JPH01285668A - Knock controlling and device thereof - Google Patents

Abstract

PURPOSE:To invariably perform proper knock control regardless of the rotating speed of an engine by changing the minimum value in the control region of the lag angle quantity based on the rotating speed of the engine and controlling the ignition timing to the optimum one in response to the octane of fuel. CONSTITUTION:A CPU 13 calculates the knock frequency based on the knock detection information outputted from a knock detecting circuit 11 connected to a knock sensor 12 and the engine rotating speed information outputted from a wave-form shaping circuit 16 connected to a distributor 17. The octane value of fuel is judged based on the knock frequency, and the control region in response to the octane value is selected. The minimum value of the control region is changed based on the rotating speed information, the region width of the control region is corrected. The lag angle quantity indicated in a lag angle control circuit 14 connected to an igniter 15 is calculated based on the knock detection information, the calculated lag angle quantity is controlled within the corrected control region.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a knock control method and apparatus for suppressing knock occurring in a gasoline engine.

2. Description of the Related Art Conventionally, this type of 7-knock control device is, for example, as shown in FIG. 6, in which a knock sensor 1 converts vibrations of an engine block into electrical signals. Then, a knock detection circuit 2 in contact with the knock sensor 1 determines the presence or absence of knocking based on the output from the knock sensor 1 and the gate signal from the CPU,
The results are sent to the CPU 3. Further, a waveform shaping circuit 5 connected to the distributor 4 transmits rotation speed information for starting ignition and charging to the CPIJ 3. Then, the CPtJ3 creates a gate from the rotation speed information sent from the waveform shaping circuit 5, and calculates the amount of retardation based on the presence or absence of knock sent from the knock detection circuit 2. So, this signal is octagonal #Jt1) circuit 6
is sent to the igniter 7 as the output of the knock control device u.

The CPU 3 also determines the frequency of knock detection (for example, the past 2
The octane number of the fuel is determined based on the result (4 out of 56 ignitions had knocks), and the retard angle tIJwJ is determined based on this determination result.
It was supposed to be instructed to run M6.

As shown in Fig. 7, the retard amount is controlled by first controlling the retard amount in the range of 0° to 8° when the knock frequency is 3/256 or less, and then 4/256 or more. When the angle was 0.00 to 12.0 degrees, the measurement was performed in the range of 00 to 12 degrees.

Problems to be Solved by the Invention However, the above conventional knock control device! In this case, if it is incorrectly determined that there is no knock when there should be knock due to factors such as differences in engine characteristics, fl! There is a problem that the angle is restricted to O°,
Particularly in the case of high speed rotation where it is difficult to detect knocking, the amount of retardation is controlled to be small even if knocking occurs, causing problems such as engine damage.

The present invention solves these conventional problems and makes it possible to ensure stable and safe engine fuel without knocking even when regular gasoline is put into an engine whose ignition timing is adjusted exclusively for VI1% octane gasoline. The object is to provide an excellent knock control method and device.

:! Means for Solving the Problems In order to solve the above problems, the method of the present invention provides control based on knock detection information sent from a knock detection circuit and rotation speed information sent from a waveform shaping circuit. ) The device calculates the knock frequency, determines the octane number of the fuel from this knock frequency, and controls the control device with a plurality of retardation amounts set in advance according to the octane number.
A control region corresponding to the determined octane number is selected from the range, and the width of the control region is changed to #! by varying the minimum value of the selected control region based on the rotation speed information. The retard amount to be instructed to the retard control circuit is calculated based on the knock detection information, and the calculated retard amount is controlled within the corrected control range.

In addition, Honkomei's device includes a waveform shaping circuit that is connected to the distributor and detects the engine rotation speed, a retard control circuit that is connected to the igniter to control the advance and retard of the ignition timing, and a knock sensor. A knock detection circuit is connected to the knock detection circuit to detect knocking, and an IIi11wJ device is connected to a waveform shaping circuit, a retard control circuit, and a knock detection circuit, and this control m@w is sent from the knock detection circuit. The knock frequency is calculated based on the knock detection information sent from the knock detection information and the rotation speed information sent from the waveform shaping circuit, and the octane number of the fuel is determined from this knock frequency, and the octane number is set in advance in the control device according to the octane number. The control range corresponding to the determined octane number is selected from among the plurality of control ranges for the retard amount, and the minimum value of the nine selected control ranges is determined based on the rotation speed information. By varying the area width of the control area, the retard angle 11i is adjusted.
The retard amount to be instructed to the 1J control circuit is calculated based on the knock detection information, and the calculated retard amount is controlled within the corrected Gino head range of IfI.

Effect: Due to the structure of the above method, knocking is less likely to occur.
In addition, at low speed rotation where knocking is easily detected, the minimum value of the control region J of the retardation amount is made small, so that the retardation a can be controlled to be small, and the torque and fuel efficiency of the engine can be maintained. In addition, at high speed rotations where knocking is likely to occur and knock detection is difficult, the minimum value of the control range for the retardation amount can be increased to greatly control the retardation amount, resulting in stable and knock-free operation. Safe driving conditions can be achieved.

In addition, with the configuration of the device described above, the minimum value of the retard amount instructed from the control m+ device to the retard control circuit is controlled to be small at low speed rotation and large at high speed rotation. The amount of retardation is controlled accordingly.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings. In FIGS. 1 and 2, a knock detection circuit 11 is connected to a knock sensor 12, which converts vibrations of the engine block into electrical signals. And the knock detection circuit 11.

