehicle voltage reduced by an occurring voltage jump of n volts calculated or signaled by receiving a signal from an engine control unit of the vehicle, regardless of the height of the voltage of the Starthilfespeichers the start assist system that the on-board battery connected in parallel, and the power supply is interrupted as soon as the vehicle electrical system voltage rises above a predefinable voltage. Further developments of the invention are defined in the dependent claims.

As a result, a start assist system is created, in which by providing the Starthilfespeichers parallel to the starter battery this in the power requirement during a boot process or during the boot-initiating functions required by the operation. Discharging the booster battery and charging the starter battery before starting the boot process is prevented by the targeted connection, so that no unwanted charge balance between the memories occurs. The nominal voltage of the internal auxiliary starting memory can differ significantly from the nominal or operating voltage of the vehicle electrical system. The parallel connection of internal starting aid storage and starter battery takes place at very different voltages of both energy storage without previous voltage adjustment. This is an advantage that the prior art systems do not have. For the purposes of the present invention, the term "at the same time" not only means an absolutely simultaneous connection, but is also regarded as a simultaneous connection, in which a time delay for detecting a voltage dip is taken into account and in which there is a time delay due to the required computing time of a microcontroller To trigger the switching of the circuit breaker is the signal of detecting a voltage dip as well as the activation with a signal from the engine control.

In the method for jump starting in a vehicle, a load jump or voltage jump can be detected. It is also possible to query a corresponding signal of an engine control unit and in response thereto switch on the starting assistance memory. A connection of the startup memory is in each case only when it is really necessary, a shutdown after the boot process. Compensating charges between the starter battery and the auxiliary battery in the form of the auxiliary starting memory are therefore not available. After the starting process has been completed, the starting aid memory can be recharged via the vehicle electrical system to a specified end-of-charge voltage by closing the circuit breakers and direct recharging without a DC / DC controller or by recharging via an internal DC / DC controller with the circuit-breaker open.

If the vehicle electrical system voltage falls below a predefinable or predetermined threshold several times during the starting process, the starting aid system also switches several times on and off; so that whenever the lower or upper threshold is reached, the power supply or the start assistance is turned on or interrupted. An interruption of the power or voltage supply can alternatively be done after a predetermined period of time.

The voltage of the auxiliary starting memory and the rated or vehicle electrical system voltage of the vehicle may differ considerably. For batteries, e.g. a rated voltage of at least about 10 V be useful in double-layer capacitors, for example, three double-layer capacitors can be provided with a nominal voltage of about 2.5 to 2.7 V, respectively. However, in these cases, the principle of performance adjustment can no longer be used. In principle, it would also be possible for the rated voltage and / or operating voltage of the auxiliary starting memory to correspond to the nominal voltage and / or operating voltage of the vehicle electrical system battery.

Advantageously, a starting aid battery or a starting aid memory with a higher rated voltage than is now commonly used, so that the required power can be provided with a smallest possible battery. The voltage limits during startup can still be met. If e.g. a battery with 18 V operating voltage and an internal resistance, which corresponds to the load resistance of the starter during startup, is used, the output voltage of the battery or the auxiliary starting memory during startup is about 9 V and the startup process can be performed easily.

Advantageously, the voltage of the Starthilfespeichers with batteries is chosen so large that the optimum charging voltage of the booster battery is about twice as high as the vehicle electrical system voltage while the alternator is running. It should be noted that the memory is made up of a series connection of individual cells with a defined internal resistance. The aim should be to choose the number of cells so that the internal resistance and the load resistance have an equal value, so that a Power adjustment with maximum output power and minimum losses is achieved.

Thus, during the start-up procedure, a starting aid memory with an unusual rated or operating voltage is used, in particular a battery or a double-layer capacitor, with a nominal voltage of at least approximately 10 V. The capacity of the starting aid battery can amount to at least approximately 2 Ah, in particular 2 to 10 Ah, in particular 6 to 7 Ah. Even a capacity of just under 2 Ah is possible in principle, but usually capacity values of more than 2 Ah will be used. When a nickel-metal hydride battery is used, it may have, for example, a capacity of about 6.5 Ah and an internal resistance of about 1.3 to 1.6 mΩ per cell after a millisecond discharge with a discharge current in the range from about 600 to 800 A. ,

Advantageously, the internal resistance of the auxiliary starting memory is chosen or selected so that the internal resistance of the auxiliary starting memory corresponds approximately to the internal resistance of the starter in the operating state of a start. The total voltage of the booster battery in the idle state can advantageously be about twice as high as an optimum voltage occurring during the starting process. Regardless of the rated voltage thus has the starting aid memory required for a starting operation on internal resistance area and the electrical system of the vehicle, the jump start is given, can be protected from a nominal voltage outside the permissible range.

