JP4978075B2 - Engine ignition timing control method and engine ignition timing control device - Google Patents

Description

  The present invention relates to an ignition timing control method for an engine (internal combustion engine) and an ignition timing control device for the engine.

In an engine having a variable valve timing mechanism in which the intake valve opening / closing timing (opening timing and closing timing) is advanced or retarded according to a command value while the intake valve operating angle remains constant, the intake valve closing timing IVC is the intake bottom dead center. (The bottom dead center of the piston at the end of the intake stroke) is the trace ignition timing basic value, and when the intake valve closing timing IVC deviates from the intake bottom dead center, There is one that calculates a trace ignition timing estimated value by adding a trace ignition timing correction amount corresponding to a deviation amount from the intake bottom dead center of the intake valve closing timing IVC to the trace ignition timing basic value (see Patent Document 1). .
JP-A-2005-23806

  By the way, in addition to the variable valve timing mechanism described above, there is an engine including a variable valve mechanism that variably controls the valve lift maximum amount of the intake valve and the operation angle of the intake valve according to a command value. In such an engine, the command value given to the variable valve timing mechanism does not change, but the command value given to the variable valve mechanism causes the opening / closing timing (open timing or closing timing) of the intake valve to advance or retard, The optimum trace ignition timing basic value for the intake valve opening / closing timing after the advance / retarding is different from the optimum trace ignition timing basic value for the intake valve opening / closing timing before the advance / retarding.

  However, since there is no description about the variable valve mechanism in the technique of Patent Document 1, the technique of Patent Document 1 is applied to the variable valve mechanism when the technique of Patent Document 1 is applied as it is to an engine having a variable valve timing mechanism and a variable valve mechanism. When the opening / closing timing of the intake valve is advanced or retarded by the command value, no response can be made, and an error occurs in the calculation of the basic value of the trace ignition timing.

  Therefore, the present invention provides an engine having a variable valve timing mechanism and a variable valve mechanism, and the command value given to the variable valve timing mechanism does not change, but the intake valve open / close timing (open timing or It is an object of the present invention to provide an engine ignition timing control method and an engine ignition timing control device that can accurately calculate a trace ignition timing basic value even when the closing timing is advanced or retarded.

The present invention provides a variable valve timing mechanism for advancing and retarding the opening / closing timing of an intake valve according to a command value while the operating angle of the intake valve is constant, and a command value for a valve lift maximum amount and an intake valve operating angle. In an engine including a variable valve mechanism that variably controls according to the above , the trace ignition timing basic value is approximated by a first primary expression of any one of a command value given to the variable valve timing mechanism and an intake valve central angle, The trace ignition timing basic value is calculated based on one of the command value given to the variable valve timing mechanism and the intake valve central angle, and spark ignition is performed using the calculated trace ignition timing basic value . (1) Any one of a command value, an intake valve operating angle, and an intake valve lift maximum amount that gives the slope and intercept of the linear expression to the variable valve mechanism. Approximated by a linear equation, the command value to be given to the variable valve timing, the intake valve operating angle, configured to calculate the slope and intercept of the first linear expression based on any one of the intake valve lift maximum amount .
The present invention also provides a variable valve timing mechanism for advancing / delaying the opening / closing timing of the intake valve according to a command value while maintaining the operating angle of the intake valve, the maximum valve lift of the intake valve, and the operating angle of the intake valve. In an engine including a variable valve mechanism that variably controls according to a command value, a third one of a command value, an intake valve operating angle, and a maximum intake valve lift that gives a trace ignition timing basic value to the variable valve mechanism. The trace ignition timing basic value is calculated based on one of the command value given to the variable valve mechanism, the intake valve operating angle, and the maximum intake valve lift. The spark ignition is performed with the calculated trace ignition timing basic value, while the slope and the intercept of the third primary expression are used as the variable valve timing mechanism. Approximating with any one of the fourth linear expression of the command value to be given and the intake valve central angle, and the inclination of the third primary expression based on one of the command value to be given to the variable valve timing mechanism and the central angle of the intake valve And intercept are calculated.

