DE3314216A1 - METHOD FOR CONTROLLING THE ROTATIONAL PER MINUTE OF COMBUSTION ENGINES - Google Patents

Description

The present invention relates to a method for controlling the number of revolutions per minute of an internal combustion engine. In particular, the present invention relates to a method of this type, by which the accuracy of the control the number of revolutions per minute of the machine by minimizing the fluctuations in the number of revolutions per minute of the Machine as a result of changes to the machine while controlling the number of revolutions per minute of the machine applied loads can be improved.

A feedback control method for idle revolutions per minute is disclosed in Japanese, for example Patent application 55-98628 known, in which after setting the desired idling revolutions per minute in response to the load on the engine at the time of engine idling and after additional air is supplied to the machine, its amount depends on the difference between the desired idle speed per minute and the actual number of revolutions per minute of the machine depends, this difference is made to zero, thereby the number of revolutions per minute of the machine to the desired idling number of revolutions per minute. During the feedback control of the number of idle revolutions per minute, hereinafter referred to as "feedback control" is referred to, leads in the known method, the operation of electrical devices, such as for example headlights, an air conditioning system, etc., to an increase in the machine load. In addition, to Charging the battery to supply it with power

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electrical facilities when the output voltage of the If the battery drops below a predetermined level, the generator will work, resulting in an increased machine load and leads to a consequent drop in the number of revolutions per minute of the machine. Even in the case of one If the number of revolutions per minute of the machine drops, the number of revolutions per minute is achieved by the control in the Feedback operation again a value which is in the vicinity of the desired idle number of revolutions per minute. But in the case where the electrical load applied to the machine is very large, it can happen that the machine stalls or if the vehicle is simultaneously with the application of such an electrical load is started, the clutch cannot be operated smoothly.

There is also known a method for controlling the number of revolutions per minute of the machine, by means of which the amount additional air supplied to the machine gradually with a decrease in the number of revolutions of the machine from the The time at which the number of revolutions per minute of the engine reaches a level which is below a predetermined number of revolutions per minute, up to the time at which the machine has reached the upper limit of the desired Range of idling revolutions per minute reaches a standstill while the machine is slowing down with the throttle valve fully closed the machine by a sudden drop in the number of revolutions per minute as a result of the clutch disengaging prevent (e.g. Japanese Patent Application 55-98629). Even in the case of such control the supply of additional air to the machine during deceleration, hereinafter referred to as "control in deceleration mode" is referred to, if an electrical

Load added particularly when the clutch is disengaged is the speed of the machine drop abruptly, which leads to a standstill of the machine if the amount of additional air then delivered becomes insufficient.

Also, falls in the case where the engine is idling with the throttle valve open during the control Machine in feedback mode is accelerated when the supply of additional air to the machine at the same time with the opening of the throttle valve is interrupted, the entire amount of the delivered to the machine Intake air suddenly decreases, causing a drop in the number of revolutions per minute of the engine and causing it it becomes difficult to engage the clutch without stalling the machine or bringing it to a standstill.

In order to avoid this difficulty, it was proposed by the applicant of the present patent application, the amount of additional air to be supplied immediately after opening the throttle valve to an amount of additional air Air to be set when the control is in feedback mode immediately before the throttle valve opens was determined. This amount of additional air is then gradually increased in proportion to the increase in the number of revolutions per minute of the machine. During the gradual reduction in the supply of additional Air, which will hereinafter be referred to as "accelerator control", falls when an electrical load is applied Added to the machine load, the speed of the machine abruptly decreases, causing inconvenience for the driver, because in this state the number of revolutions per minute of the machine is not yet high enough and the output power of the machine is not yet sufficient.

The object of the present invention is to provide a control method for the number of revolutions per minute a machine, which effectively prevents a drop in the number of revolutions per minute of the machine it can be said that an increased amount of additional air is immediately supplied to the machine, if at least an electrical load is added to the machine load while the number of revolutions per minute of the machine is increasing is controlled by controlling the additional amount of air. This can cause the machine to come to a standstill or stall and any inconvenience to the driver can be prevented.

The present invention relates to a method for controlling the number of revolutions per minute of an internal combustion engine having an intake passage, one in the intake passage provided throttle valve and an air passage, one end of which with the suction passage at a Communicating location downstream of the throttle valve provided in the intake passage and the same the other end communicates with the atmosphere and through which additional air is supplied to the machine. The amount of additional air is controlled in response to the operating conditions of the machine.

The method of the invention is by the following Steps marked:

a) Setting an amount of different predetermined amounts of additional air to be added to the machine are to be delivered, the different quantities individually corresponding to the size of the electrical loads that be applied by devices of the aforementioned electrical devices.

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b) Determining the switched-on or switched-off state of each electrical device.

c) increasing the amount of additional air by one of the various predetermined amounts mentioned above, which corresponds to the size of the electrical load caused by the switched-on electrical device is applied, simultaneously with the determination of the switched-on state of each of the electrical Facilities.

If two or more of the electrical devices are switched on at the same time, preferably corresponds to the aforementioned predetermined amount by which the additional amount of air is increased, the sum of the aforementioned predetermined Quantities that depend on the electrical loads caused by the electrical equipment being switched on be effected.

