SE538825C2 - Method and apparatus for starting an internal combustion engine driven with alcohol or alcohol-mixed fuels - Google Patents

Abstract

SUMMARY Procedure and apparatus for operating an alcoholic and alcohol-containing internal combustion engine (10). A method and an apparatus for operating an alcohol and alcohol-containing mixed fuel internal combustion engine, the ignition of which is effected by a special device, are described, with at least one heating device (20, 22) for heating the fuel and a single-heating control device (30) for control and / or regulating the heating effect of the heating device (20, 22). Upon fulfillment of a criterion indicative of an impending start of the internal combustion engine (10) and upon fulfillment of a criterion from which the cold start of the internal combustion engine (10) can be concluded, the heat control device (30) is activated. Depending on the use or non-use of an ignition and starting device (31, 46) for the internal combustion engine (10), different temperature setpoints (T_SP_LOW, T_SP_H | GH, T_SP_ST) are set for the fuel medium heat control device (30). The temperature setpoint (T_SP_HIGH) when the ignition is switched on and the unused starting device (31, 46) of the internal combustion engine is then selected higher than the temperature value (T_SP_LOW) when the ignition is switched on. The temperature setpoint (T_SP_ST) when the ignition is switched on and use the starter (31, 46) is selected higher than the temperature setpoint (T_SP_HIGH) at the ignition and the unused starter (31, 46).

Description

1Procedure and device for starting an internal combustion engine powered by alcohol or alcohol fuels TEKN | s | The invention relates to a method and a device for driving an alcohol and alcohol-containing mixed fuel internal combustion engine, the ignition of which is effected by a special device, with a heating device for heating the fuel and a single heat control device for controlling and / or regulating the heating effect of said heating device.

BACKGROUND Vehicles are known which can be operated optionally both with alcohol or with alcohol containing mixed fuels, ie. with fuels with variable alcohol content, as with Otto fuels (petrol), ie. fuels for Otto engines. Alcohols, e.g. ethanol or methanol in the fuel can then be present in different proportions in the range between 0 and 100%. Such fuels are also referred to as III as "Flex Fuel" or "Flexible Fue (FF) and the motor vehicles that can be driven as FlexibleFuel Vehicle (FFV). Common alcohol mixtures are, for example, M85, ie. 85% methanol in the fuel, and E85, ie. 85% ethanol in the fuel, in which case the petrol content consequently in both cases is 15%. In the Brazilian market in particular, motor vehicles were used, in which pure ethanol (E100) was used as fuel.

The use of such mixed fuels with a high alcohol content has the disadvantage that the vehicle is difficult to start at low temperatures, since alcohol evaporates very poorly at low temperatures. For vehicles that are refueled with 100% ethanol, for example, a start below + 12 ° C (flash point ethanol) is almost impossible. Since cold start problems thus occur with special measures, small, fixed-built fuel add-on tanks are carried in vehicles as permissible operation with very high alcohol concentrations, which fuel add-on tanks contain a small amount of starting fuel, e.g. Brazilian gasoline ("Gasohol", E20 fuel). To start the vehicle under certain external temperatures, petrol is then used as starting fuel or injected in addition to the 1G 2 alcohol so that a combustible mixture is formed. The problem with this, however, is that always very small amounts of fuel are taken out of the additional container at the initial start as the content starting fuel and this starting fuel becomes worse with time. Linder "worse" is understood in this context that the volatile hydrocarbon aerodynes such as propane and butane easily evaporate and leak out of the additional container due to the high temperatures in the engine compartment of the internal combustion engine and thus the vehicle, and the high temperatures during the summer months, during which no starting fuel is needed. The ingredients necessary for a cold start are then lost or at least greatly reduced. Under certain circumstances, a cold start can no longer be performed. The pressure forces US 4,911,115 A and US 45646591 A describe the fuel systems for internal combustion engines of a motor vehicle which are operated with alcohol and have separate cold starting tanks containing petrol, which is used to start the engine. Then, when the local engine has started and starts to get hot, the main tank is connected to the alcohol-containing fuel instead of the cold-start fuel. It is disadvantageous here that both tankers require a separate filling, ie. supply lines to the body exterior and any separate tank hatches must be provided. The driver must also monitor the fuel level in both tanks in order to be able to top them up on time. Furthermore, the driver must distinguish between two separate tank filling pipes, which in the event of negligence can lead to an incorrect filling of the two tanks.

From DE-OS 25 36 432 an internal combustion engine is known which is drivable with alcohol and alcohol-containing mixed fuels and in which a cold start device with an electric drive heating device is provided in a side suction duct which engages a main mixture forming device. The necessary air for the cold start mixture is taken from the main air suction duct, whereby the flow connection can be interrupted by a shut-off device. By heating the fuel-air mixture, the starting probability (Startfreudigkeit) of the internal combustion engine at low ambient temperatures is improved.

