JPS6043175A - Ignition timing controlling device of engine - Google Patents

Abstract

PURPOSE:To prevent generation of knocking upon starting control by a method wherein differences until the knock limit ignition timings of respective cylinders are obtained by a feedback control based on a knocking signal and the differences are memorized into memories corresponding to respective operating conditions of respective cylinders of an engine as memory correcting values with a predetermined period of renewing. CONSTITUTION:A reference control value generating means 3 provides respective operating conditions with reference ignition timing characteristics while a memory means 6 memorizes the correcting control value of ignition timing of a cylinder discriminated by a cylinder discriminating means 4 into addresses corresponding to respective operating conditions and reads out the memorized values from the addresses corresponding to respective cylinders in accordance with the detecting outputs of a revolving number detecting means 1 and a load detecting means 2. Sequential control values, correcting the ignition timings of respective cylinders based on the output of a knocking detecting means 5, are operated by an operating means 7 and the memorized values in the addresses corresponding to the operating conditions are renewed into the direction of delaying spark angles in case the knocking is generated during a predetermined operating period while the operating means 7 renews and controls the memorized values into the direction of advancing the spark angles in case the knocking is not generated in the same period. These signals are sent to an igniting means 9 through the control value operating means 7 and the optimum ignition control may be effected.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ignition timing control device for controlling the ignition timing of an engine.

In general, it is known that an engine is most efficient when operated at an ignition timing at which slight knocking occurs (knock limit) from the viewpoint of engine output and fuel efficiency characteristics.

In the conventional device of this glaze, the ignition timing is set in advance based on the standard ignition timing characteristics, and -1 is set at one foot angle each time knocking occurs, or at an angle corresponding to the knocking intensity. There is a system that performs feedback control on the ignition timing at the knock limit to reduce the retardation phase shift by a sufficient time constant when knocking does not occur. Ta.

In order to suppress knocking, all the support cylinders are retarded in the same way with a sufficient retardation phase shift control amount, so if knocking occurs in a certain cylinder, 1 will occur and 7'21: Of course, the cylinder will be affected by other cylinders. Also, the control amount KL is uniformly retarded.

In general, the common cylinders of one engine have slight differences in structure.

Due to variations in component parts, differences in air-fuel mixture distribution between cylinders, knock occurrence conditions are different, and the knock limit ignition timing is different for each cylinder.

Therefore, if a conventional device that performs such control is used, the ignition timing is set to the knock limit of the cylinder where knocking is most likely to occur. This is.

7Q fire timing control is not necessarily optimal for the engine,
All cylinders are at the knock limit ignition timing and are not supposed to fire Q.

Therefore, several proposals have been made for cylinder ignition time control devices that control the retard phase shift n1 control amount of the ignition timing for common cylinders.

By the way, in this type of foot knock control, including the control for each cylinder, the control for suppressing knocking is to control the amount of retardation from the reference ignition timing.

Therefore, the reference ignition timing must be set in advance at a point where the knock limit is also advanced. Therefore, the ignition timing at the start point of control is always beyond the knock limit, so that large knocking occurs at the start of control. It is desirable to set the reference ignition timing at an ignition timing that is slightly ahead of the knock limit.

However, if we also take into account the above-mentioned variation in the knock limit between cylinders, it is practically impossible to set it in this way. Under certain operating conditions, it is inevitable that the reference ignition timing will be set on the retarded side with respect to the ignition timing at the knock limit. In the operating state of the engine installed on the late n side, engine 1 will ignite at the optimum ignition timing at the knock limit, and ignition at the C side delay fL'fc timing, and all cylinders will be ignited at the optimum ignition timing in all operating states. cannot be controlled.

``IYC, with conventional devices, even if the operating condition of the engine changes, the ignition timing before the change in operating condition is applied.
Therefore, a large time lag occurs before the control amount reaches the control target value in the operating state after the change.

That is, the responsiveness to changes in operating conditions is poor and k. Furthermore, since all operating ranges that require knock suppression are controlled by changes in the magnitude of the foot knock control amount, a wide dynamic range is required for control cylinder manufacturing. However, the occurrence of knocking is influenced by the ignition timing air-fuel ratio, intake air temperature, intake air humidity, and many other factors among the operating characteristics of an engine.

However, things that depend on changes in natural conditions, such as intake air temperature and intake air humidity, have very long cycles of change, such as one day or one season. Therefore, changes in the occurrence of knocking due to changes in these factors also occur over a long period. In other words, the knocking that occurs in a short period of time under the same operating conditions is approximately the same level, and there is no big difference in the frequency and intensity of knocking. Since the correction control value required to suppress knocking that occurs under the same operating conditions is almost the same in a short period of time, the correction control value required to suppress knocking that occurs under the same operating conditions is almost the same in a short period of time. The corrected control value is controlled as the current corrected control value, and if a slight knock occurs during control, the ignition timing correction range may be narrow. If you do.

With extremely high precision and responsiveness, it suppresses knocking and can control the ignition timing to the knock limit. The above-mentioned long-period change factors can be corrected by increasing the correction control value by 〈υ.

This invention memorizes the correction control value of the common cylinder in the normal operating state of one engine, and successively obtains the correction value by combining this correction control value and the knocking signal that occurs every cycle. The large correction value is synthesized and the standard control value in the normal operating state of the engine is corrected for each normal cycle, and the above-mentioned corrected control value of the normal cylinder is sufficient for the increase in temperature during the π-long period. By updating based on the sequential correction value of the common cylinder at a cycle of 1, knocking is suppressed reciprocally with a small number of sequential correction values, and the response of the knocking suppression control is improved when the operating state changes.

It is an object of the present invention to provide a device for controlling the ignition timing of a common cylinder to an individual knock limit over all operating conditions.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the general configuration of the present invention.