The following are the invention and its developments explained in more detail in connection with the figures. It shows:

Fig. 1 is a block diagram of the entire arrangement

a feedback system applicable in connection with the present invention Control system for the number of idle revolutions per minute;

Fig. 2 is a timing diagram illustrating the inventive

Indicates the type of control that will be executed if an electrical load is present during the Control of idle revolutions per minute in feedback mode is applied to the machine;

Fig. 3 is a flow chart showing a routine for

Calculation of the value of the term DE of the electrical load of the opening period DOUT of the control valve, showing the flow chart of the electronic control unit of Fig. 1 is executed;

Fig. 4 is a timing diagram showing the control mode of the

Invention shows which is carried out when an electrical load is applied to the machine while the machine is at completely closed throttle valve is slowed down, whereby the number of revolutions of the machine per minute towards the feedback control range of idle speed drops per minute;

Fig. 5 is a graph showing the relationship between the

Number of revolutions per minute of the machine and - the value of the term DX of the opening period DOUT of the control valve when decelerating sbe operation shows;

Fig. 6 is a timing chart showing the control mode of the

Invention shows carried out 'if an electrical load is being applied to the machine while the machine is being operated by the Feedback control area for idle speed is accelerated per minute from;

Fig. 7 is a flow chart showing a routine for

Execution of the method according to the invention Fig. 3 which is carried out in the electronic control unit of Fig. 1; and

Fig. 8 is a pie chart showing an electrical

Circle shows, which is arranged within the electronic control unit of FIG is.

In the following the invention is explained in connection with the figures.

FIG. 1 shows a schematic representation of a feedback control system for the number of revolutions per minute when idling in a schematic representation that is related to can be used with the method according to the invention. In FIG. 1, reference numeral 1 denotes an internal combustion engine or an internal combustion engine, which can be a four-cylinder engine. With the machine are an inlet or. Intake pipe3, on whose open end an air filter 2 is attached, and an outlet or. Exhaust pipe 4 on the intake side or on the exhaust side the machine 1 connected. A throttle valve 5 is arranged in the intake pipe 3. An air passage 8 opens at its one end 8a into the intake pipe 3 at a location which is downstream of the throttle valve 5. The other The end of the air passage 8 is in communication with the atmosphere and has an air filter 7. A control valve 6 for an additional amount of air, hereinafter referred to simply as "the control valve", is over the air passage 8 arranged to control the amount of additional air that is supplied to the machine 1 via the Air passage 8 is supplied. This control valve 6 is normally closed and has a solenoid 6a and a valve 6b arranged to open the air passage 8 upon energization of the solenoid 6a. The solenoid 6a is electrically connected to an electronic control unit 9, hereinafter referred to as "ECU" connecting. A fuel injector 10 is arranged so that it is in a location between the engine and the open end 8a of the air passage 8 protrudes into the intake pipe 3. The injection valve 10 is with

connected to a fuel pump, not shown. It is also electrically connected to the electronic control unit 9.

A sensor 17 for opening the throttle valve is on Throttle valve 5 arranged. A sensor 12 for the absolute pressure is connected to the suction pipe 3 via a line 11 a location downstream of the open end 8 a of the air passage 8. A sensor 13 for the Temperature of the cooling water of the machine and a sensor 14 for the number of revolutions per minute of the machine are on the Body or block of the machine 1 arranged. All of these sensors and other sensors for determining other parameters the operating state of the machine 1 are electrically connected to the electronic control unit 9.

Reference numerals 15, 18 and 20 denote a first, one second and third electrical devices, such as headlights, an air conditioning system, a brake lamp and a radiator fan, each via switches designated 16, 19 and 21 with the electronic control unit 9 are connected.

The feedback control system constructed as above operates as follows: The sensor 17 for the opening of the Throttle valve, the sensor 12 for the absolute pressure, the sensor 13 for the temperature of the cooling water of the machine, the sensor 14 for the number of revolutions per minute of the machine and the sensors 22 for other machine parameters The generated signals, which represent the operating parameters of the machine, are sent to the electronic control unit 9 delivered. The electronic control unit 9 then determines the operating states of the machine 1 and those connected to it electrical loads based on the readout values of these machine operating parameters and the

generated by the first, second and third electrical devices 15, 18 and 20 and sent to the electronic control unit 9 supplied signals that indicate the electrical loads. Then the electronic control unit calculates 9, a desired amount of fuel to be supplied to the engine 1, i.e., a desired valve opening period of the fuel injector 10 and also a desired one Amount of additional air to be supplied to the machine, i.e., a desired valve opening period of the control valve 6, based on the particular operating conditions of the machine and the electrical loads associated with it. The electronic control unit 9 then supplies the fuel with drive pulses corresponding to the calculated values injector 10 and to control valve 6. The valve opening period of the control valve 6 is by the ratio of the switch-on period to the pulse interval a the rotation of the machine 1 determined synchronous signal Signal is, for example, a pulse signal in which each pulse is at a predetermined crank angle the machine 1 is generated or a pulse signal, the pulses of which are generated at constant time intervals.