In addition to this, cold start systems are already known for having a high alcohol content in the fuel, propulsive motor vehicles which heat the fuel to higher temperatures by means of electrical energy from the detelectric vehicle system (battery). The fuel heating in the injector or in the spreader bridge can then take place by means of a resistive or inductive heating principle. 1G 3 From LP-A-SZ 665/1982, a heating device is known for heating an inlet line, the heating device being controlled depending on the output signal of an alcohol concentration sensor and in which the heat production amount of the heating device becomes larger when the alcohol concentration is greater than the reference concentration.

All these electric heating systems have the disadvantage that they need a certain heating time which depends in particular on the coolant temperature of the motor vehicle before the starting procedure of the internal combustion engine and that not much power for the heating systems can be taken out of the electric vehicle system. Üenna preheating resp. The heating time of the electric heating systems appears to be a loss of comfort which cannot be neglected compared to a starter system with an additional tank for a starting fuel.

SUMMARY OF THE INVENTION The object of the invention is to show a method and a device for propelling an internal combustion engine containing alcohol or alcohol containing mixed fuels, which method resp. which device ensures a rapid start of the internal combustion engine even at low temperatures and very high alcohol content in the fuel and thereby not excessively strain the electric vehicle system.

This task is solved according to the features of the independent claims. Advantageous further developments and embodiments of the invention are characterized in the subclaims. The invention is characterized by a method and a corresponding device for driving an alcohol and alcohol-containing mixed fuel internal combustion engine, the ignition of which is effected by a special device, with at least one heating device for heating the fuel and a thermal control device for controlling and / or regulating the heating effect of said at least one heating device. Upon fulfillment of a criterion indicative of an impending start of the internal combustion engine and upon fulfillment of a criterion from which it is possible to conclude a call start of the internal combustion engine, the heat control device is activated. Depending on the use or non-use of an ignition and 4-start device for the internal combustion engine, different temperature setpoints for the fuel are set by means of the heat control device. The temperature setpoint when the ignition is switched on and the unused starting device of the internal combustion engine is then chosen higher than the temperature value when the ignition is switched on. The temperature setpoint when the ignition is switched on and the starter is used is selected higher than the temperature setpoint when the ignition is switched on and the starter is not used.

With the method according to the invention it is on the one hand possible to clearly reduce the time preheating of the fuel and thus the waiting time for the driver of the motor vehicle until it can safely start the internal combustion engine, which increases comfort in comparison with known heating systems with constant heating power.

In the event of certain events that indicate an imminent cold start of the combustion engine, the fuel is heated up to a first, relatively low temperature setpoint. This first temperature setpoint is selected in such a way that no vapor bubble formation occurs in the fuel. A typical value is 60 ° C. Should afterwards still no start of the internal combustion engine take place within a first predetermined period, e.g. since the driver has admittedly opened the car door, but has not switched on the ignition, the heating device is deactivated again, ie. is turned off.

By selecting a lower first temperature setpoint at a first time, at which a start of the internal combustion engine is probable, but where it is finally not yet certain that it will be carried out, an excessive load on the electric vehicle system can be avoided.

If after such preheating the first, lower temperature setpoint is also switched on during the first period, it is a stronger indication that a start of the internal combustion engine could take place immediately. Therefore, the fuel is heated to a second temperature setpoint, which is higher than the first temperature setpoint, for example to a value of 100 ° C.

Occurs during a second predetermined period since ignition "ON" no start of the internal combustion engine, ie. the starting device is not activated, as the driver e.g. only switched on the ignition to listen to music by means of the car radio, it is regulated to the first, lower temperature setpoint and after the end of the first period the heating device is deactivated, 5dvs. is turned off. It also helps reduce the load on the electric vehicle system.

Since after switching on the ignition in this case a heating only needs to take place from the first temperature setpoint to the second temperature setpoint, this results in both a totally smaller heating effect and a shortened heating time compared to a heating based on a lower starting temperature up to the second temperature setpoint.

If the starting device is also used within the first period, the fuel is heated up to a third temperature setpoint, which is higher than the second temperature setpoint, for example to 12G ° C, whereby a safe and fast start of the internal combustion engine is ensured even at low ambient temperatures. in this case the heating only needs to take place from the second temperature setpoint to the third temperature setpoint, so that only a small heating effect still needs to be supplied. This results in a shortened heating time compared to a heating starting from a lower starting temperature up to the third temperature setpoint.

According to an advantageous design, when the internal combustion engine, ignition is switched on and the unused starter is stopped, it is checked how often the ignition is switched on without using the internal starter. When a predetermined threshold value for this number is exceeded, a temperature setpoint is selected which corresponds to the temperature setpoint at ignition ignition, since in this case it is not clear whether the driver wants to start the internal combustion engine at all. Such an approach also contributes to the reduction of the heating effect and thus to a lesser load on the electric vehicle system.

