JP3211631B2 - Ignition timing control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition timing control device provided in an engine in which an upper portion of an engine body is formed by a pair of first and second banks, and more particularly, each of intake camshafts of both banks has a timing. The present invention relates to an ignition timing control device mounted on a DOHC type engine driven by receiving an engine speed via a belt.

[0002]

2. Description of the Related Art A V-type engine in which an upper portion of an engine body is formed of a pair of a first bank and a second bank, wherein both banks have an intake camshaft and an exhaust camshaft, respectively.
OHC-type engines are known. DOHC of this kind
In a V-type engine of the type, the valve train transmits the rotation of a crankshaft sprocket integral with the crankshaft to each camshaft sprocket integral with the intake camshaft and exhaust camshaft of each bank via a timing belt. The timing belt of the valve train is provided with an idler pulley and a tensioner for controlling the loosening of the timing belt so that the engine speed can be transmitted without displacement between the intake and exhaust camshaft sprocket and the crankshaft sprocket of each bank.

In such a valve train, each intake camshaft and exhaust camshaft of the V-type engine drives intake and exhaust valves of cylinders facing each other by an intake cam and an exhaust cam integrated therewith. Of air intake and exhaust. At the same time, in the ignition system of the engine, the ignition processing of each cylinder is performed in an appropriate ignition order, and the output torque is sequentially generated in each cylinder to generate a relatively smooth engine rotation. The ignition system of this engine sequentially calculates a predetermined crank angle before compression top dead center of each cylinder as an ignition timing according to the engine operating state, drives an ignition circuit at the same ignition timing, and ignites each cylinder. . In this basic control of the ignition timing, the reference ignition timing is set according to the operating conditions, for example, the engine speed, the intake air amount, etc., during the steady operation of the engine,
This is corrected appropriately within a range where knocking does not occur, a target ignition timing is obtained, and an ignition process is performed at the same ignition timing.

It is known that by controlling the ignition timing, the output generated by each cylinder increases by advancing the reference ignition timing (advance) and decreases by retarding the ignition timing (retard). . By the way, in the DOHC type V-type engine, the intake and exhaust cam shafts of both banks are simultaneously driven by the timing belt at the time of driving. At this time, depending on the valve closing biasing force of each valve spring and the cam shape at the overlap position (see OL1 and OL2 in FIG. 4), a force is generated on the intake / exhaust camshaft in a direction to advance the rotation or in a direction to delay the rotation, This causes a displacement in the expansion and contraction direction with respect to the timing belt.

That is, when the cylinders are driven, when the overlap region is reached, the exhaust cams of the first and second banks are changing in the valve closing direction and the intake cams are changing in the valve opening direction. For this reason, as shown by the broken line in FIG. 4, the valve closing operation of the exhaust cam EX is urged forward by the spring force, and the valve opening operation of the intake cam EX is urged backward by the spring force. A force is generated on the shaft in a direction that slows the rotation or advances the rotation. This rotational displacement is partly tolerated by the elastic displacement of the timing belt, and as shown by the two-dot chain line A in FIG. 2, the first bank 11 located closer to the crankshaft sprocket 14 in the timing belt rotation direction r. The timing belt 19 between the intake and exhaust camshafts bends to, and the timing belt 19 of the distant second bank 12 shows a tendency to pull.

Similarly, an exhaust system is provided at the center of both banks, and an engine of a type using a single timing belt (see FIG. 14A), and an intake system or exhaust system is provided at the center of both banks. An engine of a type that uses a different belt for each bank in which the banks are shifted by a predetermined amount back and forth (FIG. 1)
4 (b) and 4 (c)), the first bank 11 in which the timing belt is wrapped around the exhaust camshaft sprocket integral with the exhaust camshaft, the intake camshaft sprocket integral with the intake camshaft, and the crankshaft sprocket in this order. At the second bank 12 where the timing belt is stretched in the order of the intake camshaft sprocket, the exhaust camshaft sprocket, and the crankshaft sprocket.

[0007]

As described above, when the valve trains of both banks are driven by a single timing belt 54, an engine of the type in which an intake system is provided at the center of the bank as shown in FIG. In particular, the bending tendency of the timing belt in the first bank 11 located on the side closer to the timing belt rotation direction r with respect to the crankshaft sprocket greatly appears as the bending to in FIG. (See OL1 in FIG. 4), for example, the cam angle is reduced by about 5 °. In the first bank in which the overlap amount is reduced as described above, the blow-by amount is reduced and the output is improved in a low-speed rotation range such as during idling, and conversely, the volume efficiency is reduced in a high-speed rotation range. Therefore, there is a problem that the output is reduced. Note that the timing belt is hardly pulled or displaced in the second bank 12 on the far side in the timing belt rotation direction r with respect to the crankshaft sprocket, and the influence on the output is not great.

