JPS62135665A - Internal combustion engine ignition timing control device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a V-type cylinder in which a plurality of cylinders are divided into a plurality of banks,
Of the horizontally opposed types! ! ! , relates to an engine ignition timing control device.

[Conventional technology]

In electronically controlled HC (overhead camshaft) engines, a distributor with a built-in crank angle sensor is installed on the camshaft located above the cylinder row, and the ignition of each cylinder is controlled based on the crank angle signal obtained by this distributor. Calculating the time.

Furthermore, in a ■-type or horizontally opposed OHC engine, camshafts are provided on each of the two cylinder banks, and in this case, the camshaft provided with the distributor is used as the reference camshaft. The ignition timing of the cylinders in both banks is calculated based on the crank angle signal obtained by the crank angle sensor.

Conventionally, in V-type or horizontally opposed HC engines,
The ignition timing was calculated for each cylinder at a specific reference angle determined by the output of the crank angle sensor, for example, 60°C^BTDC for each cylinder, and the ignition timing of each cylinder was controlled based on this.

[Problem that the invention seeks to solve]

However, the rotational speed of the crankshaft usually changes sinusoidally depending on the combustion cycle, and therefore the rotational speed of the camshaft also changes sinusoidally. In this case, the relative speed of the reference camshaft with respect to the crankshaft changes at a cycle of 240° CA in the case of a six-cylinder engine, for example, as shown in FIG. Therefore, the top dead center TDC of each cylinder is used as a specific reference angle.
When set to the previous 60° CA, the first cylinder shown by arrow
The reference camshaft rotational speed for the first bank to which the third and fifth cylinders belong, and the second and fourth cylinders shown by arrow Y.

There is a problem in that there is a difference between the rotation speed of the reference camshaft and the second bank to which the sixth cylinder belongs, and as a result, there is a difference in ignition timing between the banks.

[Means for solving problems]

An object of the present invention is to eliminate the difference in ignition timing between banks in an engine in which a plurality of cylinders are divided into a plurality of banks, and the configuration thereof is shown in FIG. 1A.

As shown in FIG. 1B.

In FIG. 1A, a plurality of cylinders are divided into a plurality of banks and arranged, for example, the first . The third and fifth cylinders are arranged in the first bank, and the second and fifth cylinders are arranged in the first bank. 4゜The sixth cylinder is arranged in the second bank, and a camshaft is arranged corresponding to each bank to open and close the intake and exhaust valves of each cylinder, and each of these camshafts is connected to one crankshaft. In an internal combustion engine that is rotatably driven via a shaft, the specific reference angular position determining means is one of the camshafts.
One is set as a reference camshaft, and it is determined whether or not this reference camshaft is at a specific reference angular position. For example, the specific reference angular position determining means determines whether the camshaft of the first puncture is at a position corresponding to 60° CA BTDC of the first, third, or fifth cylinder. As a result, when the reference camshaft reaches this specific reference angular position, the first specific cylinder ignition timing calculating means calculates the ignition timing for the specific cylinder corresponding to the specific reference angular position, for example, the first. Third,
Alternatively, the ignition timing of the fifth cylinder is calculated. At the same time, the second specific cylinder ignition timing calculating means calculates the ignition timing for the second cylinder, for example, the second cylinder, which is next to the specific cylinder corresponding to the specific reference angular position. Calculates the ignition timing of the fourth or sixth cylinder. In this way, the calculated ignition timing of the specific cylinder (first, third, fifth cylinder) and the cylinder next to the specific cylinder (second, fourth, fourth, etc.) are calculated.
The ignition timing control means controls the ignition timing of the specific cylinder and the next cylinder in accordance with the ignition timing of the sixth cylinder.

In FIG. 1B, the first specific reference angle determining means is the first
This corresponds to the specific reference angle determining means in Fig. A, and further includes a second specific reference angle determining means and a load change determining means. That is, the second specific reference angular position determining means determines whether the reference camshaft is at the second specific reference angular position. For example, the second specific reference angular position determining means determines that the camshaft of the first bank is the second bank. 60° for the 4th or 6th cylinder
It is determined whether the position corresponds to CABTDC. Further, the load change determining means determines whether a change in engine load, which indicates a change in rotational speed of the engine, is less than or equal to a predetermined value. As a result, the second
The specific cylinder ignition timing calculating means calculates a first specific ignition timing corresponding to the first specific reference angular position when the reference camshaft reaches the first specific reference angular position when the load change is less than a predetermined value. The ignition timing of the second specific cylinder (2nd, 4th and 6th cylinders) following the cylinders (1st, 3rd and 5th cylinders) is calculated, and on the other hand, when the load change exceeds a predetermined value, calculates the ignition timing of the second specific cylinder (2nd, 4th, 6th cylinder) corresponding to the second specific reference angular position when the reference camshaft reaches the second specific reference angular position It is.

