JPH02102378A - Cylinder discriminating device of internal combustion engine - Google Patents

Abstract

PURPOSE:To make it possible to discriminate a specific cylinder by finding the cycle of the firs standard position, or the value of the ratio of the period of the first and the second standard position to the second standard position and the next first standard position period to each cylinder, and comparing the mean value of the ratio of the all cylinders and the value of the ratio of each cylinder. CONSTITUTION:To a rotary disk 2 installed to a rotary shaft 1 rotating synchronously to an engine, windows 3 are provided at the positions responding to desired detecting angles, and at the same time, a window 3' to discriminate a specific cylinder is positioned asymmetric to the windows 3 to discriminate the other cylinders. And to detect the windows 3 and 3', a luminous diode 4 and a photo-diode 5 to receive the output light from the luminous diode 4 are provided to compose a rotary signal generator of a cylinder discriminating device. As a result, the relative size of a specific cylinder and the other cylinders in respect of the signal duty ratio to the signal generation cycle responding to the cylinder can be discriminated, and an accurate cylinder discrimination can be carried out in the discrimination method of a specific cylinder from a rotary signal of a single system.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cylinder identification device for an internal combustion engine that identifies cylinders from one system of signals from a one-rotation signal generator.

[Prior Art] In order to control the ignition timing, fuel injection, etc. of an internal combustion engine, a signal synchronized with the rotation of the engine is used.

This signal generator usually detects the rotation of the engine's camshaft or crankshaft. An example of such a rotation signal generator is shown in FIGS. 4 and 5.

In the figure, (1) is a rotating shaft that rotates in synchronization with the engine (not shown), and (2) is a rotating disk mounted on the rotating shaft (1), which corresponds to the desired detection angle. Window in place (3)
is provided. (4) is a light emitting diode.

(5) is a photodiode that receives the output light from the light emitting diode (4), (6) is an amplifier circuit that is connected to the photodiode (4) and amplifies the output signal of the photodiode (4), and (7) is a photodiode that receives the output light from the light emitting diode (4). It is connected to the amplifier circuit (6) and is an open collector output 1 to transistor.

The rotation signal generator outputs two types of signals as shown in FIG. The crank angle reference signal (SGT) shown in FIG. 6(b) is a signal that is inverted at a predetermined crank angle for each cylinder, and is used as a reference signal for the crank angle.

The cylinder identification signal (SGC) shown in FIG. 6(a) is output when a signal for the #1 cylinder is generated, and is used to identify the #1 cylinder.

In particular, by detecting the timing of a specific cylinder (#1 cylinder in FIG. 5) using this cylinder identification signal (SGC), it is possible to perform cylinder-by-cylinder control for all cylinders in the above control.

Further, as shown in FIG. 7, the output signal of the rotation signal generator (8) is inputted to the microcomputer (10) via the interface circuit (9) and used for control calculations such as ignition timing and fuel injection.

[Problems to be Solved by the Invention] In the conventional internal combustion engine cylinder identification device as described above, the crank angle reference signal (SGT) and the cylinder identification signal (SGC
), it is necessary to generate two systems of signals in the rotation signal generator, which results in a complicated configuration and increased cost.

The present invention was made to solve this problem, and is an internal combustion engine that uses a single signal system to obtain a signal that includes both functions of a crank angle reference signal and a cylinder identification signal, and to identify a specific cylinder from that signal. The purpose is to obtain a cylinder identification device.

[Means to solve the problem] A cylinder identification device for an internal combustion engine according to the present invention.

The engine includes a rotation signal generator that generates signals indicating predetermined first and second reference positions corresponding to each cylinder in synchronization with the rotation of the engine, and offsets the second reference position only for a specific cylinder. 1. A cylinder identification device for an internal combustion engine that identifies a cylinder from an output signal of a rotation signal generator, wherein: (1) the first reference position period or the second reference position period and the next first reference position period; A specific cylinder is identified by determining the value of the ratio between the periods of the first and second reference positions for each cylinder, and comparing the average value of the ratio for all cylinders with the value of the ratio for each cylinder. It is.

[Operation] In the present invention, the one-rotation signal generator generates signals indicating predetermined first and second reference positions corresponding to each cylinder in synchronization with the rotation of one engine, and only a specific cylinder Offset the reference position.

[Embodiment] FIG. 1 is a diagram showing the structure of a rotation signal generator of a cylinder identification device for an internal combustion engine according to an embodiment of the present invention. In the figure, a window (3') for identifying a specific cylinder is provided asymmetrically with a window (3) for identifying other cylinders, and is provided on one rotating plate (2), so that signals can be obtained from one system. The outside is the same as the conventional one shown in FIG.