The rotation speed detection means 1 detects the rotation speed of an engine (not shown),
The load detection means 2 detects the load state of the engine. The reference control value generating means 3 has a memory for providing a reference ignition timing characteristic stored in advance at an address divided into two days from the engine speed and load condition V determined by the means 1 and 2. Read out the standard control value at the corresponding address among the standard control values. The storage means 6 corresponds to the ordinary cylinder of one engine.

It has an area for storing corrected control values in addresses partitioned into two parts depending on the rotational speed and load condition, and contains information on the cylinder to be ignited this time from the cylinder identification means 4, information on the current cylinder from the rotational speed detection means 2, etc. A correction control value (stored correction value) is read out from the address specified by the rotation speed information and the load state information from the load detection means 2 and sent to the correction value calculation means 7. The correction value calculation means 7 is.

The knocking suppression successive correction value for each cylinder is calculated from the cylinder information of the cylinder identification means 4 and the knocking signal detected by the knock detection means 5, and the stored correction value is corrected with the resultant value, thereby determining the ignition timing for one ignition timing. Correction value? It is created and output to the control value calculation means 8. -1k, when knocking occurs during a predetermined engine operation period, the correction value calculation means 7 updates and stores the correction value for the cylinder to a value on the retarded side;
If the occurrence of knocking is serious, the value is updated to the advanced angle side and stored. The control value calculating means 8 calculates the previously read f'Lfc.
The reference control value is corrected by the ignition timing correction value created by the correction value calculation means 7 for the cylinder to be ignited this time, one ignition timing is determined, and one ignition means 9 is caused to ignite at the determined ignition timing.

FIG. 2 is a block diagram showing an embodiment of the present invention applied to a four-stroke, four-cylinder engine. In the figure, 10 is an angle detector which generates a signal 10a & generates a signal 10a whose signal level is inverted every 360 degrees of rotation angle of the crank in conjunction with the engine force/mushaft rotation, and 11 is a signal 10a of the angle detector 10.
An angle detector that generates a signal 11aY having a phase difference of 180 degrees with respect to the angle detector.

12 is a pressure sensor that detects the intake pipe pressure of the engine and generates a signal 12ak corresponding to the pressure; 13 is a digital signal 13aK that outputs a signal 12a output from the pressure sensor 12;
Analog-to-digital (A/D) converter, 14
15 is a speed sensor that is attached to the engine and detects the vibration acceleration of the engine and outputs a signal 14a, and 15 is a speed sensor that discriminates from the signal 14a of the acceleration sensor 14 the period in which engine knocking has occurred and outputs a signal 15a. discrimination detector, 16
digitizes No. 46 15a of the discriminator 15 and outputs the signal 1.
It is an A/Dg converter that converts to 6a. 20 is a microcomputer, mainly a microprocessor (CPU) 21
, memory (ROM and RAM) 22, and interface (110) 23. 18 is a timing switching circuit which converts the ignition timing control amount signal 23a & timing signal 18aK into the signal calculated by the microcomputer 20, and 17 is a timing switching circuit 1B, which ignites the engine at the timing when C is generated and the signal 18a. This is the ignition circuit.

The operation of this embodiment configured in this manner will now be described. FIG. 3 is a diagram of the output waveforms of the angle detectors 10 and 11 shown in this embodiment, and the signal 11a of the first angle detector 11.
follows the rotation of the engine, and at 90° BTDC of the first cylinder, °L
"No level, the 4th cylinder's BTDC becomes IH° level at 90°. - The signal 12a of the F7C angle detector 12 is 18 degrees in crank angle with respect to the signal 11a of the angle detector 11.
It becomes a delayed signal. These two signals 11 a a
12a is input to the interface 23 of the microcomputer 20. The pressure sensor 12 detects the intake pipe pressure of the engine and generates a voltage level signal 72 corresponding to the pressure.
2a is generated. Since the intake pipe pressure of the engine changes sensitively in response to the load state of the engine, the load state of the engine can be determined from the level of the signal 12a obtained by detecting this intake pipe pressure. Now, the pressure sensor 12 generates n'
The fc signal 12a is converted into a C,9 digital signal by the first A/Dl converter 13, and is inputted to the interface 23 as a signal 13a.

The acceleration sensor 14 is attached to the engine and constantly detects vibrations of the engine. Signal 1 which is this detection output
In 4a, a noise signal due to mechanical vibration occurring during engine operation and a knocking component due to vibration occurring during knocking of one engine are superimposed. The discriminator 15 receives the signal 14a
The knocking component is discriminated and detected from the knocking component, integrated into V, and a signal 15a having a level corresponding to the knocking intensity is output. This signal 1ja is digitized by the A/D converter 16 and becomes a signal 16a, which is sent to the interface 23.
L, then read 1fL into the cPU21. Also.

The integral value of the discriminator 15 is reset by the signal 23b from the interface 23 under the command of the microprocessor 21, and is initialized for detection of other knocking.

Memory 21j of microcomputer 20: ROM and R
AM'a'! However, the ROMK has an area (hereinafter referred to as an advance angle map) for storing reference control values that give reference ignition timing characteristics in each operating state of the engine at redundant addresses in advance according to the engine speed and load state. In the f'L RAM, memory correction values of the common cylinder in the operating state corresponding to each address are stored in the name address added corresponding to the engine speed and load state of each cylinder of one engine. A storage area (hereinafter referred to as a learning map) is provided.

The CPU 21 includes angle detectors 10, 11 . The optimal ignition timing of the common cylinder is determined from the sensor information of the pressure sensor 12 and the acceleration sensor 14, and the signal 18a is output from the timing converter 18 at the determined ignition timing, and the first ignition circuit 17 ignites the second engine. let

A flowchart of the process executed by the CPTJ 21 is shown in FIG. P□ to p33 in the figure indicate the execution steps of the flowchart.

