JPH09170479A - Method and equipment for controlling fuel-quantity adjustingdevice - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve accuracy in metering the fuel at the beginning of injection by determining the amount of time to the target value of the beginning of injection with a referenced point, to determine the amount of correction based on the difference between the point detected the actual beginning of injection and the amount of time to the target value of the beginning of injection. SOLUTION: An adjustor 230 determines a signal P for controlling an injector controller 125 from an adjustment difference SBD between a target value by a target value setting section 250 and an actual value SBI with respect to the beginning of injection from a sensor 205. The adjustment differences SBD is supplied to a switching module 270 to determine if the adjustment difference SBD is out of predetermined threshold range, then a second switch 235 is switched to the position shown by the dashed line, and a switch 225 is turned to up or down position according to the magnitude of the adjustment differenced SBD. An initial module 265 is being incorporated into the circuit and the output from a maximum value setting device 232 or a minimum value setting device 234 in output to the controller 125.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses an adjusting member for influencing the start of discharge, in which an adjustment deviation can be determined starting from a target value for the start of discharge and an actual value for the start of discharge and a regulator. Relates to a method for controlling fuel metering for a diesel engine and a device for carrying out this method, for example, for determining a regulation variable for controlling the regulation member starting from the regulation deviation.

[0002]

2. Description of the Prior Art A method and a device of this kind are known, for example, from DE-A 42 42 252. In particular, it describes a method and a device for controlling a fuel metering device for a diesel engine. There, a so-called injection regulator that influences the discharge rate of the fuel metering is controlled. For this purpose, the engine control device sends a signal instructing the desired start of discharge in relation to the crankshaft. Then the second control device controls the adjusting element depending on the angular position of the camshaft.

As long as each angular position of the crankshaft can be associated with a predetermined angular position of the camshaft, this type of control ensures accurate fuel metering. This is not possible under certain operating conditions. This is because vibrations occur between the crankshaft and the camshaft due to the relatively loose connection between the crankshaft and the camshaft. Based on this vibration, there is no fixed relationship between the crankshaft angular position and the camshaft angular position,
This causes inaccuracies in fuel metering in prior art devices.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to improve the accuracy of fuel metering, in particular the adjustment setting of the discharge start, in a fuel metering method and device of the type mentioned at the outset. In particular, we want to be able to compensate for the effect of the loose coupling between the crankshaft and the camshaft.

[0005]

This problem is solved by the arrangement according to claim 1 for the method and by the arrangement according to claim 7 for the device.

Further, German Patent Publication No. 4 of the Federal Republic of Germany
From 308541, a regulator for controlling an injection regulator is known.

Advantageous and preferred embodiments and improvements of the invention are described in the further claims.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 1 schematically shows the fuel metering device of the present invention. The fuel pump 100 consists of various components and is arranged in the region of the internal combustion engine 90. Low voltage section 1
At 10, the fuel is under a relatively low pressure maintained by a fuel delivery pump, not shown.

The fuel high pressure portion 120 is reached via the solenoid valve 115. The high-pressure unit is driven by the driving unit 130 via the discharge start controller 125. In the high pressure section 120, the fuel is compressed to the pressure required for injection.

The rotation speed of the drive unit 130 is detected by using the sensor 135. This speed substantially corresponds to the camshaft speed. The sensor 135 scans and detects a mark on the increment wheel 136 arranged on the cam shaft of the internal combustion engine or the pump drive shaft 130. The pump drive shaft 130 is driven by the crankshaft 152 of the internal combustion engine by the drive unit 137 shown in broken lines. A toothed belt is preferably used as the drive. A segment wheel 156 is arranged on the crankshaft, and the mark thereof is scanned and detected by the sensor 155.

The output signal of the rotation speed sensor 135 reaches the pump control unit 140. This pump control unit 1
Reference numeral 40 applies a control signal to the solenoid valve 115 and the discharge start adjuster 125.

In a particularly advantageous embodiment, the pump control unit consists of two separately arranged components. In that case, the original pump control unit 140 is
The engine control unit 150 is connected via corresponding coupling means 142.
And various sensors and possibly another control unit. As the coupling means 142,
The BUS system is preferably used.

The engine controller then processes engine-specific parameters and sends corresponding signals to the pump control unit 140 via the coupling means 142. The engine control unit 150 applies a corresponding signal to the pump control unit 140 via the coupling means 142. That is, for example, the angular position of the camshaft and / or crankshaft at which fuel discharge should be initiated is transmitted as a digital quantity. Another advantageous digital signal is indicative of the desired delivery rate as well as the desired delivery start angle associated with the camshaft.

