JPS58170856A - Knocking control device for internal-combustion engine - Google Patents

Abstract

PURPOSE:To reduce the capacity of a memory by a method wherein in an engine control device using a knocking feedback system, a control signal value is stored only in the zone where knocking takes place. CONSTITUTION:A memory 12 is generally used in common with other purpose and a plurality of kinds of data are stored in the memory. Accordingly, it is necessary to design the memory to have a small storing capacity. The memory 12 is so constructed that it operates only in an operation condition in which knocking generates in the engine. As a consequence, the capacity of the memory can be minimized.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a knock suppressing device for an internal combustion engine, and relates to a method of performing control based on a control amount stored in a memory.

Recently, in order to improve the efficiency (fuel efficiency) and output of internal combustion engines, knock suppression fI that detects and suppresses knocking has been introduced! Development of 4 devices,
Recruitment is booming.

Knocking occurs depending on one of the operating conditions of an internal combustion engine, such as ignition timing, intake air temperature, intake air humidity, air-fuel ratio, and combustion chamber temperature. Among these factors, in practice, intake air temperature, greatly affected by changes in intake air humidity,
Knocking does occur. Since the temperature and humidity of these intake airs change depending on the season, the state in which knocking occurs changes depending on the season. Furthermore, since the seasons change in a yearly t-cycle, the state of occurrence of knob kings also changes in a yearly cycle. However, the knocking that occurs in the same operating condition in a short period of time is of the same degree, and there is no significant difference in the degree and size of the knocking that occurs in the same operating condition. is almost the same in a short period of time and To! the law of nature,
In addition to the basic control based on these average control signals, the system sequentially performs correction control for buffiness every time knocking occurs.

Knocking can be sufficiently suppressed.

In view of the above characteristics of knocking, the present invention detects knocking that occurs in an internal combustion engine, generates a control signal in response to the detected force, and performs feedback control that suppresses knocking based on the average value corresponding to the operating state. The purpose of this system is to efficiently store control signals, store them when knocking occurs, and in addition to the nine control signals, sequentially correct small noise μ differences each time knocking occurs, thereby suppressing knocking with good responsiveness. .

Hereinafter, one embodiment of the present invention will be described based on the drawings. As mentioned above, there are many factors that cause knocking to occur, and knocking can be suppressed by controlling any of them, but in this explanation, the case of ignition timing control, which is most often put into practical use, will be explained.

In Figure 1, α) is an ignition signal generator that generates a reference ignition signal as the internal combustion engine rotates, and ■ is a high-point signal generator (
1) A waveform shaping circuit receives the reference ignition signal from the waveform shaping circuit and outputs an ignition pulse with a desired pulse width by shaping the waveform and controlling the closing angle. The phase shifter (!1) shifts the phase to the delayed side in time and outputs the output according to the control signal from the phase shifter II (!1). The continuous switch circuit (・) is attached to the internal combustion engine and detects the vibration acceleration of the engine. +71 is used to select nine knocking components generated as the engine knocks from the detected force of the acceleration sensor (6). (8) is a pressure sensor that detects the intake pipe pressure of the internal combustion engine and outputs a pressure signal corresponding to that pressure; (9) is the knock detector that outputs a knocking signal of a level corresponding to the knocking intensity; The AD converter converts each output from the detector (7) and the pressure sensor (8) into digital μ according to its repay, and receives the voltage waveform of the drive terminal of the ignition coil A'+61 for a fixed period of time. A waveform shaping circuit that outputs pulses to a knock detector (7) and an arithmetic unit (Ill), where the arithmetic unit (Ill is an AD converter (
9), the operating state of the engine is determined from the output of the nine-pressure counter (8) and the output of the waveform shaping circuit, and the knocking is detected from the output of the knock detector (7), which is input via the %AD converter (9). The intensity is determined, and a reference control signal is also determined from a memory QZ, which will be described later, and the control signal is output. Memo 9tJ'AIr
It is controlled by an l calculator (11) and stores a reference control signal.