In this flowchart, ignition is the first step. 3rd degree 2nd degree.
The case of a four-cylinder engine in which the fourth cylinder is fired is shown.

The control calculation by the CPU 21 is performed once every ignition cycle in synchronization with the timing when the state of the output signal of the angle detector 10.11 is reversed.

1. First, turn off the power output of the timing conversion circuit 18 using Pl.
and start counting operation.

P2 is the time interval from the start of the previous process to the current time 1,
That is, a period corresponding to 180 rotations of the crank angle is measured. At P, this is converted into the measured periodic rotation speed.

Input the pressure signal at P, and then P.

The load condition of the engine can be calculated from this signal.

At P, the address of the advance angle map corresponding to the rotational speed and load condition calculated at P and P is read out and the corresponding reference control value data is stored in the A register.

At P7, the state of the signal 10a of the angle detector 10 is checked. If the state is "L", the cylinder to be ignited immediately before is the first cylinder or the second cylinder, as shown in FIG. Next, at P8, check the state of the signal 11a of the second angle detector 11, and if the output state is l L l, the immediately preceding ignition cylinder is identified as the first cylinder. to remember identification information.

The number 1 indicating the firing order of the first cylinder is stored in the fLk register n provided in the memory 22. If the state of the signal 11a is IH1 at P8, then P□. Indicates the firing order of the second cylinder with the number 4.
is stored in register n. -Sword.

If it is determined that the signal 10a of the first angle detector 1o is IH1 at P7, then the immediately preceding ignition cylinder is the third or fourth cylinder. Hereinafter, at P□1, check the state of the signal 11a of the angle detector 11 in the same way as P8, and if 'L1, use P to register nI/C, which is the number 2? indicating the firing order of the third cylinder 2? :Pl3 for “memorize, use”
Then, the number 3 indicating the ignition J@ of the fourth cylinder is stored in the register n.

At pHl, a knocking signal 16a (Δk) is read, and at Pl, a signal 23bY for resetting the integral value of the discriminator 15 is generated to prepare for detecting the occurrence of knocking. At P16, among the registers fL and sequential correction value storage registers provided in the memory 22 corresponding to the common cylinders, the register f corresponding to the 8VC identified at P7 to P□ is selected.
The signal 16a (Δ1
Correct it with (] and store it again in C(n). In P□7, compare the rotation speed at the time when the engine steady state counter (described later) starts counting and the rotation speed recorded in P, and if the difference is 50 rpm or more. In the case of , the engine rotation speed changes and the process proceeds to P26. If it is less than 50 rpm, the engine is considered to be operating at a constant rotation speed.Next, in P18, the load condition from the time when counting starts is similarly determined. Check the fluctuation of the load condition.If the change in the load condition is 5% or more, it is assumed that the engine operating condition Fi has changed and the process proceeds to P26.If the change in the load condition is less than 5%, it is assumed that the engine is being operated in a single load condition. .In PI3, 1 is added to the value of the register D(n) of the corresponding cylinder among the registers that count 1 engine rotation speed and load state.In P2□, the count value of this register D(n) is 1.
00, that is, whether the cylinder in question has been operated in the above-mentioned foot-operation state for 100 consecutive ignition cycles. If the number has not reached 100, no processing is performed and P2f is executed.
Proceed to step 1. If D (n), = 100 then P
In step 21, it is checked whether the sequential correction -m C(n) of the cylinder previously created in P□6 is O.

In the case of C(n) - 0, no knocking has occurred in the relevant cylinder during 100 consecutive ignitions, so P5. The rotation speed and load condition determined in P5, and P
- P □ Reads the corresponding memory correction value B (n) on the learning map from the cylinder information identified by hand.

This n=ri1? Subtract and store B(n)K again.

If C(n)'=O, it is assumed that knocking occurred during this continuous 10-point period, and P2. , the correction value C(n) is sequentially added to the memory correction value B(n) on the corresponding learning map, and it is stored again in B(n), and P
In step 07, the sequential correction value C(n) in step 1 is set to 0 (initialization is performed).Next, in step P2, the register for counting the number of ignitions li' D ( n
) is cleared, and the engine speed and load condition at this point in time are stored as a reference for steady-state operating conditions. −
If P1□ or pxs determines that there is a change in the operating state of the engine, P26 considers the successive correction values created in the operating state before the change to be meaningless.

The value of register C(n) storing this sequential correction value is cleared. In the second P27, P2. Similarly, the register D (n) for counting the number of ignitions is cleared, the current m Sekiguchi rotation numbers and load conditions are stored, and the kth update of the stored correction value is initialized.

In this way, the correction value on the learning map is calculated during steady operation of one engine for 100 ignitions for each cylinder.

If f' is held, it is updated. If no knocking occurs during 100 ignition cycles, the stored correction value is determined to be excessive and is updated in a decreasing direction. This correction value does not need to be a particularly positive value, and can also be a negative value if knocking does not occur continuously.

- If the occurrence of knocking is detected in the nth case.

The correction value is updated in the increasing direction. Also, if one machine is not in a steady state, update of the correction value is prohibited.

To prevent meaningless updating of memory correction values due to knocking occurring before the operating state of an engine changes.

As described above, when the process for dealing with the knocking caused by the previous ignition is completed, the process for determining the ignition timing of the cylinder to be ignited immediately begins.

In P2B, P
7 - Add 1 to the ignition j of the previously ignited cylinder determined in PL5. For example, if the previous ignition was in the first cylinder and the value of the register n is 1, the value of the register n will be 2 when 1 is added to this ignition, so the ignition for this n will be This type of cylinder is the third cylinder. P2. In step P28, it is checked whether the value of register n is 5 or not. If n=5, the previous ignition cylinder was the second cylinder.