Since the existing starter and vehicle power supply battery remains in the car, so two batteries are connected in parallel with different voltage. Therefore, a control device is advantageously provided, which controls the connection of the internal start-up memory of the jump start system to the electrical system, so that both batteries or storage, the on-board battery and the starting aid memory, are operated in parallel only during load time. Problems due to the design of the batteries or memory with different voltage can be avoided because due to the low load resistance and the then flowing from both memories currents the common voltage of both energy storage in the allowable voltage range remains. Separating diodes, which prevent a current flow from the auxiliary starting memory with its higher voltage in the electrical system battery with its lower voltage, and which are described in the above-described references of the prior art, are not required under the selected internal resistance conditions. The resulting costs as well as their additional internal resistance can be avoided.

As an alternative to the method described above, the object can also be achieved by a method in which, with a favorable choice of the rated and operating voltage of the auxiliary starting memory, especially if it is below the operating voltage of the electrical system battery, the control logic and the switch operated by it by a passive Component, eg a diode, to be replaced. Alternatively, the function of the control logic and the switch operated by it may thus be controlled by a passive semiconductor switch, e.g. a diode, which only becomes conductive when the voltage of the auxiliary starting memory is above the voltage of the starter battery, which is greatly reduced during the starting process. If a passive component is provided instead of the control logic and the switch actuated by this, this allows the flow of current from the starting assistance memory to the starter at the time when the starter motor is energized, and interrupts the current flow again as soon as the starter motor is disconnected from the electrical system.

As it turns out to be advantageous if a diode is connected between a starting aid memory with an operating voltage below the usual electrical system voltage in the idle state and the electrical system, which then allows a flow of current from the starting aid memory, if the vehicle electrical system voltage due to the voltage drop during startup under the voltage of the startup auxiliary memory sinks.

Next, the task for a method for starting assistance in a vehicle can be achieved in that the starting assistance memory is manually switched on at low vehicle electrical system voltage or by connection to the Fahrzeugelektrik is automatically switched on when the starting process of the vehicle is actuated.

A boot process via the external start assist system without a built-in system battery is usually not provided, since the vehicle should remain functional after the startup and then running engine even after disconnecting the Jump Start system. This would not be possible without a battery in the vehicle. Further demands on the performance and voltage of the built-in system battery are not set up here.

In order to protect in the case of a failure of the control logic and / or a circuit breaker between the startup assistance system and electrical system this against too high a voltage of the auxiliary starting memory, a protective circuit is advantageously provided. Advantageously, the protective circuit comprises at least one resistor or a diode, via which the starting aid memory is discharged or discharged starting at a predefinable voltage which is above the voltage to be expected during operation of the vehicle electrical system voltage and the load of the vehicle electrical system. The protective circuit is advantageously made of a diode, so that is shorted at a voltage exceeding the inadmissible current through this device. The protective circuit is advantageously connected hard with the output terminals of the starting aid system, so it is always active. Advantageously, it is not engaged when loading the Starthilfespeichers. If a continuous load of this protective circuit acting as a bypass is not possible, advantageously an acoustic warning message can be issued, which prompts for disconnecting the starting aid system.

Advantageously, at least one device for smoothing the voltage is provided in the case of frequent switching operations by the control logic, in particular in the case of manual activation of the starting aid memory. Such a smoothing device may e.g. be a smoothing capacitor.

