JPH0692782B2 - Electronic ignition device for internal combustion engine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electronic ignition device for an internal combustion engine.

(Technical background of the invention and its problems) The internal combustion engine ignition timing is adjusted to the optimum timing according to the engine operating parameter values such as the engine speed, the intake pipe internal pressure, and the engine temperature, and the engine is always in good condition. It is designed to maintain a good driving condition. In such a conventional ignition device, for example, a control circuit for controlling ON / OFF timing of energization of the primary coil is connected to the primary coil in an ignition coil including a primary coil and a secondary coil, A spark plug is connected to the secondary coil. Then, each predetermined time is counted from a predetermined crank angle position of the engine, an energization time for starting energization of the primary coil, and an ignition timing for turning off the energization to generate a high voltage for ignition in the secondary coil. Are controlled at predetermined times. Therefore, it is necessary to provide the ignition device with two counters, one for energization timing counting and one for ignition timing counting.

As this counter, when the central processing unit (hereinafter referred to as “CPU”) that executes the calculation control process of the ignition timing is a so-called 1-chip CPU, an internal counter provided inside the CPU can be used, but the CPU does the calculation, etc. Since it is not possible to simultaneously perform the processing of 1) and the monitoring of the operation of the internal counter in parallel, there is a problem that if the energization / ignition timing is controlled using this counter, the control cannot be accurately performed. On the other hand, when a hardware (external) counter provided outside the CPU is used, once this external counter receives a count start signal from the CPU, it counts independently of the CPU thereafter, and the count value reaches the set value. And can output an energization or ignition signal, and thus an accurate energization or / or
And the ignition timing can be controlled. However, if the individual hard counters are used, there is a problem in that the installation space increases correspondingly and the cost increases.

(Object of the Invention) The present invention has been made in view of such conventional problems, and an object of the present invention is to provide an apparatus requiring a plurality of counters for energization timing and ignition timing counting, In controlling both the energization timing and the ignition timing, the ignition timing is controlled accurately by using an external counter in order to maintain a good operating condition, and the energization timing is controlled by using an internal counter. An object of the present invention is to provide an electronic ignition device for an internal combustion engine, which can be downsized and reduced in cost.

(Structure of the Invention) In order to achieve the above object, according to the present invention, a plurality of spark plugs, an ignition signal output means for applying a high voltage for ignition to the spark plugs, and a plurality of crank signal rotations each time the crankshaft makes one rotation. Crank angle signal generating means for outputting the crank angle position signal, crank angle position detecting means for detecting passage of a predetermined crank angle position of the crankshaft of the engine based on the generated crank angle position signal, and an operating state of the engine. An energization timing data indicating the time from the passage of the predetermined crank angle position detected by the crank angle position detection means based on the engine parameter detected accordingly to the start of energization of the ignition signal output means, and the predetermined crank angle position Required calculation processing including calculation of ignition timing data indicating time from passage to stop of energization corresponding to ignition timing A central processing unit for operating the power source, an energization counter means arranged inside the central processing unit for counting the energization timing data and outputting an energization timing signal, and disposed at an external position of the central processing unit. Ignition counter means for counting the ignition timing data and outputting an ignition timing signal, stage means updated by the crank angle position detecting means, and the energization counter means and the ignition counter means of the updated predetermined stage. There is provided an electronic ignition device for an internal combustion engine, comprising: start means for starting counting, and controlling energization start and ignition timing at a predetermined time from a predetermined crank angle position by angle-one-hour conversion.