The pump controller converts these advantageously digital signals into corresponding control signals for controlling the solenoid valve 115 and the discharge start regulator 125. In addition, a signal R is transmitted which characterizes the advantageous position of the crankshaft.

A sensor 145 connected to the pump control unit detects pump-specific data, such as the position of the drive shaft 130 of the pump. Using the sensor 152, engine-specific data and further operating parameters such as temperature and pressure values are detected and supplied to and processed by the engine control unit 150. The traveling pedal position generator 160 sends a signal indicating the driver's intention to the engine control unit 150.

The mechanical components of the fuel pump 100 are essentially the same as the published German patent application DE 35 40 31.
It corresponds to the components of the fuel pump shown in FIG.

However, the operation of this device in connection with the pump control unit of the invention is different. By controlling the solenoid valve 115, the start and end of discharge are determined in the device of the present invention. These quantities are related by the pump control to the angular position of the camshaft. The solenoid valve 115 can also be regarded as a first adjusting means for determining the start and end of discharge. A discharge start adjuster 125, which is used in the prior art for adjusting the discharge start, is used here to offset the pump drive shaft with respect to the crankshaft. The discharge start adjuster 125 is also referred to as a second adjusting means.

In order to achieve less harmful fuel and better efficiency, the injection is carried out at a given position of the crankshaft depending on various operating conditions. Engine control unit 15
0 sends a corresponding signal to the pump controller 140.

In FIG. 2, the device according to the invention is shown diagrammatically on the basis of a block diagram. 90 is an internal combustion engine. It receives metered fuel from fuel pump 100.
The injection regulator control unit 125 can be used to control the injection regulator in the pump for adjusting and setting the injection start or the discharge start of the fuel.

The regulator 23 via the first switch 225
An output signal P of 0 reaches the injection regulator controller 125. The output signal D of the connection point 240 is supplied to the regulator 230 via the second switch 235. The output signal SBD of the connection point 245 is applied to one input side of the connection point 240. The output signal SBI of the needle movement detector 205, which is preferably arranged in the internal combustion engine, reaches this connection point 245. The output signal SBS of the target value setting unit 250 is applied to the second input side of the addition point 245.

By using the first switch 225, the output signal PMAX of the maximum value setting unit 232 or the output signal P of the minimum value setting unit 234 is alternatively used for the injection controller control unit 125.
MIN is supplied. The output signal of the initialization module 265 is supplied to the regulator using the second switch 235.

The output signal SBI of the module 260 is connected to the second input side of the connection point 240 via the third switch 262.
M is added. At least the output signal SBI of the needle movement detector 205 and the adjustment amount PI at that time are added to the module 260. In the simplest embodiment, this module is a PTI element or integrator. However, it is also possible to implement this model using an observer or a more or less sophisticated calculation program.

The output signal of the connection point 245 further reaches the switching module 270 via the initialization module 265 and the fourth switch 272. The output signal of the node 240 can also be selectively supplied to the switching module using the switch 275. The switching module 270 is the switch 2
Corresponding control signals are supplied to 35 and 225.

Typically, these switches are in the positions shown in solid lines. In this case, the device operates as follows. A target value SBS given by the target value setting unit 250,
Starting from the comparison between the actual value SBI for the injection start, the regulator 230 determines the signal P for controlling the injection regulator control 125. The regulator 230 is preferably P
It has the I characteristic. However, the invention is not limited to regulators with PI characteristics. The invention can also be used in systems with regulators having other characteristics.

The signal P is the adjustment angle. This adjustment angle is realized by the injection regulator control, preferably by controlling the solenoid valve using the keying ratio. This solenoid valve can be used to influence the pressure in the injection regulator. Depending on this pressure, the injection regulator is in position. Depending on the position of the injection regulator, injection starts at different times. The exact time of the start of injection is
For example, it is detected using a so-called needle movement detector 205.

The actual value SBI for the start of injection, which is detected in this way, is compared with the target value SBS and supplied to the regulator.

This occurs in particular when the setpoint SBS changes significantly, but when a large adjustment deviation occurs, the injection regulator requires some time before it reaches the new setpoint. And Therefore, according to the present invention, the adjustment deviation SBD is set to be supplied to the switching module 270. When the switching module detects that the adjustment deviation SBD is greater than or less than the higher threshold value, the second switch 235 is moved to the position indicated by the dashed line.