The solenoid 6a of the control valve 6 is by each its drive pulses energize the air passage for a Open time period equal to the calculated value of the valve open period so that an amount of additional air corresponding to the calculated value of the valve opening period is supplied to the engine through the air suction passage 8 and the suction pipe 3.

The fuel injection valve 10 is through each of its Drive pulses energized to it for a period of time open which corresponds to its calculated value of the valve opening period in order to feed fuel into the intake pipe 3

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inject. The electronic control unit 5 works so that it supplies an air-fuel mixture to the engine 1 which has a predetermined air-fuel ratio having.

When the valve opening period of the control valve 6 increases is to increase the amount of additional air, an increased amount of the mixture is sent to the machine 1 supplied to increase the performance of the machine, resulting in an increase in the number of revolutions per minute Machine leads. On the other hand, it causes a decrease in the valve opening period a corresponding reduction in the amount of mixture, resulting in a reduction in the number of revolutions per minute the machine performs. In this way the speed of the machine is controlled by controlling the amount additional air or the valve opening period of the control valve 6 is controlled.

In the following, in connection with FIG. 1 and with FIGS. 2 to 6, details of the electrical load dependent control of the additional amount of air produced by the feedback control system as described above are performed.

Fig. 2 shows a control process of increasing the supply of additional air to the engine which is carried out when an elastic load is applied to the machine during the feedback control of the revolutions per minute im Idle is applied. As shown in Fig. 2a, the control is carried out in the feedback mode, the number of revolutions per minute Ne of the engine between an upper limit NH and a lower limit NL des the desired range of the number of revolutions per minute in idle. With such a control in reverse

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Coupling operation is the difference between the actual number of revolutions per minute Ne of the machine as it is determined by the sensor 14 for the number of revolutions per minute of the machine, and the desired number of revolutions per minute idling, which is set in response to the machine load and determined by the electronic control unit 9 is calculated and the opening period of the control valve 6 is controlled in response to this difference so that that this becomes zero.

If now, as shown in FIG. 1, while the machine is being controlled in the feedback mode, at least one of the switches 16, 19 and 21 of the first, second and third electrical device 15, 18 and 20 is turned on, thereby placing an electrical load on the machine is generated when no countermeasure is taken and when the number of revolutions per minute Ne of the engine falls to a large extent, as shown by the broken line in Fig. 2a, this is Decrease in proportion to the increase in the electrical load. In response to the extent of the drop in the number of revolutions the minute Ne of the machine, the control takes place in the feedback mode, i.e. the amount of the to the machine supplied additional air enlarged (broken line in Fig. 2c) to immediately go to the number of revolutions per minute Ne return the machine which is within the upper limit NH and the lower limit NL of the desired range the number of revolutions per minute is idle. However, if the drop caused by the electrical load the number of revolutions per minute Ne of the engine is very high, this can possibly lead to a standstill or stall the machine, and when the vehicle is started, if the electrical load is applied to the machine at the same time, it can be difficult to smooth the clutch

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Engage without stalling the machine, which adversely affects the drive performance of the machine.

When an electric load is added to the machine load on the above occasions, the amount of increase may be the opening period of the control valve, hereinafter referred to as the "electrical load term", and in the Fig. 2c is denoted by DE, and which is required to provide an increased amount of required additional air to deliver (Fig. 2c) to the number of revolutions per minute Ne of the machine at the desired number of revolutions per minute to keep idling can be estimated by the nature of the electrical equipment causing the electrical load. According to the invention, therefore, switch-on signals of the electrical devices, which the additional electrical Show load, determined and at the same time as the power of such a switch-on signal, is the electrical load term DE of the corresponding electrical device, which is specified in advance for each of the electrical '. Facilities determined is added to the current base value of the opening period DPI in order to calculate the opening period DOUT (Fig. 2c) for the control valve. In this way, the valve opening period DOUT is determined by the following equation:

DOUT = DPIn + DE ·. . (1)

DPIn denotes a basic value of the valve opening period, the one with a change in the difference between the actual number of revolutions per minute of the machine and the desired one Revolutions per minute while idling varies.

It is therefore possible to quickly increase the number of revolutions per minute of the machine to the desired idle speed

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per minute by delivering an increased amount of additional air to the machine at the same time when the electrical load is applied to the machine and the delay of the control in feedback mode can be reduced to a great extent (Figs. 2a and c).

Fig. 3 is a flowchart showing a routine for performing the calculation of the DE term of the electrical load in the electrical control unit 9.

If this program is called in step 1 of FIG. 3, the stored value of the term DE is reset to zero in step 2. Then, in step 3, it is determined whether the switch 16 of the first electrical device 15 shown in FIG. 1 is turned on or not. If the answer to this question is "no", the program proceeds to step 5. When the answer to step 3 is "Yes", a predetermined term DE., The electrical load corresponding to the electrical load generated by the electrical equipment 15, is added to the stored value of the term DE of the electrical load and becomes the resultant one Sum value DE + DE- set as a new stored value of the term DE of the electrical load for the electrical device 15 in step 4. Since in this case the stored value DE is reset to zero in step 2 (DE = O), the newly stored value of the term DE + DE.J of the electrical load is equal to the value DE ₁ .

