JPH0670399B2 - Crank angle reference position confirmation method immediately after starting of internal combustion engine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a crank angle reference position confirmation method immediately after starting of an internal combustion engine, and particularly to an operation control device,
For example, the present invention relates to a method for easily and accurately confirming a crank angle reference position detected immediately after the engine is started in an ignition timing control device as a normal crank angle reference position.

(Technical Background of the Invention and Problems Thereof) An internal combustion engine, for example, has an ignition timing regarding its operation
The optimum operating time is adjusted according to the engine operating parameter values such as the engine speed, the intake pipe internal pressure, and the engine temperature so that a good operating condition can be maintained at all times. When such an ignition timing control is performed by an electronic ignition timing control device using a macro computer, accurate crank angle reference position information as well as crankshaft rotation angle information is indispensable.

Examples of such a generator of the rotation angle of the crankshaft and the reference position information are as follows. That is, in this generator, a rotating body having a magnetic body is attached to a crankshaft of an engine, and convex portions are provided on an outer peripheral portion thereof at intervals of a unit rotation angle α °, which serves as a rotation angle information generating portion. . Also, only one convex portion is missing, and this is the generating portion of the crank angle reference position information. On the other hand, outside the rotating body, two electromagnetic pickups, a first and a second electromagnetic pickup, are arranged along the circumference of the rotating body with a distance corresponding to an integral multiple of the unit rotation angle α °. With the rotation of the engine, first and second pulse signals are generated from the first and second electromagnetic pickups, and the rotation angle information of the crankshaft is obtained from either one of the pulse signals. The crank angle reference position is detected from the differential output of the pulse signal.

Immediately after the start of the engine, the engine rotation is usually unstable, and the speed at which the rotation angle information generating portion consisting of the convex portion of the magnetic material passes through the electromagnetic pickup arrangement position decreases. The signal level of the pulse signal that is induced in the field decreases. Therefore, even if the second electromagnetic pickup does not correspond to the missing position of the convex portion, the output may be missing and the crank angle reference position may be erroneously detected. Therefore, it is necessary to confirm whether or not the correct crank angle reference position is detected immediately after the start of the engine.

(Object of the Invention) The present invention has been made in view of the above circumstances, and an object of the present invention is to make a detected crank angle reference position a normal reference position immediately after the start of the engine. (EN) It is intended to provide a crank angle reference position confirmation method immediately after the start of the start of an internal combustion engine, which can be easily and accurately confirmed.

According to the present invention, the first crank angle position signal is sequentially generated at each of a plurality of predetermined crank angle positions while the crankshaft of the engine makes one revolution. An internal combustion engine in which a second crank angle position signal is generated at at least one predetermined rotation position of the crank shaft every time the shaft makes one rotation, and the crank angle reference position is detected by the first and second crank angle position signals. In the crank angle reference position confirmation method for an engine, from the time when the second crank angle position signal is detected immediately after the start of the engine until the time when the next second crank angle position signal that follows is detected. The number of times the first crank angle position signal is generated, and when the counted number of times is a predetermined number, the first and second clutches are generated. There is provided a crank angle reference position confirmation method immediately after starting the internal combustion engine, characterized in that the crank angle reference position detected by the crank angle position signal is confirmed to be a normal crank angle reference position.

Embodiments of the Invention The present invention will be described below with reference to the drawings.