[For production]

According to the configuration shown in FIG. 1A, the first . When calculating the ignition timing of the third or fifth cylinder, the second cylinder belonging to the second bank. Since the ignition timing of the 4th or 6th cylinder is also calculated, there is no difference in engine rotation speed between the two, which is the basis for calculating the ignition timing.
Therefore, there is no difference in ignition timing between banks.

According to the configuration shown in FIG. 1B, when the rotational speed of the engine suddenly changes, the calculation of the ignition timing of the second, fourth, or sixth cylinder belonging to the second bank is performed at a point close to the actual ignition timing. This is done at a specific reference angular position for the second bank. In other words, in this case, the ignition timing for the second bank calculated at the specific reference angular position for the first bank will deviate from the actual ignition timing due to subsequent changes in rotational speed, so this is not used. I tried to avoid it. In this manner, the configuration shown in FIG. 1B operates effectively even when the engine rotational speed is in a transient state.

〔Example〕

The present invention will be described in detail with reference to the drawings from FIG. 3 onwards.

FIG. 3 is an overall schematic diagram showing an embodiment of an ignition timing control device for an internal combustion engine according to the present invention. In Figure 3, 6
A cylinder ■ type hall is shown. 1st, 3rd. The fifth cylinder is arranged in the first bank, the second. 4th. The sixth cylinder is arranged in the second bank. Air taken in through the air cleaner 11 is fed to the combustion chamber 19 of the engine body 18 through an intake passage 17 that includes an air flow meter 12, a throttle valve 13, a surge tank 14, an intake port 15, and an intake valve 16. The combustion chamber 19 is formed by a cylinder head 20, a cylinder block 21, and a piston 22, and the exhaust gas generated by combustion of the air-fuel mixture is passed through an exhaust valve 23, an exhaust port 24, and an exhaust manifold 2.
5, and is discharged to the atmosphere via the exhaust pipe 26.

Cam shafts 27 and 28 for opening and closing the intake valve 16 and the exhaust valve 23 are provided above each cylinder row arranged on the left and right sides. Camshaft 27 corresponding to the cylinder row arranged on the right side
is a reference camshaft for determining the timing for igniting the spark plug 41 of each cylinder;
It is connected to the shaft 31 of. On the other hand, a pulley 3 is attached to a crankshaft 33 connected to the piston 22 via a connecting rod 32.
4 is fixed, and this pulley 34 is connected via an endless timing belt 35 to pulleys 36 and 37 fitted to the camshafts 27 and 28. timing belt 3
A tensioner 38 that engages with the outer peripheral surface of the timing belt 5 is provided to adjust the tension of the timing belt 35.

Note that the output of the air flow meter 12 is supplied to an A/D converter 101 with a built-in multiplexer of the control circuit 10.

The distributor 30 has a crank angle sensor 42 whose shaft 31 generates a reference position detection pulse signal every 720 degrees in terms of crank angle, and a crank angle sensor 42 which generates a reference position detection pulse signal every 30 degrees in terms of crank angle. A crank angle sensor 43 is provided that generates. The pulse signals of these crank angle sensors 42 and 43 are supplied to the input/output interface 102 of the control circuit IO, and the output of the crank angle sensor 43 is supplied to the interrupt terminal of the CPU 103.

44 is an ignition coil whose primary side coil is connected to an igniter 45 connected to the input/output interface 102 of the control circuit 10, and whose secondary side coil is connected to the distributor 30.

That is, the secondary current of the ignition coil 44 is supplied via the distributor 30 to the ignition plug 41 provided for each cylinder.

The control circuit 10 is configured as a microcomputer, for example, and includes an A/D converter 1o1, an input/output interface 102. , timer counter 1 outside the CPU 103
04, ROM 105, RAM 106, etc. are provided. The timer counter 104 includes, for example, a free run counter, a conveyor register for controlling ignition timing, a comparator that detects a match between the value of the free run counter and the value of the conveyor register and generates an interrupt signal, and an ifI electric flag register input permission flag register. It is composed of etc. Note that the interrupt order for the CPU 103 is
When the A/D converter 101 finishes, when the input/output interface 102 receives a pulse signal from the crank angle sensor 43, when the conveyor interrupt signal from the timer counter 104 is received, etc.