The distance is from the ignition to the first cylinder, so P. Set the value of register n to 1.

In this way, the next ignition cylinder is determined.

At P, □, P5 and P, the number of rotations determined.

Correction value B(n) for cylinders that should be slightly ignited in a loaded state
is read out from the learning map, and this value is added to the sequential correction value of the cylinder that is to be ignited at the same time to create one ignition timing correction value.

Read the reference control value A from the address on the advance angle map according to the rotation speed and load condition determined by P and P in P32, and subtract the ignition timing correction value BY from X26 in P51.
Create a control value that determines the ignition timing of the cylinders that are slightly ignited.

The control value as a result of this calculation is data that indicates the ignition position to the value of the angle ratio. At P55, this data is converted into n time delay data from the inversion time of the outputs of the angle detectors 11 and 12 (the time when the counter starts counting at Pl). This angle-to-time conversion calculation is easily possible based on the period information at P2.

The fLfc ignition timing control value converted into a 2-hour signal at P55 is set in a latch in the timing converter 1B.
Ru.

The counter of the timing converter 18 starts counting when the division process of the CPt 121 starts, that is, when the state of the output of the angle detector 10 or 11 is reversed.

When this count value matches the latte value set in P55, the timing converter 18 generates a signal 18aY to cut off the current supply to the other side of the 11 ignition coil in the 1st ignition circuit 17, and the microcomputer 20 The engine is ignited at the determined ignition timing.

In this embodiment, the steady operating state of one engine is determined.
In a steady state of operation, the memory correction value of the nk learning map provided for the common cylinder is updated so that the sequential correction value for each cylinder becomes a small value, and the reference ignition timing ft is set using the memory correction value and the small sequential correction value. By making corrections for each cylinder, it is possible to ignite at the ignition timing of each cylinder's individual knock limit. On the other hand, updating of the memory correction value is prohibited in the transient operating state of one engine.

Ignition is configured to ignite at an ignition timing corrected using a stored correction value that is already in a steady state, which is the reference ignition timing. Therefore, even if the operating status of one engine changes, the ignition timing of the Namiminkan is quickly controlled to the ignition timing of the individual knock limit.The responsiveness of the ignition timing feedback control using the knocking signal is very good, and further corrections are made sequentially. Since the control range based on the value only needs to be narrow, the control accuracy is the same as above. 1. Since the memory correction value of the learning map can take values of both positive and negative polarities, it is possible to control the ignition timing on the advanced side beyond the standard ignition time W4, and the standard ignition timing Even when the timing is set to the ignition timing slightly retarded side of the knock limit, ignition can be performed at the ignition timing of the knock limit by updating the advance power of the stored correction value.

Note that in the above embodiment, the stored correction value is updated only once for the cylinder concerned.
Although this is carried out every 00 ignitions, this may be carried out every predetermined period of time. In the above embodiment, the cylinder is identified using the output information of the two angle detectors, but the invention is not limited to this; for example, a detection means for identifying the standard ignition cylinder may be provided. The essence of the present invention is not affected even if a method such as counting the number of ignitions and identifying the number of cylinders is employed.

As described above, in this invention, the reference ignition timing of one engine is set in advance in accordance with @operating condition, and the difference in the actual knock limit of the ordinary cylinder at ignition timing 1 is calculated from this reference ignition timing. Request feedback control by knocking signal,
This difference value is updated and stored at a predetermined period in a read/write memory that corresponds to the normal operating state of the common cylinder of one engine as a memory correction value. Absorbs variations in the ignition timing at the knock limit, and suppresses knocking that occurs within a short period of time by making small sequential corrections using the knocking signal. I can do it well. In addition, even if the operating condition of one engine changes, the ignition timing of the common cylinder is quickly controlled to the ignition timing of the knock limit, preventing large knocks during transients and deterioration of engine performance due to transient retardation. san
Ru. Furthermore, since the memorized correction value can be corrected to advance the reference ignition timing, even in driving modes where the reference ignition timing is retarded relative to the knock limit ignition timing, @ While controlling the actual control ignition timing to the advanced side with respect to the reference ignition timing for each cylinder, it is possible to perform feedback control on the knocking signal individually. Therefore.