Depending on whether the adjustment deviation SBD falls below the lower threshold value or is above the higher threshold value, the switch 225 is switched to the upper position or the lower position. In this case, the maximum value PMAX or the minimum value PMIN is added to the injection controller control unit 220. As a result of this, the injection regulator, and therefore also the actual value, takes its new value very quickly. If the adjustment deviation SBD lies outside the region defined by the two values, the regulator is switched off and the maximum or minimum value for the adjustment amount is given. The regulator 230 is active when the regulation deviation is within the defined region.

In the embodiment of the present invention, a plurality of areas may be defined. In this case, different values can be selected in different areas.

While this means opening switches 235 and 225, when the regulator is shut off, the I component of the regulator is frozen. That is, the output amount P of the regulator is stored. When the regulator is re-applied, that is, when the switch 225 again moves to the position shown by the solid line, the switch 2
35 is returned to its original position with some delay.

Instead of the regulator 230, a PID is preferably used
It is also possible to use customary regulators with properties. In this embodiment, the input point is input to the regulator as a connection point 24.
5 output signals are provided.

FIG. 3 shows various quantities with respect to time or the angular position of the crankshaft.

The various signals and quantities of this are then represented as follows: FB represents the start of ejection. This is the time from which fuel can be discharged. This time point can be detected, for example, based on the response of the electromagnetic valve flow.
The time when the discharge is started is represented by TFB, and the angular position of the crankshaft at the start of the discharge is represented by WFB.

The start of injection is represented by SB. This is the time when injection actually begins in the internal combustion engine.
Typically this amount is confirmed by a needle motion detector. The time when the injection start SB occurs is represented by TSB and the corresponding angular position of the crankshaft is represented by WSB.

Top dead center is represented by OT. The time when the crankshaft reaches its top dead center is represented by TOT and the angular position is represented by WOT.

A reference pulse R is provided on the pulse wheel that is scanned and detected by the sensor 155 for each cylinder. The time at which the reference pulse R occurs is represented by TREF and the corresponding angular position of the crankshaft is represented by WREF.

The distance between the reference pulse R and the top dead center OT is represented by ΔTREF as a time amount and ΔWREF as an angular amount. The distance between the top dead center OT and the injection start SB is represented by ΔWSB as an angular amount and ΔTSB as an amount of time.

The interval between the discharge start FB and the injection start SB corresponding to the wave delay time is represented by ΔWWL as an angular quantity and ΔTWL as a time quantity. The wave delay time ΔWWL is the angle at which the crankshaft rotates between the start of ejection and the start of injection. It is a measure for the interval between the start of ejection and the start of actual injection.

The interval between the reference pulse R and the start of ejection is
It is represented by ΔTFB as the amount of time and by ΔWFB as the amount of angle.

The angle amount W and the time amount T can be mutually converted. In this case the following equation holds: T = W · 6 · N where N is the number of revolutions of the shaft (crankshaft, camshaft or pump drive shaft) with which the quantity is associated.

The problem then is that the pump control can only calculate different quantities in relation to the camshaft. The position of the crankshaft is known in the pump control unit only when the reference pulse R transmitted from the engine control unit to the pump control unit is generated. If the connection between the crankshaft and the camshaft is fixed and stipulated, no error will occur. The connection between the crankshaft and the camshaft is loose,
Unless specified, there is no fixed relationship between the angular quantities associated with the camshaft or crankshaft. This error is compensated as described below.

In FIG. 4, the control signal is not the camshaft,
A block diagram of an embodiment is shown in which error is reduced by associating with a crankshaft. The output signal ΔWSBS of the injection start characteristic map 250, which processes the signals of the various sensors 251, reaches the connection point 305. At the second input side of the junction, the angular amount ΔWREF provided by block 310 is applied. The output signal of the node 305 reaches another node 315. The output signal ΔWWL of the wave delay time map 310 is connected to the second input side of this connection point.
Is added. The signal of the sensor 321 is used as an input signal for the wave delay time map 320. These are, for example, signals characterizing the amount of fuel to be injected, the start of discharge, the number of revolutions and the temperature.

The output signal ΔWFBS at node 315 reaches another node 325. On the second input side of this junction,
The output signal NKW of the block 330, which processes the output signal of the sensor 155, is added as an input quantity. Connection point 325
Output signal ΔTFBS of reaches the comparison point 335. The output signal Δ of another comparison point 340 is connected to the second input side of this comparison point.
TFBI is added. The connection point 340 is B on the minus side.
The output signal TFBI of the IP detection unit 345 is supplied, and the signal TREF indicating the time point of the reference pulse is supplied to the positive side. The output signal of the comparison point 335 is the injection regulator 1
The regulator 300, which controls 25, is reached. For example, the regulator 300 can correspond to the regulator 200 shown in FIG.