According to the present invention, in an engine having a variable valve timing mechanism and a variable valve mechanism, a first primary expression of any one of a command value and an intake valve central angle that gives a trace ignition timing basic value to the variable valve timing mechanism. The trace ignition timing basic value is calculated based on one of the command value given to the variable valve timing mechanism and the intake valve central angle, and spark ignition is performed using the calculated trace ignition timing basic value. On the other hand, the variable valve mechanism is approximated by any one of the second primary expression of a command value, an intake valve operating angle, and an intake valve lift maximum amount that gives the inclination and intercept of the first primary expression to the variable valve mechanism. command value given to the intake valve operating angle, so that calculates the slope and intercept of the first linear expression based on any one of the intake valve lift maximum amount Further, the present invention includes a variable valve timing mechanism to advance retarded in accordance with the command value closing timing of the operating angle remains constant intake valve of an intake valve, an operating angle of the valve lift up amount and the intake valve of the intake valve In an engine including a variable valve mechanism that variably controls according to a command value, a third one of a command value, an intake valve operating angle, and a maximum intake valve lift that gives a trace ignition timing basic value to the variable valve mechanism. The trace ignition timing basic value is calculated based on one of the command value given to the variable valve mechanism, the intake valve operating angle, and the maximum intake valve lift. While the spark ignition is performed with the calculated trace ignition timing basic value, the slope and intercept of the third primary expression are used as the variable valve timing machine. Is approximated by any one of the fourth linear expression of the command value given to the intake valve central angle, and the third primary expression is calculated based on any one of the command value given to the variable valve timing mechanism and the intake valve central angle. Since the inclination and intercept are calculated, the command value given to the variable valve timing mechanism does not change, but the opening / closing timing (opening timing or closing timing) of the intake valve is advanced or retarded by the command value given to the variable valve mechanism. Even if it does, the trace ignition timing basic value can be calculated with high accuracy, and the calculation (estimation) accuracy of the trace ignition timing basic value is improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a schematic configuration of an ignition timing control apparatus for an engine that is directly used for carrying out an ignition timing control method for an engine.

  The air is stored in the intake collector 2 and then introduced into the combustion chamber 5 of each cylinder via the intake manifold 3. Fuel is injected and supplied from a fuel injector 21 disposed in the intake port 4 of each cylinder. The fuel injected into the air is vaporized and mixed with the air to form a gas (air mixture) and flows into the combustion chamber 5. This air-fuel mixture is confined in the combustion chamber 5 when the intake valve 15 is closed, and is compressed by the rise of the piston 6.

  In order to ignite this compressed air-fuel mixture with a high-pressure spark, an ignition device 11 of an electronic power distribution system is provided in which an ignition coil with a built-in power transistor is arranged in each cylinder. That is, the ignition device 11 includes an ignition coil 13 that stores electric energy from the battery, a power transistor (not shown) that supplies and shuts off the primary side of the ignition coil 13, and an ignition coil that is provided on the ceiling of the combustion chamber 5. 13 includes a spark plug 14 that receives a high voltage generated on the secondary side of the ignition coil 13 by cutting off the primary current 13 and performs spark discharge.

  When a spark is blown by the spark plug 14 slightly before the compression top dead center and the compressed air-fuel mixture is ignited, the flame spreads and then explosively burns, and the gas pressure by this combustion works to push down the piston 6. This work is taken out as the rotational force of the crankshaft 7. The combusted gas (exhaust gas) is discharged into the exhaust passage 8 when the exhaust valve 16 is opened.

The exhaust passage 8 includes three-way catalysts 9 and 10. When the air-fuel ratio of the exhaust is within a narrow range (window) centered on the stoichiometric air-fuel ratio, the three-way catalysts 9, 10 can efficiently remove harmful three components such as HC, CO, and NOx contained in the exhaust simultaneously. Since the air-fuel ratio is the ratio of the intake air amount and the fuel amount, the intake air amount introduced into the combustion chamber 5 per one cycle of the engine (crank angle 720 ° section in a four-cycle engine) and the fuel injector 21 The engine controller 31 uses the intake air flow rate signal from the air flow sensor 32 and the signal from the crank angle sensor (33, 34) to cause the fuel from the fuel injector 21 so that the ratio to the fuel injection amount becomes the stoichiometric air-fuel ratio. The injection amount is determined, and the air-fuel ratio is feedback controlled based on a signal from an O ₂ sensor 35 provided upstream of the three-way catalyst 9.