In all operating conditions, each cylinder is controlled to the optimum ignition timing at the knock limit, and there is no longer a need to set the standard ignition timing to the advance side of the knock limit ignition timing. By setting the reference ignition timing with the center value of the knock limit as the target, it is possible to prevent the occurrence of large knocking at the start of control due to the reference ignition timing being advanced too much.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the general configuration of the device of the present invention, and FIG.
The figure is a block diagram showing one embodiment of the device of the present invention, Figure 3 is a waveform diagram of the output of the angle detector shown in Figure 2, and Figure 4 is a waveform diagram of the output of the angle detector shown in Figure 2.
3 is a flowchart of the operation of the microcomputer shown in the figure. 1... Rotation speed detection means, 2... Load detection means, 3.
・Reference control value generation means, 4 . . 8 identification means, 5.
Knock detection means, 6 Memory means, T Correction value calculation means, 8 Control value calculation means, 9 Ignition means. Agent Masuo Oiwa Figure 1 Figure 2 Figure 3 Figure Procedure Amendment (Voluntary) 1981 12F! 6. Dear Commissioner of the Japan Patent Office. 1. Indication of the incident: Japanese Patent Application No. 58-151286 2, Title of the invention: Engine ignition J4A control device 3, Part 5 to the representative of the person making the amendment, Katayuni 5, Subject of amendment (1) Full text of the specification (2) Drawing 6, Contents of amendment (1) The entire specification is amended as shown in the attached sheet. (2) Correct Figure 4 as shown in the attached sheet. 7. List of attached documents (1) Document stating the entire text of the amended specification 1 copy (2) Document stating Figure 4 after the amendment 1 copy or more Full text 1. Name of the invention Engine ignition timing control device 2. Scope of Claims A knocking detection means for detecting knocking of an engine, an operating state sensor for detecting an operating state of the engine, and a machine.
means for generating a reference control value giving a reference ignition timing characteristic for each operating state of the engine; cylinder identification means for identifying the ignition cylinder of the engine; and correction control of the ignition timing of the cylinder identified by the cylinder identification means. a memory means for storing values at addresses corresponding to each operating state of the engine, and reading the stored values from addresses corresponding to each cylinder in accordance with detection outputs from the operating state sensors; and based on the output of the knock detection child actor. A sequential control value for correcting the ignition timing of each cylinder is calculated, and if knocking occurs in the cylinder during a continuous predetermined operation period, the operating state at the time of processing in the area corresponding to the cylinder in the memory means is calculated. an itching hand that updates the stored value at the address corresponding to the value in the retard direction, and controls the update to the value in the advance direction when knocking does not occur; the stored value read from the memory means; determining means for determining the ignition timing of each cylinder of the engine by correcting the reference control value with the value obtained by calculating the sequential correction value; and ignition means for igniting the engine at the ignition timing determined by the determining means. Equipped with an engine ignition timing control device. 3. Detailed Description of the Invention The present invention relates to an ignition timing control device for controlling the ignition timing of an engine. In general, it is known that, in terms of output and fuel consumption characteristics, an engine is most efficient when operated at an ignition timing in which knocking occurs (knock limit). This type of conventional device has a reference ignition timing characteristic set in advance; the ignition signal generated based on this characteristic is retarded by a fixed angle each time knocking occurs, or by a predetermined angle depending on the knocking intensity. If no occurrence of knock occurs, there is a system that feedback-controls the ignition timing to the ignition timing at the knock limit by reducing the retard phase shift amount by a predetermined number of points. However, in order to suppress knocking, all cylinders are retarded in the same way using a specific retard phase shift control amount, so if knocking occurs in a certain cylinder, not only will the cylinder in which knocking occur be affected, but other cylinders will also be affected by that control amount. Therefore, the angle is uniformly retarded. In general, each cylinder of an engine has different knock occurrence conditions due to slight structural differences, variations in component parts, differences in air-fuel mixture distribution between cylinders, etc. In other words, the knock limit ignition timing differs for each cylinder. There is. Therefore, if a conventional device that performs such control is used,
The ignition timing is set to the knock limit of the cylinder where acid knocking is likely to occur. This does not necessarily result in optimal ignition timing control for all four cylinders, and does not mean that all cylinders are ignited at the ignition timing at the knock limit. Therefore, several proposals have been made for cylinder-specific ignition timing control devices that perform feedback control of the ignition timing retard phase shift control amount for each cylinder. By the way, in this type of feedback control ζ, including control for each cylinder, the control for suppressing knocking is to control the amount of retardation from the reference ignition timing. For this reason, the reference ignition timing must be set in advance to be more advanced than the knock limit. Therefore,
Since the ignition timing set at the start point of control is always at a point that exceeds the knock limit, large knocking occurs at the start of control. For this reason, it is desirable to set the reference ignition timing to an ignition timing that is slightly ahead of the knock limit. However, when considering the above-mentioned variation in the knock limit between cylinders, it is practically impossible to set it in this way. In a certain operating state, it is inevitable that the reference ignition time M(l!) will be delayed with respect to the knock limit revamp timing.In an engine operating state that is set to the delayed side, the engine will not reach the knock limit. The ignition occurs at a later time than the optimum ignition timing, and all cylinders cannot be controlled to the optimum ignition timing under all operating conditions.Furthermore, with conventional devices, even if the operating condition of the engine changes. As for the ignition timing, the timing before the change in the operating condition is applied as is, so there is a large time lag until the control amount settles to the control target value in the operating condition after the change. Furthermore, since the control device controls all operating ranges that require knock suppression by changing the magnitude of the feedback control amount, a wide dynamic range is required and accurate control over all operating ranges is required. Controlling the ignition timing has been a challenge. By the way, the occurrence of knocking is influenced by the ignition timing air-fuel ratio, intake air temperature, intake air humidity, and many other factors among the operating characteristics of the engine. However, for things that depend on changes in natural conditions such as intake air temperature and intake air humidity, the period of change is very long, such as one day or a season.Therefore, knocking due to these changes is Changes in the occurrence conditions also occur over a long period.In other words, knocking that