FIG. 2 is a signal waveform obtained from the rotational signal generator of FIG.

FIG. 3 is a diagram showing a flowchart of the cylinder identification routine of the present invention.

In the cylinder identification device for an internal combustion engine configured as described above, the rise of the signal shown in FIG.
BTDC75°) is used as the reference angle for control. Also, the second
The falling signal shown in the figure.

BTDC5 for other cylinders (#2 cylinder, #3 cylinder, #4 cylinder)
°, and the specific cylinder (#1 cylinder) is retarded by 10 degrees.
° Offset (top dead center f & 5°). When controlling, the rising edge of the signal (B T DC75
The basic method is to calculate the ignition timing based on °) (no problems occur because the same timing can be detected for all cylinders)
. Also, when cranking one engine, the ignition occurs at the falling edge of the signal shown in Figure 2. In this case, the specific cylinder is retarded by 10 degrees compared to other cylinders, but since it is on the retarded side, starting failure due to premature ignition does not occur.

Next, the cylinder identification operation will be explained using the flowchart shown in FIG. The microcomputer (10) shown in Figure 7 is 1
Calculate the period (T) of the rising period (T) of the "high level" output period (1) of the signal based on the signal (FIG. 2) sent from the rotational signal generator (8) via the interface circuit (9) (step S1). Next, in step S2, depending on t and T obtained in step S1, the rising period period (T) of the signal shown in FIG. 2 or the "low level" output period (
"High level °" output period (1) for T - t )
The ratio t/T or t/(T-1,) is calculated for each cylinder.

Next, in step S3, an average threshold value [α] which is the average of the ratios for all cylinders is determined. -(1-k)αnl+
+k(t/T), or k(t/(T-t)
), )]. Here, is a constant and n is an ordinal number.

The ratio value for each cylinder and the average threshold value α obtained as described above. (Step S4). If the determination result is large, it is identified that it is a specific cylinder; in this case, the #1 cylinder is identified, and a flag is set in the register corresponding to the #1 cylinder (step S5). If the determination result is small, return (step S6). In this way, when a specific cylinder is identified, in this case, the specific cylinder is #1
Since it is a cylinder, when identifying #1 cylinder, #1 cylinder → #
Since rotation signals are obtained in the order of cylinder 3 → cylinder #4 → cylinder #2, the other cylinders can be identified in the order of cylinder #3 → cylinder #4 → cylinder #2.

It should be noted that since the above-mentioned cylinder identification is performed by comparing the size based on the ratio of t/T or t/(Tt), accurate judgment can be made even if rotational fluctuation occurs.

[Effects of the Invention] As described above, the present invention provides a method for determining the magnitude relationship between a specific cylinder and other cylinders with respect to the signal duty ratio with respect to the signal generation period corresponding to the cylinder, and identifying a specific cylinder from one system of rotation signals. .

This has the effect of allowing accurate cylinder identification.

[Brief explanation of the drawing]

FIG. 1 is a structural diagram of a rotation signal generator of a cylinder identification device for an internal combustion engine according to an embodiment of the present invention, FIG. 2 is an operational waveform diagram of a cylinder identification device for an internal combustion engine according to an embodiment of the invention, and FIG. 4 is a structural diagram of a conventional rotation signal generator, FIG. 5 is a signal processing circuit diagram of a conventional rotation signal generator, and FIG. 6 is a diagram of a conventional rotation signal generator. The generator signal waveform diagram, FIG. 7, is a schematic block diagram of a cylinder identification device for an internal combustion engine. In the figure, (1)... rotating shaft, (2)... rotating plate, (3), (3')... window, (4)... light emitting diode, (5)... photo diode. be. In addition, the same reference numerals in each figure indicate the same or equivalent parts.

Claims (1)

[Claims] The engine includes a rotation signal generator that generates a signal indicating predetermined first and second reference positions corresponding to each cylinder in synchronization with the rotation of the engine, and offsets the second reference position only for a specific cylinder. A cylinder identification device for an internal combustion engine that identifies a cylinder from an output signal of a rotation signal generator, the cylinder identification device for an internal combustion engine, wherein A specific cylinder is identified by determining the value of the ratio between the periods of the first and second reference positions for each cylinder, and comparing the average value of the ratio for all cylinders with the value of the ratio for each cylinder. A cylinder identification device for an internal combustion engine, characterized by: