JPS6223575A - Spark advance measuring device for engine - Google Patents

Abstract

PURPOSE:To further enhance the accuracy of measuring a spark advance, by reflecting a variation in the rotation of a crank shaft before and after the top dead center, precisely upon computation of the spark advance. CONSTITUTION:Sensors 3 through 5 for detecting detection marks 2 on the outer periphery of a crank pulley 1 are arranged at a position 90 deg. before the top position (top dead center), the top position and a position 90 deg. after the top position around a crank shaft as an angular center. An ignition sensor 7 detects ignition timing and the sensors 3 through 7 deliver their outputs to a computing section 8 through latch circuits 1 through 4. When an ignition is carried out before the crank pulley reaches its top position, an angular velocity is computed during a compression stroke from the position 90 deg. before the top position to the top position, and a spark advance is obtained in accordance with the thus computed value. further, when an ignition is carried out during an combustion stroke after the top dead center, an angular velocity is computed, and a spark advance is computed in accordance with the thus computed value. Accordingly, it is possible to detect a spark advance with a high degree of accuracy.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to an ignition advance angle in engine ignition control [Prior art 1] In engine ignition control, the actual ignition advance angle as a result of control is accurately detected. This is extremely important for various controls such as engine combustion pressure control.

Conventionally, as an engine ignition advance angle measuring device, it was developed in 1982.
Publication No. 160865 describes [a rotating body that is attached to the engine crank pongee and rotates together with it, and two detection marks provided on this rotating body at a small constant angle in the direction of rotation of the rotating body. It outputs a pulse signal in response to detection marks A and B, respectively, and is fixed at a position where detection mark B is detected when a specific cylinder of the engine is at top dead center. a sensor, means for outputting a spark pulse that coincides with the ignition time of the specific shilling, and means for determining the time between the spark pulse and the detection pulse of the detected mark B of the sensor;
An ignition advance angle measurement device for an engine, comprising means for calculating an ignition advance angle based on the detection pulse of the detected mark A and the detection pulse of the detected mark B of the sensor. ' has been proposed.

This advance angle measurement device can detect the angular velocity in a relatively narrow angular range and calculate the advance angle, so the detection accuracy can be improved. , still contains essential problems.

Now, if we consider the vicinity of compression top dead center of a cylinder, before top dead center, the crankshaft is decelerated due to the rise in internal pressure associated with compression, and conversely, when it passes top dead center, the crankshaft is decelerated. It shows rotational fluctuations such as the shaft being accelerated,
As is clear from its measurement principle, the proposed measuring device described above cannot accurately reflect the rotational fluctuations described above in the advance angle calculation, and the average angular velocity in the angular range between the two marks A and B is It simply performs calculations using .

[Object of the Invention] An object of the present invention is to accurately reflect rotational fluctuations of the crankshaft before and after top dead center in calculation of the advance angle, thereby further improving advance angle measurement accuracy.

[Structure of the Invention] Therefore, in the present invention 1, the first angular velocity detection means detects the angular velocity of the crankshaft before the top dead center, and the second angular velocity detection means detects the angular velocity of the crankshaft after the top dead center. angular velocity detection means; ignition timing determination means for determining whether the ignition timing is before or after the top dead center; and when the ignition timing is before the top dead center, the angular velocity detected by the first angular velocity detection means is The basic feature is that the engine includes advance angle calculation means for calculating the ignition advance angle using the angular velocity detected by the second angular velocity detection means when the angular velocity is after the dead center.

[Effects of the Invention] According to the present invention, rotational fluctuations of the crankshaft before and after top dead center can be accurately reflected in calculation of the advance angle, thereby further improving advance angle measurement accuracy.

[Example] Examples of the present invention will be specifically described below.

FIG. 1 shows the system configuration of this device.

This device uses three detection sensors 3, 4, and 5 capable of detecting the detection mark 2 formed on the outer periphery of the crank boot 171 as a detection device, with the crank Tsumugi center as the angular center, and the top position (top dead center). ), a top position, and a position 90 degrees after the top position, and an ignition sensor 7 that detects the ignition timing from the current flowing through the ignition coil 6 that drives the spark plug of the engine, The respective outputs of these sensors 3, 4, 5.7 are inputted to an arithmetic unit 8 consisting of a microcomputer via a total of four stages of latch circuits R1, R2, R3, R4. Furthermore, there is a display section 9 for displaying the calculation results of the calculation section 8, and an operation switch 10 for starting and stopping.As shown in FIG. Two 7s into which the outputs of 3 and 4 are respectively input.
Rip 70 tube circuit 11.11, each 7 lip flow, 2
As shown in the figure, after the output of the 90 degree double side output sensor 3 is first input to the first 7-lip 70-tub circuit 11, If the output of the top detection sensor 4 is input to the second 7-lip 70-tub circuit 11 after a time τ, the exclusive OR circuit 12 outputs a pulse with a width equal to the time τ. . In this way, the outputs of the respective latch circuits R1 to R4 are output from the timers T, , T2 . It is input to T,,T, and is timed. Moreover, the output of the detection sensor 5 after 90 degrees is
The Hil11 signal is input to another 7-lip 70-tub circuit 13 provided separately from the 7-lip flop circuit 11 of the latch circuits R1 to R4, and the Hil11 signal is output to the St input terminal of the arithmetic unit 8 connected to its Q output. '+Ha〃Nosa-11 Origin η1L All flip-flop circuits 11, 11 of the latch circuits R1 to R4 are reset by the reset signal from the h terminal.
．． . . . is reset, and another flip-flop circuit 1 is connected to the detection sensor 5 after 90 degrees.
3 is also reset by a reset signal from another Rs output terminal, and the output of the detection sensor 5 after 90 degrees is sent to the second stage latch circuit R2.
The read command RD is output at a timing after the time reaches h.

