SU1229413A1 - Device for measuring advance angle fuel injectiton - Google Patents

Description

The invention relates to the diagnosis of internal combustion engines and can be used to measure the advance angle of diesel fuel injection.

The purpose of the invention is to increase efficiency.

On. 1 shows a block diagram of the proposed device; Fig. 2 shows timing diagrams of the device when used to measure the advance angle on a two-stroke diesel engine; in fig. 3 - the same for a four-stroke diesel.

The device includes a sensor 1 at the top dead center of the cylinder, connected via the first driver 2 rectangular pulses with zero input of trigger 3 to the installation inputs, fuel injection sensor 4 connected via a second fork to the fifth input pulses of the first 6 And 6 The output of the latter is connected to the single input of trigger 3 with the installation inputs, the first moving contact of the dual switch 7 and the counting input of the trigger 8, the input of the inverter 9 through the button 10 is connected to the zero terminal of the power supply, and the output Inverter 9 is connected to the summing input of the reversible counter 11, the subtracting input of this counter is connected to the second fixed contact of the first section of the switch 7, and the inverse output of the high bit of the reversible counter is connected to the second non-contact contact of the second section of the switch 7. The first fixed contact of the second section of the double switch 7 connected to zero (positive or negative, depending on the type of the element base on which the device is implemented) power supply terminal.

The direct output of the counting trigger 8 is connected to the input of the first integrator 12, the first input of the second circuit 13 and the inverse output of the counting trigger 8 is connected to the input of the second integrator 14 and the first input of the third circuit II 5. The second inputs of the second 13 and third 15 circuit And connected to the direct output of the trigger 3 with the installation inputs and the first input of the dividing device 16.

0

941

- 0 0 i 0 5

0 5

2

The output of the second cxeNffii AND 1 3 through the first time delay element 17 is connected with the reset bus to zero of the second integrator 14, the code of which is connected to the first input of the first circuit OR 18. The output of the third circuit P 1 And 15 through the second delay time element 19 is connected with the reset bus in the bullets of the first integrator 12, which is connected to the second input of the first circuit OR 18, and the last code connected to the second input of the dividing device 16. The first and second inputs of the second OR circuit 20 are connected to the outputs of the first 17 and second 19, respectively delay elements and the output of the circuit OR 20 is connected to the first input of the fourth circuit AND 21. The second inputs of the fourth 21 and first 6 circuits are connected to the second moving contact.the second section of the dual switch 7. The output of the dividing device 16 is connected to the input of the controlled generator 22 pulses high frequency, and generator 22 is connected to the input of register 23, the reset bus of which is connected to the output of the fourth circuit And 21. The outputs of the cells of all bits of the register 23 are connected to the inputs of the decoder 24, and the outputs of the decoder are connected to the inputs of the gully 25 indication.

Consider first the operation of the device when measuring the advance angle of a two-stroke diesel fuel injection. Timing diagrams for this case are EE: The ones in FIG. 2, while the signal index corresponds to the number of the element from the output of which it is removed. The signal Ug is removed from the direct code of the counting trigger 8, and

signal and ,, - with inverse output about

this trigger.

The device can operate in two modes: when the injection advance angle is measured and indicated by the indicating unit 25 in each shaft revolution during the entire diesel operation time and when the injection advanced angle is measured and displayed in each shaft rotation to the operator’s cycle of interest, and the angle value the advance of the cycle of interest is indicated until the operator sets another measurement cycle number. At the same time during the indication of the angle in the specified cycle

The process of measuring the angle of advance to the next operator command is not carried out.

In the first case, the double switch 7 is set to position A, the second input to the circuits AND 6 and 21 in this case receives a single signal from the power source and these circuits act as signal repeaters arriving at their first inputs.