According to a further advantageous design, during a post-start phase after a successful start of the internal combustion engine, the temperature setpoint is reduced with increasing time based on the temperature set point when the ignition is switched on and the starting device is used. The reduction in temperature setpoint correlates with the increasing combustion chamber temperature and helps to relieve the electric vehicle system.

A further relief of the electric vehicle system is obtained, the local heat control device is deactivated completely after the expiration of a period after a successful start of the internal combustion engine. This period is advantageously determined depending on the temperature of the coolant at the start of the internal combustion engine, on the 2G 5aikohoiandeien of the fuel and on the air / lance ratio. This ensures on the one hand that the tilting motor does not die again after the start, and on the other hand that the heating only takes place as long as absolutely necessary.

Yet another advantageous design is that the temperature setpoints for the fuel are fixed depending on the temperature of the cooling medium at the start of the combustion engine and an air-fuel ratio, whereby an optimum heating effect under these margins is obtained for the result.

According to the invention, the activation of the heating device and the output of the heating effect are copied to events which, in terms of time, lie before the start of the internal combustion engine.

According to a further advantageous design, it is used as a criterion for a possible impending start of the internal combustion engine in connection with the use of the door handle of the driver's door in the vehicle driven by the internal combustion engine, the signal of a switch at the door lock of the driver's door actuator. Since already other functions, such as the activation of the housing in the interior space, are triggered in modern motor vehicles by touching the use of the door handle or by opening the stool door, a simple and cost-effective variant is obtained for activating the heating device prematurely for the result.

Yet another advantageous design is used as a criterion for a possible start of the internal combustion engine signaled by a sensor device to identify the seat attachment of the driver's seat of the vehicle powered by the internal combustion engine. Then also sign! yet present in modern motor vehicles, a cost-effective solution is obtained for activating the heating device prematurely to the resultant. If the vehicle is secured by an active or passive access system against unauthorized access, then the possibility of such an identification identifier is analyzed, in the simplest case the transmitter also has a radio-controlled remote control for centralization. Here again, no further components are necessary, 1G 2G FIGURE DESCRIPTION An embodiment of the invention is explained in more detail below with the aid of drawings. Fig. 1 shows: Fig. 1 in the form of a block diagram an internal combustion engine with petrol, alcohol or with optional mixed ratios of these fuels with associated control device, Fig. 2 a flow chart of a program for controlling the fuel system for such an internal combustion engine.

DESCRIPTION OF PERFORMANCE ESFGRMS Figure 1 shows in schematic representation an internal combustion engine 1G of a motor vehicle which can be driven with petrol, alcohol as well as with optional mixing ratios of these fuels. Such motor vehicles are referred to as flexible fuel vehicles (FFV) or as variable vehicles.

When the term fuel is used in the following, it means a fuel which either consists of pure petrol (Otto fuel), or of a mixture of optional proportions of petrol and alcohol or of pure alcohol, in particular pure ethanol (Elüöl. L Figure 1 are only those components In particular, the ignition device necessary for igniting the fuel / air mixture is omitted. The invention is explained by means of an internal combustion engine 1G with four cylinders 21-24, however, it is also useful for internal combustion engines with a second cylinder number and more particularly independently. the nature of engine concepts, such as four-stroke Otto engine, two-stroke engine or rotating piston notches.

An intake section 11 and an exhaust section 12 are connected to the internal combustion engine 1G, by means of which non-manufactured intake and exhaust valves are connected to the combustion chambers of the cylinders 21-24 of the internal combustion engine 10. The combustion of the fuel / air mixture is necessary for the combustion. Due to the combustion of the fuel / air mixture 1G 8biidade exhaust gases are purified in a non-produced exhaust aftertreatment device and reach via ambient muffler to the environment.

To start the pre-combustion engine 10, a starting device is provided which, for example, comprises an electric starting device 46 and an ignition starting contact 31.

The internal combustion engine 10 has a refueling supply system which, among other things, has a refueling supply housing 13 and an electrically driven electric pressure pump 14 which connects fuel from the fuel supply container 13 via a self-propelled fuel supply line 15 to each other. of the fuel injector 19 with the aid of the fuel can be injected directly into the combustion chambers of the cylinders 21 to 24 and which are in this case in fluid communication with the spreading bridge 18 via lines not further specified.

Since the operating ratio of the internal combustion engine 10 also depends to a large extent on the nature and composition of the fuel, an aikohoi concentration sensor 26 is provided in the fuel supply system, which aikohoi concentration sensor 26 detects andeienaikohoi in the hrier. In the exemplary embodiment according to Figure 1, this alcohol concentration sensor 20 is arranged in the pressure relief line 15. Alternatively, the alcohol concentration in the fuel tank may be determined by means of a mode of operation of operating parameters of the internal combustion engine 10, which may already be present. exhaust sensor 28, as exemplified in US 6,257,174 B1.

To ensure a start-up of the internal combustion engine 10 even at low temperatures during operation with a high alcohol content, an electric heating system for the fuel is provided, which is described in more detail below.