Similarly, in each type of engine shown in FIGS. 14 (a), (b) and (c), the timing belt is bent in each first bank, and the overlap amount is smaller than a normal value (see FIG. 4). OL1), and in a low-speed rotation range such as during idling, the blow-by amount decreases and the output increases,
Conversely, when the rotation speed is in the high-speed rotation range, there is a problem that the volume efficiency is reduced and the output is reduced. As described above, by reducing the overlap amount in each first bank, the intake air amount A /
N changes, and at this time, since the fuel supply amount is constant for each cylinder, the air-fuel ratio changes. In this case, the fuel injection amount is substantially constant between the cylinders. As a result, as shown in FIG. 15, the air-fuel ratio increases and decreases, and the waveform of the indicated mean effective pressure pi changes to the first waveform.
The cylinder on the bank side becomes large, the rotational torque fluctuates, and unpleasant vibrations of the first order of 1.5 are excited on the vehicle body, giving rise to a problem that passengers feel uncomfortable.

Similarly, in an engine in which the exhaust systems of both banks face the center side, the first bank side 11a is rotated by a timing belt in the order of an exhaust camshaft, an intake camshaft, and a crankshaft-side rotating body. The second bank is rotated by the timing belt in the order of the intake camshaft, the exhaust camshaft, and the rotating body on the crankshaft side. SUMMARY OF THE INVENTION It is an object of the present invention to provide an ignition timing control device capable of eliminating a vehicle body vibration caused by a displacement of an overlap amount between both banks of an engine having a first bank and a second bank.

[0010]

According to a first aspect of the present invention, a cylinder is disposed in a first bank and a second bank, and an exhaust camshaft and an intake camshaft are provided on the first bank. The second bank is mounted on a DOHC type engine which is rotated by a timing belt in the order of a crankshaft-side rotating body, and the second bank is rotated by a timing belt in the order of an intake camshaft, an exhaust camshaft, and a crankshaft-side rotating body. In the ignition timing control device, the ignition timing of at least one of the cylinders of the first bank is corrected so that the ignition timing of the cylinder of the first bank is retarded with respect to the ignition timing of the cylinder of the second bank . Timing belt deflection
The output of the first bank and the second bank
An ignition timing correction means for suppressing generation of a difference from the output is provided.

[0011] In the invention of claim 1, said ignition timing correction means, also can be corrected retarding the ignition timing of the cylinders of the second bank, the ignition timing of the cylinders of the first bank
You.

According to the first aspect of the present invention, the ignition timing correction means sets the ignition timing of the cylinder in the second bank to the first timing.
It is also possible to make advance correction from the ignition timing of the cylinder in the bank
I can do it.

According to a second aspect of the present invention, in the ignition timing control device according to the first aspect, the ignition timing of the cylinders of the second bank is controlled by a basic ignition timing set according to an operating state, and the first bank is controlled. And an ignition timing control means for controlling the ignition timing of the cylinder with the ignition timing delayed by the ignition timing correction means with respect to the basic ignition timing.

According to a third aspect of the present invention, in the ignition timing control apparatus according to the first aspect, the ignition timing correction means is provided when the engine is in at least one of an idle state and a low-speed low-load region. Ignition timing correction for correcting the ignition timing of at least one of the cylinders of the first bank by the ignition timing correction means such that the ignition timing of the cylinder of the first bank is retarded with respect to the ignition timing of the cylinder of the second bank; Means are provided.

According to the first to third aspects of the present invention, when the engine shifts from an operation state in which the ignition timing of the cylinder in the first bank is retarded to an operation state in which the ignition timing is not retarded, ignition of the cylinder in the first bank is performed. The timing may be gradually returned to the basic ignition timing .

In the invention according to any one of claims 1 to 3, when the engine shifts from an operation state in which the ignition timing of the cylinder in the first bank is not retarded to an operation state in which the ignition timing is retarded, the ignition of the cylinder in the first bank is performed. The timing can be gradually retarded from the basic ignition timing .