  A so-called electronically controlled throttle 22 in which a throttle valve 23 is driven by a throttle motor 24 is provided upstream of the intake collector 2. Since the torque required by the driver appears in the amount of depression of the accelerator pedal 41 (accelerator opening), the engine controller 31 determines a target torque based on a signal from the accelerator sensor 42, and a target air for realizing this target torque. The amount is determined, and the opening degree of the throttle valve 23 is controlled via the throttle motor 24 so as to obtain this target air amount.

  The intake valve 15 and the exhaust valve 16 are opened / closed by operation of cams provided on the intake side camshaft 25 and the exhaust side camshaft 26, respectively, with the crankshaft 7 as a power source. On the intake side, a variable valve mechanism (VEL mechanism) 28 configured by a multi-node link-like mechanism that continuously and variably controls the valve lift maximum amount and the operating angle of the intake valve 15 is provided. The VEL mechanism 28 is provided with a VEL angle sensor 43 that detects the maximum valve lift and the operating angle of the intake valve 15.

  Similarly, on the intake side, the rotational phase difference between the crankshaft 7 and the intake camshaft 25 is continuously variably controlled to change the opening / closing timing (open timing IVO and close timing IVC) of the intake valve 15. A valve timing mechanism (VTC mechanism) 27 is provided. A cam angle sensor 34 for detecting the rotational position of the intake side camshaft 25 is also provided at the other end of the intake side camshaft 25.

  FIG. 2 shows valve lift characteristics when the VEL mechanism 28 and the VTC mechanism 27 are provided. Assuming that the valve lift characteristic when the VTC mechanism 27 is not operated and when the VEL mechanism 28 is not operated is a solid line, the VEL mechanism 28 is operated by giving a command value (VEL angle) to the VEL mechanism 28 when the VTC mechanism 27 is not operated. Sometimes the operating angle and maximum valve lift of the intake valve 15 are larger than when the VEL mechanism 28 is not operated, so that the valve lift characteristic shifts to the broken line characteristic, and the intake valve opening timing IVO is advanced from when the VEL mechanism 28 is not operated. The intake valve closing timing IVC is retarded from when the VEL mechanism 28 is not in operation. Further, when the VEL mechanism 28 is operated with a command value (VTC angle) applied to the VTC mechanism 27, the intake valve opening timing IVO and the intake valve closing timing IVC are advanced while the operation angle remains constant, so that the valve lift The characteristic shifts to the one-dot chain line characteristic. Further, when the VTC mechanism 27 is operated by giving a command value and the VEL mechanism 28 is also operated by giving a command value, the characteristics of the two-dot chain line are shifted. In this manner, by using the VEL mechanism 28 and the VTC mechanism 27 in combination, it is possible to control the opening / closing of the intake valve at an arbitrary crank angle position. Since the specific configurations of the VEL mechanism 28 and the VTC mechanism 27 (variable valve operating device) are known from Japanese Patent Application Laid-Open No. 2003-3872, detailed description thereof is omitted.

  When the actuators of the VEL mechanism 28 and the VTC mechanism 27 are commanded to change the lift characteristics of the intake valve 15 (valve timing (open / close timing) and maximum valve lift of the intake valve 15), the inert gas remaining in the combustion chamber 5 The amount of changes. As the amount of the inert gas in the combustion chamber 5 increases, the pumping loss decreases and the fuel efficiency improves. Therefore, the target intake valve closing timing and the target valve indicate how much inert gas should remain in the combustion chamber 5 depending on the operating conditions. The maximum lift amount is determined in advance, and the engine controller 31 determines the target intake valve closing timing and the target valve lift maximum amount from the operating conditions (engine load and rotation speed) at that time, so that these target values can be obtained. Further, the closing timing of the intake valve 15 and the maximum valve lift are controlled via the actuators of the VTC mechanism 27 and the VEL mechanism 28.