Then, in the manner described above, the switched-on or switched-off state of the switch 19 becomes the second electrical device 18 determined in step 5. If the switch is not on, that will progress

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Program to step 7. When the switch is on, a predetermined electrical load term DE2 relating to the electrical load generated by the second electrical device 18 is added to the stored value of the electrical load term DE, and becomes the resultant sum value DE + DE ₂ as a new stored value of the electrical load term DE for the electrical device 18 at step

6 set. The switched-on or switched-off state of the switch is also shown in the manner described above 21 of the third electrical device 20 at step

7 determined. If the switch is not turned on, the program is ended at step 9. When the switch is switched on, a predetermined term DE., the electrical Load related to the third electrical device 20 to the stored value of the term DE is added to the electrical load and the resulting sum value DE + DE., becomes a new stored value of the term DE of the electrical load for the electrical device 20 is set in step 8. After that, will the program ends.

In the manner explained above, the electrical load term DE of Equation 1 is determined by first the respective switched-on or switched-off state of the first, second and third electrical devices 15, 18 and 20 is determined and that for each When electrical equipment is switched on, a predetermined term of the electrical load that is affected by the Device generated electrical load is added to the stored value of the term DE of the electrical load and that this new value is set as the updated term DE of the electrical load.

Fig. 4 shows a manner of controlling the amount of Increase in the amount of additional air to be supplied to the machine that is applied when the electrical Load is placed on the machine while the machine is slowing down with the throttle valve fully closed.

If the number of revolutions per minute of the machine with fully closed throttle valve 5 (Fig. 1) decreases, and below the specified number of revolutions per minute NA falls, opens the control valve 6 to initiate the delivery of additional air to the machine, as shown in FIGS. 4a and c is shown. This additional amount of air is removed from the machine when you decrease the number of revolutions per minute predetermined number of revolutions per minute NA gradually increased until it reaches the upper limit NH of the desired range the number of idling revolutions per minute is reached. At the upper limit NH it is adjusted to a quantity which is required to keep the number of revolutions per minute of the machine in the desired range of idle speed per minute at a time when there is no electrical load on the machine. This control additional Air is hereinafter referred to as "control in decelerating mode".

As soon as the number of revolutions per minute Ne of the machine falls below the predetermined upper limit NH of the desired range the idle RPM falls, the controller puts in feedback mode, which is related to of Fig. 2 was explained, a.

In the manner described above, while the engine is slowed down with the throttle valve 5 fully closed, a gradual increase in the supply of the amount of additional air with a decrease in the number of revolutions per minute

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the machine causes when the revolutions per minute Ne of the machine is smaller than the predetermined number of revolutions per minute NA of the machine, which is greater than the specified upper limit NH of the desired range of idling revolutions per minute. It can therefore even if the clutch is disengaged while slowing down, a drastic drop in the number of revolutions per minute Minute of the machine, which leads to the machine stalling, can be avoided.

When an electrical load is added to the machine load while the machine is being controlled in the slow down mode is, as shown in Fig. 4b, the engine load is increased in the same way as at the control in the feedback mode, which is shown in FIG. On this occasion, despite the Delivery of a gradually increased amount of additional air to the machine when the control is in slow mode the amount of additional air thus increased will be sufficient to cause the Revolutions per minute of the machine drops abruptly, as shown in Fig. 4a by the broken line is, and that depending on the size of the electrical load, the machine will stall, in particular when the clutch is already in the disengaged state.

Even if the machine is controlled in slowdown mode, it is possible to send the required information to the machine Amount of additional air to be delivered in relation to the electrical load, the type of electrical switched on Establishment corresponds to estimate. According to the invention, therefore, it becomes the switch-on or switch-off state signal indicating the electrical equipment

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wakes up and at the same time when the signal is turned on, the valve opening period becomes DOUT of the control valve 6 increased by an amount corresponding to the DE term of the electrical load on the electrical device which is switched on, as shown in FIG. 4c. This means that the opening period DOUT of the control valve according to the following equation is determined.

DOUT = DX + DE (2)

DE is determined in the same way as was explained in connection with FIG. DX denotes one Term of the slowdown operation.

Fig. 5 shows an example of the relationship between the term DX of the decelerating operation and the number of revolutions per minute Ne of the engine. If the number of revolutions per minute Ne of the engine lies between a predetermined number of revolutions per minute NA and the upper limit NH of the desired range of the idling number of revolutions per minute, the opening period DX of the control valve corresponds to a value Me which is proportional to the reciprocal value of the actual number of revolutions per minute Ne of the machine is. If the number of revolutions per minute Ne of the machine is greater than the predetermined value NA, ie Ne - ^> NA _,.; _ The value DX is kept at zero and if the number of revolutions per minute Ne of the machine is below the upper limit NH , ie Ne ~ = ς NH, the value DX is set to a predetermined value DXH. Here, the predetermined value DXH is set to a value which is necessary to achieve a desired idling number of revolutions per minute at the time of the engine idling with no load on the machine, including the electrical load. The above

Wert Me is used for the purpose of processing in the electronic Control unit and corresponds to the time interval between adjacent pulse signals shown in Answer to the number of revolutions per minute of the machine are generated, which are determined by the sensor 14 for the number of revolutions per minute of the machine. This means, that the value Me becomes smaller, the greater the number of revolutions per minute Me of the machine.