[0017] In the invention of claims 1 to 3, and the retard amount is variable in accordance with the engine operating condition
You can do it.

[0018]

1 is mounted on a DOHC V-type six-cylinder internal combustion engine (hereinafter simply referred to as engine 10). In the engine 10, an upper portion of the engine body is formed by a first bank 11 and a second bank 12. Here, each intake camshaft 1 of the first bank 11 and the second bank 12
51, 152 are arranged at the center side of the engine main body, intake air is supplied to each cylinder of both banks 11, 12 through an intake manifold (not shown), and each exhaust camshaft 11, 12 of the first bank 11 and the second bank 12 is provided. 162 is provided on the side end sides of both banks 11 and 12, and the exhaust gas of each cylinder is discharged through an exhaust manifold on the side end sides of both banks (not shown). The timing belt 19 of the valve train is composed of the intake and exhaust camshaft sprockets 171, 172, 181 and 182 of each bank and the crankshaft sprocket 14 as a rotating body on the crankshaft side.
So that the engine speed can be transmitted
An idler pulley 20 and a tensioner 21 for restricting the loosening of the timing belt 19 are provided.

The intake valves and exhaust valves (not shown) of each cylinder of both banks 11 and 12 are opened and closed by intake cams 22 and exhaust cams 23 of the cylinders facing each other. Here, the intake cam 22 and the exhaust cam 23 are connected to the intake and exhaust cam shafts 151, 15 respectively.
2, 161 and 162, and the intake and exhaust camshaft sprocket 17 is attached to each end of these intake and exhaust camshafts.
1,172,181,182 are integrally attached,
This sprocket is connected to the crankshaft sprocket 14 via a timing belt 19, so that the intake and exhaust camshaft is rotated at half the engine speed. In the engine 10 having such a valve train, the first cylinder # 1, the third cylinder # 3, and the fifth cylinder # 5 are provided in the first bank 11, and the second cylinder # 5 is provided in the second bank 12.
Equipped with the second, fourth and sixth cylinders # 4 and # 6, the ignition processing of each cylinder is performed in the ignition order shown by the inverted triangle in FIG. 8, and the output torque is sequentially generated in each cylinder.

The engine 10 shown in FIG. 1 is provided with an ignition plug 22 for each cylinder, and a plug 24 for each of the cylinders # 1 to # 6 has an ignition coil 25 as an ignition drive means, a power transistor 26, a drive circuit 27, and an engine control. Connected to unit 28.

The drive circuit 27 is provided with an ignition drive section 271 (272 to 276 not shown because of the same configuration) shown in FIG. 5 for each cylinder. The ignition drive unit 271 here is driven by a reference signal (（o detected based on the TDC sensor signal s1) and a crank angle signal (Δθ detected based on the crank angle sensor signal s2). Here, at the time of steady operation in which the target ignition timing Δt is determined, the one-shot circuit is triggered by the reference signal Δo before the top dead center (for example, 75 °), and the crank angle signal Δθ is determined by a predetermined number (ignition timing Δo). It is configured to output the energization start signal after counting only the delay time t1) corresponding to −Δt (see FIG. 6).

In this case, the target ignition timing Δt is determined by the code θadv in step p11 of the flowchart of FIG.
It was requested as. The one-shot circuit A is configured to be triggered by the energization start signal, to count a predetermined number of crank angle signals corresponding to the dwell angle θd, and to output an ignition signal. The flip-flops FF are set by an energization start signal from the one-shot circuit B and reset by an ignition signal from the one-shot circuit A. Further, when the flip-flop is set, the drive circuit PC outputs the power transistor 26 by the output signal.
Is turned on to allow a current to flow to the ignition coil 25. When the power transistor 26 is turned off, the ignition coil 25 generates a high-voltage current on the secondary side, and this current is transmitted to the spark plug 24 of the first cylinder # 1, and ignition is performed.

Similarly, the ignition driving units 271 to 276 of the second to sixth cylinders # 2 to # 6 are also configured, and the secondary high voltage of the ignition coil 24 of the cylinder facing the target ignition timing Δt is supplied to each cylinder #. Supplied to 2, ♯3 spark plugs 24,
Each cylinder is ignited. FIG. 8 shows all cylinders # 1 to # 1.
An example of the reference ignition timing of # 6 is shown. Here, the ignition timing of each cylinder is alternately performed for each cylinder at an interval of approximately 120 ° crank angle. The main part of the engine control unit (ECU) 28 is formed by a microcomputer, and controls fuel supply to the engine 10.
A well-known control process such as throttle valve drive control is performed, and ignition timing control is performed. In the fuel supply control, it is well known that the basic fuel pulse width Tf based on the intake air amount is calculated, and this is multiplied by an air-fuel ratio or other correction coefficient to determine the injector drive time, and the injector of each cylinder is driven. Is performed.