  Further, in the engine controller 31 in which the signal from the knock sensor 37, the signal of the engine load and the rotational speed are input together with the signal of the VEL angle from the VEL angle sensor 43 and the signal of the VTC angle from the cam angle sensor 34, the ignition coil 13 is used to control the ignition timing which is the primary current cutoff timing of the spark plug 14. Here, the VEL angle is a command value given to the VEL mechanism 28. When the VEL angle is zero, the VEL mechanism 28 is in a non-operating state, and the positive valve value of the intake valve 15 increases as the VEL angle increases. The operating angle and maximum valve lift are increased. The VTC angle is a command value given to the VTC mechanism 27. When the VTC angle is zero, the VTC mechanism 28 is at the most retarded position in the non-operating state, and the VTC angle becomes a positive value and becomes larger. The intake valve opening timing IVO and the intake valve closing timing IVC are advanced.

  The ignition timing is determined from MBT (minimum advance value for obtaining the maximum torque) and the trace ignition timing. Here, the trace ignition timing is an ignition timing that allows a light knock without damaging the engine, and it must be avoided to advance the ignition timing rather than the trace ignition timing.

  Then, the place which examined the trace ignition timing for the engine provided with the VEL mechanism 28 in addition to the VTC mechanism 27 is described next.

  FIG. 3 shows what happens to the basic value of the trace ignition timing when the engine speed NRPM and the charging efficiency ITAC are kept at predetermined values and the VTC angle and the VEL angle are varied, and the horizontal axis shows the VTC angle. The graph shows the trace ignition timing on the vertical axis (experimental results).

  As shown in FIG. 3, when the VTC angle is the minimum VEL angle, the basic value of the trace ignition timing increases toward the advance side, and when the VTC angle is small, the basic value of the trace ignition timing increases as the VEL angle increases. In the region where the VTC angle is large, the basic value of the trace ignition timing is directed toward the reverse retard side as the VEL angle is increased. Therefore, in the present invention, as shown by the solid line, the characteristic of the trace ignition timing basic value with respect to the VTC angle is approximated by a linear expression (straight line). That is, the basic value of the trace ignition timing is calculated by the following equation using the VTC angle as a variable.

Tray ignition timing basic value = primary equation slope × VTC angle + primary equation intercept
... (Supplement 1)
However, the primary intercept: the basic value of the trace ignition timing when the VTC angle is zero,
In this way, when the basic value of the trace ignition timing is approximated by a linear expression, the linear expression can be specified by the slope and intercept, so the primary slope (approximation slope) and the primary intercept (approximation intercept) are plotted on the horizontal axis. Are again summarized as VEL angles. As a result, the characteristics shown in FIG. 4 were obtained for the primary slope and the characteristics shown in FIG. 5 were obtained for the primary intercept. From FIG. 4 and FIG. 5, in the present invention, it is assumed that the linear equation with respect to the VEL angle and the characteristics of the primary equation intercept with respect to the VEL angle are also approximated by the linear equation. That is, the primary equation slope and the primary equation intercept are calculated by the following equation using the VEL angle as a variable.

Linear slope = primary slope slope × VEL angle + primary slope intercept
... (Supplement 2)
Primary intercept = slope of primary intercept x VEL angle + intercept of primary intercept
... (Supplement 3)
Where the intercept of the primary slope: the slope of the primary slope when the VEL angle is zero,
Intercept of primary intercept: primary intercept when VEL angle is zero,
Then, a linear expression that approximates a linear expression gradient and a linear expression that approximates a linear expression intercept can also be specified by the inclination and the intercept. In this case, the slope and intercept (k, l, m, n) of the linear expression shown in FIGS. 4 and 5 should be different for each engine speed NRPM and charging efficiency ηc. The slope and intercept of the linear expression shown (primary slope slope k, primary slope intercept l, primary intercept slope m, primary intercept intercept n), that is, the slope of the primary slope shown in FIG. , Intercept (k, l), and the slope and intercept (m, n) of the linear intercept shown in FIG. 5 are maps of engine speed NRPM and charging efficiency ηc.