Embodiments of the Invention The present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an embodiment of the present invention. First, the configuration will be described. In the figure, reference numeral 1 is a V-type engine having four cylinders or two cylinders, and the like.
Is an electronic control unit (hereinafter referred to as "ECU")
The V-type engine 1 has a cylinder included angle of 45 °, 60 °, 90 °, 128.
Any angle such as °, 135 ° and in-line 4-cylinder 180 ° can be applied, and the figure shows a partial cross section of a main part of one cylinder among a plurality of cylinders. Reference numerals 10a and 10b are spark plugs, and although only two spark plugs are shown in the drawing, these spark plugs are separately attached to respective cylinders.
Further, as will be described later, each of the spark plugs 10a and 10b is connected to a separately provided ignition coil, and an ignition system without a distributor is employed. For a four-cylinder engine, another spark plug (not shown) is electrically connected in series to the spark plug 10a, and similarly to this, a spark plug 10a is used.
For the spark plug b, another spark plug (not shown) 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 denotes a combustion chamber of the engine 1. An intake pipe 4 and an exhaust pipe 5 are communicated with the combustion chamber 3, and 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, 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. The intake pipe absolute pressure signal converted into an electric signal by 9 is sent to the ECU 2. Engine 1
The peripheral wall of the cylinder 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. Reference numeral 12 is a piston, and this piston 12 is communicated with a crankshaft 14 via a connecting rod 13. Then, according to the rotation of the crankshaft 14, a fifth
A pulse generation mechanism for generating the first and second pulse signals Pc ₁ and Pc ₂ as shown in FIGS. That is, first, the rotating disk 15 is attached to the crankshaft 14, and the reactors 16a to 16g formed of the protrusions made of a ferromagnetic material are arranged on the circumference of the crankshaft 14 at equal positions except one position on the circumference, for example,
It is projected 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 the magnetic body may be embedded in the rotating disk. Outside the rotating disk 15, first and second electromagnetic pickups (hereinafter referred to as pulsars) 17,1 formed by winding coils 17b, 18b around magnet bodies 17a, 18a along the circumference thereof.
8 are arranged. The arrangement angular interval between the first and second pulsers 17 and 18 is defined in accordance with the number of cylinders at the top dead center interval of the engine to be applied. Shown when applied to an engine, 2
The arrangement angular interval between the individual pulsers 17 and 18 is specified to be about 180 °.

On the other hand, the ECU 2 is roughly divided into blocks. An input circuit 19, an input / output LSI (hereinafter referred to as “I / 0 / LSI”) 21, a C
PU22, A / D converter 23, and first and second output circuits 2
It is equipped with 4a and 24b. Further, the input circuit 19 has first and second pulse signals Pc ₁ and Pc ₂ generated by the first and second pulsers 17 and 18, respectively (see FIG.
(B)) is a waveform shaping circuit 25, 26 and each of these waveform shaping circuits 2
First and second flip-flop circuits 27, 28 for latching the outputs from 5, 26 are provided. The output line of the output of the first flip-flop circuit 27 is I / 0.
-Connected to the INT terminal (not shown) of the CPU 22 via the LSI 21, and the output line of the Q output of the second flip-flop circuit 28 is I / 0.-The STATUS terminal (not shown) of the CPU 22 via the LSI 21. )It is connected to the. Reference numeral 29 is a clear signal line for the first and second flip-flop circuits 27, 28.

The CPU 22 executes various programs for calculating the energization timing and the ignition timing. A read-only memory (hereinafter referred to as "ROM") 31 that stores the Tw-Δθig table, the cylinder included angle table, and the like, and a random access memory (hereinafter referred to as "RAM") 32 that stores the above calculation results, and input / output. There is a buffer 33 for this, and the energization counter 34 is installed in this CPU.
Is provided as an internal counter. Energization counter 34
Compares the count value with the energization timing data on the spark plug 10a side and the energization timing data on the spark plug 10b side stored in RAM 32, and when the count value exceeds each energization timing data value, the energization signal The power-on signal on the spark plug 10a side is guided to the power-on signal line 40a to the first output circuit 24a via the I / 0 LSI,
The energization signal on the spark plug 10b side is guided to the energization signal line 40b to the second output circuit 24b via the I / O LSI. Reference numeral 34a,
34b is an energization register for program processing, and 35a, 35b are comparators for program processing.

On the other hand, a first ignition counter 36 for the ignition plug 10a and a second ignition counter 37 for the other ignition plug 10b are arranged at a portion of the I / O / LSI 21, that is, at a position outside the CPU 22. Reference numeral 38 is an ignition register for latching ignition timing data on the spark plug 10a side, and 39 is the spark plug 10
Ignition registers for latching the ignition timing data on the b side, and 42 and 43 are first and second comparators. Lines for starting signals from the CPU 22 are connected to the first and second ignition counters 36 and 37, respectively. And the first comparator 42
The output line 44a of the second comparator 43 communicates with the first output circuit 24a, and the output line 44b of the second comparator 43 communicates with the second output circuit 24b. Reference numerals 45 and 46 are first and second ignition coils, and these ignition coils 45 and 46 are respectively provided with a primary coil and a secondary coil (not shown). The primary coil of the first ignition coil 45 has a first output circuit 24a
The output line from is connected and the secondary coil is the spark plug 10
connected to a. The output line from the second output circuit 24b is connected to the primary coil of the second ignition coil 46, and the secondary coil is connected to another ignition plug 10b. The reference numeral 47 in the I / 0 / LSI 21 portion is Me which will be described later.
It is a timer.