An activation of a permanently installed start-up assistance system can take place simultaneously with the activation of the starter motor by the engine control. A Activation of the starter assist system as an external device, which is only connected in parallel to the vehicle power supply battery during startup problems, can take place when a load jump is detected by a voltage jump. Therefore, a device for detecting a load jump is advantageously provided, which is advantageously encompassed by the control logic and which emanates from the measured before the start of the vehicle electrical system voltage and switching on or Leitendmachen a circuit breaker. As a result, the booster battery is automatically connected via the circuit breaker and disconnected, so that a startup process via the Starthilfespeicher and a reload of this is done automatically by the on-board battery. However, the starting aid battery can also be configured manually switchable when a load jump can not be detected and / or when the vehicle electrical system voltage is so low that the starting process of the vehicle by its control units is no longer einleitbar. The jump start memory can also be automatically connected when connected to the vehicle control via the vehicle control upon application of a signal to start the engine. If necessary, the starting aid storage can be connected in parallel to the battery of the vehicle and, in particular, disconnected from the battery of the vehicle if the vehicle electrical system voltage rises above a predefinable limit value when the vehicle engine is running. Because at this time the jumper terminals have the same voltage as the on-board battery, there is no sparking when disconnected. Incidentally, no sparking occurs even when connecting the booster with the electrical system, since the terminals of the booster are de-energized. A protection against reverse polarity is automatically ensured by the control unit and the sequence when connecting and disconnecting is not relevant.

Advantageously, a circuit arrangement for directly charging the start-up memory, in particular two halves of the start-up auxiliary memory or the starting aid battery, provided via the electrical system. The starter assist system can advantageously be connected directly to the starter battery of the vehicle for recharging or remain connected after completion of the jump start, so that recharging takes place via this. There are no discharge and no equalization currents, so that consequently no problems when connecting and disconnecting occur. The jump start memory can advantageously via an external Voltage source or an external charger that provides the desired charging voltage, or be recharged. Furthermore, an internal charger may be provided for charging the start-up memory. The charging power is advantageously designed so that in a short time, for example, about one minute, the charge taken in the jump start charge is again largely loaded into the starting aid memory, ie the charging current is for example a few 10 amps. The separation of the starting aid memory in two halves, which can be loaded in parallel with half of the otherwise required voltage, is advantageous for direct charging via the electrical system. The two halves of the Starthilfespeichers can be connected to each other via at least one switch and with the electrical system battery via other switches. The one switch can be identical to the circuit breaker of the start assist system, which can be switched on via the control logic. The switch may also be identical to the switch of the starter motor, which connects the starter motor during startup with the electrical system.

Advantageously, at least one device can be provided for evaluating the data of the start-up assistance system for assessing the onboard power supply battery. About such an evaluation can be quickly and easily determined whether, if necessary, the electrical system battery is damaged and, if necessary, must be replaced or whether a short circuit in the electrical system is present. Such a data logger is advantageously designed as an independent unit of the start-up assistance system in order to be able to evaluate data and to be able to record further data even after the starting process and disconnection of the start-up assistance system. With a connected start-up assistance system, if necessary, an engine hood of a vehicle can no longer be closed, which is why the start-up assistance system should be removed in order to drive the vehicle into a workshop or other location. The datalogger measures the voltage of the vehicle electrical system and stores it with a high temporal resolution, such as 1 kHz. It can be switched on manually and either begins to save the data by means of another manual intervention or it starts to save as soon as the voltage changes by more than a predefinable value, eg 0.5 V when switching on control units. For this purpose, a corresponding query and evaluation of the voltage values is provided. As further advantageous, it turns out that the starting aid system is modular. Depending on the type of vehicle, the integrated starting aid memory can be individually adapted with regard to energy content, continuous power output, peak power, voltage, temperature behavior, etc. On the other hand, the other components of the start-up assistance system can be used independently of the start-up assistance store in all embodiments of start-up assistance systems.

With regard to the structure of the starting aid system, it proves to be advantageous to make the housing so that it is designed in the manner of a cover, which is in particular adapted to shape, can be placed on the weak electrical system battery. In case of an explosion there would be protection against splinters.

For a more detailed explanation of the invention, an embodiment of this will be described in more detail below with reference to the drawings. These show in:

1 shows a diagram with internal resistances of different NiMH modules with 6 cells at different current amplitudes,

FIG. 2 shows a schematic illustration of the structure and the coupling of a starting aid according to the invention to a vehicle electrical system,

FIG. 3 shows a diagram showing the voltage curve during a starting process (low-level battery) with indicated switching thresholds (U1, U2) of the starting assistance system,

4a, 4b is a schematic representation of a direct charge circuit for recharging the booster battery, wherein the state of the circuit breaker between the on-board battery and the two halves of the booster battery during the startup process (Figure 4a) and during the recharge (Figure 4b) are shown

5a, 5b is a schematic representation of a start-up procedure (FIG. 5a) and a charging process (FIG. 5b) for recharging the starting aid battery, wherein the state of the power switches between the onboard power supply battery and the two halves of the starting aid battery during the starting process (FIG. 5a) and during the recharging (FIG. 5b), and FIG. 6 shows a schematic representation of a device according to the invention

Connection of the two halves of a booster battery when starting a vehicle.