The engine control unit 2 here
In FIG. 8, the rotation speed Ne of the engine 10 from the engine rotation sensor 30, the intake air amount A information from the air flow sensor 31, the vehicle speed Sv from the vehicle speed sensor 32, the crank angle sensor signal s1 from the crank angle sensor 33 (based on the same signal). The crank angle signal Δθ is detected).
From the TDC sensor signal s2 (the reference signal ψ
o is detected), the throttle opening θs is received from the throttle opening sensor 35, the water temperature Wt signal is received from the water temperature sensor 36, and the knock signal Kn is received from the knock sensor 37, respectively. Engine 1 provided with such a valve train
The operation of the ignition timing control device of the present invention together with the drive of 0 will be described.

Here, the engine 10 includes the first cylinder # 1, the third cylinder # 3, and the fifth cylinder # 5 in the first bank 11, the second cylinder # 2, the fourth cylinder # 4, and the like in the second bank 12. 6th cylinder # 6
The ignition process and the combustion process of each cylinder are performed in the ignition order shown by the inverted triangle mark に in FIG. 8, and the output torque is sequentially generated in each cylinder. FIGS. 11, 12, and 13 show an ECU 2 used in an ignition timing control device according to an embodiment of the present invention.
8 shows a flowchart of the control program No. 8. This EC
U28 enters the control of the main processing by key-on of a main switch (not shown).

Here, first, an initial function set such as a check of each function, an initial value set, and the like is performed. Then, various operation information of the engine is read, and then the process proceeds to step s2. Then, an operating range is calculated from the engine speed N and the intake air amount A / N, and a fuel cut zone is determined from an operating range map (not shown).
The program proceeds to 4, where the air-fuel ratio feedback FBFLG is cleared, the fuel cut FCFLG is set to 1, and the routine returns. On the other hand, if it is determined in step s2 that the fuel cut is not in the fuel cut range and the process reaches step s3, the fuel cut FCFLG is cleared, and it is determined whether the air-fuel ratio feedback condition is satisfied. At the time before the warm-up is completed, the current operation information (A
/ N, Ne), and a warm-up increase correction coefficient Ka corresponding to the cooling water temperature Tw is calculated from an appropriate warm-up increase correction coefficient calculation map, and these values are stored in the address K _AF . Store in the area and proceed to step s10.

If the air-fuel ratio feedback condition is satisfied from step s6, a target air-fuel ratio is calculated according to the current operation information (Pb, Ne), and a fuel amount correction coefficient _KFB that can achieve the air-fuel ratio is calculated. In step s9, the address KAF
Then, the fuel amount correction coefficient K _FB is stored in the storage area, and the process reaches step s10. Here, the other fuel injection pulse width correction coefficient KDT and the correction value TD of the dead time of the fuel injection valve are set in accordance with the operating conditions, and further, each correction coefficient used for calculating the target ignition timing θadv is calculated.

Here, the correction value of the target ignition timing θadv is calculated as a water temperature correction value θwt which is advanced in accordance with a decrease in the water temperature, and an acceleration retard-θacc corresponding to the differential value Δθs obtained by differentiating the throttle valve opening θs. There is an intake air temperature correction value θat that is advanced according to a decrease in intake air temperature, a knock retard -θk value according to an increase in the knock signal Kn, and a battery correction value tb that increases the energization time according to a decrease in the battery voltage VB. Is calculated.

Further, when the process reaches step s11, control in other main routines such as a fuel supply control process is performed, and the process returns. During the execution of such a main routine, the ignition timing calculation routine of FIG. 12 and the ignition control of FIG. 13 are executed. That is, in the ignition timing calculation routine of FIG. 12, each cylinder is 75 ° before top dead center (75 ° BTDC).
基準 o (when the crank angle is θco, it is ON)
Is executed based on the input. Step p here
1, the airflow sensor 31 and the engine rotation sensor 3
The intake air amount A / N and the engine speed Ne are calculated based on each detection signal of 0, and the current intake air amount A / N and the engine speed Ne are calculated using a basic ignition timing calculation map set in advance. Is calculated.