Figure 2 is a memo! J　Reference control signal stored in Q21.

FIGS. 3, 4, and 5 are operation waveform diagrams of the part shown in FIG. 1.

First, the operation of the igniter section consisting of the ignition signal generator (1) to ignition coil /l/(51) will be explained.The ignition signal generator (1) generates an ignition signal as the internal combustion engine rotates.

The waveform shaping circuit Q) shapes the waveform of the ignition signal, controls the closing angle, and outputs an ignition pulse with a desired pulse width. The above ignition pulse is inputted to the switch circuit (4) via a phase shifter, and the switch circuit (4) responds to the ignition pulse by ignition coil A/ (51 power supply t - continuing 0 ignition coil y
When the power supply is cut off in (6), an ignition voltage is generated, and the internal combustion engine is ignited and operated.

The pressure sensor (81 detects the intake pipe pressure of the internal combustion engine and outputs a pressure signal corresponding to the pressure. This pressure signal is
The signal is converted into a digital signal by a D converter 191 and inputted to a computing unit (11) as a signal representing the load condition of the internal combustion engine. The intake pipe pressure of the internal combustion engine mentioned above sensitively responds to and changes depending on the load condition of the engine, so the load condition of the internal combustion engine is determined from the level y of the pressure signal from the pressure sensor (8) obtained by detecting the intake pipe pressure. can be found.

The waveform shaping circuit operates in accordance with the voltage at the drive terminal of the ignition coil V (6) and outputs a fixed time pulse at the ignition timing.

The acceleration sensor (8) is attached to the internal combustion engine.

Vibration of the internal combustion engine is constantly detected. This detection force includes noise signals (
For example, a knocking component due to vibration generated due to knocking is superimposed on the noise signal detected as a result of the operation of a pump valve.

The knock detection aI (?l) selects a knocking signal from the detected force from the acceleration detector (6) and outputs a VbeμO knocking signal corresponding to the knocking intensity.

This knocking signal is converted into a digital signal by an AD converter (9) and inputted to an arithmetic unit (11). The output of the knock detector (7) is reset by a fixed time pulse from the waveform shaping circuit. The computing unit Cl1l calculates the load condition of the engine from the pressure signal from the pressure sensor (3) inputted via the AD converter (9), and also calculates the rotation of the internal combustion engine from the period of the fixed time pulse from the waveform shaping circuit. Find the numbers and use these to determine the engine's operating status. Furthermore, the occurrence of knocking is detected from the knocking signal from the knocking detector (7) inputted via the AD converter (9).

If knocking is occurring in the internal combustion engine, the calculator (
11) determines the operating state of the internal combustion engine from the pressure signal from the pressure sensor (8) and the fixed time pulse from the waveform shaping circuit not, and calculates the knocking signal from the knock detector (7) corresponding to the knocking level y. The above-mentioned knocking signal is stored in memory O as a reference control signal in the above-mentioned operating condition.
Store it in z. In each operating state in which knocking occurs in the internal combustion engine, a knocking signal corresponding to the above-mentioned operating state is stored in the memory a21, and a map of reference control signals corresponding to each operating state is created.

Figure 2 shows an example of the storage state of the reference control signal (self-answered in memory az) corresponding to the above operating state. Here, the operating state is determined by the load and rotational speed of the internal combustion engine. Therefore, the number of revolutions is determined by dividing it into No. 4, N4% load, and Mustard. The stored reference control signal is 1, for example, in the range of rotational speed N, to N, in the case of operation from load - to Ll, VL, for load - to L3, V illusion, and for load - to L3, Vll. However, as the load increases, vl, ■□.

■It gets bigger in order of illusion.

Here, the load range in which the reference control signal is stored is limited to the range where knocking occurs in the internal combustion engine, and the memory (
The storage capacity of lfi is reduced and the efficiency of memory +121 is increased.

Next, explanation will be given using waveform diagrams of FIGS. 3, 4, and 5.