First, FIG. 1 is a diagram showing the overall configuration of an electronic ignition timing control device as an electronic operation control device applied to the present invention. In the figure, reference numeral 1 is a V-shaped engine such as a 4-cylinder or 2-cylinder engine, 2 is an electronic control unit (hereinafter referred to as “ECU”), and the V-shaped engine 1 has a cylinder included angle of 45 °, 60 °,
Any angle such as 90 °, 128 °, 135 ° and in-line 4 cylinder 180 ° can be applied. The figure shows a partial section of one cylinder of a plurality of cylinders. There is. Code 10
A and 10b are spark plugs, and although only two spark plugs are shown in the figure, these spark plugs are separately attached to each cylinder. And as described later, each spark plug 10a, 1
0b is connected to an ignition coil provided separately, and is an ignition system without a distributor. For a 4-cylinder engine, another spark plug (not shown) is electrically connected in series to the spark plug 10a, and similarly, a spark plug 10b is not shown. One spark plug is electrically connected in series. Each of the two spark plugs connected in series is ignited by the same ignition signal, and one of the two spark plugs ignited at the same time is ignited in the exhaust stroke. Be taken. Reference numeral 3 is a combustion chamber of the engine 1. An intake pipe 4 and an exhaust pipe 5 are connected to the combustion chamber 3,
An intake valve 6 and an exhaust valve 7 are provided at each communication port. A throttle valve 8 is provided in the middle of the intake pipe 4.
Is provided, and a relative pressure or absolute pressure sensor (hereinafter simply referred to as “absolute pressure sensor”) 9 is provided downstream of the throttle valve 8.
Is provided, and the absolute pressure signal in the intake pipe converted into an electric signal by the absolute pressure sensor 9 is sent to the ECU 2.
Further, the cylinder peripheral wall portion of the engine 1 is filled with cooling water, and an engine water temperature sensor 11 including a thermistor or the like is inserted in this portion. The detection signal of the engine water temperature sensor 11 is supplied to the ECU 2. 12 is a piston, this piston 12
Are connected to a crankshaft 14 via a connecting rod 13. The crankshaft 14 is provided with a pulse generating mechanism for generating first and second pulse signals Pc ₁ and Pc ₂ as shown in FIGS. 2 (a) and 2 (b) according to its rotation. There is. That is, first, a rotary disk 15 as a rotary member is attached to the crankshaft 14, and reactors 16a to 16g formed by a protrusion made of a ferromagnetic material are equally divided on the circumference thereof except one place on the circumference. The projections are provided at positions, for example, at an angle of 45 °. In the illustrated example, the reactor is thus cut off at only one position between the reference numerals 16d and 16e, and the angular interval between the cutouts is 90 °. The reactor is not limited to the raised body, and a magnetic body may be embedded in the rotating member. Outside the rotating disk 15, first and second electromagnetic pickups (hereinafter referred to as “pulsars”) 17 formed by winding coils 17b and 18b around magnet bodies 17a and 18a along the circumference thereof, 18 are arranged. The arrangement angular intervals of the first and second pulsars 17 and 18 are defined in accordance with the interval of the top dead center of the engine to be applied, the number of cylinders, etc. The case of application to a cylinder engine is shown, and the arrangement angular interval between the two pulsers 17 and 18 is specified to be about 180 °.

Based on the signal symbols of the sensors 9 and 11 and the pulse signals Pc ₁ and Pc ₂ from the pulsars 17 and 18, the ECU 2 advances the lead angle data θig and the energization time To of the ignition coil described below.
It calculates n and the like and outputs this as a drive signal, and its output line is connected to each ignition plug 10a, 10b via an ignition coil 21, 22, respectively. Ignition coil 2
Each of 1 and 22 is provided with a primary coil and a secondary coil (not shown), and the output ends of the secondary coil are connected to the respective spark plugs 10a and 10b. Ignition coil 2
Currents 1 and 22 supplied to the primary coil are controlled by a drive signal from the ECU 2, and a high voltage is generated in the secondary coil to cause spark discharge in the spark plugs 10a and 10b.

On the other hand, in the ECU2, in order to perform the arithmetic processing as described above,
First, roughly dividing this into blocks, the input circuit 19, the input / output
An LSI (hereinafter referred to as “I / O / LSI”) 23, a central processing unit (hereinafter referred to as “CPU”) 24, an A / D converter 25, and an output circuit 26 are provided. Further, the input circuit 19 has a waveform for shaping the first and second pulse signals Pc ₁ and Pc ₂ (FIGS. 2A and 2B) generated by the first and second pulsers 17 and 18, respectively. Shaping circuits 27 and 28 and each of these waveform shaping circuits 2
First and second latching output from 7 and 28 respectively
Flip-flop circuits 29 and 31 are provided. First
Flip-flop circuits 29 and 31 are provided. First
In the flip-flop circuit 29 of, the output line of the Q output is I /
The second flip-flop circuit 31 is connected to the INT terminal (not shown) of the CPU 24 via the O.LSI23, and the output line of the Q output of the second flip-flop circuit 31 is connected to the STATUS terminal (not shown) of the CPU24 via the I / O.LSI2. Connected). Reference numeral 32 is a clear signal line for the first and second flip-flop circuits 29 and 31. Reference numeral 33 in the I / O / LSI 23 portion is a Me timer described later.