  Next, a description will be given of whether or not the approximation method using the linear expression of the basic value of the trace ignition timing is appropriate.

  FIG. 6A uses the above-mentioned linear slope, the slope of the primary intercept and the intercept (k, l, m, n), and trace ignition timing is based on the position where the VTC angle is close to the maximum value and the VEL angle is approximately in the middle. The place where the basic value of the trace ignition timing is set as a conforming point of the value (see the ★ mark) is entered with a broken line, but the first trace ignition timing basic value indicated by the broken line is enclosed in a circle Since the first trace ignition timing basic value (broken line) is advanced from the actual trace ignition timing at the VEL angle and VTC angle, that is, other than the matching point, knocking occurs.

  Therefore, as shown in FIG. 6B, the occurrence of knock can be suppressed by offsetting the first trace ignition timing basic value to the retard side to the position where the actual trace ignition timing is traced (see the one-dot chain line). It becomes. However, according to the trace ignition timing basic value that is set to be offset to the retarded angle side so as not to advance from the actual trace ignition timing except at the conforming point, that is, according to the second trace ignition timing basic value indicated by the one-dot chain line, In this case, when the VTC angle is a conforming point indicated by an asterisk, an ignition timing error occurs between the actual trace ignition timing and the second trace ignition timing basic value (one-dot chain line). For this reason, it is necessary to add a correction function for matching the second trace ignition timing basic value with the actual trace ignition timing at the VTC angle of the matching point. However, if the second trace ignition timing basic value is matched with the actual trace ignition timing by correcting only at the VTC angle of the conforming point, the second trace ignition timing basic value is obtained when the VTC angle is out of the conforming point. There is a possibility that a difference in ignition timing occurs between the actual trace ignition timing and a torque step is induced.

Therefore, as shown in FIG. 6C, a predetermined correction range is provided centering on the VTC angle of the matching point, and when the VTC angle of the matching point is within this correction range, the second trace ignition timing basic value and the actual value are obtained. A trace point timing correction amount that smoothly connects the trace ignition timing so as to coincide with the trace ignition timing is introduced. That is,
Trace ignition timing correction amount = actual trace ignition timing of conforming point-value of second trace ignition timing basic value at VTC angle of conforming point
... (Supplement 4)
Trace ignition timing correction amount given by the equation (1) becomes the maximum, and thereafter, the VTC angle gradually decreases as it moves away from the matching point (or toward the larger side) and finally becomes zero at the boundary of the correction range. Calculate the amount of time correction.

  Then, the value obtained by adding the trace point timing correction amount to the second trace ignition timing basic value is used as the trace ignition timing estimated value, that is, the trace ignition timing estimated value is calculated by the following equation.

Trace ignition timing estimated value = second trace ignition timing basic value + trace ignition timing correction amount
... (Supplement 5)
Since the unit of the second trace ignition timing basic value on the right side of (Supplement 5) is the value [degBTDC] measured on the advance side from the compression top dead center, the positive value of the trace ignition timing correction [deg] is set to a positive value. The addition means that the lead angle is advanced from the second trace ignition timing basic value. The trace ignition timing estimated value calculated in this way is within the correction range, as shown by the broken line shown in FIG. 6C, and is away from the second trace ignition timing basic value (dashed line) and is the actual trace timing of the matching point. A straight line (broken line) toward

  In FIG. 3, the horizontal axis is taken as the VTC angle, and in FIGS. 4 and 5, the VEL angle was taken as the horizontal axis. However, in fact, it is confirmed that the same is true even if the VTC angle and the VEL angle are switched. Yes. That is, even if the VEL angle is taken on the horizontal axis in FIG. 3, the same characteristics as shown in FIG. 3 can be obtained, and even if the VTC angle is taken on the horizontal axis in FIGS. Since the same characteristics as those shown in FIG. 6 can be obtained, a method of calculating the trace ignition timing estimated value can be considered in this case as in the case described with reference to FIGS. 6 (A) to 6 (C).