occurs in the same operating condition in a short period of time is approximately the same level, and there is no significant difference in the frequency or intensity of knocking.In other words, knocking that occurs in the same operating condition The correction control # value required to suppress this is almost the same over a short period of time, so in the same operating state of the engine specified by specific operating parameters, the previously stored correction control value is increased by the current correction control value. The ignition timing correction range only needs to be narrow in case of slight occurrence of knocking during control, so if the correction control is performed sequentially based on the knocking signal for each occurrence, knocking can be suppressed with extremely high precision and responsiveness. The ignition timing can be controlled to the knock limit.The above-mentioned long-cycle change factors can be corrected by slowly changing the correction control value. The correction control value for each cylinder in each engine state is memorized, and the standard control value in each operating state of the engine is determined using the correction value obtained by combining the sequential correction values calculated from the knocking signal generated for each cylinder based on the correction control value. Correction is made for each cylinder, and for the aforementioned long-cycle change factors, the correction control value for each cylinder is updated at a predetermined period based on the sequential correction value for each cylinder, allowing slight sequential correction. To provide a device that accurately suppresses knocking based on the value, improves the response of knocking suppression control when operating conditions change, and controls the ignition timing of each cylinder to the knock limit in all operating conditions. The purpose is to An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a plotter diagram showing the general configuration of the present invention. The rotation speed detection means 1 detects the rotation speed of an engine (not shown),
The load detection means 2 detects idle load conditions. The reference damping value generating means 6 has a mesh, and is used to provide reference ignition timing characteristics stored in advance at addresses two-dimensionally partitioned according to the engine speed and load condition according to the means 1 and 2ζ. Find out the base control value at the corresponding address from the base control values. The storage means 6 stores addresses 41 that are two-dimensionally partitioned according to the rotational speed and load condition, corresponding to each cylinder of Isoaki.
It has an area for storing the J value, and is specified by the current ignition generous information from the cylinder identification means 4, the current rotation speed information from the rotation speed detection means 2, and the load status information from the load detection means 2. The correction control value (memorized correction value) is read from the f5 area and sent to the correction value calculation means 7. The correction value calculation means 7 calculates a knocking control sequential correction value for each cylinder from the cylinder information of the cylinder identification means 4 and the knocking signal detected by the knock detection means 5,
By correcting the stored correction value at NtIli, an ignition timing correction value is created and output to the control value calculating means 8. In addition, when knocking occurs during a predetermined engine operation period, the correction value calculation means 7 updates and stores the memory correction value for the relevant cylinder to a value on the retard side, and when knocking does not occur, the correction value calculation means 7 updates and stores the stored correction value for the cylinder concerned. The corner side value ζ is updated and stored. The control value calculating means 8 corrects the reference control value read out using the ignition timing correction value created by the correction value calculating means 7 for the cylinder to be ignited this time, determines the ignition timing, and outputs the ignition timing to the ignition means 9. Ignition is performed at the determined ignition timing. FIG. 2 is a block diagram showing an embodiment of the present invention applied to a four-stroke, four-cylinder engine. In FIG. 1, 10 is an angle detector that generates a signal 10a whose signal level is inverted every 36o0 of rotation angle of the crank in conjunction with the rotation of the camshaft of the engine, and 11 is a signal 10a of the angle detector 10.
An angle detector that generates a signal 11a having a phase difference of 180° with respect to An analog/digital (A/D) converter converts the digital signal 12a into a digital signal 13a.
) Converter 14 is an acceleration sensor attached to the engine that detects the vibration acceleration of the engine and outputs a signal 14a: 15
16 is an A/D converter that digitizes the signal 15a of the discriminator 15 to produce a signal 16a. be. 20 is a microcomputer, mainly a microprocessor (CP
U) 21 and memory (ROM and R, AM) 22
and an interface (Ilo) 23. 18 is a timing conversion circuit that converts the ignition timing control amount signal 23a calculated by the microcomputer 20 into a timing signal 18a, and 17 is an ignition circuit that ignites the engine using the timing signal 18a generated by the timing conversion circuit 18. Next, the operation of this embodiment configured as described above will be explained. FIG. 3 is an output waveform diagram of the angle detector 10.11 shown in this embodiment, and shows the signal 10a of the first angle change detector 10.
follows the rotation of the engine, and the first cylinder's BTDC is 90', which is 1L.
The signal 11a from the angle detector 11 is delayed by 180 degrees in terms of crank angle relative to the signal 11a from the angle detector 11. The two signals 11a and 12a are input to the interface 26 of the microcomputer 20.The pressure sensor 12 detects the intake pipe pressure of the engine and generates a signal 12a with a voltage level corresponding to the pressure. Pipe pressure changes in response to engine load conditions, so
The load condition of the engine can be determined from the level of the signal 12a obtained by detecting this intake pipe pressure. Now, the signal 12a generated from the pressure sensor 12 is digitized by the first A/D converter 13 and inputted to the interface 26 as a signal 13a. On the other hand, the AN speed sensor 14 is attached to the engine and constantly detects vibrations every moment of the engine. The signal 14a, which is the detection output, contains a noise signal due to mechanical vibration caused by engine operation and a knocking component due to vibration generated by engine knocking. The discriminator 15 discriminates and detects the knocking component from the signal 14a, further integrates it, and outputs a signal 15a having a level corresponding to the knocking intensity. This signal 15a is digitized by the A/D converter 16 to become a knocking signal 16a, which is read into the CPU 21 via the interface 26. Also,
The integral value of the discriminator 15 is reset by the signal 25b from the interface 26 under the command of the microprocessor 21, and initialized for the next knocking detection. The memory 22 of the microcomputer 20 includes ROM and R,
AM, and in the ROM, there is an area (
An advance angle map (hereinafter referred to as an advance angle map) is provided in the RAM, and each address determined corresponding to each cylinder of the engine, engine speed, and load state is provided with information about each cylinder in the operating state corresponding to each address. An area (hereinafter referred to as a learning map) for storing memory correction values is provided. The CPU 21 determines the optimal ignition timing for each cylinder from the sensor information of the angle i detectors 1o and 11, the pressure sensor 12, and the acceleration sensor 14, and causes the timing converter 18 to output a signal 18a at the determined ignition timing. The engine is ignited by the ignition circuit 17. A flowchart of the processing executed by the CPU 21 is shown in FIG. P and ~Pss in the figure indicate each process execution step of the flowchart. In this flowchart, ignition is the first step. 3rd degree 2nd degree.