When a diesel engine is operating, when the fuel is supplied to the injectors, the electrical pulse signal of the fuel injection sensor 4 (such as a sensor is, for example, the injector needle displacement sensor) with the help of the second driver 5 converts into a square pulse whose duration is equal to the duration of the fuel injection, and The amplitude is equal to the level of the log. 1. The output pulse of the driver 5 passes through the AND 6 circuit to the single input of trigger 3 with the installation inputs, set it to the single state, and to the subtracting in :: one reversible counter 11, but the latter does not affect the operation of the device elements as switch 7 is open. The impulse from the AND 6 circuit also arrives at the input of the counting trigger 8, sets it to one stable state, for example, to one (in Fig. 2 this moment corresponds to t tj). Since the counting trigger 8 is cocked, a signal with amplitude is set at its output Log 1, which is fed to the first input of the second circuit AND 13 and to the input of the second integrator 12, the output signal of which from the time t t increases linearly with time

and

12

 TO

 t)

where K is the transmission coefficient of the integrator; Since the first and second inputs of the second circuit And 13 in this case there are single signals, this circuit is open and its output signal is fed to the input element 17 of the delay. The third scheme And 15 at the same time acryta. Simultaneously with | This the output signal of the integrator 12 passes through the first circuit OR 18

to the second input of the divider device 16. The output signal of the first integrator 14, linearly growing in the previous shaft revolution at t t, is also larger than zero and also passes to the second input of the divider device 16.

At the first input of this device, the output signal of the trigger 3 acts, in connection with which the output signal of the dividing device is

b

 L and.

 u, g- it.i.ts,

where and is the logical addition operation.

This signal is fed to the input of a controlled pulse generator 22, which produces high-frequency rectangular pulses fed to the input of register 23. The frequency of these pulses is equal to

25

22 2g; ;

where K 22 is the transmission coefficient of the controlled generator of 22 pulses.

A number is written to the register 23, the decimal equivalent of which, formed by the decoder 24, is indicated by the display unit 25. At time t tj, the diesel piston enters the upper dead center at the output of sensor 1

a pulse is produced, which with the help of the first shaper 2 is converted into a rectangular pulse with an amplitude corresponding to the Log level. 1. Under the influence of this impulse. The trigger 3 with the set-up inputs is reset, the AND circuit 13 is closed, and the AND circuit 15 is kept in the same closed state. When locking the circuit AND 13, the first delay element 17 begins to form a short rectangular pulse arriving at the first input of the circuit OR 20 and onto the reset bus to zero of the first integrator 14. Due to the reset of trigger 3

with the installation inputs, the single signal at the first input of the dividing device 16 disappears, the output signal of this device assumes a zero value, the generation of high-frequency pulses by the generator 22 is stopped, and the recording of the number in the register 23 also stops. In this connection, after resetting the trigger 3, the state

the register cells do not change and the indications of the display unit 25 are not changed.

After a delay in time At, the delay element 17 delays a single short right angular-first impulse, resetting the first integrator 14 and the register 23 to the zero state, as a result of which the indication display unit 25 is zeroed. The signal at the output of the second integrator 12 during the considered time interval t - t grows linearly, since the input voltage of this integrator is applied to a single voltage from the direct output of the counting trigger 8,

At time t ty, fuel injection starts in the next turn of the shaft, injection sensor 4: and produces an electrical impulse that is converted by the second driver 5 into a rectangular unit impulse. The last one, passed through the AND 6 circuit, cocks the trigger 3 with the installation inputs and resets the counting trigger 8. As a result, the AND 13 circuit is closed - since its first input has a zero signal from the forward output of the trigger 8), and the And 15 circuit turns out to be open , since at its first and second inputs there are single signals from the inverse output of the trigger 8 and the direct output of the trigger 3. In addition, under the action of the single signal, there is also the perimeter input of the dividing device 16 connected to the output of the trigger 3. Since the trigger 8 reset, The signal at the input of the first integrator is 14 unit and its output voltage starts to grow from zero linearly fy in time, and the signal at the input of the second integrator 12 is zero and its output voltage remains constant from the moment t, this voltage is linear increases from time tj to time t. (This time interval is the period of rotation of the shaft T) and its value is determined by belief

Y and kg.