  In the embodiment, as shown in FIGS. 6A to 6C, the conforming point is set to the position where the VTC angle is close to the maximum value and the VEL angle is approximately the center. It is not limited to.

  In this way, since the way of thinking about the method of calculating the estimated value of the trace ignition timing has been determined, a specific consideration will be given next.

  Since the above VTC angle and VEL angle are command values for the VTC mechanism 27 and the VEL mechanism 28, they are not values that directly represent the lift characteristics of the actual intake valve 15. Therefore, as shown in FIG. If the crank angle section from the crank angle at the position to the intake bottom dead center (BDC) is defined as the “center angle” of the intake valve 15, the operating angle of the intake valve 15 and the maximum valve lift are determined by the VEL angle. Since the center angle of 15 is determined by the VTC angle, the above equations (complement 1) to (complement 3) can be rewritten as follows.

Tray ignition timing basic value = approximate equation slope x center angle + approximate equation intercept
... (Supplement 1 ')
Approximate formula tilt = approximate formula tilt slope x working angle (or lift) + approximate formula tilt intercept
... (Supplement 2 ')
Approximation formula intercept = Approximation formula intercept slope x Working angle (or lift) + Approximation formula intercept intercept
... (Supplement 3 ')
The operating angle on the right side of (Supplement 1 ′) and (Supplement 2 ′) is the crank angle section from the opening timing IVO of the intake valve 15 to the closing timing IVC. In addition, the maximum valve lift of the intake valve 15 is the valve lift amount at the position where the valve lift of the intake valve 15 is maximum. However, in the following, including (complement 1 ′) and (complement 2 ′) Is simply referred to as “lift” of the intake valve 15.

  Further, in the (complement 1 ') to (complement 3') equations, the following equations can be considered in which the operating angle (or lift) and the central angle are interchanged.

Tray ignition timing basic value = approximate equation slope x operating angle (or lift) + approximate equation intercept
... (Supplement 1 ")
Approximate formula slope = Approximate formula slope x center angle + approximate formula intercept
... (Supplement 2 ")
Approximation formula intercept = Approximation formula intercept slope x center angle + approximation formula intercept intercept
... (Supplement 3 ")
In these (complement 1 ′) to (complement 3 ′) and (complement 1 ″) to (complement 3 ″), three slopes and three intercepts appear. 1 ′) to (complement 3 ′) are converted into the following (complement 6) to (complement 8), and (complement 1 ″) to (complement 3 ″) are replaced with the following (complement 6 ′). ) Formula to (Supplement 8 ′).

Tray ignition timing basic value = operating angle sensitivity x operating angle + operating angle intercept
... (Supplement 6)
Operating angle sensitivity = Operating angle sensitivity Center angle sensitivity x Center angle + Operating angle sensitivity Center angle intercept
... (Supplement 7)
Working angle intercept = Working angle intercept center angle sensitivity x Center angle + Working angle intercept center angle intercept
... (Supplement 8)
Tray ignition timing basic value = lift sensitivity x lift + lift intercept
... (Supplement 6 ')
Lift sensitivity = lift sensitivity center angle sensitivity x center angle + lift sensitivity center angle intercept
... (Supplement 7 ')
Lift intercept = lift intercept central angle sensitivity x central angle + lift intercept central angle intercept
... (Supplement 8 ')
As will be described later, the case according to (complement 6) to (complement 8) is the first embodiment, and the case according to (complement 6 ') to (complement 8') is the second embodiment.

  This control executed by the engine controller 31 will be described in detail based on the following flowchart.

  7 to 10 are flowcharts of the first embodiment. Among these, FIG. 7 is for calculating the estimated value of the trace ignition timing, and is executed every time the Ref signal is input.

  In step 01, the engine speed NRPM [rpm] detected by the crank angle sensors (33, 34) and the intake air amount MA [kg / s] detected by the airflow sensor 32 are read. From this intake air amount MA, the charging efficiency is calculated by the following equation.