The one configured as a one-chip IC is applied to the CPU 24, and various calculation programs and energization counters are provided inside the CPU 24.
34, described later A read-only memory (hereinafter referred to as "ROM") 35 that stores a -θig map, a Tw-θig table, a cylinder included angle table, and the like, and a random access memory (hereinafter referred to as "RAM") 36 that stores the above calculation results and the like 36 , And an input / output buffer 37 are provided.

The CPU 24 then controls the first and second pulse signals Pc ₁ , Pc
_{2. In} other words, first, the crank angle position is detected by the output signals (FIGS. 2 (c) and 2 (d)) from the first and second flip-flop circuits 29 and 31. That is, when the first pulse signal Pc ₁ is latched by the first flip-flop circuit 29, the Q output signal causes an interrupt request to the CPU 24 via the I / O / LSI 23. Upon receipt of this interrupt request, the CPU 24 outputs the Q output of the second flip-flop circuit 29 (Fig. 2 (d)).
Identifies whether it is at "H" level or "L" level.
At this time, the position where the Q output of the second flip-flop circuit 31 is at the "L" level at the timing when the interrupt request is generated (the position indicated by the k line in FIG. 2) is once per one revolution of the crankshaft 14. Exists. The crank angle position at this time is defined as a reference crank angle position q. In this embodiment, a plurality of _second pulse signals Pc ₂ are generated for each revolution of the crankshaft 14, and the signal missing position (position where the Q output is at “L” level) is at the corresponding position. Although the angular position q is detected, the generation mode of the second pulse signal Pc ₂ for finding the reference crank angular position q is not limited to the generation mode as described above, but a position corresponding to the signal missing position described above. It is sufficient to generate at least one second pulse signal (crank angle position signal). Reference crank angle position q
After the detection of, each generation interval of the _first pulse signal Pc ₁ is defined as a stage, and a stage number is assigned to each stage. This number can be assigned in various ways according to the cylinder included angle of the engine 1. The number of the stage in which the reference crank angle position q is detected depends on the engine specifications.
It is stored in the M35. In the example of FIG. 2 (a), the reference position q
Is numbered as stage 1, and is numbered as stages 2, 3 ... Thus, the CPU 24 detects the crank angle position, that is, the stage position each time an interrupt request by the Q signal from the first flip-flop circuit 29 occurs, and outputs the F / F CLR signal when the detection of the stage position is completed. Then, both flip-flop circuits 29 and 31 are reset.

After detecting the reference crank angle position q, the first pulse signal P
The generation time interval of c ₁ , that is, the Me value is measured by the Me timer 33 with a clock pulse. The Me value is proportional to the reciprocal of the engine speed Ne (1 / Ne), and this Me value indirectly measures the engine speed Ne. Then, the engine speed Ne calculated from the Me value, the absolute pressure sensor 9 and the engine water temperature sensor 11
Of the intake pipe absolute pressure P _BA and the engine water temperature Tw, which are detected by the A / D converter 25 and converted into digital values by the A / D converter 25.
From these values, the advance angle data θig given by the following equations (1) and (2) and the energization time Ton to the ignition coils 21 and 22 are calculated.

θig = θigmap + Δθig (1) Ton = f (Ne) (2) where θigmap is the basic lead angle data, and engine speed Ne and absolute pressure in the intake pipe And functions And is stored in ROM35 Read from the map. Δθig is a correction value of the advance angle data and is a function of the engine temperature Tw (Δθig = f (Tw)),
It is read from the Tw-Δθig table stored in the ROM 35. Further, the energization time Ton is a function of only the engine speed Ne as shown in the equation (2), and is read from the Ne-Ton table stored in the ROM 35 as in the above. The advance angle data θig and the ignition timing data Ton thus obtained are stored in the RAM 36.