Each of the individual fuel injectors 19 is provided with an electric heating device 20 and a temperature sensor 21 which registers the temperature of the fuel in the respective fuel injector 19. It is also possible to provide only a single temperature sensor 21 at one of the fuel injectors 19, the measured value of the fuel injector 19. Alternatively, the temperature can be determined via a change in the material properties of the fuel injectors. Alternatively, in addition to heating the fuel injectors 19, an electric heating device 22 is provided in or near the spreader bridge 18. If the heating system consists exclusively of the heating device 22, the spreading bridge 18 is provided with a temperature sensor 23 serving to record the fuel temperature.

For control and / or control of the described heating system, a single heat control device 30 is provided, by means of which the heating effects can be varied the preheating devices 20, 22, so that different fuel temperature setpoints are set. The signals of the temperature sensors 21, 23 for the fuel, the signal of an average temperature sensor 25 and the signal of the alcohol concentration sensor 26, as will be explained in more detail with the aid of Figure Z, are evaluated by the heat control device 30.

Thermal control device 30 contains a calculation unit 36 which is connected to a program memory 37 and a value memory 38 (data memory). The computing unit 36, the program memory 37 and the value memory 38 may each comprise one or more microelectronic components. Alternatively, these components may be partially or completely integrated in an endamicroelectronic component. In the program memory 3 "? or the value memory 38 are programs or value-saved which are necessary for the operation of the internal combustion engine 10. In particular, a method for heating the fuel is implemented, which is processed by the calculation unit 36 before and during the operation of the internal combustion engine 10, as will be explained. in more detail with the aid of figure 2. in the value memory 37 are, among other things, different setpointsT_SP_LOW, T_SP__l-llGl ~ l. T___SP_ST for the fuel temperature in the fuel injectors 19 and the ice spreader bridge 18 and different threshold values t furthermore, two timers 33A, 398 are present, the function of which will also be explained in more detail with the aid of the description of the method sequence according to Figure 2.

The heat control device 30 is connected to the ignition starting contact 31, which in position 1 releases the ignition of the internal combustion engine 10 and in position 11 activates a starting device for starting the internal combustion engine 10, for example an electric starter. Reference numeral 32 denotes an electrical switch element, the activation of which is interpreted as an indication of a possible imminent starting procedure of the internal combustion engine 10. This may be the signal of a switch arranged at the door lock of the driver's door or a door opening contact which also activates the interior. If the driver 's seat is equipped with a sensor device to identify the seat occupancy, the signal of this sensor can also be used.

If the vehicle has such a whimsical, active or passive entry system, then the signal of a mobile identification sensor which serves for the opening and closing and closing of doors of the internal combustion engine motor can be used. In the single case, the use of the transmitter by a radio-controlled remote control for centrally locking the doors and luggage compartment may be construed as indicative of a potentially imminent start-up procedure of the internal combustion engine 10. In Figure 1, such a transmitter is marked with the associated vehicle number 34 and reference numeral.

The mentioned devices 32, 34 make it possible to already activate the heating devices 20, 22 before the driver of the motor vehicle uses the ignition-start switch 31 resp. a start-stop button.

Furthermore, the heat control device 30 is connected to a voltage circuit 35, preferably to the vehicle battery of the electric vehicle system. It supplies, among other things, via non-produced power outputs, the electrical energy of the heating devices 20, 22.

For controlling and controlling the internal combustion engine 10, an electronic control unit (ECU) 24 is provided which is electrically connected to the heat control device 30, preferably with a CAN bus 40. Thereby, rabbit input signals from sensors which are directly supplied to the motor control device 24 are also controlled by the motor control device. for further processing. Likewise, rabbit input signals from sensors which are directly fed to the motor control device 24 are also transmitted to the heat control device 30 for further processing. In addition, operating quantities and / or calculated quantities can be exchanged via this CAN bus 40.

Additional sensors are arranged on the motor control device 24, which sensors record the respective measured quantities and determine the respective measured value for the measuring quantity. In addition to measured quantities, operating quantities also include quantities derived therefrom. The ivory control device 24 determines control quantities depending on at least one of the measuring quantities and / or the operating quantities, which control quantities are then converted into one or more control signals for controlling actuators by means of corresponding actuators. The sensors are, for example, the temperature sensor temperature 25 for the cooling coil temperature TKW, a crankshaft angle sensor 27 which registers a crankshaft angle, to which a speed N is then assigned, an alcohol concentration sensor 26 and the exhaust gas sensor 28 in the exhaust section 12 and further fuel with reference numeral ES. The levers are, for example, a throttle 29 in the intake section 11, the fuel injectors and the low pressure fuel pump 14. Additional signals for additional actuators which are necessary for the operation of the internal combustion engine 10, but which are not explicitly produced, are generally denoted by reference numeral AS. The motor control device 24 comprises in a known manner a calculation unit 41 which is connected to a program memory 42 and a value memory 43 (data memory).