Next, the operation will be described with reference to FIGS. 2 to 5 (a) to (g). 2 is a schematic flowchart of the main routine executed by the CPU 22, and FIG. 3 is Me (engine speed Ne
Calculation of the reciprocal of) and the engine speed Ne from this Me value
Of the subroutine for determining the value of
Fig. 4 shows the interrupt processing program INT for controlling energization timing, etc.
5A to 5G are timing charts of the first and second pulse signals and the like.

First, the outline of the main routine executed by the CPU 22 will be described with reference to FIG. Immediately after the ignition switch (not shown) is turned on, the CPU 22 and the like are initialized, and in step 51, the crank angle reference position is detected. After the reference position is detected, the time Me required for one revolution of the crankshaft 14 is calculated, the value of the engine speed Ne is determined based on the Me value (step 52), the advance angle data θig is calculated, and the calculated value is calculated. Store processing to RAM32 (step 53), calculate energization time T _ON and store this calculated value to RAM32 (step 54), advance angle θi
Calculation of ignition timing data Tig and energization time data Tcg by g and energization time T _ON and storage processing of these calculated values in RAM 32 (step 55) are sequentially performed, and each such arithmetic processing is interrupt processing described later. It is repeated when the program INT is not executed.

Next, the processing in each of the above steps will be described in detail. In step 51 of reference position detection, when the first pulse signal Pc ₁ is input to the CPU 22 as shown in FIG. 5, the CPU 22 causes the Q output of the second flip-flop circuit 28 (FIG. 5 (d) to be “H”). It is discriminated whether it is "level" or "L" level. At this time, the Q output of the second flip-flop circuit 28 is "L" level at the input timing of the _first pulse signal Pc ₁ . The position (the position of the line k in Fig. 5) exists once per one rotation of the crankshaft 14. The crank angle position at this time is defined as the reference crank angle position q. Each generation interval of the first pulse signal Pc ₁ is defined as a stage, and a stage number is assigned to each stage.The numbering method can be variously defined according to the cylinder included angle of the engine 1 and the reference crank angle. The number of the detected stage at position q Is either stored in the ROM31 for each specification of the engine. In the example of FIG. 5 (a),
The stage when the reference position q is detected is numbered as stage 1, and is numbered as stages 2, 3 ...

After detecting the reference crank angle position q, in step 52, Me is calculated and the engine speed Ne is determined. This will be described with reference to the flowchart of the subroutine of FIG. In step 56, each generation time interval Tsi (i = 1 to 7) (FIG. 5 (a)) of the first pulse signal Pc ₁ is measured by the clock pulse by the Me timer 47, and the total of one rotation is measured. Time Me is processed. In step 57, the time Ts = Me required for the crankshaft 14 to rotate by one stage, in other words, by a crank angle of 45 °, from this total time Me, Ts = Me
÷ 8 and the time ΔT = Ts ÷ 45 required to rotate the crank angle by 1 ° are calculated and stored in RAM32,
Prepare for calculation processing of ignition timing Tig and the like, which will be described later.

Next, in order to determine whether or not the current engine speed Ne is in the high speed rotation region, it is determined from the Me value whether the engine speed Ne is equal to or higher than a predetermined speed N _IGAC (for example, 3000 rpm). If this determination result is affirmative (Yes), the flag N2
Is set to 1 (step 59), and if negative (No), flag
N2 is set to zero (step 60). This flag N2 is for determining whether or not the acceleration correction of the Tig value and the Tcg value at the time of sudden acceleration / deceleration of the engine, which will be described later, may be executed, and when the engine speed Ne is higher than a predetermined value N _IGAC Acceleration correction is prohibited because the calculation processing time cannot be secured sufficiently. It should be noted that the discriminant value N _IGAC of step 58 is provided with a hysteresis in order to stabilize the control, and even if the engine speed Ne exceeds the discriminant value N _IGAC , it may be set to a different value. Good.