Thereafter, the process proceeds to step p3, where the engine speed Ne is an idle determination value Nea which is a set value.
It is determined whether it is lower or not. If it is higher, the process reaches step p4 and sets the ignition timing correction amount Δθinj at the time of non-idling to a set value (for example, zero in this case), and proceeds to step p10. On the other hand, when the engine reaches idling in step p3 and reaches step p5, first, the current engine speed Nen is taken into the smoothed engine speed Ne1 (n-1) up to the previous time at a predetermined take-in ratio α, and the current time is taken up. Is calculated along the equation (1).

Ne1n = Ne1 (n-1) × α + (1−α) × Nen (1) Thereafter, the process proceeds to step p6, where the number of the current cylinder is a reference signal. It is calculated from ψo (the crank angle is ON at θco) and the crank angle signal Δθ. Next, at step p7, the current cylinder is set in either the first or second bank V1, V2.
The first bank V1 determines in step p8 that the second bank
In the bank V2, the process proceeds to Step p9.

In step p8, assuming that the current bank of the cylinder is the first bank, the absolute value of the ignition timing correction amount -.DELTA..theta.inj increases as the current rotational speed Ne decreases, along the ignition timing correction amount map m1 in FIG. Set, step p9
Then, assuming that the current bank of the cylinder is the second bank, the ignition timing correction amount Δθinj is set to zero, and the process proceeds to step p10.

In step p8, the ignition timing correction amount-
Although Δθinj is increased or decreased according to the current rotational speed Ne, it may be adjusted according to the engine load information, for example, the throttle opening θs, or may be adjusted according to both the engine rotational speed and the load. May be. In step p10, the ignition timing correction amount Δθinj set in steps p4, p8, and p9 is set to the current ignition timing correction amount Δθinjn, and the current ignition timing is set to The correction amount Δθinj is taken in at a predetermined take-in ratio β, and the current smoothed ignition timing correction amount Δθinjn is newly calculated according to the equation (2).

Δθinjn = Δθinj (n-1) × β +
(1−β) × Δθinjn (2) Thereafter, the process proceeds to step p11, where the basic ignition timing θb, the water temperature correction value θwt, the acceleration retardation −θacc, and the intake air temperature advanced according to the intake air temperature decrease. The correction value θat and the ignition timing correction amount Δθinj are fetched, and the target ignition timing θad
The calculation of v is performed by the following equation (3).

.Theta.adv = .theta.b + .theta.wt + .theta.at-.DELTA..theta.inj-.theta.acc (3) Thereafter, in step p12, the target ignition timing .theta.adv by the knock retard -.theta.k value according to the increase of the knock signal Kn.
Is retarded, and in step p13, the storage area of the previous smoothed rotation speed Ne1 (n-1) is stored in the current smoothed rotation speed Ne1n.
And the previously smoothed ignition timing correction amount Δθinj (n−
The storage area of 1) is stored in the current smoothed ignition timing correction amount Δθinj.
Rewrite with n and return to the main routine. Note that the knock retard map is set in advance. The ignition control routine of FIG.
Each time the temperature reaches ° (75 ° BTDC), the main routine is interrupted and executed based on the input of the reference signal ψo (ON at the crank angle θco). In step q1, predetermined data is fetched, and in step q2, the latest target ignition timing θadv is set to the ignition drive units 271-2.
In 76, set it to the ignition drive unit that fires this time,
Return to the main routine.

Here, ignition of each of the cylinders # 1 to # 6 is performed by driving the igniter 25, and the crank angle 120
Each time the first, third, and fifth cylinders of the first bank and one of the second, fourth, and sixth cylinders of the second bank are selectively and alternately ignited, in particular, The target ignition timings θadv of the first, third, and fifth cylinders are retarded by the ignition timing correction amount −Δθinj during idling, and the outputs of the first, third, and fifth cylinders of the first bank are suppressed to be low. it can. For this reason, the timing belt 19 is originally bent between the intake and exhaust camshaft sprockets 171 and 181 of the first bank 11, and as shown in FIG.
When the overlap area between the intake and exhaust cams 22 and 23 integral with the 161 is narrower than the normal OL2 to OL1 and the output during idling is increased due to the reduction in blow-through, the target ignition in steps p6, 8, 9 and 10 is performed. Timing θad
By retarding v, it is possible to suppress an increase in output of each cylinder of the first bank 11 during idling.