In the waveform diagram, Q is the output of the waveform shaping circuit (output 0), @ is the output of the knock detector (ma), %0 is the output of the arithmetic unit (output 0 of Il+)
indicates the output of the phase shifter (groan).

FIG. 3 shows a case where no knob king occurs in the internal combustion engine.

In this case, since no knob king occurs, knocking is detected f
There is no output of i (gate 19 in Figure 3), and there is no output of the arithmetic unit (11
) (Fig. 3(C)), therefore the phase shifter (3)
Since phase shift control is not performed at
0) in FIG. 3 is input to the switch circuit (4). The switch circuit (4) responds to this ignition pulse to turn on the ignition coil/I.
/(6) Continue power supply.

As a result, the reference time t1. and t, the ignition coil (6
) is cut off and the ignition voltage is generated.

FIG. 4 shows a waveform diagram for an operation that requires knocking control. In this case, the operating state that requires knocking control occurs after ignition at time t, and the arithmetic unit (11) controls the AD converter (9). The above-mentioned operating state is determined from the pressure signal level p from the pressure sensor (8) inputted via the pressure sensor (8) and the period of the fixed-time pulse from the waveform shaping circuit Co., Ltd., and the reference control signal corresponding to this operating state is stored from the memory (I21). VR4 (Fig. 4 0
) is read and output. The phase shifter (3) receives this reference control signal vR4 and outputs the ignition pulse (
The ignition pulse (Fig. 4) whose phase is shifted by an angle θ1 to the side temporally delayed by the angle θ1 is output. With this ignition pulse 0, the switch circuit (4) continues to supply power to the ignition coil A/(set), and from the reference time points t and t, the switch circuit (4)
At times jls and 11 when the angle is retarded by 1, the ignition voltage is generated and the internal combustion engine is operated. As a result, the internal combustion engine is operated without knocking.

FIG. S shows a waveform diagram in the case where the combustion conditions between the cylinders are slightly different and the control based on the nine reference control signals shown in FIG. 4 is slightly insufficient.

Immediately after the ignition time t, a computing unit (111 is a pressure sensor (8)
The load and rotation speed of the engine are detected from the level μ of the pressure signal from the waveform shaping circuit and the period of the fixed time pulse from the waveform shaping circuit, and the reference control signal corresponding to these operating conditions is memorized in memo 91.
! It reads from fi and outputs the control signal V (Fig. 5) t-. This control signal Vl is received by a phase shifter ('4 is an ignition pulse that shifts the phase of the ignition pulse (portion in Figure 5) from the waveform shaping circuit (2) by an angle I! (
Figure 5 0) is output.

In response to the ignition pulse 0, the switch circuit (4) supplies power to the ignition coil μ (M+), and ignition voltage is generated at a reference time t and a later time tm, and the engine is operated.

However, even though the ignition was ignited at the time t, which was delayed by the above angle θ, the combustion status was slightly fluctuating and the Vbeta was low.
If knocking continues to occur, the knock detector (?l
A knock signal K is output from.

The arithmetic unit (Ill) receives this knock signal Kt- and outputs a control signal vRJ which is obtained by adding a correction corresponding to this level μ to the control signal v1. As a result, the next ignition is started at an angle starting from the reference ignition timing time t3. 0. Correction is performed at the retarded time point t1, and knocking is sufficiently suppressed.

Therefore, the angle θ is greater than the angle θ3, and the difference between them.

The toe clutter correction angle is (θm-'j), which corresponds to the level μ of the knocking signal.

By the way, the above-mentioned memory α is usually used for other purposes, and a plurality of different types of data are stored in one memory. Therefore, the storage capacity of the memory (11J) is as small as possible.
It is necessary to design it so that it can be dissolved in a small amount. For this reason,
As is clear from the above-mentioned operation explanation □, the memory (lz) is operated and stored only in operating conditions where knocking occurs in one engine.