In the manner described above, by providing a magnified one calculated using equation (2) Amount of additional air to the machine at the same time that the electrical load becomes the machine load is added, not only can an abrupt drop in the number of revolutions per minute of the machine be avoided, but the driving efficiency of the machine can be improved.

Fig. Δ shows a method of controlling the increase the amount of additional air to be supplied to the machine, applicable to the case where the electric load is applied to the machine while the machine is accelerating is, the throttle valve (Fig. 1) from a state it is during the control of the idle holds in feedback mode is opened. If the machine, starting from an idle state in which the Throttle valve 5 is completely closed when controlling in feedback mode, as shown in FIG. 6a is accelerated with the throttle valve 5 fully open, the control of the supply of intake air can be performed then effected in response to the opening of the throttle valve 5. Accordingly, the supply of additional air become unnecessary. However, if the supply of additional air is interrupted at the same time that the throttle

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valve 5 is opened, the number of revolutions per minute of the machine decreases as a result of an abrupt decrease in the Delivery of additional air, which causes difficulties in smoothly engaging the clutch * - and without a The engine stalling is caused. "To prevent this, the valve opening period is DOUT of the control valve 6 immediately after opening the throttle valve 5 at a value DPI _ .. maintained during the last control loop of the feedback operation was determined immediately before the opening of the throttle valve 5 was executed. Thereafter, this valve opening period DOUT is gradually increased by a fixed amount for each of the TDC pulses reduced, hereinafter referred to as "control in Accelerating operation ". When the gradually decreased valve opening period DOUT is a very reached a small period Do (ineffective period) at which the control valve 6 due to the decrease in the energization period of the solenoid 6a of the control valve 6 substantially does not open, the valve opening period DOUT is set to 0, because then the excitation of the control valve 6 leads to a loss of electrical power and to a reduced durability of the control valve 6. This is known as the "stop operation".

When an electrical load occurs during the above-described Control of the machine 1 is applied in the acceleration mode, this electrical load increases the .Maschinenlast and the number of revolutions per minute Ne of the engine therefore drops abruptly (broken line in Fig. 6a), thereby causing inconvenience to the driver and reducing the driving efficiency of the machine is adversely affected, as described above in connection with FIGS. 2 and 4 for the control in the Feedback operation and for the control in the decelerated

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operation was explained in each case. It is in the same even during the control in the accelerating operation As explained in connection with FIG. 2, it is possible to add the necessary amount of additional to the Air to be supplied to the machine, which corresponds to any type of electrical device causing the electrical load, to estimate. The signal of the switch-on or switch-off state is therefore also during the control in the slowing mode monitors any electrical device that indicates the presence of an electrical load and at the same time the valve opening period DOUT of the control valve 6 becomes even when a switch-on signal is output increased by the term DE of the electrical load, as shown in FIG. 6a. That means that the Valve opening period DOUT is determined by the following equation:

DOUT = DPI _n-1 - mDA + DE (3)

DPI _ ₁ denotes an opening period of the control valve which was determined in the last control loop in the control in the feedback mode immediately before the opening of the throttle valve. DA denotes a constant determined experimentally, m denotes the number of pulses of the TDC signal counted from the time the throttle valve 5 is opened. The term DE of the electrical load is determined in the same way as was explained in connection with FIG.

An increased amount of additional air calculated according to Equation 3 above becomes simultaneous with the occurrence of electrical load on the machine is supplied to the machine, which not only causes some abrupt drop in the number of revolutions per minute of the machine is prevented, but also thereby reducing the drive efficiency of the machine

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is improved. When the valve opening period DOUT off of the equation (3) falls below the ineffective valve opening time Do, the period DOUT is regarded as if it has the value 0, the excitation of the control valve 6 is interrupted in order to close this, as this is shown in Fig. 6c.

Fig. 7 shows a flow chart of a program routine for Performing control of the increase in the additional air supplied to the machine at the time an electrical load is applied to the machine. This carried out by the electronic control unit 9 of FIG Routine has already been explained in connection with FIGS.

When this program is called in the electronic control unit 9, it is determined in step 1 whether the value Me, which is proportional to the reciprocal value of the number of revolutions per minute Ne of the engine, is greater than the value MA. or not, which is proportional to the reciprocal of the determined value NA (Fig. 4a). In step 1, when the answer is "no" (ie, Me J = S ^ MA is not satisfied), ie, when the number of revolutions per minute Ne of the engine is greater than the predetermined value NA, the valve opening period DOUT in step 2 becomes zero set, as the supply of additional air to the machine is then unnecessary. The program ends in step 13. On the other hand, if the answer to step 1 is "Yes" (Me P> - MA is satisfied), that is, if the number of revolutions per minute Ne of the engine is smaller than the predetermined value NA, it is determined in step 3 whether the throttle valve 5 is then fully is closed or not. When the throttle valve 5 is fully closed, it is determined in step 4 whether the value Me is greater than the value MH or

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not. When the answer to step 4 is "No", that is, when the number of revolutions per minute is Ne of the engine is greater than the specified upper limit NH of the desired range of idling revolutions per minute, as will be explained in detail later, at step 5 it is determined whether the last loop im Feedback operation occurred or not. If the answer is negative, this is previously discussed in connection with Fig. 3 The program is called and the term DE is the electrical load of the valve opening period DOUT des Control valve 6 as a function of the switched-on or switched-off states of the electrical devices 15, 18 and 20 are calculated in step 6. Then using the term DX of the deceleration mode and the term DE of the electrical load calculated in step 6, the valve opening period DOUT in the slow down operation is obtained from the equation (2) in step 7, and then the program is executed completed.