After the advance angle data θig and the energization time data Ton are obtained, the ignition timing data Tig is further calculated based on these values.
And energization timing data Tcg is calculated. First, the ignition timing data Tig will be described as ignition timing data Tig indicating the time from the generation of the pulse signal Pc ₁ ′ (stage 6 signal) of the stage (stage 6 in the illustrated example) designated by the engine type. Calculate by angle / time conversion. Regarding the energization timing, the stage is traced back from the ignition timing by the crank angle corresponding to the energization time Ton, and the energization stage (stage 3 in the example of the figure) is obtained. Then, the energization timing data Tcg representing the time from the generation of the pulse signal Pc ₁ ″ (stage 3 signal) at which the energization stage starts to the energization timing is calculated. The calculated ignition timing and energization timing data Tig, Tcg are both Stored in RAM36.

Energization and ignition are performed based on each data calculated in this way. This execution will be described with reference to the spark plug on the side 10a. The stage position is first detected for each interrupt by the Q output of the first flip-flop circuit 29. When the energization stage, that is, the stage 3 signal Pc ₁ ″ is detected, the energization counter 34 is started at the timing of generation of the stage 3 signal Pc ₁ ″, and the count value is stored in the RAM 3
Comparison is made with the energization timing data Tcg read from 6. When the count value exceeds the energization timing data Tcg, the output circuit 2
An energization signal is sent to the ignition coil 21 via 6 to energize the primary coil. Then the ignition timing executed, the ignition stage, namely 'when is detected, the stage 6 signal Pc _1' stage 6 signal Pc ₁ to start the ignition counter (not shown) from the generation time point of setting the ignition register (not shown) When the count value exceeds the generated ignition timing data Tig, an ignition signal (energization off signal) is sent to the primary coil of the ignition coil, and a high voltage is generated in the secondary coil to generate the spark plug 10a.
A spark discharge is generated in the cylinder and the air-fuel mixture in the cylinder is ignited. Regarding the execution of energization and ignition to the other spark plug 10b, only the energization and ignition stages are different, and the other aspects are substantially the same as those described above, and therefore description thereof is omitted. Therefore, engine speed Ne, absolute pressure in the intake pipe And the engine cooling water temperature Tw controls the energization timing Tcg and the ignition timing Tig that are optimum for the operating state of the engine at that time.

The present invention provides a crank angle reference position q used as described above in such an electronic ignition timing control device.
Is a method for easily and accurately confirming immediately after the start of
It is executed by a control program executed by the CPU 24.

FIG. 3 is a flow chart showing a program for executing an embodiment of the crank angle reference position confirmation method immediately after the start of the internal combustion engine according to the present invention.