Figure 1 shows a diagram showing the internal resistances of various nickel-metal hydride modules with six cells at different current amplitudes. Values up to approx. 200 A represent the usual field of application for modules of hybrid vehicle applications. The six cells of the nickel-metal hydride modules have a nominal voltage of 7.2 V in the example shown.

It can be further seen from FIG. 1 that nickel-metal hydride modules or batteries having a capacity of approximately 6.5 Ah in the range of approximately 600 A have an internal resistance of approximately 1.3 to 1.6 mΩ per cell after one millisecond Have discharge. After one second, the value increases to approx. 2 to 2.3 mΩ per cell.

With fifteen series-connected cells rated at 18 V and operating at approximately 20 V when fully charged, they will then have approximately an internal resistance equal to the starter load, terminals, cabling, etc. during start-up. The batteries are operated at their maximum power in the startup process under these conditions. At rest of the starter, however, the resistance of the armature is much lower than the internal resistance of the battery. The battery is therefore almost always operated in short-circuit when switched on. The current is much higher than in other operating states. The voltage drops, but should remain above the lower limit voltage for the starting process. This is made possible by switching many cells of the battery in series and the starter battery of the electrical system. Although this can no longer deliver the required power, it also helps to ensure that the vehicle electrical system voltage does not collapse. Figure 2 shows schematically the structure of a starting aid system 10 according to the invention, which can be connected to an electrical system 11 of a motor vehicle, including a starter, and a starter battery 12, when the starting process with the built-in electrical system battery alone can not be performed successfully. In Figure 2, this is shown in the connected state. The starting aid system 10 comprises a control logic 1 and an internal starting aid memory 2, for example, with a rated voltage above 12 V, which can be connected in parallel with the starter battery to assist in the power request during the startup process. The switch-on and switch-off thresholds or criteria for the internal start help memory can be specified exactly to the control logic, so that the switching thresholds for the memory technology used can be adjusted accordingly. The switching thresholds are dynamically changeable by the logic unit or control logic depending on the terminal voltage of the electrical system. A schematic representation of the voltage curve during a starting operation of a weak battery can be seen together with the switching thresholds LM and U2 of the starting aid system in FIG.

As can be seen further in FIG. 2, the control logic 1 is supplied with power by the starting aid memory 2. Therefore, the control logic 1 is provided with a switch or circuit breaker 7 for manually disconnecting the control logic of the starting aid memory 2, so that the starting aid memory in the form of a battery is not discharged at a standstill.

For loading the start-up memory, an external or internal charger 3 is provided and connected to the jump start memory 2. Furthermore, the start-up assistance system comprises a data logger 4, which is integrated between the starter battery and the control logic. This data logger can be designed as a separate unit that can be separated from the other components of the startup assistance system. Current, voltage and possibly temperature values can be recorded via this data logger 4 and stored with high temporal resolution, eg with a resolution of 1 kHz. The data stored in the data logger 4 data can be read, for example via a USB port. An evaluation can be made via a normal PC, which is not shown in Figure 2.

According to FIG. 2, the start-up assistance system also has a 12 V vehicle electrical equipment 6. However, this is not essential. However, if the onboard power supply battery has such a low voltage that not even the engine startup control devices can be switched on, the 12 V onboard power supply device can generate a required vehicle electrical system voltage in the permissible range instead of the starting aid memory or in addition to this. The onboard power supply 6 can be connected via a switch 8 to the electrical system 11.

