DE4338824A1 - Method and device for pulse-wise metering of additives into a line of a consumer - Google Patents

Description

The invention relates to a method for pulse-wise Adding additives to a line of a Ver according to the preamble of claim 1 and a device for carrying out the method.

Since the introduction of catalytic converter technology in the automotive industry lead-containing additives, such as lead tetraethyl, can not More can be used. The catalyst is on the Ver use of unleaded fuel. To Ge certain functions in the engine and be Certain fuel properties are as additive He been developed, for. For example, organic sodium salt compounds. These must be in certain minimum concentrations in the fuel. If the Additives are supplied to a fuel tank result within the tank local concentration  fluctuations, thereby ensuring compliance with the minimum requirements tration is no longer guaranteed.

The invention is based on the object, a method for pulsed metering of additives into one To specify the direction of a consumer with whom sicherge is that the supplied to the consumer Flüs always the required minimum concentration Contains additive.

The solution of this task is inventively with the features specified in claim 1.

In the method according to the invention, the current Behavior of the consumer thereby festge provides that the number of characteristic Betriebszu measured within a calculation interval becomes. Depending on the operation thus measured then the pulse interval of the metering pulses will behave each set a predetermined amount of the additive injected into the line of the consumer becomes.

Preferably, the inventive method is used for Adding additives to the fuel line of a Vehicle. In this case can be considered more characteristic Operating state evaluated the start of the vehicle with the frequency of starting, i. H. of Increasing the speed from zero to determined becomes. The volume of the added amount of active ingredient can while driving according to the current operation behave, and possibly taking into account the driving type of calculation. Preferably, the Metering of the active substance into the fuel line,  which leads to the engine. A dosage in the force Return line is also possible and technically easier to implement, if you have that there due to the resulting concentration fluctuations of the Ad additives in the fuel, caused by difference Liche filling levels of the fuel tank, accepted.

An example of a drug that is the fuel can be supplied to a vehicle is an or ganic sodium salt compound or another for the unleaded operation of petrol engines (with Kata lysator) suitable additive. Another example is an active substance for the improvement of the exhaust behavior of diesel engines.

The following is with reference to the only Figure of the drawing an embodiment of the Er invention explained in more detail.

In the drawing is a block diagram of Dosiervor Direction for metering an additive into a force fuel line of a vehicle shown schematically.

A counter 10 detects the number of start-up operations of the vehicle, so the starting frequency, in a Be calculation interval t _max . For this purpose, the counter 10 is provided with an input line 11 which is connected to a suitable sensor, which z. B. detects the wheel revolutions or signals that give the start, receives from the ignition coil. The counter reading of the counter is continuously fed to a memory unit 12 , in which table 3, which is explained below, is stored. Depending on the count of the counter 10 , the memory unit 12 supplies a factor X₁ to the arithmetic unit 13th In the arithmetic unit 13 , a normal value of the pulse interval Δt _{N is} multiplied by the factor X 1 . This normal value Δt _N is stored in a memory 14 , which is connected to the Rechenein unit 13 .

Furthermore, a preselection switch 15 is provided, at which the vehicle type corresponding average consumption per 100 km can be set. This average consumption value is assigned the factor X₂ in the memory unit 16 , for which only integer values are possible.

The factors X₁ and X ₂ are multiplied in the arithmetic unit 13 with the standard value .DELTA.t _N , so that the computing unit determines the pulse interval .DELTA.t of the metering pulses as follows:

Δt = X₁ × X₂ × Δt _N.

The metering pulses whose time interval is .DELTA.t and whose duration is fixed, z. B. one second, are supplied via an association unit 17 to an amplifier 18 whose output drives the metering pump 12 such that whenever a metering pulse occurs, a predetermined amount of liquid is injected into the line 20 connected to the consumer.

The length of the calculation interval is determined by a timer 21 which is connected to the arithmetic unit 13 as well as to other components of the circuit.

The dosing start signal, which is supplied to the logic circuit 17 via line 22 , is generated, for example, by the magnetic switch of the starter of the vehicle. The logic circuit 17 becomes conductive upon the occurrence of this signal and maintains the conductive state until the ignition of the vehicle has been turned off.

Hereinafter, a calculation example of the Be measuring the pulse intervals explained.

Conditions or assumptions:

• 1. The active ingredient (additive) is in a Konzen added to the fuel by 1 vol. d. H. in 1000 l of fuel is 1 l of additive ent be hold.
• 2. The additive concentration is adapted to the vehicle type, z. B. by setting by means of the switch 15 before. In the following calculation example, it is assumed that the average consumption of the vehicle is 10 l per 100 km.
• 3. The average distance covered should 20 000 km per year. This means, at a distribution over 300 days a daily drive distance of about 67 km per.
• 4. These 67 km will be according to the current Be driving behavior of the vehicle within 10 Hours completed.  
• 5. The vehicle is therefore with a mean Ge speed of 50 km per hour.

The arithmetic unit 13 for calculating the dosing pulse intervals receives the following information:

• 1. starting frequency of the vehicle,
• 2. Dosing start by pressing the vehicle on Lasser.