In the characteristic map 250, the angle amount with respect to the target value ΔWSBS of the injection start is stored as the angle amount related to the crankshaft depending on various operation characteristic amounts. This target value is, for example, the amount of fuel to be injected, the number of revolutions,
Stored depending on temperature and pressure values. Target value Δ
WSBS represents the difference angle between the desired start of injection and the top dead center OT.

In block 310, the angular position ΔWR with respect to the top dead center OT of the crankshaft when the reference pulse R is generated.
EF is stored. Connection point 30 of signal ΔWREF
5, the connection with the signal ΔWSBS and the connection point 315
The coupling with the wave delay time .DELTA.WWL at .alpha. Produces a quantity .DELTA.WFBS at the output of the node 315, which is an angular quantity related to the crankshaft and which indicates the distance between the reference pulse R and the start of discharge FB. This amount ΔWFBS corresponds to the amount of time with respect to the target value for starting discharge. The target value for the start of injection is converted into the target value for the start of ejection using the wave delay time ΔWWL.

Starting from the signal of the sensor 155, the block 330 calculates the crankshaft speed NKW. At the connection point 325, using the crankshaft speed, the angle amount ΔWFBS with respect to the target value is the time amount ΔT with respect to the target value.
Converted to FBS. This quantity is supplied by the connection point 335 as a target value.

On the second input side of the connection point 335, the connection point 34
An output signal ΔTFBI of 0 is added. A signal indicating the time point of the actual ejection start is applied to one input side of the connection point 340, and a signal TREF indicating the time point of the reference pulse is applied to the other input side. This connecting point compares these quantities with each other and at its output the signal ΔTF
BI is retrieved. The signal TFBI is the BIP detection unit 34.
Formed by 5.

An output signal of the crankshaft rotation speed sensor 155 is used as the reference value TREF. Actual discharge start TF
The signal indicating BI as the amount of time is formed by the BIP detection unit. The BIP detector determines when the solenoid valve reaches the position where fuel metering begins. This is possible, for example, by evaluating the course of the current flowing through the solenoid valve. The signal TFBI corresponds to the actual value of the start of ejection as a quantity of time.

At the output of the connection point 340, a signal ΔTFBI appears, which indicates the actual time interval between the reference pulse R and the actual ejection start FB. At point 335, the target value ΔTFBS and the actual value ΔTFBI for the interval between the start of ejection and the reference value R are compared with each other and their adjustment deviations are supplied to the regulator 300. The regulator controls the injection regulator 125 accordingly, depending on the comparison signal between the actual start of delivery (actual value of start of delivery) and the desired start of delivery (target value of start of delivery).

According to the present invention, in this embodiment, the target value for the start of discharge and the actual value for the start of discharge are determined as the amount of time with respect to the crankshaft synchronization reference R. The deviation between the actual value ΔTFBI and the target value ΔTFBS is directly adjusted as an adjustment deviation, and is adjusted by the controller 3 for the injection controller.
00 is supplied. A regulator having at least a PI characteristic is preferably used as regulator 300.

Correspondingly, the setpoint value and the actual value can also be associated with a time synchronization reference instead of the crankshaft synchronization reference.

FIG. 5 shows another embodiment of the present invention. Various sensors 402 provide signals to the characteristic map 400. The characteristic map 400 shows the signal W at the connection point 405.
Supply FBS. The output signal of the connection point 410 is applied to the second input side of the connection point 405. The output signal of the block 330 is applied to the input side of the connection point 410. This block processes the speed signal of the sensor 155. The output signal of the connection point 415 is applied to the second input side of the connection point 410. The first of the connection points 415 with a negative sign
The output signal of the connection point 340 is added to the input side. The output signal of the block 420 is applied to the second input of the connection point 415, which is provided with a positive sign. Block 420 processes the signal WFBS of the characteristic map 400 as well as the output signal of block 330.

This device operates as follows. In the characteristic map 400, the setpoint value for the start of discharge is stored as the angular quantity WFBS, depending on various operating parameters such as the amount of fuel to be injected, various temperature and / or pressure values and rotational speed.

At the connection point 340, the time difference ΔTFBI between the generation time TREF of the reference pulse R and the actual discharge start time TFBI is determined as described with reference to FIG. This amount depends on the generation of the reference pulse R and, for example, B
It corresponds to the time interval between the actual start of ejection, which can be determined using the IP detector.

Starting from the difference between the angular quantity WFBS with respect to the target value for the start of ejection taken from the characteristic map 400 and the known angular position of the crankshaft WREF at the time of the generation of the reference pulse R, the rotation in block 420 An angle quantity is generated which is converted into a time quantity ΔTFBS using the number NKW. This amount indicates a desired time interval between the ejection start FB and the reference pulse R. This amount Δ
TFBI is compared to the quantity ΔTFBS at comparison point 415. On the output side of this connection point 415, a time deviation between the target value and the actual value with respect to the duration between the ejection start and the reference pulse R appears. The time TFBI at which the actual ejection start occurs and the amount of time ΔTF with respect to the target value of the ejection start
Starting from the deviation from the BS, it is possible to define a correction quantity which takes into account the deviation between the angular quantity associated with the camshaft and the angular quantity associated with the crankshaft.

This amount of time is converted into a corresponding angular amount at the connection point 410 using the number of revolutions formed in block 330. The output quantity at the connection point 410 is a measure for the deviation between the crankshaft angle and the camshaft angle. The target value WFBS for the start of ejection is corrected by this comparison signal. The output signal of the connection point 405 is the connection point 245 of FIG.
To the output of the characteristic map 250 for correction.

According to the present invention, the target time point and the actual time point for starting the ejection are determined relative to the crankshaft synchronization reference mark. This deviation is additionally added to the injection regulator regulator of FIG. 2 as a correction amount.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a fuel metering device of the present invention.

FIG. 2 is a block diagram of the injection start regulator of the present invention.

FIG. 3 is a diagram of various signals shown with respect to time.

FIG. 4 is a block diagram of another embodiment of the present invention.

5 is a block diagram of the improved configuration of FIG.

[Explanation of symbols]

90 internal combustion engine, 100 fuel pump, 115 solenoid valve, 125 injection regulator regulator, 150 engine control unit, 135, 145, 155, 251, 32
1, 402 sensor, 205 needle motion detector,
230 regulator, 250, 330 Target value setting unit or injection start characteristic map

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Peter Schmitz, Federal Republic of Germany Leiskirchen Jan Strasse 9

Claims (7)

[Claims] 1. An adjusting member is used for influencing the start of discharge, wherein an adjustment deviation can be determined starting from a target value for the start of discharge and an actual value for the start of discharge, and a regulator starting from the adjustment deviation. Then, the adjustment amount for controlling the adjusting member is determined. For example, in a control method of a fuel amount adjusting device for a diesel engine, a time amount with respect to a target value of discharge start can be determined with respect to a reference time point (R), and Between the angular quantity associated with the camshaft and the angular quantity associated with the crankshaft, starting from the deviation between the time when the start of discharge is detected and the amount of time relative to the target value of the start of discharge. A method of controlling a fuel metering device, characterized in that a correction amount that takes into account the deviation of the fuel quantity can be determined. 2. The method according to claim 1, wherein the amount of time for the target value of the discharge start can be determined starting from the angle amount for the target value of the discharge start. 3. The method according to claim 1, wherein the angle amount with respect to the target value of the discharge start can be determined depending on the operation characteristic amount. 4. The method according to claim 3, wherein the correction amount can be supplied as an adjustment amount to a regulator that processes the start of ejection as a time amount. 5. An adjuster capable of correcting an angle amount with respect to a target value of discharge start by using the correction amount, and processing the corrected angle amount with respect to the target value of discharge start with the discharge start as an angle amount. 4. The method according to claim 3, wherein the adjustment amount can be supplied. 6. The method as claimed in claim 1, wherein the crankshaft is in an advantageous position during the generation of the reference pulse. 7. An adjusting member for influencing the start of ejection, wherein the adjustment deviation can be determined starting from a target value for the start of ejection and an actual value for the start of ejection and starting from the adjustment deviation. In a control device of a fuel metering device for a diesel engine, which is provided with an adjuster that determines an adjustment amount for controlling the adjusting member, for example, a reference time (R) is a time amount with respect to a target value for starting discharge.
Starting from the deviation between the time when the actual start of discharge is detected and the amount of time relative to the target value of the start of discharge and the angular amount associated with the camshaft and the crankshaft. A control device for the fuel metering device, characterized in that means is provided for determining a correction amount that takes into consideration a deviation from the present angular amount.