That is, as shown in FIG. 9, in the non-corrected state, as shown in FIG. 9B, the indicated mean effective pressure pi is large in each cylinder of the first bank, When the unpleasant vibrations are excited and corrected by the present invention, as shown in FIG. 9A, the deviation of the indicated mean effective pressure pi is reduced in both banks, and the output variation is eliminated. Exciting unpleasant vibration to the vehicle body can be prevented. In the above description, the engine 10 has an intake system in the center of both banks, and the first bank 11 is arranged on the near side in the rotation direction of the timing belt 19 with respect to the crankshaft sprocket 14, and the second bank 12 is arranged on the far side. Thus, the valve trains of both banks are driven by a single timing belt 54, but instead of this, each engine as shown in FIGS. 14 (a), (b) and (c) is also used. The invention can be applied, and the same operation and effect can be obtained.

That is, the engine 10a shown in FIG.
In this case, the exhaust system is arranged at the center of both banks, and the second bank 12a is arranged on the side closer to the crankshaft sprocket 57 in the rotational direction of the timing belt, and the first bank 11a is arranged farther from the crankshaft sprocket 57. The valve system is driven by a single timing belt 54. Here, the timing belt 54 includes, on the second bank 12a side, an intake camshaft sprocket 55 integral with the intake camshaft, an exhaust camshaft sprocket 56 integral with the exhaust camshaft, and an idler 5
3 and in the first bank 11a side,
Exhaust camshaft sprocket 5 integral with exhaust camshaft
1. An intake camshaft sprocket 52 integral with the intake camshaft and a crankshaft sprocket 57 are wound around in this order.

Also in this case, when the timing belt 54 rotates in the rotation direction r, the timing belt 54 bends between the exhaust camshaft sprocket 51 and the intake camshaft sprocket 52 of the first bank 11a, causing the timing belt 54 to flex. The timing belt 54 shows a tendency to be pulled between the intake camshaft sprocket 55 and the exhaust camshaft sprocket 56. However, by the ignition timing control of the present invention, the timing belt 54 is bent between the intake and exhaust camshaft sprockets 51 and 52 of the first bank 11a, and as shown in FIG. The output of the cylinders of the first bank 11a at the time of idling is increased by performing the retard correction of the target ignition timing θadv in the same manner as described above. Can be suppressed.

On the other hand, the engine 10b shown in FIG.
In the case of, the intake system is located in the center of both banks,
The belts 1b and 12b and the two belts 541 and 542 are provided with a predetermined amount of shift in front and rear. Here, the timing belt 541 on the first bank 11b side is wound around the exhaust camshaft sprocket 51, the intake camshaft sprocket 52, and the crankshaft sprocket 57b in this order. The timing belt 542 on the second bank 12b side is wound around the intake camshaft sprocket 55, the exhaust camshaft sprocket 56, and the crankshaft sprocket 57b in this order.

In this case, the timing belt 541 is bent between the exhaust camshaft sprocket 51 and the intake camshaft sprocket 52 of the first bank 11b, and
The timing belt 542 of the second bank 12b shows a tendency to be pulled. However, by the ignition timing control of the present invention,
Intake and exhaust camshaft sprocket 5 of first bank 11b
As shown in FIG. 4, the timing belt 541 bends between the positions 1 and 52, and the overlap area between the intake and exhaust cams 22 and 23 narrows from the normal OL2 to the OL1. The
The retarded correction of the target ignition timing θadv in the same manner as described above can suppress an increase in the output of each cylinder of the first bank 11b during idling.

Similarly, the engine 50 shown in FIG.
In the case of c, the exhaust system is provided at the center of both banks, and both banks 11c and 12c and both belts 541 and 542 are provided with a predetermined amount of shift in front and rear. Here, the timing belt 542 on the second bank 12c side is wound around the intake camshaft sprocket 55, the exhaust camshaft sprocket 56, and the crankshaft sprocket 57c in this order.
The timing belt 541 on the first bank 11c side is wound around the exhaust camshaft sprocket 51, the intake camshaft sprocket 52, and the crankshaft sprocket 57c in this order.