The voltage .and, 3, is applied to the second input of the circuit OR 18, the first input of which receives a signal from the output

integrato1) a 14. Since the transfer coefficients of π1Ientent K are the same for both integrators, then for t., - t, 3. j (which is less than the rotation period), the signal at the output of the integrator 14 does not have time to grow to the value P (T and the signal at the first input 1 of the II 18 is less than 5 than at its second input. As

10 is known, the output signal cxeNsbi OR acts the largest input signal, as a result of which the output signal of the second integrator 15 acts at the second input of the divider device 16. Therefore, the output signal

equal signal divider

and

ie

TO

20 a controlled pulse frequency

generator 22 is determined by the impulse

35

To

Using these pulses, a number is recorded in the register 23, the decimal equivalent of the quotient, formed by the MSF with the decoder 24, is indicated by the display unit 25.

At time t - t. (FIG. 2) the piston is raised to the upper dead point and at the output of the sensor 1 a pulse is generated, the beginning of which coincides with the specified moment. This impulse, after being transformed by the first generator of 2 pulses into a single short direct impulse, arrives at the zero input of trigger 3 with the installation inputs, setting it to the zero state. The latter leads to the locking of the AND 15 circuit, the disappearance of a single signal at the first input of the dividing device 1 6 and the appearance of 22 pulses at the input of the controlled generator.

In this case, the generation of high-frequency rectangular single ‑ pulses and the process of recording them in the register 23 terminate pc. The code combination coming from the outputs of all the bits of the register to the inputs of the decoder 24 is converted using the last

from the binary numeral system in the ten 1 st th and is displayed on the display of the display unit 25. Consequently, the recording of pulses in the register occurs during the time from the time t, to the time t. (This interval is nothing more than a fuel injection advance time). The number of pulses arriving at this time at the input of register 23 is determined by the formula

N f .t. 22 on KG

where ton is the fuel injection advance time.

If you express the period of rotation of the shaft through the angular velocity of the shaft, the last expression takes the form

N

L-yy-i, -ton -U .. „.bilUiie.

 TO

2 -K

where 2f is the angle of rotation of the shaft in one

turnover;

9 t - (o- the advance angle of the injection of toliv.

The values of Uj (log level 1), Kj, 2, K, and 21 are constant, due to which the relation between N and 0 is single-valued, i.e. the indications of the indication unit 25 are proportional to the advance injection angle. When choosing these parameters, such that

  , 2ft -K

the readings of the display unit exactly coincide with the advance injection angle.

After the time ut, from the moment of locking the circuit AND 15, the second element 19 of the time delay produces a short unit impulse arriving at the reset bus to zero of the second integrator 12 and the second INPUT of the circuit .OR 20, and through the latter to the first input of the circuit AND 21. Since the second In this case, the input of this circuit is connected to a non-zero clamp of the power supply, it works as a normal repeater and the signal from its first input goes to the reset bus at the register 23. At that moment, the pulse appears. Sa at the output of the delayed time element I9 causes the second integrator 12 and the register 23 to reset to zero states, and also to zero the indications of the display unit 25.

1229A138

After resetting the second integrator 12 and the register 23, the state of all elements of the device, except the first integrator 14 and the first circuit OR 5 18, does not change. The output of this integrator linearly increases according to the law.

and „K.t

ten

and passes through the first circuit OR 18 to the second input of the dividing device 16. However, the output signal of this device is zero,

since at its first input a zero signal acts from the output of the trigger 3. In accordance with this, neither the generation of high-frequency square pulses nor their writing to the register

no occurrence and the display of the display unit 25 displays zeros. This state of the device elements is maintained until the next fuel injection cycle.