The internal starting aid memory 2 usually has a different terminal voltage than the starter battery 12. For batteries as starting aid storage, the voltage will be above the vehicle electrical system voltage, so that they can be operated in the range of their maximum power. For double-layer capacitors (DSC) as start-up memory, a lower voltage can be used to minimize the cost of the double-layer capacitors. In the case of very large double-layer capacitors, a voltage which is significantly above the maximum permissible vehicle electrical system voltage is usually not possible since very large double-layer capacitors close to the short circuit initially show only a small voltage dip. For example, six double-layer capacitors are realized with a charging voltage of 2.7 V per cell, since their maximum voltage of 16.2 V at the start of the starting process will fall below 16 V, provided such a high voltage is permissible for the particular application. In addition, rated voltages of very large double-layer capacitors with very low internal resistance are usually not possible with a 12 V electrical system. For example, the use of 600 F double-layer capacitors with respect to the internal resistance ratio would be unproblematic, whereas 3000 F double-layer capacitors would lead to a voltage overload for the battery and the vehicle electrical system. The starting aid memory 2 normally has a significantly higher rated voltage than the vehicle electrical system. In a 12 V electrical system, the voltage of the auxiliary starting memory 2 will be in the range of about 20 V to about 26 V. 20 V are provided by eg 15 NiMH cells with a rest voltage of about 1.32 V / cell, whereas 26 V are realized by eg 18 NiMH cells with a voltage of about 1.45 V / cell, measured a short time after disconnection from the charge sustaining voltage. For 24 V on-board systems, the values are twice as high, that is, at about 40 V to about 52 V.

In order to protect the vehicle electrical system 11 against excessive voltages in the event of a failure of the control logic 1, a protective circuit is provided (not visible in FIG. 2) which starts at a predefinable voltage which exceeds the expected during operation vehicle electrical system voltage and the consumer On-board network damaging voltage is, for example a voltage of about 15 V, the starting aid memory, e.g. a battery, discharges through a resistor. Here, e.g. a Zener diode may be provided, which becomes conductive from a certain voltage.

As already mentioned above, the provision of a device for reloading the Starthilfespeichers makes sense. Such a device may be a DC / DC converter, which uses the voltage of the electrical system, as soon as the electrical system has a voltage above about 13V. Another possibility is to provide as a device, the cigarette lighter of a vehicle and a DC / DC converter or a 240 V socket, a plug-in power supply or a conventional charger can be used. The control logic monitors the charging process and releases the DC / DC converter. An overload of the memory is also prevented by the control logic.

Alternatively or additionally, with a suitable choice of the nominal voltage of the auxiliary starting memory 2, the charging can also take place directly through the vehicle electrical system battery 16, as outlined in FIGS. 4a and 4b. Here, a circuit breaker 13 is inserted between the two halves of Starthilfespeichers. This is closed during the starting process for connecting the two halves 20, 21 of the booster battery or the memory (Figure 4a) and is for the reloading process opened (Figure 4b). In terms of function, the switch 13 corresponds to the switch 7. Two other circuit breakers 14, 15, the two halves 20, 21 of the start-up memory 2 are connected to the electrical system battery at the two ends or poles. The two circuit breakers 14, 15 are open during startup and are closed for reloading. Immediately after the end of the starting process, the vehicle electrical system voltage rises very quickly to over 13 V, so that then the booster battery can be charged.

FIGS. 5a and 5b correspond in principle to FIGS. 4a and 4b. 5a and 5b, the starter motor 17 is shown in addition to the structure in FIGS. 4a and 4b, as is the internal resistance 18 of the vehicle electrical system battery 16. The starter motor 17 is in each case parallel to the series connection of the two halves 20, 21 the booster battery and the circuit breaker 13 switched. The starting assistance system is thus installed in the immediate vicinity of the starter motor 17 and loads the vehicle electrical system battery 16, so that they only have to deliver a comparatively small proportion of electricity during the starting process.

With fixed installation of the auxiliary starting memory, the power switch 13 may also be identical to the magnet switch of the starter motor, which is actuated via the engine control unit or the ignition key for switching on the starter motor. FIG. 6 shows this variant. Here, the power switch 13 is formed as a magnetic switch and has a coil 19 for actuating the magnetic switch. A parallel to the power switch 15 provided diode 22 is provided only in the event that the coil 19 of the magnetic switch 13 of the starter motor 17 and all other consumers of the circuit are not sufficiently high impedance, so for example, about 50 mΩ below, corresponding to a load current of 60 A. ,

The two power switches 14,15 for charging the two halves 20,21 of the booster battery can also be looped into the circuit for actuating the magnetic switch 13. The charging voltage of a NiMH battery is for example in the range of 1, 4 to 1, 6 V / cell, ie in a nine-cell battery with a rated voltage of 10.8 V at a vehicle electrical system voltage between 12.6 and 14.4 V. The advantage of in Figure 4a, b outlined charging circuit is that this does not require a DC / DC converter and thus is easier and cheaper. The recharging of the auxiliary starting memory takes place immediately after the end of the starting process until the starting aid system is disconnected. The charging circuit also has the advantage that standard chargers can be used for 12 V vehicle electrical systems.