The presence or absence of knocking is determined from the gate signal from the CP Ll 13, which serves as the υ control device described above, and the electric signal from the knock sensor 12, and the result is transmitted to the CPU 13 as knock detection information. Further, the retard 11jll11 times 114 is connected to the igniter 15, and is configured to control the advance and retard of the ignition timing according to instructions from the CPU 13. The waveform shaping circuit 16 is connected to the distributor 17, detects the rotational speed of the engine, gives an ignition instruction to the retard control circuit 14, and transmits rotational speed information to the CPU 13. The CPU 13 is connected to the knock detection circuit 11, the retard control circuit 14, and the waveform shaping circuit 16, and is configured as follows. That is, the knock frequency is calculated based on the knock detection information sent from the knock detection circuit 111 and the rotation speed information sent from the waveform shaping circuit 16, and the octane number of the fuel is determined from this knock frequency. From among the plurality of control areas A and 8 for the amount of retardation preset in CP IJ 13 according to the octane number,
The control tIII corresponding to the above determined octane number!
By selecting the i region and varying the minimum value of the selected control region m based on the rotation speed information, the width of the control region can be changed! lit, the retard amount to be instructed to the retard control circuit 14 is calculated based on the knock detection r4 report, and the calculated retard amount is 11i1Jall within the iu 1ilJWa range. There is. The minimum value of this retard angle ω is defined as shift mC, and is set in proportion to the rotational speed as shown in FIG.

Of course, this shift suspension C can be set not only in proportion to the rotational speed but also to any number of intervals, and can be set to an optimal function according to the characteristics of each engine.

The operation of the above configuration will be explained below.

First, the CPU 13 selects the retard amount control region A or B based on knock detection information and rotation speed information.
is selected. For example, if we detect a knock frequency of 4 out of 256 ignitions after starting the engine, then l! 1lIII head area B is selected. Then, every time knocking is detected thereafter, the CPU 13
The amount of retardation given to the retard control circuit 14 is retarded by 1° from then on, and advanced by 1° if the knock frequency decreases. At this time, the minimum value of control region B varies with the rotation speed, so even if the same knock frequency is detected, the retardation amount is By reducing the minimum value of the control I1gA area B, that is, the shift IC, the retard amount can be started from a small value.In addition, at high speed rotations where knocking is likely to occur and knock detection is difficult, By increasing the shift range C in the control region B of the retard angle, the retard amount can be started from a large value, and knocking can be appropriately eliminated. 4 and 5 show the characteristics of another embodiment of the present invention. In this embodiment, the octane number is determined in three stages X, Y, and Z, and the shift ω characteristics are also determined in two types α and β. Even when it is necessary to set a large number of octane numbers, the same effect as in the previous embodiment can be obtained.

Effects of the Invention As described above, according to the present invention, depending on the rotation speed,
Control of retardation amount l]f! By varying the minimum value in the 4 ranges, it is possible to control the optimal ignition timing according to the octane number of the fuel, and it can also be controlled appropriately whether the rotation speed is high speed or low speed! l can.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing the characteristics of the retard amount in the block diagram of FIG. 1, and FIG. 3 is a diagram showing changes in the shift amount in FIG. 2. , FIG. 4 is a diagram showing the characteristics of the amount of retardation in another embodiment of the present invention,
Figure 5 is a diagram showing the change in shift amount in Figure 4;
The figure is a block diagram showing a conventional knock control device.
FIG. 7 is a diagram showing control characteristics of the retard amount in FIG. 6. 11... Knock detection circuit, 13... CPU, 14.
...Retard angle control circuit, 16...Waveform shaping circuit. Agent Yoshi Morimoto Private use Figure 1 →/Tsuku frequency Figure 5-〇Tsushiki gL-, Lord Yamufu-

Claims (1)

[Claims] 1. The control device calculates the knock frequency based on the knock detection information sent from the knock detection circuit and the rotation speed information sent from the waveform shaping circuit, and also calculates the knock frequency from this knock frequency. The octane number of the fuel is determined, and the control region corresponding to the determined octane number is selected from among a plurality of control regions of the retard amount set in advance in the control device according to the octane number, and the selected control region is The area width of the control area is adjusted by varying the minimum value of the rotation speed information based on the rotation speed information, and the retard amount to be instructed to the retard control circuit is calculated based on the knock detection information. A knock control method for controlling the angle amount within the modified control range. 2. A waveform shaping circuit connected to the distributor to detect the engine speed, a retard control circuit connected to the igniter to control advance and retard of the ignition timing, and a knock sensor connected to detect knocking. a knock detection circuit, a control device to which a waveform shaping circuit, a retard control circuit, and a knock detection circuit are connected;
Based on the knock detection information sent from the knock detection circuit and the rotation speed information sent from the waveform shaping circuit, the knock frequency is calculated, and the octane number of the fuel is determined from this knock frequency, and the octane number of the fuel is determined in advance by the control device. The control region corresponding to the determined octane number is selected from among the plurality of control regions of the retard amount set according to the octane number, and the minimum value of the selected control region is determined based on the rotation speed information. The area width of the control area is corrected by varying the width of the control area, the retard amount to be instructed to the retard control circuit is calculated based on the knock detection information, and the calculated retard amount is within the corrected control area. Knock control device configured to control.