at time t tj, the next fuel injection starts, the injection sensor 4 generates an electrical signal, which is converted into a rectangular with the help of the second driver

single impulse. The latter, as before, passed through the first circuit AND 6, cocks the trigger 3 into the one state and translates the trigger 8 from the zero state into the one. AT

As a result, the second circuit And 13 is cleared, a single signal from the direct output of the counting trigger 8 is supplied to the input of the second integrator 12, the third circuit And 15 is closed

(since there is a zero signal at its first input), and at the input of the first integrator 14, the single signal changes to zero. The latter leads to the termination of the growth of the output signal

this integrator, which now has a value

and ,, K

50

(in this case, T is the time from time t to time t). The output signal of the integrator 12 is thus less than QD, 55 since its integration time is less than the period of rotation of the shaft (Fig. 2). Since the output of the OR circuit always has a signal equal to the largest of the input signals, the output voltage of the first integrator 14 is present at the second input of the divider device 16. As the first trigger 3 is cocked, the first input of this device receives a voltage Uj equal to , in this case, the level of the log. 1. In this case, the dividing device generates a signal

and.

and

(four

and t

The received signal is fed to the input of a controlled generator of 22 rectangular pulses, which generates rectangular pulses with a frequency

f - to tg "ie CT

Since the output of the OR 20 circuit in this case is zero, there is no prohibition on writing the number to the register 23 and the generator pulses are recorded in the cells of this register. The recording process continues until tg. At t tg, the piston enters the upper dead center, the upper dead point sensor 1 generates an electrical signal, which is converted into a rectangular single impulse by means of the second driver 5. This pulse resets the flip-flop 3 with the set-up inputs to the zero state, as a result of which the circuit 13 is closed, the circuit 15 remains closed, and at the first input of the dividing device 16 the single signal is replaced by zero. At the same time, the output voltage of the dielectric device becomes zero, the controlled oscillator 22 stops producing pulses, and the writing of the number to the register 23 stops. The duration of the recording process from the time tj to the time t is the fuel injection advance time and during this time the number 23 was recorded in register 23

Kgg-Uvt,

.f.

2g K.T.

which is converted from a binary number system to a decimal number system using a depotraser 2A. Display unit 25 flashes

122941310

on its scoreboard is the number on the decimal c; 1 system.

If we express the period of rotation of wa la T through the angular velocity, the latter relation takes the form

-.-one

21T

U

 0 Ti TK

(2)

ten

those. readings of the display unit are uniquely related to the advance angle of the injection. With the same you

Bore K,

and,

and K these readings

 22 2,

coincide with the injection advance angle. After the time ut (which is the delay time of the first time delay element 17), the mIehtta lock the AND 13 (moment tg) circuit. 20. Through the last AND 21 scheme, the indicated impulse passes to the reset bus to the zero of register 23. As a result, the first integrator 14 is reset to the zero state, the register 23 clears and the readings of the display unit 25 are reset. In subsequent shaft revolutions, the device operates in the same way, from where it can be seen that the measurement and indication of the fuel injection advance angle occurs in all those revolutions of the diesel shaft, where the fuel is injected.

From expressions (1) and (2) it follows that the indications of the display unit depend on the parameters K, U, 2 n, K and the measured angle of advance. But since the indicated parameters are determined only by the characteristics of the device units and do not depend on the rare work nor on the diesel fuel advance angle, the readings of the display unit are unambiguously related to the fuel injection advanced corner. When selecting - 2 kK, these readings coincide with the leading angle 0.

The device on a two-stroke diesel, in the event that the advance angle of the injection is in the operator of interest, the cycle must be maintained for the time required by the operator, for example, to build any graphs, tables, etc., works as follows.