The intake air amount data Q of the air flow meter 12 is A/D converted at predetermined time intervals and stored in a predetermined area of the RAM 106. In other words, data Q in the RAM 106 is updated at predetermined intervals. In addition, rotation speed data Ne
is calculated by the crank angle sensor 43 every 30° CA and stored in a predetermined area of the RAM 106.

A first form of operation of the control circuit 10 in FIG. 3 will be described with reference to the flowcharts in FIGS. 4 and 5 and the timing diagram in FIG. 6.

FIG. 4 shows an ignition timing calculation routine, which is executed every time a predetermined crank angle, for example, a 30° CA multiplied signal interrupt from the crank angle sensor 43 is interrupted. In step 401, it is determined whether the angle is a specific reference angle or not. Here, time jl, L3 in FIG.
+LS belonging to the first bank as shown in FIG. Third,
and 60″CA before top dead center of the 5th cylinder (60°CA
BTDC) position.

This is determined by using a counter that is counted up by the 30° CA signal from the crank angle sensor 43 in a not-shown routine and is cleared if the 720° CA signal from the crank angle sensor 42 is input at that time.

If it is a specific reference angle, the process proceeds to step 402, and if it is not a specific reference angle, the process directly proceeds to step 407.

In step 402, a specific reference angle flag is set, and the process proceeds to step 403, where ignition timing is calculated.

For example, if it corresponds to time t in FIG. 6, the energization start time t1 and energization end time (ignition time) to of the igniter 45 for the first cylinder are calculated, and the energization start of the igniter 45 for the second cylinder is calculated. The time t,' and the energization end time t,' are also calculated. Specifically, for example, in a routine (not shown), the intake air amount Q/N per revolution is calculated in advance using the intake air amount data Q and the rotational speed data Ne, and the intake air amount Q/N per revolution is A basic advance angle value θ8 is determined by interpolation calculation using a two-dimensional map. Note that the basic advance angle value OB is corrected as necessary. Next, the current time CNT (=tl) is read from the free run counter of the timer counter 104, and the energization start time for the first cylinder is determined as: t,←CNT+T (60" CA-θB)t,←
t, 10'l' (30@CA) However, T (60'
CA-0g) and T (30' CA) are the time-converted values of the crank angle 60" CA-θ3.30° CA, and the energizing period of the igniter 45 is 30° CA.
That is. At the same time, the energization start time 1, / and the ignition time t, J for the second cylinder are also expressed as t,
'←ti +T (120°CA)t, '-t, +T
(120° CA). These values are then stored in RAM 106.

In step 404, for example, the energization start time for the first cylinder is set in the conveyor register of the timer counter 104, and in step 405, the energization flag is set in the energization flag register, and in step 406, the interrupt permission flag is set. Set the conveyor interrupt enable flag in the register. This routine then ends in step 407.

In this way, when the energization start time t8 for the first cylinder is reached, that is, when the current time CNT of the free run counter of the timer counter 104 matches the value t of the conveyor register, the timer counter 104 starts the energization. Input/output ink face 1 according to the flag register value “1”
02 to start energizing the igniter 45, and at the same time generate a conveyor interrupt to the CPU 103 to start the conveyor interrupt routine shown in FIG.

To explain the conveyor interrupt routine in Figure 5,
At time ti, both the specific reference angle flag and the energization flag are "1", so the flow goes to step 501.
．． The process proceeds to step 503 via step 502 . step 50
3, the ignition time t8 for the first cylinder is set to timer counter 1.
04, and the energization flag is reset in step 504. And step 511
and the routine ends.

In this way, when the ignition time t8 for the first cylinder is reached, that is, when the current time CNT of the free run counter of the timer counter 104 matches the value t8 of the conveyor register, the timer counter 104 registers its energization flag register. Input/output interface 102 according to the value “0”
The energization of the igniter 45 is terminated via the igniter 45 to cause ignition, and the CPU 103 generates a conveyor interrupt to restart the conveyor interrupt routine shown in FIG.

When the conveyor interrupt routine of FIG. 5 starts again, at time t, the specific reference angle flag is "l" but the energization flag is "O", so the flow proceeds to step 501. The process advances to step 505 via step 502 . In step 505, the energization start time t,' for the second cylinder is set in the conveyor register of the timer counter 104, in step 506 the energization flag is set, and in step 50
At step 7, the specific reference angle flag is reset. The routine then proceeds to step 511 and ends.