When the number of revolutions per minute Ne of the engine decreases so that the answer to the question of step 4 is "yes" (Me ^ =? R MH is satisfied), that is, the number of revolutions per minute Ne of the engine becomes smaller than the predetermined one. upper limit NH of the desired range of the idling number of revolutions per minute, the control range of the feedback mode being entered (FIG. 4c), the term DE of the electrical load shown in FIG. 3 is calculated in step 8. Then, in step 9, the valve opening period DOUT. Under the control in the feedback mode is calculated on the basis of the equation (1), and then the program is ended.

While controlling the idle revolutions per minute

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In the feedback mode it can sometimes happen that the number of revolutions per minute Ne of the machine exceeds the upper limit NH of the desired range of the idling number of revolutions per minute either as a result of external disturbances or as a result of the reduction in the machine load caused by the elimination or disconnection of the electrical load on the machine caused, · exceeds. In this case, when the slow-down control is ended and the feedback control is initiated, the amount of additional air in the feedback mode continues even if the engine revolutions per minute Ne exceeds the upper limit NH of the desired range of the idle revolutions per minute as long as the throttle valve 5 is fully closed. Since there is no chance of the machine stalling or stalling on this occasion, quick and precise control of the number of revolutions per minute is possible sooner than with the feedback control. In this way, when the number of revolutions per minute Ne of the engine exceeds the upper limit NH of the desired range of the idling number of revolutions per minute due to an external disturbance or due to the turning off of the electrical load on the engine, it is determined in step that the relationship Me , ^ ⁵ - MH is no longer valid and the program proceeds to step 5. In step 5, it is determined whether or not the last control loop was executed in the feedback mode and

if so (i.e. the answer is "yes") the program goes to step 8 and step 9 continued with the execution of the control in the feedback mode.

During control in the idle machine feedback mode (FIG. 6), when the throttle valve

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5 is opened to effect the transition to control in accelerating mode, the answer to the question of step 3 is "No" and the program therefore proceeds to step 10 to determine whether the valve opening period DOUT of the control valve 6 in the previous loop is smaller was as a predetermined value D _{Q shown} in Fig. 6c or not. If the answer is "no", in step 11 in accordance with the routine shown in FIG . The program is then ended.

When the valve opening period DOUT is gradually decreased in the accelerating operation so that the relationship DOUT "^ - Dq is established in step 10, the valve opening period DOUT is set to zero as in step 2, and the program is then ended.

Next, the electrical circuit in the electronic control unit 9 in connection with FIG. 8 which shows an embodiment of this circuit.

The RPM sensor 14 of the engine of Fig. 1 is unified with an input port 902a a central processing unit (CPU) 90 on a chip via a wave shaper 901. Each of them is connected to the output terminal 903, all of which are provided in the electronic control unit 9. The reference signs 15 ', 18' and 20 'represent sensor devices for determining the electrical loads of the electrical Means 15, 18 and 20 of Fig. 1, each with corresponding further input connections 90 2b a

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Group of connections of the central processing unit 902 via a level adjustment device 904 in the electronic Control unit 9 are connected. The sensor 13 for the temperature of the water and the sensor 17 for the opening of the throttle valve are each connected to input connections 905a and 905b of an analog-to-digital converter 905. They are also with the input of a fuel supply control unit 903 connected. The analog-to-digital converter. 905 has an output terminal 905c, the -with the Input terminals 902b of the central processing unit is connected. A group of other input ports 905d of converter 905 is connected to a group of output terminals 902c of central processing unit 902. A pulse generator 906 is connected to another input terminal 902d of the central processing unit 902, which in turn has an output terminal 902e, which via a frequency divider 907 with a terminal of a AND circle 908 is connected. The output of the AND circuit

908 is one with a clock pulse input terminal CK Down counter 909, connected. The other input terminal of AND circuit 908 is a carry output terminal B of the down counter 909 connected. This connection is also connected to a solenoid 6a of the control valve 1 via a control circuit 911 for the solenoid. The central processing unit 902 has another Group of output terminals 902f, one of which with a load input L of the down counter 909 and a further connected to the output terminal 910a of the register 910. The output terminal 910c of the register 910 is connected to the input terminal 909a of the down counter

909 connected. A data bus 912 connects each output terminal 905e of the analog-digital converter 905, an input and output port 902g of the central processing unit 902 and an input port 910b of the Register 910.

With the fuel supply control unit 903 are the Sensor 12 for the pressure of the intake air or for the absolute pressure and the sensors 22 for the other machine parameters, such as an atmospheric pressure sensor, all of which are shown in Fig. 1, are connected. The output of the fuel supply control unit 90 3 is connected to the fuel injection valve 10 of FIG. 1 tied together.