In this case, the timing belt 541 bends between the exhaust camshaft sprocket 51 and the intake camshaft sprocket 52 of the first bank 11c,
Intake camshaft sprocket 55 of second bank 12a
The timing belt 542 shows a tendency to be pulled between the exhaust camshaft sprocket 56 and the exhaust camshaft sprocket 56. However, the timing belt 5 between the intake and exhaust camshaft sprockets 51 and 52 of the first bank 11c is controlled by the ignition timing control of the present invention.
41 bends, and as shown in FIG.
The overlap region of the target ignition timing .theta.a is reduced from the normal OL2 to the OL1 and the output during idling is increased due to the reduction in the blow-through.
By the retard correction of dv, it is possible to suppress an increase in output of each cylinder of the first bank 11c at the time of idling.

[0044]

As described above, according to the first aspect of the present invention, the DO
The first bank side of the HC type engine is an exhaust camshaft,
The intake camshaft is rotated by a timing belt in the order of a rotating body on the crankshaft side, and the second bank side is an intake camshaft,
The exhaust camshaft and the crankshaft-side rotor are rotated by a timing belt in this order, and at least one of the banks of the first bank is retarded with respect to the ignition timing of the cylinder of the second bank. this for correcting the ignition timing of the cylinder
Caused by the operation of the timing belt
The difference between the output of the first bank and the output of the second bank
It is provided with ignition timing correction means for suppressing generation .
For this reason, the output of the first bank is reduced by the ignition timing retarding process, and the variation in the output of both banks can be adjusted.
The order of driving by the timing belt is different.
Unpleasant vibration of the vehicle body due to the output difference between the first bank and the second bank can be prevented.

[0045] In the invention of claim 1, when the ignition timing correction means has an ignition timing of the cylinders of the first bank-like to correct retarding the ignition timing of the cylinders of the second bank, the first bank output And the variation of the output of both banks can be adjusted, and the effect of preventing unpleasant vibration of the vehicle body excited due to the variation can be obtained.
Can be

[0046] In the invention of claim 1, the ignition timing correction means, when the ignition timing of the cylinders of the second bank-like to correct advancing the ignition timing of the cylinders of the first bank, the second
Since the output of the banks is increased, the variation in the output of both banks can be adjusted, and the unpleasant vibration of the vehicle body excited due to the variation in the output of both banks can be prevented.
The following effects can be obtained.

According to a second aspect of the present invention, there is provided the ignition timing control device according to the first aspect, wherein the ignition timing of the cylinder of the second bank is controlled by a basic ignition timing set in accordance with an operation state and the first bank is controlled. The ignition timing of the cylinder is controlled by the ignition timing delayed by the ignition timing correction means with respect to the basic ignition timing. Therefore, the output of the first bank is basically increased.
Since the output is reduced by retarding the ignition timing and adjusted to be equal to the reference output of the second bank , the output
The adjustment control is relatively simplified, and the variation in the output of both banks can be adjusted, so that unpleasant vibration of the vehicle body excited due to the increase in the output of the first bank can be prevented.

According to a third aspect of the present invention, in the ignition timing control device according to the first aspect, when the engine is in an operation state of at least one of an idle state and a low-speed low-load area, The ignition timing of the cylinder of at least one bank is corrected such that the ignition timing of the cylinder is retarded with respect to the ignition timing of the cylinder of the second bank . others
As a result, the output of the first bank tends to increase,
Is the ignition timing retarding process for the first bank in the low speed and low load range.
By doing so , the outputs of both banks can be equalized, and unpleasant vibrations of the vehicle body excited due to variations in the outputs of both banks in an idle state or a low-speed low-load region can be reliably prevented.

In the first to third aspects of the present invention, when the operating state of the engine shifts from an operating state in which the ignition timing of the cylinder in the first bank is retarded to an operating state in which the ignition timing is not retarded, the ignition of the cylinder in the first bank is performed. The timing is gradually returned to the basic ignition timing, so that the output of the first bank is gradually recovered .
In such a case, the adjustment of the output variation between the two banks is gradually released, and the output adjustment release is performed without discomfort .
The effect can be obtained.

In the first to third aspects of the present invention, when the operating state of the engine shifts from an operating state in which the ignition timing of the cylinder in the first bank is not retarded to an operating state in which the ignition timing is delayed, the ignition of the cylinder in the first bank is performed. when the time was to like be able to gradually retarded from the basic ignition timing, it will be entered gradually to adjust the variations in the output of both banks, such effect of the execution of the output adjustment is performed without discomfort Can get
Wear.