In the main routine, in the next step 53, the advance angle data θig from the reference crank angle position q is calculated, and the calculation result is stored. The advance angle data θig is detected by the Me value and the absolute pressure sensor 9 and the engine water temperature sensor 11, respectively. And each value of the engine water temperature Tw are calculated according to the following equation (1).

Read out. 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 1. The value of the advance angle data θig is specified with the maximum advance angle θig (for example, 60 °) as the upper limit. When the value obtained as described above exceeds this maximum advance angle θig ′, the maximum advance angle θig It is corrected to the value of the advance angle θig ′. The lead angle data θig thus obtained is stored in the RAM 33.

Next, in step 54, the energization time T _ON is calculated and the calculation result is stored. The energization time T _ON is a function of only the engine speed Ne as shown in the following expression (2), and is read from the Ne-T _ON table stored in the ROM 31 as in the above.

T _ON = f (Ne) (2) The energization time data T _ON thus obtained is stored in the RAM 32.

After the advance data θig and the energization time data T _ON are obtained, the ignition timing data Tig and the energization timing data Tcg are calculated in step 55 based on these values. First, the ignition timing data Tig will be described. For each engine cylinder included angle and each cylinder, a predetermined crank angle position (advance angle = 0
)) The stage number at a position advanced from q by the maximum advance angle θig ′ (stage 6 in the example of FIG. 5A), and the crank angle from the start end of this stage position to the maximum advance angle θig ′ position (this Hereinafter referred to as "angle data") and is ROM3
Remembered in 1. The CPU 22 reads out these angle data and advance angle data θig from the ROM 31 and the RAM 32, respectively, and calculates the angle DEG from the stage 6 pulse q ′ by the following equation (3).

DEG = θig′−θig + angle data (3) Next, the ignition timing data Tig is calculated from this angle DEG by the equation (4).

Tig = ΔT × DEG (4) Here, ΔT is the time required for the crankshaft 14 to rotate by 1 ° in crank angle, which is stored in the RAM 32 in step 57 of FIG.

The energization time data Tcg is calculated by the following equation (5) from the ignition timing data Tig and the energization time data T _ON obtained as described above.

Tcg = | (T _ON −Tig) −Ts × m | ... (5) where m is the ignition coil before the position stage (stage 6 in the illustrated example of FIG. 5) advanced by the maximum advance angle θig ′. The number of stages (m = 1 in the example shown in FIG. 5) up to the stage for starting the step Ts is the average value of the time required to advance the crank angle of 45 ° crank angle determined in step 57 of FIG.

The above calculated values are stored in the RAM 32.

Next, a method of performing energization and ignition will be described with reference to the flowchart of FIG. The energization and ignition are performed by interrupt processing each time the Q output is input from the first flip-flop circuit 27. First, step 61 for each interrupt.
The stage position is detected by, and then the required time Tsi corresponding to the crank angle of 45 ° is read from the Me timer 47 and stored, and the Me timer 47 is reset and restarted at the same time (step 62). Next, at step 63, it is judged if the detected stage is an ignition stage (for example, stage 6) at which the ignition counter 36 should start counting. If this determination result is affirmative (Yes), CPU22
Sends a start signal to the ignition counter 36 to start the ignition counter 36 (step 64, FIG. 5 (f)),
Proceed to step 65. The determination result of step 63 is negative (No)
If so, the process immediately proceeds to step 65, and the energization counter 34 as an internal counter is started (FIG. 5 (g)). The energization counter 34 is started each time the interrupt processing program is executed. After the counters 34 and 36 are started, it is determined whether or not 1 is set in the plug N2 (step 66). If the determination result is affirmative (Yes), acceleration correction is not performed for both the energization timing data Tcg and the ignition timing data Tig, and the process proceeds to the next step 68, and the ignition timing data Tig stored in the RAM 32 is directly stored in the ignition register 38. Set. On the other hand, if the determination result in step 66 is negative (No) and the engine speed Ne is not in the high speed region, the subroutine THSI is executed and the known acceleration correction is performed on the ignition timing data Tig and the energization timing data Tcg, and the RAM
The Tig value and Tcg stored in 32 are rewritten to the corrected values (step 67). After performing such acceleration correction, the process proceeds to step 68 as described above. Next, at step 69, it is judged if the current detection stage is the energization stage. This determination result is negative (N
If it is o), as will be described later, this interrupt process is terminated without comparing the set value of the energization register 34a with the count value T of the energization counter 34 started in step 65. Therefore, although the energization counter 34 is started in step 65, the CPU 22 does not
The power-on signal is not output to the output circuit 24a. If the determination result of step 69 is affirmative (Yes), the energization timing data Tcg stored in the RAM 32 is set in the energization register 34a. After this setting, the count value T of the energization counter 34 is compared with the energization timing data Tcg (step 71), and the count value T
When exceeds the energization timing data Tcg, the CPU 22 sends an energization signal to the first output circuit 24a to energize the primary coil of the first ignition coil 45 (step 72). On the other hand, in step 63, when the external ignition counter 39 starts counting by the activation signal from the CPU 31, the comparator 42 is set to the count value of the counter 39 and the register 37 regardless of the CPU 22, and the interrupt process is executed. The ignition timing data Tig (FIG. 5 (f)), which is updated to the latest value each time, is compared, and when the count value exceeds the ignition timing data Tig, the energization stop signal, that is, the ignition signal, is output to the first output circuit. 24a to stop the energization of the primary coil of the first ignition coil 45. As a result, a high voltage is generated in the secondary coil, spark discharge is generated in the spark plug 10, and ignition is performed. Other cylinder side spark plug 10
Regarding the processing of energization timing and ignition timing for b,
Since only the energizing and igniting stages are different and the other points are almost the same as those described above, the description thereof will be omitted.