The operator dials the number of the cycle of interest when the switch 7 is set to the position B by pressing the button 10. If the cycle number is ni, the operator presses the button 10 (P1-1) times. When this button is pressed, the input of the inverter 9 is connected to the zero terminal of the power source and a single signal appears at its output, which arrives at the summing input of the reversible counter 11. The operator performs the setting of switch 7 at position 6 at that moment, relative. but whose cycle is of interest. If it is necessary to fix the injection advance angle in the m cycle of diesel operation relative to the start time, then this installation is performed at the time of the start of the unit. If, however, it is necessary to measure and fix the injection advance angle in the m-cycle of diesel operation after changing its mode (for example, speed or load), then switching is done at the moment of changing the mode.

After the switch 7 is switched, the summing input of the reversing counter 11 is connected to the output of circuit AND 6, and the inverse output of the higher bit of this counter to the second inputs of circuits AND 6 and 21 of the match. As long as less than (m-l) injection cycles occur in a diesel engine, less than (m-l) pulses go to the subtracting input of the reversing counter 11, at the inverse output of this counter and, therefore, to the second. the inputs of the circuits And 6 and 21 there is a single signal, and the device operates in the same way as when setting switch 7 to position A

When (t-) injection cycles occur in a diesel engine, the subtracting input of the reversing counter 11 passes (ml) pulses, as a result of which it is zeroed (i.e., all the cells refuse zeros), but on the inverse output of this counter the signal is single, and the device still works. After one of the time delay elements, for example, element 17, generates a pulse, the first integrator 14 is reset, the register 23 is reset, and the readings of the display unit 25 are reset.

In this case, the output voltage of the second integrator 12 grows linearly in time, and by the next mth cycle of operation, the diesel reaches

CT values. In the m injection cycle

fuel to the subtracting input of the reversible counter 11 receives the th pulse, causing this counter to overflow and the inverse output of its higher bit of the zero signal, which causes the first 6 and fourth 21 locks of the K to be locked. th pulse scheme And

6, the trigger 3 with the set-up inputs goes to the one state, and the countable trigger 8 goes to the zero state, as a result of which the AND 15 circuit opens and to the first input

dividing device I6 is given a single signal from the output of trigger 3. To the second input of this device, a CT signal is output from the output of the second integrator 12, in connection with which

uh, rd device forms voltage

and

f6

Hi

 to.

Under the action of this voltage, the control generator 22 produces pulses of frequency

f n: Ui

yy to-t which arrive at register 23. At the time of the piston entering the top dead center, trigger 3 is reset, which ultimately leads to stopping the recording of the number in register 23. This number is equal to

N 5iiiy i

21G.T

in the decimal system, 45 is displayed on the display of the display unit 25.

After the time At, after locking the circuit AND 15, the time delay element 19 produces a rectangular impulse that goes to the integrator 12, resetting it to zero, and to the first input of the circuit 21 (through the IL-20 circuit). However, since in the high-speed diesel cycle at the inverted output of the higher bit of the reversive counter 1I, the signal is zero, the AND 21 circuit is closed and the reset pulse does not pass to the reset bus at register 23. Due to this

The number recorded in the register and the indications of the display 2.5 are saved, and the new measurement cycle turns out to be impossible, since AND 6 is closed and after the m-cycle the pulses do not arrive at the single trigger input 3 the pulses of the upper dead point only at its zero input only confirm its zero state). -

To perform the next measurement cycle, you need to open switch 7, first press button 10 to reset reversible counter 11 to zero, then dial the number of the interested cycle and close switch 7 according to the above

When a four-stroke diesel engine operates one cycle, the fuel injection is performed during two shaft revolutions, which is why the frequency of the pulses of the injection sensor is twice lower than the frequency of the upper dead center impulses (Fig. 3). After one impulse of fuel injection (Uc) Two pulses of the upper dead point (Uj) are barely blown, but the reset of trigger 3 with the installation inputs occurs under the influence of the first pulse of the upper dead point, and the next pulse does not affect the state of the trigger, but only confirms it. The unit 3 is in the next state in the next fuel injection cycle, and it is reset by the first impulse after the injection of the top meter. Since every second impulse of the top dead center does not affect the state of the trigger 3 and, consequently, the operation of the device in In general, it also works as in the case of using it to measure the advance angle of a two-stroke diesel engine.

Timing diagrams explaining the operation of the device in a four-stroke diesel engine are shown in FIG. 3. From the charts you can see that the measurement. the advance angle occurs in all those shaft revolutions where fuel is injected. Since in the considered case the integration time of the signal by the first and second integrators is equal to the double shaft rotation period (in the case of a push-pull unit, this time coincides with the rotation period), then on digital

the display unit of the display unit 25 pr | 1 lights up the number

Have

2 GK

fi

2

Therefore, the advance injection angle is equal to

b

.N

„.„,

and and j

When choosing the parameters K 1 (2 is the same as in the case of measuring the angle of advance on a two-stroke diesel engine (–2 ° K), the indication of the indication unit 25 should be doubled. DG1I to remove the measured value of the angle of advance.

Therefore, the device provides a measurement of the advance angle of fuel injection of four-stroke and two-stroke diesel engines, and no switch is required in the device to go from the measurement process on a two-stroke unit to the measurement process on a four-stroke unit (or vice versa).

Due to the fact that in the device the indications of the display unit depend only on the measured advance angle and the characteristics of its component elements (which do not depend on the diesel mode of operation), but do not depend on the mode of operation of the unit, the change in the shaft rotation frequency in the transient mode do not affect the measurement of the lead angle.

In the device, the measurement and indication processes of the measured angle occur in each shaft dump, i.e. Lost information about the value of this parameter has no place. The device on its display also saves the measured value of the advance angle in the E1 diesel cycle of interest, the time that the operator sets, and the number of the cycle of interest the operator can set at his own discretion using the button 10. At the same time, there is no need to repeat the experiment, thereby doubling the measurement performance increases and the diesel consumption is reduced by half during the experiment.

Thus, the device provides high measurement efficiency.

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Compiler H, Patrahalev

Tehred V. Kadar Proofreader A. Zimokosov

Order 2431/31 Circulation 523 Subscription

VNIISH USSR State Committee

for inventions and discoveries P3035r Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, st. Project, 4

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Claims (1)

DIESEL FUEL INJECTION ANGLE MEASUREMENT DEVICE, comprising top dead center and injection sensors, first and second formers, first, second, third and fourth AND circuits, counting trigger, first OR circuit, controlled pulse generator, register, display unit and power supply, moreover, the sensors of top dead center and injection are connected respectively with the first and second formers, the counting trigger is connected to the first input of the second circuit And, and the controlled pulse generator is connected through the register to the display unit, excellent which, in order to increase efficiency, includes a trigger with installation inputs, first and second integrators, first and second delay elements, a dual switch, a button, an inverter, a reversible counter, a dividing device, a second OR circuit, and a decoder, the first the driver is sequentially through a trigger with installation inputs, the third AND circuit and the second delay element connected in parallel with the second OR circuit and the first integrator, the other input of which is connected to the output of the counting trigger and the first input of the AND circuit, and the output through the first OR circuit sequentially through a dividing device - with a controlled pulse generator, which is directly connected to the register, and the latter is connected to the display unit through a decoder, the second driver through the first And circuit is connected in parallel with the counting trigger, trigger with installation inputs and the contact of the first section of the dual switch, the contact of the second section of which is in parallel connected with the first and fourth circuits And, the last of which is connected to the bus sat dew is zero in the register, and the fourth input And in parallel through the second integrator is connected to the first OR circuit through the second integrator, and through the first delay element to the second AND circuit, which is connected in parallel with the divider and the third And connected in parallel with the counting trigger and the second an integrator, while the button connects the zero clamp of the power source through the inverter to the summing input of the reversible counter, the inverse output of the highest level of which is connected with the second fixed contact of the second section of the double a switch, the first fixed contact of which is connected to the zero terminal of the power source, and the second fixed contact of the first section of the switch is connected to the subtracting input of the reversible counter.