Normally, knocking occurs in relation to the load condition of the engine, so the above memory α force is limited to operating when the engine load is higher than a predetermined value, thereby reducing the memory capacity and increasing utilization efficiency. is desirable.

In the above example, the actual control amount is memorized! J021
If the reference control signal read out from the reference control signal has changed significantly by a predetermined value or more, by correcting the reference control signal value in the memory α2, the reference control signal can be corrected in response to a large change in the state of occurrence of knocking in the internal combustion engine. Corrections can be made for seasonal changes in the generating elements, and reference control signals with appropriate values can be stored. It was. The initial value of the reference control signal in the memory α2 may be a value calculated from the internal combustion engine design value, or may be stored in accordance with the average value of these values. It is possible to improve the controllability at the initial stage of p compared to the case where the

Further, in the above embodiment, the output of the knock detector (7) is reset at each ignition timing, but the reset is not limited to this, and may be performed at the ignition timing after knocking occurs, or by adding the detection signals, It is also possible to perform correction control by detecting the amount of change when knocking occurs; in this case, it is only necessary to reset when the output reaches a predetermined value.

Furthermore, although there are many factors that cause knocking, air-fuel ratio control using ignition timing control or fuel control as shown in the embodiment is preferable because ignition timing control,
This is because many devices related to air-fuel ratio control have been put into practical use, and are not only easy to implement, but can also be implemented at low cost.

As described above, according to the present invention, the knocking signal generated due to knocking is selected from the output of the acceleration sensor that detects the vibration of the internal combustion engine, and the knocking generation element is controlled according to the repetition μ, thereby preventing the knocking. In the suppressing system,
Control signal values are memorized in accordance with engine load, rotation speed, and other operating conditions, limited to operating conditions where knocking occurs in the internal combustion engine, and the operating condition is detected when knocking occurs, and the control signal value is adjusted to that operating condition. Read the corresponding reference control signal,
By controlling the knocking generation elements using this reference control signal, it is possible to minimize the capacity of the storage section and quickly output and control appropriate control signals when knocking occurs. When there is a change in an element, a correction control corresponding to the change is added and successive corrections are performed, thereby achieving extremely appropriate knocking suppression.

Furthermore, when the above-mentioned correction amount becomes larger than a predetermined value, by correcting the reference control signal value in the memo ν, it is possible to always appropriately suppress knocking in response to large fluctuations in the factors that cause knocking. Excellent effects can be obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. In the figure, ■ is a point large signal generator, (2), +10) is a waveform shaping circuit, (3) is a phase shifter, (4) is a switch circuit, (
6) is the ignition switch &, flll is the acceleration sensor, and (7) is the knock detector. (8) is a pressure sensor, 191 is an AD converter, (Il
l is an arithmetic unit. a3 indicates memory. Figure 1 Figure 2 II ball Figure 3 Figure 4 Figure 5 Procedural amendment band (spontaneous) November 17, 1980 Mr. Commissioner of the Patent Office 1, Case (7) Displayed Patent Application Showa IS? -55846 No. 2
, Title of the invention: Knock suppression device for internal combustion engine 3, Representative Hitoshi Katayama of the person making the amendment, Department 5, Detailed description of the invention in the specification to be amended. 6. Amend "rvm" on page 10, line 14 of the specification of amendment to "ViaJ."

Claims (1)

[Claims] an acceleration sensor for detecting vibration acceleration of an internal combustion engine, a discrimination means for removing a noise signal output from the acceleration sensor and selecting a knocking signal component, a load detection means for detecting a load state of the internal combustion engine, and a rotation of the internal combustion engine. a rotation speed detection means for detecting the number of revolutions, a storage means for storing a knock suppression signal value corresponding to the load type and the rotation speed, and a knock suppression signal is determined from the output of the discrimination means and the stored value of the storage means. A knock suppressing device for an internal combustion engine, comprising a control signal calculation means, wherein the storage means is configured to operate when the load of the internal combustion engine is a high load equal to or higher than a predetermined value.