Figure 1@3 shows the basic configuration of the ignition advance angle measurement of the present invention.

As shown by dotted arrow A in Fig. 3, crankboo IJ1
If ignition occurs before reaching the top position,
The angular velocity θa is calculated in the compression stroke from 90 degrees before to the top position, and the ignition advance angle is calculated based on the calculation result. As shown by the solid line arrow B at the beginning of the main explosion stroke past the top position, when ignition is performed, the angular velocity θb during the explosion stroke up to 90 degrees after the top position
is calculated, and the ignition advance angle is calculated based on the angular velocity θb obtained by this calculation.

FIG. 4 shows a flowchart showing the calculation method in the calculation section 8.

Now, according to this 70-chart, the calculation method will be specifically explained with reference to FIG.

When control is started now, initialization is performed in step 101, and then step 102
When the operation switch 10 is operated to the start side, the main timers T1 to T4 are activated in step 103.
is cleared, and after 90 degrees, the side sensor 5 detects the crank pulley 1.
When mark 2 is detected (step 104), the first to fourth latch circuits R1 to R4 are reset (step 105). When it is determined in step 104 that a signal after 90 degrees has been output, a read signal RD is output from the calculation unit 8 (step 106), and reading of data is started (step 107). This data reading is performed by inputting each output of the latch circuits R1, R2, R3, and R4 to the timers Tl, T2, and T2 of the calculation unit 8. This is done by measuring the time at T, T4. Specifically, referring to FIG. The time t3 between the signal and the signal (this time is (t4-
tl). ), and for time L4 when the ignition signal is main from 90 degrees before.

In the next step 108, the angular velocity θa of the compression stroke is set to (9
0/ll), and the angular velocity θb of the explosion stroke is (9
0/12). Next, in step 109, the magnitude of the time t1 before 90 degrees - top main is compared with the time opening t4 up to one ignition before 90 degrees, and tl=t4
In this case, the advance angle is determined to be "0" (step 110). In addition, when tl > t4, it is considered that ignition occurred during the compression stroke, and the ignition advance angle is determined by integrating the time L3 between the top and ignition and the angular velocity θa obtained during the compression stroke, and then the direction of the advance angle. The sign “−”
1" and calculate the advance angle (step 111)
. When tl<t4, when ignition is in the explosion stroke, the ignition advance angle is calculated using the angular velocity θb in the explosion stroke. As described above, step 110,
The ignition advance angle determined in either step 111 or 112 is output to the built-in memory as an advance value (step 113), and displayed on the display section 9.

As is clear from the above description, in the ignition advance angle measuring device according to the present invention, when ignition occurs in the compression stroke, the ignition advance angle is determined based on the angular velocity in the compression stroke, and when ignition occurs in the explosion stroke, the ignition advance angle is determined based on the angular velocity in the compression stroke. Since the advance angle is calculated based on the angular velocity during the explosion stroke, the angular velocity at the time of ignition is accurately reflected, regardless of whether ignition occurs during the compression stroke or the explosion stroke, where the crank angular velocity is different. Since the ignition advance angle is calculated based on the angular velocity, the ignition advance angle can be detected with extremely high accuracy.

In the above example, the angle is 90 degrees before the top and 90 degrees after the top.
Although the crank angular velocity was detected at 0 degrees, the angular range is not limited to 90 degrees.

A F7I'E+sz worry ■ Su-'M 1
111 FIG. 1 is a system and configuration diagram of the measuring device according to the present invention, FIG. 2 is a circuit diagram explaining the configuration of the latch circuit, and FIG.
The figure is an explanatory diagram for explaining the measurement principle of the present invention, and FIG. 4 is a chart diagram showing the calculation control 70- of the ignition advance angle executed in the calculation section.

1... Crank pulley, 2... Detection mark, 3゜4.5... Detection sensor, 7... Ignition sensor, 8...
- Arithmetic section.

Patent applicant Mazda Motor Corporation representative Patent attorney Blue and white Two idiots Figure 3

Claims (1)

[Claims] (1) a first angular velocity detection means for detecting the angular velocity of the crankshaft before top dead center; a second angular velocity detection means for detecting the angular velocity of the crankshaft after top dead center; and an ignition timing before the top dead center. ignition timing determining means for determining whether the ignition timing is before top dead center or after top dead center; An ignition advance angle measuring device for an engine, comprising an advance angle calculation means for calculating an ignition advance angle using the angular velocity determined by the engine.