The electrical circuit of the electronic control unit 9 constructed in the manner described above operates in the In the following manner: An output from the sensor 14 for the number of revolutions per minute of the machine is sent to the central processing unit 9 both as a signal ^ which indicates the number of revolutions per minute Ne of the engine, and supplied as a signal indicative of a predetermined engine 1 crank angle (TDC). The output signal will be shaped in the electronic control unit 9 by the wave shaper 901 and then to the central processing unit 902 and applied to the fuel supply control unit 903. As previously explained, the routine of Fig. 7 is executed in synchronism with the TDC signal. After this this signal relating to top dead center has been applied, the central processing unit 902 generates a chip select signal, a channel selection signal, a start signal for analog-to-digital conversion, etc., sent to the analog-to-digital converter 905 command analog signals such as that relating to the cooling water temperature of the machine Signal and the signal relating to the opening of the throttle valve from the sensor 13 for the temperature of the cooling water and from the sensor 17 for the opening of the throttle valve, to be converted into corresponding digital signals. The digital Signals from transducer 905 that indicate the cooling water temperature and indicating the throttle valve opening are sent as data signals to the central processing unit 902 via the data bus 912

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is applied when a signal indicating the completion of each analog-to-digital conversion is applied from the output terminal 905c of the analog-to-digital converter 905 to the central processing unit 902 is created. After completing the conversion of one of these digital signals to the central processing unit 902 the same process described above is effected again to input the other digital To effect signals to the central processing unit 902. Also, the voltage levels of the electrical Load indicating signals from the sensor devices 15 ', 18' and 20 'for the electrical load by the level adjustment device 904 adjusted to a predetermined level and then applied to the central processor exnhext 902.

The central processor exnhext 902 processes these input data signals, i.e. the signal relating to the number of revolutions per minute of the machine relating to the electrical load Signal, the signal relating to the cooling water temperature of the machine and the opening of the throttle valve s relevant signal according to the control steps explained in connection with FIG. 7 in order to determine whether the control of the amount of additional air in stop mode, in feedback mode, in deceleration mode or should take place in acceleration mode. This means, for example, that the central processing unit checks whether the controls are being carried out in the decelerating mode should when the number of revolutions per minute Ne of the engine is smaller than the predetermined value NA and larger than the upper limit NH of the desired range of idle revolutions per minute, the throttle valve is completely closed if the previous control loop was not in feedback mode. The central processing unit 902 calculates the DE term of the electrical load of the

Valve opening period DOUT in accordance with the program 3 as a function of the signals relating to the electrical load from the electrical devices 15 ', 18' and 20. The central processing unit also determines 902 the valve opening period DOUT of the control valve 6 on the basis of Equation 2 corresponding to Slowdown operation. The central processing unit 902 then supplies the register 910 with the calculated value of the Valve opening period DOUT via data cable 902 after a command signal to register 910 via its Charge input terminal L has been entered.

On the other hand, a clock signal generated by the pulse generator 90 6 is used as a timing signal for the from the central processing unit 902 used control operation. At the same time, the frequency of this signal is increased by the Frequency divider 907 divided into an appropriate frequency and then applied to one input terminal of AND circuit 908.

Then the central processing unit 902 delivers in a predetermined Momentarily a start command signal to the down counter 909 via its load input terminal L to to open the control valve 6.

When the start command signal is applied to the down counter 909 from the central processing unit 902, it will entered a calculated value that corresponds to the desired valve opening period DOUT of the control valve 6 for the control in the decelerating mode, which is stored in the register 910 is indicating. At the same time, the down counter 909 produces a high level output signal of the value "1" at its carry output terminal B and applies this to the other input terminal of AND circuit 908 and

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to control circuit 911 for the solenoid. The control circuit 911 energizes the solenoid 6a of the control valve 6 to to open this as long as the above-mentioned high-level output signal of the value "1" from the down counter 909 it is put on. That is, the control valve 6 is opened with a duty cycle that corresponds to the valve opening period DOUT corresponds.

As long as at the other input terminal of the AND- ^ circuit 908, the above-mentioned high-level output signal of the value "1" is applied from the down counter 909 Clock pulses via its one connection to the input connection CK for the clock pulses of the down counter 90 9 be created. The down counter 909 counts the clock pulses and generates after going up to a number that corresponds to the calculated value of the valve opening period DOUT applied by the register 910 was, a low-level output signal of the value "0" at its carry output port B to cause the control circuit 911-the solenoid 6a of the control valve 6 upset. At the same time, the aforementioned low output of the down counter 909 is applied to the AND circuit 908 is applied to interrupt the delivery of further clock pulses to the down counter 909. Since similar explanations are applicable even if the central processing unit 902 checks whether the controller is in feedback mode or the control is to be carried out in the acceleration mode, further explanations are omitted. In addition, when the central processing unit determines that the control is being made in the stop mode should not transmit a start command signal from the central processing unit 902 to the down counter 90 9 and the down counter 909 and the control circuit 911 for the solenoid therefore remain inactive, whereby the control valve 6

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is kept in the fully closed state.

On the other hand, the fuel supply control unit processes 903 from the sensor 14 for the number of revolutions per minute of the engine, the sensor 13 for the cooling water temperature the machine, the sensor 17 for the throttle valve opening, the sensor 12 for the absolute pressure and the signals supplied to the sensors 22 for the other operating parameters of the machine, the operating parameters of the Machine concern to get a desired value of fuel Calculate supply amount so as to get the air-fuel ratio the mixture supplied to the machine 1 to an optimal value, for example a theoretical air-fuel ratio, keep, and around the fuel injection valve 10 for a period of time that corresponds to a calculated value.

Claims (5)

.... "_ _: 3314215 Patent Attorneys Dipl.-Jng. H / VjTiCKMAfiTvDiPL.-PHYS. Dr. K. Fincke Dipl.-Ing. RA-Veickmann, Dipl.-Chem. B. Huber Dr.-Ing. H. LiSKA, Dipl.-Phys. Dr. J. Prechtel VPk 8000 MUNICH 86 CQ, wyy ■ £ ■■ τ POST BOX 860 820 " MOHLSTRASSE 22 TELEPHONE (089) 980352 TELEX 5 22 621 TELEGRAM PATENTWEICKMANN MÖNCHEN Honda Giken Kogyo Kabushiki Kaisha No. 27-8, Jingumae 6-chome Shibuya-ku, Tokyo, Japan Method of controlling the number of revolutions per minute of internal combustion engines Claims Λ J Method for controlling the number of idling revolutions per minute of an internal combustion engine (1) with an intake passage (3), a throttle valve arranged in the intake passage (3), an air passage (8), one end of which is connected to the intake passage (3) at a location downstream of the throttle valve (5) and the other end of which is in communication with the atmosphere, and with a plurality of electrical devices (15, 18, 20) provided to connect to the Machine (1) to apply appropriate loads, with additional air being supplied to the machine via the air passage (8) and the suction passage (3) COPY is controlled, the amount of additional air is controlled in a predetermined manner, which is selected in response to the operating conditions of the machine (1), characterized in that a) a plurality of quantities of different air to be supplied to the machine is set, which individually Sizes of the electrical applied by one of the electrical devices (15, 18, 20) Loads correspond to that b) the switched-on or switched-off state of each of the electrical devices (15, 18, 20) is determined will, and that c) simultaneously with the determination of the switched-on state of each of the electrical devices (15, 18, 20) the amount of additional air is increased by one of the various predetermined amounts that corresponds to the size of the electrical load applied by each switched-on electrical device (15, 18, 20). 2. The method according to claim 1, characterized in that it is determined whether the machine works in a predetermined operating state in which the throttle valve is completely closed, or not and whether the number of revolutions per minute is less than one first predetermined value, which is an upper limit of the desired idling number of revolutions per minute acts or not that, if it is determined that the machine is operating in the predetermined operating condition, the amount of additional air as a given way is controlled in a feedback mode based on the difference between the actual number of revolutions per minute of the machine (1) and the desired idling speed per minute the machine responds, and that simultaneously with the determination of the switched on State of at least one of the electrical devices (15, 18, 20) during the control in feedback mode the amount of additional air is increased by at least one of the various predetermined amounts that the size of at least one electrical device applied by the at least one electrical device (15, 18, 20) Load corresponds. 3 · - Method according to claim 1, characterized in that it is determined whether the machine (1) works in a predetermined operating state in which it slows down when the throttle valve (5) is completely closed it is or not that, when it is determined that the machine (1) is operating in the predetermined operating state, the amount of additional air is controlled in the predetermined manner, so that the amount of additional air is increased gradually from the time at which the number of revolutions per minute of the machine (1) falls below a second predetermined value falls which is greater than a first predetermined value which is an upper limit represents the desired idling number of revolutions per minute, that a predetermined value is set when the number of revolutions per minute of the machine is the first reached predetermined value, and that simultaneously with the determination of the switched-on state at least one the electrical devices (15, 18, 20) during the control of the additional amount of air in the event of deceleration the machine increases the amount of additional air by at least one of the various predetermined amounts will that of size at least one by at least -: 33H216 an electrical device (15, 18, 20) applied electrical load. 4. The method according to claim 2, characterized in that it is determined whether the machine (1) is in a second predetermined operating state or not, in which the throttle valve (5) is open to the machine during the control iirr feedback operation (1) to speed up that when it is determined that the machine (1) is in the second predetermined operating state is, the amount of additional air is controlled in the predetermined manner so that it is immediately after the Opening of the throttle valve (5) is set to a value that is equal to the last value in the control in feedback mode certain value is / and that the amount is then gradually reduced, and that at the same time with the determination of the switched-on state of at least one of the electrical devices (15, 18, 20) during controlling the amount of additional air as the engine accelerates, the amount of additional air is increased at least one of the various predetermined amounts is increased corresponding to the size of at least one by at least an electrical device (15, 18, 20) applied electrical load. 5. The method according to claim 1, characterized in that the amount of additional air to the sum of at least two amounts of the different predetermined amounts is increased at the same time when it is determined that at least two of the electrical devices (15, 18, 20) are switched on at the same time, which correspond to the at least two different predetermined amounts.