[0051] In the invention of claims 1 to 3, since the retard amount is variable according to the engine operating state, place you like to be set optimum retardation amount in the engine operating condition
In this case, it is possible to adjust the variation in the output of both banks more suitable for the driving condition, and to prevent uncomfortable vibration of the vehicle body excited due to the variation in the output of both banks with good responsiveness .
Effects can be obtained.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an ignition timing control device as one embodiment of the present invention.

FIG. 2 is a front view of a valve train of an engine equipped with the ignition timing control device of FIG. 1;

FIG. 3 is a schematic plan view of an engine equipped with the ignition timing control device of FIG. 1;

FIG. 4 is a characteristic diagram illustrating a change in overlap of a valve train of an engine equipped with the ignition timing control device of FIG. 1;

FIG. 5 is a block diagram of an ignition circuit used by the ignition timing control device of FIG. 1;

FIG. 6 is a waveform diagram illustrating the ignition timing of the ignition timing control device of FIG. 1;

FIG. 7 is a characteristic diagram illustrating ignition timing control for output adjustment performed by the ignition timing control device of FIG. 1;

FIG. 8 is an explanatory diagram of an ignition sequence of the ignition timing control device of FIG. 1;

FIG. 9 is a characteristic diagram of a vibration waveform in an engine equipped with the ignition timing control device of FIG. 1;

FIG. 10 is a characteristic diagram of an ignition timing correction amount calculation map used by the ignition timing control device of FIG. 1;

FIG. 11 is a flowchart of a main routine performed by the ignition timing control device of FIG. 1;

FIG. 12 is a flowchart of an ignition timing calculation routine performed by the ignition timing control device of FIG. 1;

FIG. 13 is a flowchart of an ignition control routine performed by the ignition timing control device of FIG. 1;

14A and 14B are diagrams illustrating a difference in the layout of a belt of a valve train of each bank in an engine with first and second banks as another embodiment to which the present invention is applied, and FIG.
Is the case of using a single belt, (b) is the first bank on the left side,
In the case where the second bank is on the right side and two belts are used, (c) shows the case where the first bank is on the right side and the second bank is on the left side and two belts are used.

FIG. 15 is a characteristic diagram showing a variation characteristic of an injection amount, an intake air amount, and an air-fuel ratio at the time of idling for each cylinder of a conventional engine.

[Explanation of symbols]

 10, 10a, 10b, 10c engine 11 first bank 12 second bank 14 crankshaft sprocket 151 intake camshaft 152 exhaust camshaft 161 intake camshaft 162 intake camshaft 19 timing belt 171 intake camshaft sprocket 172 exhaust camshaft sprocket 181 Intake camshaft sprocket 182 exhaust camshaft sprocket 24 spark plug 25 igniter 271 ignition drive 276 ignition drive 28 ECU 30 engine rotation sensor 33 crank angle sensor 34 TDC sensor 35 throttle opening sensor 36 water temperature sensor 37 knock sensor θadv target ignition timing θb Basic ignition timing Δθinj Ignition timing correction amount

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F02P 5/15 F02D 43/00

Claims (3)

(57) [Claims] A cylinder is arranged in a first bank and a second bank, and the first bank side has an exhaust camshaft, an intake camshaft,
The crankshaft-side rotating body is rotated by the timing belt in this order, and the second bank side is an intake camshaft, an exhaust camshaft,
In an ignition timing control device mounted on a DOHC type engine rotated by a timing belt in the order of a crankshaft rotating body, an ignition timing of a cylinder of the first bank is set with respect to an ignition timing of a cylinder of the second bank. By correcting the ignition timing of the cylinder in at least one of the banks so as to be on the retard side ,
The first bang caused by the deflection of the timing belt.
An ignition timing control device comprising: ignition timing correction means for suppressing generation of a difference between the output of the engine and the output of the second bank . 2. The ignition timing control device according to claim 1, wherein the ignition timing of the cylinders of the second bank is controlled by a basic ignition timing set according to an operating state, and the ignition timing of the cylinders of the first bank is controlled. 2. An ignition timing control device according to claim 1, further comprising an ignition timing control means for controlling the ignition timing with respect to the basic ignition timing by an ignition timing delayed by the ignition timing correction means. 3. The ignition timing control device according to claim 1, wherein said ignition timing correction means is provided when said engine is in an operation state of at least one of an idle state and a low-speed low-load region. By the first
An ignition timing correction means for correcting the ignition timing of the cylinder of at least one of the banks so that the ignition timing of the cylinder of the bank is retarded with respect to the ignition timing of the cylinder of the second bank. The ignition timing control device according to claim 1.