In this way, when the energization start time for the second cylinder reaches ', that is, the current time CNT of the free run counter of the timer counter 104 changes to the value t of the conveyor register.
, l, the timer counter 104 restarts energization of the igniter 45 via the input/output interface 102 according to the value "1" of the energization flag register, and causes the CPU 103 to generate a conveyor interrupt to start the energization. The conveyor interrupt routine shown in FIG. 5 is further started.

When the conveyor interrupt routine in FIG. 5 starts again, at time 1, the specific reference angle flag is “0”.
”, the flow proceeds to step 50B via step 501. In step 508, the ignition time t.' for the second cylinder is set in the conveyor register of the timer counter 104, and in step 509, the energization flag is reset. Then, in step 510, the conveyor interrupt permission flag is reset.Then, the process proceeds to step 511,
This routine ends.

In this way, when the ignition time t@' for the second cylinder is reached, that is, the current time CNT of the free run counter of the timer counter 104 becomes equal to the value t of the conveyor register.
1, the timer counter 104 terminates the energization of the igniter 450 via the input/output ink face 102 according to the value "O" of the energization flag register to cause ignition, but the conveyor interrupt permission flag is set to "0". 0'', the conveyor interrupt routine of FIG. 5 does not start.

In this way, the 60° CA BTDC of the first cylinder (time t
In υ, the ignition timing of the first cylinder as a specific cylinder is calculated, and the ignition timing of the next second cylinder is calculated.

Similarly, 60° CA BTDC of the 3rd cylinder (time tz)
In , the ignition timing of the third cylinder as a specific cylinder is calculated, and the ignition timing of the next fourth cylinder is calculated, and at 60" CA BTDC (time ts) of the fifth cylinder, as a specific cylinder. The ignition timing of the fifth cylinder is calculated, and the ignition timing of the next sixth cylinder is calculated.Therefore, the ignition timing of the first bank (1st, 3rd, and 5th cylinders) and the second bank (2nd, 3rd, and 5th cylinders) is calculated. There is no difference in ignition timing between the 4th cylinder and the 6th cylinder due to uneven rotational speed.

In the first embodiment of the present invention shown in FIGS. 4 to 6, even if the rotational speed Ne is steady, the ignition timing difference between banks due to its unevenness is eliminated, but the ignition timing difference of a specific cylinder If the rotational speed Ne suddenly changes after calculating the timing and the ignition timing for the next cylinder, the ignition timing for the next cylinder may deviate from the actual ignition timing. In order to prevent such a shift in the ignition timing during a sudden change in the rotational speed Ne, the routine shown in FIG. 7 is used instead of the routine shown in FIG. 4.

To explain the routine of FIG. 7, which is the second embodiment of the present invention, in FIG. 7, steps 701 to 707 are added to the routine of FIG. 4.

That is, in step 701, a transient flag indicating whether or not the rotational speed Ne has suddenly changed is determined, and when the transient state is "1", that is, the transient flag is "1", steps 702 to 70 are performed.
7. Therefore, unless there is a transient state, the routine of FIG. 7 is exactly the same as the routine of FIG. 4. Note that setting of the transient flag will be described later in the eighth routine.

Referring also to FIG. 9, time tI+t3+ts in FIG.
The first . belonging to the first bank as shown in . If the 60° CA BTDC position of the 3rd and 5th cylinders, whether in steady state or transient state, steps 402-4
06 flow is executed, therefore, as mentioned above, the first
．． The ignition timing for the third or fifth cylinder is calculated, and the ignition timing for the next second cylinder is calculated. The ignition timing for the fourth or sixth cylinder is also calculated. However, if a transient condition occurs, the flow of FIG. 7 proceeds to step 702. For example, time t in FIG.
If it is the 60° CA BTDC position of the 4th and 6th cylinders belonging to the second bank as shown in 4-+th, the specific reference angle flag is reset in step 703, and the process proceeds to step 704. Only calculates ignition timing. For example, if the time corresponds to time t4 in FIG. 9, the energization start time t,' of the igniter 45 for the fourth cylinder and the ignition time t, l are calculated. And these values are RA
M106.

In step 705, for example, the energization start time for the fourth cylinder is set to 1 in the conveyor register of the timer counter 104, and in step 706, an energization flag is set in the energization flag register, and in step 707, an interrupt permission flag is set. Set the conveyor interrupt enable flag in the register. Then, this routine ends at Stella 5° 407.

In other words, the ignition timing for the fourth cylinder calculated together with the ignition timing for the third cylinder at time t3 is replaced by the ignition timing for the fourth cylinder calculated at time t4.