It is also advantageous to measure the current of the starting aid memory by the voltage drop across the circuit breakers 7 or 13, so that without additional components of the data logger can detect the power of the booster, and / or the battery current through a clamp meter. Advantageously, the determination of the charging and discharging current is possible here in order to enable a monitoring of the state of charge, which is calculated via the current integral.

In order to generate the at least required on-board network voltage for initiating the starting process, the starting aid memory can be used. At a correspondingly high switching frequency, with the voltage of the auxiliary starting memory, and possibly on a smoothing capacitor, is switched on and off, the smoothing capacitor can be charged to a voltage necessary for the initiation of the starting process voltage, for example 10 V. The voltage will fluctuate relatively high for small and inexpensive capacitors. It is therefore also possible to use a small replacement battery, namely the onboard power supply unit 6, if the engine control units do not work properly with such high and large voltage fluctuations, even if they are within the permissible voltage range. This replacement battery is capable of supplying a sufficiently high current for a short time, eg 10 seconds, eg a current of about 50 amps without the on-board voltage dropping below the voltage level at which the controller turns off. 10 series-connected 2.5 Ah high-rate NiCd or NiMH cells or a 12V lead-acid battery in the capacity range of approx. 2-6 Ah or a small lithium battery (3 cells) are already sufficient for this purpose. From the voltage curve of the vehicle electrical system during and after the starting process can already be concluded without current measurement, but better with current measurement, on the state of the electrical system battery. If the voltage of the generator increases to the set voltage value of the electrical system, then it can be assumed that the charging capacity of the battery is low and it is sulphated. It is then in a worse condition than a battery that pulls a high charging current at a lower voltage. In addition, from the voltage noise of the battery caused by load fluctuations of the vehicle, the internal resistance can be estimated. A damaged battery has a much higher internal resistance than a very low-discharged battery. When using a clamp meter, as already mentioned above, the corresponding evaluations are more accurate.

The procedure for starting and reloading startup memory will now be described below. For the jump start process, the control logic 1 is first switched on and supplied by the booster battery when connecting the jump start system to the electrical system of a vehicle. Next, the on-board voltage of the weak starter battery is measured. If the vehicle electrical system battery has too low a voltage or load capacity, then the power is supplied via the on-board power supply battery or the smoothing capacitor charged via the starting auxiliary storage. Here, a manual switch is provided. The control logic calculates the voltage U1 at which the switch is to be switched off from the vehicle electrical system voltage measured during clamping by a voltage jump of n volts, for example 2 volts. Such a voltage jump or break is associated with a high current load of the electrical system battery, as it exists during the starting process. The voltage supply is interrupted again, so the start assist system off as soon as the voltage is above a voltage U2, for example, of about 13 V, but at the latest after a predetermined time, such as 5 seconds. Above all, the respective switching thresholds can be specified by the manufacturer, as can the time values, so that an adaptation to any on-board network topologies and starting aid memory is possible. Advantageously, the voltage and Time values are no longer changed by the user, so that no damage to the electrical system of the vehicle by an incorrect setting of the values occur. Basically, however, a user-side adjustability of the voltage and time values can be provided. Possible here, for example, a dynamic specification of the threshold and time values depending on the height of the vehicle electrical system voltage. At a high terminal voltage can be assumed that a relatively good battery, so that an intensive support, combined with a long duty cycle, is not required. With low vehicle electrical system voltage can be assumed that a bad starter battery, so that the duty cycle is to extend.

At very low voltage, which is for example at about 0 - 6 volts, u.U. no more load jump is detected or the engine control units no longer initiate the starting process. Then, the switch 7 can be operated manually, so that the starting assistance memory 2 is switched to the electrical system. The vehicle electrical system voltage then rises immediately steeply and the switch 7 is operated via the control logic 1 so that the vehicle electrical system voltage remains in a likewise predeterminable voltage range, for example, a range between about 8 V and about 12 V. Furthermore, it may prove useful to connect a small capacitor via the terminals of the auxiliary starting memory 2, so that the voltage does not switch so fast between the two limit values.

The power switch 7 should conduct high currents with low loss and be inexpensive, which is why the use of eg a MOSFET proves to be suitable. Losses when switching on and off can usually be neglected. Because of the maximum low duty cycle of eg 5 seconds no special cooling is needed. Advantageously, the mounting of the switching elements directly on the housing in order to derive the power loss in the form of heat directly to the outside. In principle, of course, a cooling can be provided, if this is application-specific desired or should prove to be advantageous. A particularly favorable structure results in the provision of a parallel connection of MOSFETs, since then also modules with a maximum current of well over 1000 A can be built by simply connecting several MOSFETs in parallel using a driver.

For starting assistance with 24 V electrical systems, the voltage values given as examples for a 12 V vehicle electrical system would have to be doubled. However, the mentioned exemplary time values can remain the same as those mentioned above.

If the start-up assistance system is placed on the battery to be started, e.g. with a shape-adapted housing, it is possible to make the cables used 5 for the connection of the start-up assistance system to the electrical system and the starter battery or vehicle power supply very short, e.g. to be provided with a length of about 30 cm. As a result, cables can advantageously be saved and inductive overvoltages, which can have a negative effect on the electrical system, be avoided. Due to the small length, the cables can be relatively thin.

In addition to the above-mentioned and shown in the figures embodiments of starting assistance systems and methods for starting aid can be formed numerous other, in each of which at least one circuit breaker, in particular semiconductor switches and at least one internal starting aid memory are provided, the starting auxiliary memory connected in parallel to the starter battery of the vehicle is or can be switched. In particular, while the nominal voltage or operating voltage of the auxiliary starting memory is higher than usual and differs in particular from the vehicle electrical system voltage. In addition, applications are also possible in which the starting aid system described here can completely replace a starter battery, for example in vehicles in which, in addition to a vehicle power supply battery, a starter battery used only for the starting process is used, or in emergency power systems. In particular, in hybrid vehicles in which a traction battery and a starter battery are provided, can be dispensed with the second-mentioned. A DC / DC converter in combination with a small battery, which does not have to be designed for high starting power, in this case provides for the stabilization of the low voltage electrical system and the starting process of the internal combustion engine is using a modified Version of the start assist system presented here. Even with vehicles with start-stop system, the start assist system described here in the immediate vicinity of the starter motor can be permanently installed and load the onboard power supply battery, so that they only have to deliver a relatively small proportion of electricity during startup.

LIST OF REFERENCE NUMBERS

1 control logic

2 start help memory

3 external or internal charger

4 data loggers

5 cables for connection to batteries

6 onboard power supply unit

7 circuit breakers

8 switches

10 startup help system

11 board network

12 starter battery

13 circuit breakers

14 circuit breakers

15 circuit breakers

16 electrical system battery

17 starter motor

18 internal resistance

19 coil

20 half booster battery

21 half booster battery

22 diode

Claims

claims

1. start assist system (10) for a vehicle, comprising at least one power switch (7,13), in particular semiconductor switch, and an electrical system (11), characterized in that at least one internal starting aid memory (2) with a predetermined, even below and above the Nenn - or operating voltage of the electrical system lying nominal voltage provided and the at least one circuit breaker is automatically switched by a control logic, simultaneously with the current flow through a provided for starting electric drive and / or upon detection of a voltage drop below a predeterminable, from the rest voltage of a starter battery (12 ) dependent threshold, wherein the internal start help memory (2) for assisting in the power demand during the startup process to the starter battery (12) of the vehicle is connected in parallel or switched.

2. Start-up assistance system according to claim 1, characterized in that the starting auxiliary storage has a nominal voltage of at least about 10 V.

3. Starting aid system according to one of claims 1 or 2, characterized in that when using double-layer capacitors at least three double-layer capacitors are provided with a nominal voltage of about 2.5 to 2.7 V.

4. Start-up assistance system according to one of the preceding claims, characterized in that the capacity of the starting aid battery is at least about 2 Ah, in particular 2 to 10 Ah, in particular 6 to 7 Ah.

5. starting aid system (10) according to any one of the preceding claims, characterized in that the internal resistance of the starting assistance memory (2) is selected or selectable, that the internal resistance of the starting assistance memory (2) corresponds approximately to the internal resistance of the starter of the vehicle in the operating state of a start, and the total voltage of the booster battery in the idle state is about twice as high like an optimal tension occurring during the starting process.