First, immediately after turning on an ignition switch (not shown), the CPU 24 is initialized in step 41. In the initialization process, the RAM 36 area is cleared to zero and the I / O port is initialized. After initialization processing, set the stage variable STG to 1
(Step 42). Then, after resetting the first flip-flop circuit 29 by the clear signal (step 43), the first first pulse signal Pc ₁ is changed to the first pulse signal Pc ₁ .
It waits to be latched by the flip-flop circuit 29 (step 44). And the first flip-flop circuit 29
When the first pulse signal Pc ₁ is latched, the second flip-flop circuit 28 determines whether or not the second pulse signal Pc ₂ is latched (step 45). That is, in both steps 44 and 45, it is determined that the position of the first first pulse signal Pc ₁ latched by the first flip-flop circuit 29 is not the crank angle reference position. If the determination result is negative (No), the processing from step 43 is repeated. If the determination result is affirmative (Yes), the first
Reset the flip-flop circuit 29 of (step 4
6), start the Me timer 33 (step 47). Thereafter, the first flip-flop circuit 29 waits for the first pulse signal Pc _{1 to} be latched (step 48), and the first pulse signal Pc ₁ is latched.
Of the second flip-flop circuit 31 when the first pulse signal Pc ₁ is latched by the flip-flop circuit 29 of
It is determined whether or not the output is zero, that is, the second pulse signal Pc ₂ is missing (step 49). And this step
In both steps 48 and 49, the crank angle reference position q is detected as shown in FIGS. 2 (c) and 2 (d). If the determination result of step 49 is negative (No), the process from step 46 is repeatedly executed, and if the determination result is affirmative (Yes), the Me timer 33 is latched (step 50). The Me value latched by the Me timer 33 is TS ₇ immediately before the reference position q (Fig. 2 (a)).
Is the value of. Then, it is judged whether or not the latched Me value overflows (step 51). Me timer
33 overflows at a Me value corresponding to a rotation speed equal to or lower than a predetermined low rotation speed Ne _L. The determination result of step 51 is affirmative (Ye
If s), the process returns to step 46 and the process from step 46 is executed again. The engine speed Ne increases and the step
If the determination result of 51 is negative (No), it is stored in a predetermined address assigned to the RAM 36 (step 52). And Me low engine speed the engine speed Ne is a predetermined by value Ne for the TS ₇
It is determined whether or not _L2 (Ne _L2 > Ne _L1 ) or more (step 53). If the determination result is negative (No), the process returns to step 46 and the process from step 46 is executed again from the beginning. If the determination result of step 53 is affirmative (Yes), the first flip-flop circuit 29 is reset (step 54) and the Me timer 33 is started (step 55). 1st after this
Waits for the first pulse signal Pc _{1 to} be latched by the flip-flop circuit 29 (step 56), and when the first pulse signal Pc ₁ is latched by the first flip-flop circuit 29, the Me timer 33 Is latched (step 57) and the value is stored in the memory corresponding to TSi (i = 1 to 7) (step 58). Then, in step 59, the stage variable ST
G is incremented by 1 and the Q output of the second flip-flop circuit 31 is zero, that is, the missing position of the second pulse signal Pc ₂ is determined. In other words, the execution of steps 48 and 49 immediately after the start of the start. After the crank angle reference position is detected, the subsequent crank angle reference position is detected (step 60). The determination result of step 60 is negative (No)
During the period, the process returns to step 56 and the processing from step 56 is repeatedly executed. During this execution, TS ₁ , TS ₂ , TS ₃ ...
The Me value (Fig. 2 (a)) is stored in the allocated memory. If the determination result of step 60 is affirmative (Yes), it is determined whether the stage variable STG at this time is 1 (step 61). If this determination result is affirmative (Yes), it means that the stages 1 to 7 are counted and the next stage 1 is detected. In other words, the crankshaft 14 is 1
While rotating, a predetermined number (seven) of first pulse signals Pc ₁
Since it has been confirmed that the engine has occurred, it is confirmed that the detected crank angle reference position is a normal crank angle reference position, and control is shifted to normal ignition timing and the like.

(Effect of the Invention) As described in detail above, according to the present invention, from the time when the crank angle reference position is detected immediately after the start of the engine until the time when the next crank angle reference position is detected. By confirming that a predetermined number of pulse signals have been generated, the detected crank angle reference position is confirmed to be the regular crank angle reference position, so the regular crank angle reference position can be easily and surely confirmed. The effect of being able to do is obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of an electronic ignition timing control device applied to the present invention, FIG. 2 is a timing chart showing respective signal waveforms in the same device, and FIG. 3 is a start-up of an internal combustion engine according to the present invention. It is a flowchart which shows the Example of the control program of the crank angle reference position confirmation method immediately after a start. 1 ... Engine, 14 ... Crankshaft, 16a-16g ... Reactor, 17,18 ... First and second pulsers, 10a, 10b ... Ignition plug, 24 ... CPU

Front page continuation (72) Inventor Haruhito Mito 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd.

Claims (1)

[Claims] 1. A first crank angle position signal is sequentially generated at each of a plurality of predetermined crank angle positions while the crankshaft of the engine makes one revolution, while the crankshaft is rotated by one.
A crank of an internal combustion engine that generates a second crank angle position signal at at least one predetermined rotation position of the crank shaft each time the crank shaft rotates, and detects a crank angle reference position by the first and second crank angle position signals. In the angle reference position confirmation method, the first crank angle position signal is detected immediately after the start of the engine, and the second crank angle position signal subsequent to the second crank angle position signal is detected. The number of occurrences of the crank angle position signal of 1 is counted, and when the counted number of occurrences is a predetermined number,
A crank angle reference position confirmation method immediately after starting of an internal combustion engine, characterized in that the crank angle reference position detected by the first and second crank angle position signals is confirmed to be a normal crank angle reference position.