Among other things, the engine control device 24 determines, depending on a load signal and the speed N, during evaluation of the signal of the alcohol concentration sensor 26 for the composition of the fuel the appropriate ignition time and injection period.

Program resp. values are stored in program memory 42 resp. the value memory 42, which program responses. values are necessary for the operation of the internal combustion engine 10. Among other things, quantities of off-characteristic curves ('to be explained in more detail with the aid of figure 2, are stored in the value memory 43).

Figure 2 shows in the form of a flow chart a method for controlling a cold start system within a fuel supply system of an internal combustion engine.

The process starts when at least one criterion is met which is indicative of an impending start of the internal combustion engine 1G (step S1). The touch or use of the stool door handle by a person can, for example, be used as a criterion or sign which makes a start of the internal combustion engine 10 probable. Also by evaluating the signal of a switch arranged at the driver's door load switch or of a door opening contact, for example activating the interior lighting of the passenger compartment, can be interpreted as an indication of a possibly imminent start of the internal combustion engine. If the driver 's seat is equipped with a sensor device for identifying the seat occupancy, then also a signal generated by this sensor device can be interpreted as an indication of a possibly imminent start of the internal combustion engine.

If the vehicle powered by the internal combustion engine has a so-called keyless entry system, the activation of the transmitter by a radio-controlled remote control for opening and closing and / or reading the vehicle doors can be used as an indication of a possible imminent starting procedure of the internal combustion engine. The signal of a radio-controlled remote control for opening a door of a garage in which the vehicle is parked or in front of which the vehicle is parked can also be interpreted as an indication of an imminent start of the internal combustion engine 10. Are none of these criteria resp. the characters are fulfilled, the processing is continued again in step S1, possibly after the expiration of a predetermined waiting period t_WAiT.

However, if there is an indication in step S1 that could indicate an imminent start of the internal combustion engine 1G, the engine control device (ECU) 24 is activated and it is announced whether it is necessary to install the cold start system for heating the fuel (step S2). Such a cold start system is required especially when the fuel has a high alcohol content, since alcohol evaporates very poorly at low temperatures and thus defends or even makes a cold start of the internal combustion engine impossible. In detail, in step S2, the temperature of the refrigerant TKW, the alcohol content of the ALQAN fuel and a time period t_ST after starting the internal combustion engine were used to determine whether the cold start system is needed.

If the temperature of the coolant TKW, which as a very good approximation reflects the temperature of the internal combustion engine 10, is below a predetermined threshold value TKW_SW, then the cold start system must be activated. Since the temperature at which a safe cold start of the combustion engine 10 can still be carried out depends on the alcohol content ALQAN in the fuel, this threshold value TKW__SW due to the alcohol content ALQAN stored in a plurality of off-characteristic curves KF1 in the value memory 43 of the engine control device 24. , the more the threshold value TKW__SW, from which the cold start system must be activated, shifts to higher temperature values. 2G 13The value of the temperature of the cooling medium TKW is obtained from the signal of the temperature sensor 25, the value of the aliquot ALQAN is obtained from the signal of the aikoho concentration sensor 26. From these values, empirically threshing values TKW_SW are determined and saved in the set of characteristic curves KFZi ..

Furthermore, in step S2, it is checked whether a predetermined period t__ST has elapsed since the start of the internal combustion engine 10. i-iartiii is counted for a time-after-start-up 44 still present in the engine control device 24 and also for other control and / or control purposes. such a fixed period t_ST larger than a predetermined threshold value t_ST_SW, it is assumed that the starting procedure of the internal combustion engine 10 is successfully completed and that the internal combustion engine 10 runs stably. The quay start system is not needed resp. is no longer needed and can thus be deactivated (step S3) and the process is complete (step S29).

The threshold value t_ST_SW is determined empirically depending on the temperature TKW of the chimedium and on the koikohidei ALC_AN and is stored in a set of characteristic curves KFZ within the value value 43 of the motor control device 24. This means that for a visskyimedei temperature TKW and a certain aikohoiandei within ALCHAN the kaiistart device must be activated.

If the result of the de-icing in step S2 is that a heating of the fuel is necessary for a proper start of the internal combustion engine 10, the heat control device 30 is activated in a step S4. This is preferably done via the CAN bus 40. In a subsequent step SS it is checked whether the combustion engine 10 is running, that is to say whether its speed is above a predetermined value (logic variance LV_ERU = 1). at the first review of the process is so not faiiet and the process continues with a step Sö. in step Sö it is announced whether the ignition of the internal combustion engine has been switched on. in the case of a conventional ignition ignition switch 31, the position (position i, figure 1) of the ignition key (ionic variable LVJGK = 1) is evaluated here. If the ignition is not switched on (position G, figure 1), the procedure continues with a step S7. It is determined whether a predetermined period t_SP__LOW determined by the timer 39A is utiupen, that is, greater than a predetermined threshold value tmSPJtQWMSW. At the first 2G 14 review of the process, the counter setting of the counter 39A is still noii, i.e. it is not started yet and the process continues with a step S8. in step S8, a first setpoint T__SP___LOW is determined for the temperature, at which point the fuel is scraped up. This setpoint T_SP__LOW is due to the temperature of the starting medium TKW at the start of the internal combustion engine 10 and to the air-fuel-promoting AFR stored in a plurality of uncharacteristic curves of the value memory 38 of the heat control device 30. 18, so that the determined first temperature setpoint t__SP__i.OW, for example 60%, is reached.

The maintenance of the setpoint temperature is monitored with the aid of the temperature sensors 21 at the fuel injectors 19 and 19, respectively. of the temperature sensor 23 at the spreader ridge 18 and thereby enables a control of the heating power of the heating devices 20, 22. in a subsequent step S9 the counter control of the timer 39A is raised and the procedure continues with step S2. If the start-up system is still necessary, the engine is still running and the ignition is still switched off, steps S2, S4 to S9 are then completed, and step S7 is determined for the first time that the predetermined period t__SP__LGW, exernpeivis30 seconds, is elapsed. in this case, step S10 is branched off, in which case the power supplies of the heating devices 20 and 20, respectively. 22 is turned off.

The above-described review of the process reflects the fact that although there was an indication of a possible start of the combustion engine 10, however, within the predetermined period LSPHLOW since then no start attempt was made. This can, for example, occur when a person has opened the door of the vehicle, but not used the ignition key, because he only wants to retrieve something from the vehicle or put something in it. in this case no further heating is required.

However, during the described procedure in step 6, it is obtained for the result that the ignition is switched on (position 1 of ignition-start contact 31, figure 1), i.e. the logical variable LVJGK = 1, this is a further, compared with criteria in step S1, a stronger indication that a possible start of the internal combustion engine 10 is imminent. in a subsequent step S11 it is announced how the ignition ignition had already once been brought into position in jiogic variable LV ___ iGi <,, - 1 = 1). If so (yes), it is announced in a subsequent step S13 whether the number of ignition uses 1G 26 3G (position 0 to position 1) has exceeded a predetermined threshold value CTRJGKWNÛNQSW. If the result of the reading is positive, the procedure continues with step S7. The threshold value CTR_EGK__ON_SW can, for example, be located 3 and 5 and is stored in the value memory 43 of the motor control device 24.

If the reading in step S11 results in a negative result (nêii, then in a step S12 the counter position CTRJGEQCN of the counter 45 is satisfied and the procedure also continues with step S13.

On the basis of the readings in steps S11 and S13, the idea is that there is no intention to start the combustion engine when the use of the ignition key in position is subsequently carried out and the subsequent use of position ii. The use of the lighter, for example, was only intended to appear on the radio in a similar way. in this case, then, the activation of the heating device 2G, 22 takes place with a heating effect having a relatively low temperature, for example the stated 66% at the same time, ie when the predetermined period is exceeded, the complete deactivation of the heating device. however, it was identified in step S13 that the ignition key was either used for the first time or repeatedly several times, but this number has not yet reached the threshold value CTR_iGK_ON_SW, so in the next step S14 it is seen whether a non-predetermined by the timer 398 is fixed in the period ie. is greater than a predetermined threshold value twjSPwi-iiGHWSW. The timer 398 starts to start when it is determined in step S6 that the ignition is turned on. If the pea threshold value T_SP__LOW has not yet been reached, a second, in comparison with the first setpoint T_SP__LOW increased setpoint TL__SP__i-iiGH for the temperature is determined, until the fuel is heated up (step S15). Also this setpoint T__SP_i-iiGi-i is dependent on the temperature of the cooling medium TKW at the start of the internal combustion engine 10 and on the air-fuel ratio APRsparated in an amount with characteristic curves of the host 38 of the heat control device SO. The heating devices 20 of the fuel injectors 19 and / or the heating device 22 of the spreading bridge 18 are activated by means of signals of the heating control device 30, so that the determined second temperature value T_SP_HiGi-i, for example 100%; achieved. The maintenance of this elevated setpoint temperature is also monitored with the aid of the temperature sensor 21 at the cleaning injectors 19 and 19, respectively. of the temperature sensor 23 at the diffuser bridge 18 and thus a control of the heating effect is made possible. 1G 16 in a subsequent step S16, the counter position of the timer 398 is raised and the procedure continues with step S2.

The determination of an elevated setpoint T_SP_HEGH for the temperature compared with the first setpoint T_SP__LOW is justified in that a starting procedure of the internal combustion engine10 is soon more probable at ignition (iogic variable LVJGK = 1) than at rejected ignition. If it really does start the internal combustion engine 1G, then the fuel is then optimally heated and the starting procedure of the internal combustion engine 10 is successful even at low temperatures. Even if only once the ignition is turned on and off, the ignition start switch 31 may not be operated to position ii within the predetermined period_SP__i-iiGi-i (reading in step S14), so no start of the internal combustion engine 1G is initiated. Post-resuscitation at the end of the period t_SP__HiGi-i, for example 2G seconds, the procedure continues with step S7 which has already been preceded.