If 67 km within an interval with a through average speed of 50 km / h become, so creates a measuring interval duration of 67 km 50 km / h = 1.3 hours. This corresponds to about 80 minutes.

The aforementioned operating mode of the vehicle is called "Normal operation" defined. The drug dosage at Normal operation is defined as 100%.

In normal operation, the pulse interval Δt is the Dosing pulses 30 sec. Each dosing pulse corresponds an amount of active ingredient of 50 ul.

On the basis of the above assumptions, the calculation of the addition of the additive takes place as follows:
100% metering takes place when the vehicle is running, when at a speed of 50 km / h the average consumption of 10 l per 100 km is created within two hours. The timer 21 forms measuring intervals t _max . After a measurement interval, the timer 21 restarts.

The determined by the counter 10 starting frequency in each respective measuring interval is led to the memory unit 12 , which then delivers the factor X₁ to the Rechenein unit 13 . If 10 liters of fuel consumed within two hours, this corresponds to an average additive admixture of 5 cc per hour. If one chooses a metering volume of 0.05 cm³ per metering stroke, 100 metering strokes per hour or every 36 seconds result in a metering stroke of 50 μl.

The arithmetic unit 13 for calculating the metering pulse intervals sets for the metering interval .DELTA.t a normal value of 30 sec. based. This corresponds to a factor X₁ of "1" for normal operation. This factor X₁ varies depending on the mode of operation such that the following dosing ratios result:

Normal operation (X₁ = 1) = 100% dosage
Long distance operation = 80% dosage
Short distance operation = 150% dosage.

The factor X₁ thus takes into account that at Lang stretch operation (low starting frequency) of the force fuel consumption of the vehicle low and short route operation (eg city traffic) is high.  

The dosing behavior as a function of the starting frequency is shown in Table I below.

Table 1

This results in the following actual average operating times t _b for the vehicle within a calculation interval of 80 minutes.

Table 2

For _tb <80 min. the calculation interval _duration t _max = 120 min. set for the timer 21 . After expiration of t _max , the timer restarts and the calculation of the factor x₁ is restarted.

Table 3 below gives the relationships between the Starting frequency or the number of starting operations (start) and the size of the factor X₁ again.

0.5 Anf. per 120 sec. X₁ = 1.25 1 × Anf. X₁ = 1 2 × Anf. X₁ = 0.83 3 × Anf. X₁ = 0.76 4 × Anf. X₁ = 0.71 5 × Anf. X₁ = 0.66

This results in multiplication X₁ × Δt _N the following Dosierimpulsintervalle .DELTA.t:

Table 4

Another possibility influencing the pulse intervals of drug dosing can be done by the factor X₂, which is given in dependence on the preset average consumption of the vehicle. At the previously determined metering pulse intervals, an average consumption of 10 l / 100 km a was assumed. In Table 5 below, the factor X₂ for the average consumption of 10 l / 100 km is given as "1.0". In addition, other factors X₂ are given for higher and lower average consumptions. The table 5 is stored in the memory device 16 .

Depending on the factors X₁ and X₂, the computing unit 13 calculates the calculation interval Δt of the metering pulses according to the relationship

Δt = X₁ × X₂ × Δt _N.

Table 5

Claims (8)

1. A method for the pulse-wise metered addition of additives in a line ( 20 ) of a consumer, preferably in the fuel line of a driving zeugs, characterized in that the current performance of the United consumer measured in a calculation interval (t _max ) ge and depending on the Pulse spacing (.DELTA.t) of the metering pulses is determined. 2. The method according to claim 1, characterized in that when adding the additives in the fuel line of a vehicle as operating behavior, the Anfahrhäufigkeit (Anf.) Of the vehicle in the Be calculation interval (t _max ) is measured. 3. The method according to claim 2, characterized in that different areas for the driving frequency to a factor (X₁) is assigned, which is multiplied by a normal value (At _N ) of the pulse interval. 4. The method according to claim 2 or 3, characterized marked records that the dosing start by pressing the Starter of the vehicle is initiated. 5. The method according to any one of claims 1 to 4, characterized in that the pulse interval of the metering pulses in addition via a selector switch ( 15 ) can be influenced. 6. Apparatus for carrying out the method according to any one of claims 1 to 4, characterized in that a counter ( 10 ) for counting charac teristischer operating conditions of the consumer within predetermined calculation intervals (t _max ) is provided that a table is provided, the corresponding the counter reading of the counter ( 10 ) different factors (X₁) outputs and that a computing unit ( 13 ) multiplies the respective factor (X₁) with a normal value (.DELTA.t _N ) of Impulsab stood and thereby calculates the current pulse spacing (.DELTA.t). 7. Apparatus according to claim 6, characterized in that the arithmetic unit ( 13 ) receives from a second table of a second factor (X₂) in dependence on the setting of a preselection scarf age ( 15 ). 8. Apparatus according to claim 6 or 7, characterized in that a timer ( 21 ) for the loading calculation intervals (t _max ) is provided, which shortens the calculation intervals with increasing count of the counter ( 10 ).