The case of a four-cylinder engine is shown in which the fourth cylinder is operated in this order. The control calculation by the CPU 21 is performed once every ignition cycle in synchronization with the timing when the states of the output signals of the angle detectors 10 and 11 are reversed. First, the counter of the timing conversion circuit 18 is reset to O at P, and a counting operation is started. P2 is the time interval from the start of the previous process to the current time,
That is, a period corresponding to a rotation of 180 degrees in terms of crank angle is measured. At P, this measured period is converted into the number of rotations. Input the pressure signal at P4, and then press P4. The load condition of the engine can be calculated from the lever signal. At P6, the address of the advance angle map corresponding to the rotational speed and load condition calculated along P, , P is specified, the corresponding reference control value data is read out, and is recorded in the A register. At P, check the state of the signal 10a of the angle detector 10. If the state is 'L', the cylinder that was ignited immediately before is the first cylinder or the second cylinder as shown in FIG. 3. Next, in P8, the state of the signal 11a of the second angle detector 11 is checked Check, if the output status is %L, the immediately preceding ignition cylinder is the 1st one.
The number 1 indicating the ignition order of the first cylinder is stored in the register n provided in the memory 22 in order to store the identification information of the ignition cylinder at P. P, signal 1
If the state of 1a is 'J(#, P, .), the number 4 indicating the firing order of the second cylinder is stored in register n. On the other hand, at P, the signal 10a of the first angle detector 10 is SH1. If it is determined that there is, the immediately preceding ignition cylinder is the 3rd or 4th cylinder. Hereinafter, Pl is P. Similarly, check the state of the signal 11a of the angle detector 11.
$1. In the case of /, the number 2 indicating the ignition order of the third cylinder is stored in the register n using Pl, and in the case of SH1, the number 3 indicating the ignition order of the fourth cylinder is stored in the register n using Plj. At Pt4, the knocking signal 16a (Δk) is read, and at Pill, a signal 23b for resetting the integral value of the discriminator 15 is generated to prepare for the next generation of knocking. In the PUS, among the successive positive value storage registers provided in the memory 22 corresponding to each cylinder,
Register C (corresponding to the cylinder identified by P, ~pHl)
The knocking signal 16a (Δ
k) and stored again in C(n). At P1'F, compare the rotation speed at the time when the engine steady state counter (described later) starts counting and the rotation speed determined by Ps, and the difference is s o rp.
If it is greater than or equal to 50 rpm, it is assumed that the engine speed has changed and the process proceeds to PTS; if it is less than 50 rpm, it is assumed that the engine is being operated at a constant speed. Subsequently, at Pl, the variation in the load state from the time of starting counting is similarly checked. If the change in load state is 5% or more, the operating state of the engine is assumed to have changed and the process proceeds to pHfi. When the load state change is less than 5 inches, it is assumed that the vehicle is operated under a constant load state. At ``t.'', 1 is added to the value of the register D (n) of the corresponding cylinder among the registers that count the engine speed and load condition. At PH1, the count value of this register D (n) is 100. Check whether there is, that is, whether the air level has been operated in the above constant operating state for 100 consecutive ignition times.If it has not reached 100, do not take any action.
Proceed to lm processing. l when D (n) = 100
Also, in Plm, it is checked whether the sequential correction IC(n) of the cylinder in question previously created at pH+ is 0. If c (n) = o, no knocking occurred in the relevant cylinder during 100 consecutive ignitions, so P2t
j Here, the rotational speed and load condition determined earlier at P, , P, and P, ~P1. The memory correction value B (n) on the learning map corresponding to the cylinder information and force identified in is read out, 1 is subtracted from this value, and the value is stored again in B (n). C(n)
'=j O, it is assumed that knocking has occurred during these 100 consecutive ignitions, and the correction value C is sequentially added to the memory correction value B (n) on the corresponding learning map at Pt8.
(n), store it in B (n) again, and use %”l? to set the previous sequential correction value C(n) to 0 (initialize)
. Next, at P□, the next update lζ of the memory correction value B (n)
In preparation, the value of the register D (n) for counting the number of ignitions is cleared, and the engine speed and load condition at this time are stored as a reference for determining the steady operating state. On the other hand, to. Alternatively, if Pt6 determines that there is a change in the operating state of the engine, Pt6 considers the sequential correction value created in the operating state before the change to be meaningless, and registers C which stores this sequential correction value. Clear the value of (n). Next PI? Then, similarly to Pt11, the register D (n) for counting the number of ignitions is cleared, the current engine speed and load condition are stored, and initialization is performed for updating the stored correction value. In this way, the correction value on the learning map is updated in a decreasing direction, assuming that the stored correction value is excessive if no knocking occurs on the aircraft. This correction value does not need to be a particularly positive value, and can be a negative value if knocking does not occur continuously. On the other hand, if the occurrence of knocking is detected, the correction value is updated in the increasing direction. Furthermore, when the engine is not in a steady state, updating of the correction value is prohibited, thereby preventing meaningless updating of the stored correction value due to knocking that occurs before the operating state of the engine changes. Now, when the process for the knocking that occurred in the previous ignition is completed as described above, the process begins to determine the ignition timing of the cylinder to be ignited next. In p2g, in order to specify the cylinder to fire next, P
, ~pts Add 1 to the firing order n of the cylinder that was fired last time. That is, for example, if the previous ignition was in the first cylinder and the value of register n is 1, by adding 1 to this, the value of register n becomes 2, so the corresponding cylinder in the ignition order is the first cylinder. It will have 3 cylinders. In P□, P7. Check whether the value of register n is 5 by the operation. In the case of n-5, the previous ignition cylinder was the second cylinder,
Next is the first cylinder in the firing order, so P. Set the value of register n to 1. When the next ignition cylinder is determined in this way, the rotational speed determined at P3+ and P5 and the correction value B(n) of the cylinder to be ignited next in the loaded state are read out from the learning map, and this value is read out from the learning map. The ignition timing correction value is created by adding the value and the sequential correction value for the next cylinder to fire. In PI2, P