Thereby a lowering of the higher temperature setpoint T__SP_HIGH takes place to the lower temperature setpoint "f___SP__LOW, which is equivalent to a lowering of the heating power.

If it is determined in a repeated review in step 5 that the internal combustion engine 10 is running (LV__ERU = 1), it is announced in a step S17 whether the internal combustion engine 1G is still in the starting phase or in the post-start phase. The internal combustion engine 10 is in the post-start phase when the speed has exceeded a predetermined threshold value, for example ltiöü min * (logic variable LV__ST__END = 1), otherwise in the start phase.

If the combustion engine 10 is still in the starting phase, when the starting device 46 is still activated, for example an electric starter which is still engaged with the pivot shaft of the internal combustion engine 1G, the process continues with a step S18. in this step S18 a third is determined, in relation to the first setpoint T_SP__LOW and the second setpoint 'LSPj-iiGH once to the increased setpoint' f_SP_ST for the temperature, to which the fuel is to be heated. Also this setpoint "fSP_ST is dependent on the temperature of the cooling medium TKW at the start of the internal combustion engine 10 and the air-fuel ratio APR stored in a plurality of characteristic curves of the thermal memory 38 of the thermal control device 30. ivedeist 1G 17 signals of the thermal control device 20 or the heating device 22 of the spreading bridge 18, so that the determined third temperature setpoint T_SP__ST, for example 120 ° C, is reached.

If the reading in step S17 results in the internal combustion engine 10 being in the post-start phase, i.e. a successful start of the internal combustion engine 10 is completed due to the heating of the fuel, then the heating devices 20, 22 are not immediately deactivated, but the sub-post-start phase of the internal combustion engine 10 is determined. characteristic curves for the setpoint T__SP__ST, by weighting this set of off-characteristic curves depending on the period after the start t_ST (step S19). Over time, the heating effect and thus the temperature of the fuel is reduced. The longer the internal combustion engine 10 is running, the less the fuel needs to be heated to ensure proper operation of the internal combustion engine 10.

If it is subsequently determined in step S2 that the period LST has expired, for example 6G seconds have elapsed, then heating of the fuel is no longer necessary, the heating devices 2ö, 22 in step S3 are switched off, the heating device deactivated and the process ends with step S29. the invention was explained by means of an example, in which the motor control device 24 and the protection control device 30 are manufactured as separate components. However, it is also possible to fully integrate the heat control device 3G with the associated output stages of the heating devices 20, 22 in the motor control device 24 or to integrate only the control electronics and to externally arrange the output stages of the heating devices 2G, 22. In the described embodiment, the motor vehicle has a conventional The invention is equally useful for modern motor vehicles, in which no key in the true sense needs to be inserted in a reading to activate the ignition and start the engine. keyless-go systems suffice the presence of the "electronic key", also often referred to as a mobile identification sensor, in the interior space, the start-up procedure then being sufficient by pressing a start-stop button, in which case the signals of these components for activation are analyzed to heat early. the scheme. 18When reference is made to a combustion meter, the ignition of which is effected by special means, here and in the hot document it refers to what in German is summed up with the single word "fremágezündetï" in an example, it is an combustion engine which does not work according to the principle of self-modification. 19 conceptually / HÄNVlSNlNGSBETECKNlNGSLlSTA 113.213141,518lå21222324262728293G3132333436373839A395 förbränningsrnotor lnsugnlngssträcka exhaust distance bränsleförrådsbehâllare low-pressure fuel lågtrycksbränslelednlng sprldarbrygga bränslelnjaktor värrneanordnlng lnjektorer ternperatursensor lnjektor heating device sprldarbrygga ternperatursensor spridarlaryggamotorstyrnlngsanordnlng (ECU Electronic Control Unit) tarnperatursonsor kylmadelalkonolkoncentratlonssansor vevaxelvinkalsansor exhaust gas sensor throttle värmestyrnlngsanorclning (l-LCU, heater control unit) the ignition-starter switch electrically switching the transmitter of the radio remote, mobile ldentlflkatlorssglvaremottagare of radio remote voltage source, fordonsbatterl unit L LCU programmlnna HCU värdomlnrre, datarnlnne HCU tlclräknare for heating the ignition of tloräknara for heating at ignition on 4142434446 N "RKW rkw__swrwkstLsgLovvLsm-iaei-ir fi srwsrT_sP__Asr Es As 21-24 Ara sm kr:: Qvvair iHsT i__s “r __svvLsauiowgseiovvmsvvLsrgnieiißvvALC__ANLvæeau CAN ~ bus unit ECUprograrnminne ECUvärdeminne, data memory ECUtidräknare for the period after the start counter for the use of the ignition starting device of the internal combustion engine varvtai kvimedeistemperatur tröskeivärde kvimedeistemperatur temperature of the fuel first set point for KST ternperatur second set point for KST terriperatur third öörvärde for KST terriperatur iaörvärde for bränsietemperatur in efterstartsfaseningångssignaier output signals, control signals cylinders of internal combustion engine iuft-fuel ratio amount of characteristic curves amount of characteristic curves waiting period period after start of internal combustion engine threshold value for period after start of internal combustion engine period for heating during ignition of pre-ignition pre-heating in the fuel iogisk variabei engine running 21LVJGK iogisk variable ignition LVMSTMPENÜ log isk variabei engine operation outside start