In this way, when a transient condition occurs, the first . Third. Calculation of ignition timing for the fifth cylinder and the calculation of the ignition timing for the second cylinder belonging to the second bank. The ignition timing calculations for the 4th and 6th cylinders are performed separately and at crank angle positions, each close to the actual ignition timing. Therefore, the actual ignition timing follows the sudden change in the rotational speed Ne.

FIG. 8 shows a routine for setting the transient flag used in step 701 in FIG. 7, and is executed at every predetermined crank angle, for example, 30° CA. In step 801, the period T of the 30° CA signal of the crank angle sensor 43 is
30CA is incremented by 1 based on the difference between the previous value CNTO and the current value CNT of the free run counter of the timer counter 104. That is, T 3 0 CA-CNT-CNTO Next, in step 802, the average value T30CA (or smoothed value) of multiple T 30CA values is calculated,
In step 803, ΔTNe=lT30CA−T30CAl is calculated.

At step 804, it is determined whether ΔTNe >α (positive value). As a result, if ΔTNe > α, the change in the rotational speed Ne is large, so the transient flag is set; on the other hand, if ΔTNe≦α, the change in the rotational speed Ne is small, so the transient flag is reset.

This routine then ends in step 807.

In FIG. 8, the transient state is determined based on the change in the rotational speed Ne itself, but other load parameters indicating the rotational speed, such as the intake air amount Q, the intake air amount per rotation Q/Ne, A transient state can also be determined based on changes in intake air pressure PM or throttle valve opening TA.

〔Effect of the invention〕

As explained above, according to the present invention, differences in ignition timing between banks due to uneven rotational speed can be eliminated.

Furthermore, when the rotational speed suddenly changes, the ignition timing can be adjusted appropriately.

[Brief explanation of drawings]

1A and 1B are overall block diagrams for explaining the present invention in detail, FIG. 2 is a timing diagram showing the rotational speed of the camshaft, and FIG. 3 is an ignition timing control device for an internal combustion engine according to the present invention. FIG. 4, FIG. 5, FIG. 7, and FIG. 8 are flowcharts for explaining the operation of the control circuit in FIG. 3, and FIG. 6 and FIG. FIG. 3 is a timing diagram illustrating the invention in detail. 10... Control circuit, 16... Intake valve, 23...
...Exhaust valve, 27, 28...Camshaft, 41...
・Spark plug, 42, 43...crank angle sensor. Figure 4 Figure 5

Claims (1)

[Claims] 1. A plurality of cylinders are arranged and divided into a plurality of banks,
In an internal combustion engine in which a camshaft is disposed corresponding to each bank in order to open and close the intake and exhaust valves of each cylinder, and each of these camshafts is rotationally driven via one crankshaft, the camshaft a specific reference angular position determining means that takes one of the reference camshafts as a reference camshaft and determines whether or not the reference camshaft is at a specific reference angular position; a first specific cylinder ignition timing calculation means for calculating ignition timing of a specific cylinder corresponding to a specific reference angular position; a second specific cylinder ignition timing calculating means for calculating the ignition timing of a specific cylinder next to the specific cylinder; An ignition timing control device for an internal combustion engine, comprising: ignition timing control means for controlling ignition timing of a cylinder and the next cylinder; 2. Multiple cylinders are arranged and divided into multiple banks,
In an internal combustion engine in which a camshaft is disposed corresponding to each bank in order to open and close the intake and exhaust valves of each cylinder, and each of these camshafts is rotationally driven via one crankshaft, the camshaft a specific reference angular position determination means that takes one of the reference camshafts as a reference camshaft and determines whether or not the reference camshaft is at a first specific reference angular position; a first specific cylinder ignition timing calculation means for calculating the ignition timing of the first specific cylinder corresponding to the first specific reference angular position when the reference camshaft is at a second specific reference angle; second specific reference angular position determining means for determining whether or not the engine is in the specified reference angular position; load change determining means for determining whether a load change of the engine indicating a change in the rotational speed of the engine is less than or equal to a predetermined value; When the load change is less than or equal to a predetermined value, when the reference camshaft reaches the first specific reference angular position, the second specific cylinder next to the first specific cylinder corresponding to the first specific reference angular position is calculates the ignition timing of the specific cylinder, and when the load change exceeds a predetermined value, the reference camshaft corresponds to the second specific reference angular position when the reference camshaft reaches the second specific reference angular position. Second to do
a second specific cylinder ignition timing calculating means for calculating the ignition timing of each of the first and second specific cylinders according to the calculated ignition timing of the first and second specific cylinders; An ignition timing control device for an internal combustion engine, comprising: ignition timing control means for controlling ignition timing; and ignition timing control means for controlling ignition timing.