3 and P, read out the reference control value A from the address on the advance angle map based on the rotation speed and load condition that you determined, and subtract the ignition timing correction value B that you determined at step P31 from this value to determine the ignition timing of the cylinder to be ignited next. Create control values. The control value as a result of this calculation is data indicating the ignition device by a value corresponding to the angle. In Pss, this data is converted into delay time data from the inversion time of the output of the angle detector 10 or 11 (the time when the counter in PI starts counting). This angle-to-time conversion calculation is easily possible based on the periodic information in P. P8. The ignition timing control value, converted to a time signal, is set in a latch within timing converter 18. The counter of the timing converter 18 starts counting at the start of the arithmetic processing of the CPU 21, that is, when the state of the output of the angle detector 1o or 11 is reversed, and this count value matches the latch value set in P33. At that point, the timing converter 18 generates a signal 18a and the ignition circuit 17
cuts off the power to the primary side of the ignition coil and ignites the engine at the ignition timing determined by the microcomputer 2°. In this way, this embodiment determines the steady operating state of the engine,
In steady-state operating conditions, the memory correction values in the learning map provided for each cylinder are updated so that the sequential correction values for each cylinder are small, and the reference ignition timing is set using the memory correction values and the small sequential correction values. By correcting each cylinder's limit, it is possible to ignite at the ignition timing of each cylinder's individual knock limit. On the other hand, updating of the memory correction value is prohibited in the transient operating state of the engine.
Ignition is configured to ignite at an ignition timing that is a reference ignition timing that has been corrected using a stored correction value that has already been set during a steady state. Therefore, even if the operating condition of the engine changes, the ignition timing of each cylinder is quickly controlled to the ignition timing of the individual knock limit, and the responsiveness of the ignition timing feedback control using the knocking signal is very good. Since the control range only needs to be narrow, control accuracy is improved. In addition, since the memorized correction value of the learning map can take values of polarity on both positive and negative sides, it is possible to control the ignition timing in advance beyond the standard ignition timing, and the standard ignition timing is knocked. Even when the ignition timing is set to the retarded side than the limit ignition timing, ignition can be performed at the knock limit ignition timing by updating the stored correction value in the advance direction. Note that in the above embodiment, the stored correction value is updated only once for the cylinder concerned.
Although this is carried out every 00 ignitions, this may be carried out every predetermined period of time. Further, in the above embodiment, the cylinders are identified based on the output information of the two angle detectors, but the invention is not limited to this.For example, it is possible to provide a detection means for identifying a reference ignition cylinder and sequentially count the ignitions. Even if a method such as identifying cylinders is adopted, the essence of the present invention is not affected in any way. As described above, in this invention, the reference ignition timing of the engine is set in advance in accordance with each operating state, and the difference between this reference ignition timing and the actual knock limit ignition timing of each cylinder is determined by knocking. Through feedback control using signals,
By updating and storing this difference value as a memory correction value in a read/write memory corresponding to each operating state of each cylinder of the engine at a predetermined period, knocks caused by variations in each cylinder of the engine, seasonal changes, secular changes, etc. By absorbing variations in the critical ignition timing and suppressing knocking that occurs within a short period of time with small sequential corrections using the knocking signal, knocking can be suppressed with high precision through ignition timing control. . In addition, even if the engine operating condition changes, the ignition timing of each cylinder is quickly controlled to the ignition timing at its knock limit, preventing large knocks during transient periods and deterioration of engine performance due to excessive retardation. be done. Furthermore, the stored correction value can be corrected to the advanced side relative to the standard ignition timing, so even in the driving mode where the standard ignition timing is set to the retarded side relative to the knock limit ignition timing, While the actual control ignition timing of each cylinder is controlled to be advanced with respect to the reference ignition timing, feedback control can be performed individually using the knocking signal. Therefore, over all operating conditions, each cylinder is controlled to the optimum ignition timing at the knock limit, and it is no longer necessary to set the standard ignition timing to the advanced side with respect to the ignition timing at the knock limit. By setting the reference ignition timing with the center value of the knock limit of the cylinder as the target, it is possible to prevent occurrence of large knocking at the start of control due to too much advance of the reference ignition timing. 4. Brief explanation of the drawings Figure 1 is a block diagram showing the general configuration of the device of the present invention, Figure 2 is a block diagram showing the general configuration of the device of the present invention.
The figure is a block diagram showing one embodiment of the device of the present invention, Figure 3 is a waveform diagram of the angle detector shown in Figure 2, and Figure 4 is a flowchart of the operation of the microcomputer shown in Figure 2. be. 1... Rotation speed detection means, 2... Load detection means, 6.
,. Reference control value generation means, 4... harshness discrimination means, 5...
Knock detection means, 6... Storage means, 7... Correction value calculation means, 8... Control value calculation means, 9... Ignition means. Agent Masuo Oiwa

Claims (1)

[Claims] knocking detection means for detecting knocking of the engine; an operating state sensor for detecting the operating state of the engine; and means for generating a reference control value giving a reference ignition timing characteristic for each operating state of the engine; A cylinder identification means for identifying the ignition cylinder, and a correction control value for the ignition timing of the NYC cylinder identified by this cylinder identification means are stored in addresses corresponding to each operating state of the engine, and a detection output from the operating state sensor is stored. A memory means for reading a stored value from a corresponding address of the common cylinder according to the knock detection means, and a sequential control value for correcting the ignition timing of the cylinder also based on the output of the knock detection means for continuous operation. If knocking occurs in the relevant cylinder during the period, the memory means is updated to a value in the retard direction corresponding to the address corresponding to the operating state at the time of processing in the 'fc area corresponding to the relevant cylinder, and the knocking is prevented. If the occurrence is bad, the above reference control value is corrected using the calculation means for updating the value in the advance angle direction, the stored value read from the above memory means, and the value obtained by calculating the above sequential correction value, and An engine ignition timing control device comprising: determining means for determining the ignition timing of a cylinder; and ignition means for igniting the engine at the ignition timing determined by the determining means.