Claims (3)

A method of operating an alcohol and alcohol-containing mixed fuel combustion engine (10), the ignition of which is effected by a special device, with at least one electric heating device (20, 22) for heating the fuel and a heat control device (30) for control and / or or regulating the heat output of said at least one electric heating device (26, 22), characterized in that when fulfilling a criterion indicative of an impending start of the internal combustion engine (10) and when fulfilling a criterion from which it can be terminated a cold start of the internal combustion engine (Sat), the heat control device (30), ~ different temperature setpoints (T_SP_LOW, T_SP__lllGH, T__SP__ST) are activated for fuel setting by means of the heat control device (36) depending on the use or non-use of an ignition and start device (31, 46) 10), whereby ~ the temperature setpoint (T_SP__i-liGH) when the ignition is switched on and a non-use starting torch ignition (31, 46) of the internal combustion engine (10) is selected higher than the temperature value (T__SP_LOW) when the ignition is switched off, - the temperature setpoint (TmSP__ST) when the ignition is switched on and the starting device used (31, 46) is selected higher than the temperature setpoint (lmšPmwl-lß) with ignition on and unused starter (31, 46). Method according to Claim 1, characterized in that the stationary combustion engine (16), when the ignition is switched on and the unused ignition device (31, 46) are checked how often the ignition is switched on without using the ignition starter device (31, 46) and exceeding a predetermined threshold value (CTR_lGK__ON_SW) for this number, a temperature setpoint is selected which corresponds to the temperature setpoint (T__SP__LOW) when the ignition is switched off. A method according to claim 1 or 2, characterized in that the adjacent internal combustion engine (10) is checked, on ignition and non-use starting device (31, 46) whether a predetermined period (t__SP__1 ~ 11GH) has elapsed since the first ignition of the ignition and in the In the positive case, a 1G Zí) 3G 10. 11. 23natural setpoint corresponding to the temperature preservation (TQSPÛLÛW) is selected in the event of rejection. 1 to 3, one of the features characterized in that, according to the protection control device (30), deactivation is deactivated in the event of an ignition ignition after the expiration of a method of a predetermined period (tji-LLOW). Method according to claim 1, characterized in that the temperature setpoint during a post-start phase after a successful start of the internal combustion engine (10) is reduced with increasing time starting from the temperature setpoint (T_SP__ST) when the ignition is switched on and the starting device (31, 46) is used. according to the heat control device (šö) is deactivated after the expiration of a period (t_ST) according to Method one of the preceding claims, characterized by eighteen successful starts of the seed burning engine (10). Method according to claim 5, characterized in that the period (t_ST) is determined depending on the temperature (TKW) of a cooling part at the starting of the internal combustion engine (Sat), an alcohol content (ALC__AN) of the fuel and an air / fuel ratio (AFR). according to the temperature setpoints (T_SP_LOW, T_SP__HEGH, T__SP__ST) for the fuel are established. Method according to one of the preceding claims, characterized in that it depends on the temperature (TKW) of a core at the start of the ridge engine (10) and an air / fuel ratio (AF). method according to any one of the preceding claims, characterized in that touching or the use of the door handle of the driver's door of the vehicle driven by the preheating engine (10) is used as a criterion for an impending start of the derailleur engine (10). Method according to one of Claims 1 to 8, characterized in that the signal of a wide door lock of the driver's door of the switch operated by the internal combustion engine (19) or of a door opening contact is used as a criterion for an impending start of the internal combustion engine (16). Method according to one of Claims 1 to 8, characterized in that the signal of a single-sensor device for identifying the seat occupancy of the driver's seat of the vehicle driven by the derailleur (10) is used as a criterion for an impending start of the derailleur motor (10). 1G 12. 1 Method according to one of Claims 1 to 8, characterized in that the signal of a mobile identification sensor (33), which serves for the opening and closing and / or reading of doors of the vehicle driven by the internal combustion engine (Sat), is used as a criterion for an impending start. of the internal combustion engine (10). Apparatus for driving a fuel system of an aikohoi eiier aikohoi mixes as a fuel drivable internal combustion engine (10), the ignition of which is effected by separate means, with at least one electric heating device (20, 22) for heating the fuel and a heat control device (30) the control heat effect of said at least one electric heating device (2Û, 22), the device being designed to carry out a method according to any one of claims 1 to 12.