6. Start-up assistance system according to one of the preceding claims, characterized in that a protective circuit is provided to protect the electrical system (11) from too high a voltage of the starting assistance memory (2) in case of failure of the control logic (1) and / or a circuit breaker (7, 13 ) between starting aid system (10) and electrical system (11).

7. Starting aid system according to claim 6, characterized in that the protective circuit comprises at least one resistor or a diode, via the or the starting assistance memory (2) from a predetermined voltage, which is expected to be expected during operation of the vehicle electrical system voltage and the consumer of the electrical system (11) damaging voltage is dischargeable or discharging.

8. Start-up assistance system according to one of the preceding claims, characterized in that a device (1) for detecting a load jump, starting from the measured before starting the start-up vehicle electrical system voltage, and switching on or Leitendmachen a circuit breaker is provided.

9. Start-up assistance system according to claim 8, characterized in that the starting assistance memory (2) is manually connectable when the load jump is not detectable or when the vehicle electrical system voltage is so low that the starting operation of the vehicle by its control units no longer can be introduced.

10. Start-up assistance system according to claim 8, characterized in that the starting aid memory (2) is automatically switched on connection with the vehicle control via the vehicle control upon application of a signal for starting the internal combustion engine.

11. Start-up assistance system according to one of the preceding claims, characterized in that the starting aid memory can be clamped parallel to the battery of the vehicle and separated from the battery of the vehicle when the vehicle electrical system voltage rises above a predeterminable limit with the vehicle engine running.

12. Jump start system according to one of the preceding claims, characterized in that a circuit arrangement for direct charging of the start-up auxiliary memory (2), is provided via the electrical system.

13. Jump-start aid system according to claim 12, characterized in that two halves of the starting assistance memory are interconnected via at least one switch (13) and to the vehicle power supply battery (16) via further switches (14, 15).

14. Start-up assistance system according to claim 13, characterized in that the one switch (13) is identical to the circuit breaker (7).

15. Jump start system according to claim 13, characterized in that the switch (13) is identical to the switch of the starter motor, which connects the starter motor during startup with the electrical system.

16. Start-up assistance system according to one of the preceding claims, characterized in that an external charger for charging the starting assistance memory (2) is provided.

17. Start-up assistance system according to one of the preceding claims, characterized in that an internal charger for charging the starting assistance memory (2) is provided.

18. Start-up assistance system according to one of the preceding claims, characterized in that at least one device is provided for evaluating the data of the start-up assistance system for assessing the onboard power supply battery.

19. Start-up assistance system according to one of the preceding claims, characterized in that the starting aid system is modular.

20. Jump-start aid system according to one of the preceding claims, characterized in that a housing of the start-up assistance system is designed in the manner of a cover which is adapted to shape over a weak battery of the vehicle can be laid.

21. A method for jump-starting in a vehicle, in particular using the starting aid system according to one of the preceding claims, characterized in that when connecting one or the start assist system to the electrical system of a

Vehicle, the vehicle electrical system voltage is measured at rest, a Is supplied with power, the time of switching on the voltage of the auxiliary starting memory (2) falls below a presettable threshold based on the voltage measured during clamping vehicle voltage reduced by an occurring voltage jump of n volts calculated or by receiving a signal from one Engine control unit of the vehicle is signaled, regardless of the height of the voltage of the Starthilfespeichers the Starthilfesystems that the on-board battery connected in parallel, and the power supply is interrupted as soon as the vehicle electrical system voltage exceeds a predetermined voltage (U2).

22. A method for jump starting in a vehicle, in particular using the jump start system according to one of claims 1 - 20, characterized in that the starting assistance memory is manually switched on at low vehicle electrical system voltage or automatically connected by connection to the vehicle electrical system when the starting operation of the vehicle operated becomes.

23. The method according to claim 21 or 22, characterized in that the start assist system is activated upon detection of a load jump by a voltage jump.

24. The method of claim 21, 22 or 23, characterized in that instead of the control logic (1) and a switch actuated by this, a passive component, in particular a passive semiconductor switch is provided.

25. The method according to claim 24, characterized in that the passive component is a diode.

26. The method according to any one of claims 21 to 25, characterized in that between a starting aid memory (2) with an operating voltage below the usual vehicle electrical system voltage in the idle state and the electrical system, a diode is connected, which then allows a flow of current from the starting aid memory (2), if the vehicle electrical system voltage drops below the voltage of the auxiliary starting memory (2) due to the voltage drop during starting.