As described above, the energization timing is determined by the counter 34 inside the CPU 22.
The CPU22 compares the count value and the register set value by software, and the ignition timing is processed hard by the comparator by comparing the counter value outside the CPU22 and the register set value by the comparator. Rotational speed Ne, And the engine parameters accurately control the energization timing and ignition timing that are optimum for the engine operating condition at that time.

(Effect of the Invention) As described in detail above, according to the present invention, the energization counter means for counting the time from the predetermined rotation angle position of the crankshaft of the engine to the energization timing is provided inside the central processing unit. Since the count is processed by software, the required number of hard counters and the space for arranging the hard counters are small, and the size and cost can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of an electronic ignition device for an internal combustion engine according to the present invention, FIG. 2 is a flowchart of a main routine executed by the same device, and FIG. 3 is engine rotation. FIG. 4 is a flowchart of a subroutine for determining a specific value of the engine speed from the Me value that is the reciprocal of the number and the Me value, FIG. 4 is a flowchart of an interrupt processing program for controlling energization timing, and FIG. 4 is a timing chart showing the energization timing and ignition timing of the ignition coil in the apparatus of the figure. 1 ... Engine, 10a, 10b ... Spark plug, 22 ... Central processing unit, 24a, 24b ... Output circuit, 34 ... Energization counter, 36, 37 ... Ignition counter, 38, 39 ... Ignition register , 42,43 …… Comparator, 45,46 …… Ignition coil

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Haruhito Mito, 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. (56) Reference JP-A-56-9656 (JP, A) Kai 54-158531 (JP, A) JP 57-70936 (JP, A)

Claims (1)

[Claims] 1. A spark plug, an ignition signal output means for applying a high voltage for ignition to the spark plug, and a crank angle signal generation means for outputting a plurality of crank angle position signals each time the crankshaft makes one revolution. And crank angle position detecting means for detecting passage of a predetermined crank angle position of the crankshaft of the engine based on the generated crank angle position signal,
Energization timing data indicating the time from the passage of the predetermined crank angle position detected by the crank angle position detection means based on the engine parameter detected according to the operating state of the engine to the start of energization to the ignition signal output means, And a central processing unit for performing necessary arithmetic processing including calculation of ignition timing data indicating time from passage of a predetermined crank angle position to stop of energization corresponding to ignition timing, and a central processing unit inside the central processing unit. An energization counter means arranged to count the energization timing data and output an energization timing signal;
Ignition counter means arranged outside the central processing unit to count the ignition timing data and output an ignition timing signal, stage means updated by the crank angle position detecting means, and the updated predetermined value. And a start unit for starting counting of the energization counter unit and the ignition counter unit on a stage, wherein energization start and ignition timing are controlled by a predetermined time from a predetermined crank angle position by angle-one-hour conversion. Ignition device for internal combustion engine.