ITAC = MA / MAMX (Supplement 9)
However, MAMX: intake air amount [kg / s] with maximum charging efficiency, which is a value adapted to the actual machine In step 02, a basic trace ignition timing estimated value BESTTRACE1 [degBTDC] is calculated. The calculation of this value will be described later with reference to FIG.

  In step 03, a knock correction amount KNKRET [deg] is calculated based on the output of the knock sensor 37. For example, a retard amount of 1 deg at the crank angle is calculated as the knock correction amount when knock is determined, and an advance amount that is advanced by 1 deg at the crank angle every time a fixed time elapses when knock determination is not performed. In this case, a negative sign is added to the knock correction amount KNKRET when the knock is determined, and a positive sign is added to the knock correction amount KNKRET when the knock is not determined.

  In step 04, a value obtained by adding the knock correction amount KNKRET to the basic trace ignition timing estimated value BESTTRACE1 is set as the trace ignition timing estimated value ESTTRACE1, that is, the trace ignition timing estimated value ESTTRACE1 [degBTDC] is calculated by the following equation.

ESTTRACE1 = BESTTRACE1 + KNKRET (2)
The trace ignition timing estimated value ESTTRACE1 calculated in this way is compared with the basic ignition timing MBTCAL from which MBT is obtained in a flow (not shown), and the smaller value is selected as the final ignition timing ADV [degBTDC]. Since the unit of the ignition timing is the crank angle position measured on the advance side with reference to the compression top dead center, selecting the smaller one means that the smaller of the trace ignition timing estimated value ESTTRACE1 and the basic ignition timing MBTCAL is on the retard side. Is to select a value. The selected value is transferred to the ignition register as an ignition timing command value, and an ignition signal for cutting off the primary current is output from the engine controller 31 to the power transistor at a timing when the actual crank angle coincides with the ignition timing command value. The

  When knocking occurs when the basic trace ignition timing estimated value BESTTRACE1 is selected, a value that is retarded by the knock correction amount KNKRET from the basic trace ignition timing estimated value BESTTRACE1 at the next ignition is trace ignition timing estimated value. It becomes ESTTRACE1.

  FIG. 8 is for calculating the basic trace ignition timing estimated value, and is a subroutine of step 02 of FIG.

  In step 021, an actual VTC angle (REVTC) detected by the cam angle sensor 34 and an actual VEL angle (REVEL) detected by the VEL angle sensor 43 are read.

  In step 022, the operating angle REEVENT of the intake valve 15 is calculated by referring to the table having the contents shown in FIG. 11 from the actual VEL operating angle REVEL. The table characteristics of the operating angle in FIG. 11 are determined by the specifications of the VEL mechanism 28. The operating angle of the intake valve 15 is a crank angle section from the opening timing IVO to the closing timing IVC of the intake valve 15 as described with reference to FIG.

  In step 022, the center angle RETIMING of the intake valve 15 is calculated from the actual VTC angle REVTC by the following equation.

RETIMING = RETIMING0 + REVTC (3)
Where RETIMING0: initial position of the central angle of the intake valve,
The initial position RETIMING0 of the center angle of the intake valve on the right side of the equation (3) is the center angle of the intake valve when the VTC mechanism 27 is not operated, and is determined from the engine geometry. As described with reference to FIG. 19, the central angle of the intake valve 15 is a crank angle section from the crank angle at the position where the valve lift becomes the maximum amount to the intake bottom dead center (BDC).

In step 023, the basic trace ignition timing estimated basic value BBESTRTRACE1 [degBTDC] is calculated. In step 024, the trace ignition timing error correction amount TRACEERR1 [deg] is calculated. In step 025, the basic trace ignition timing estimated basic value BBESTRTRACE1 is trace-ignited. The value obtained by adding the timing error correction amount TRACEERR1 (the value on the advance side by the trace ignition timing error correction amount TRACEERR1) is used as the basic trace ignition timing estimated value BESTTRACE1 [degBTDC], that is, the basic trace ignition timing estimated value BESTTRACE1 is calculated by the following equation: To do. The expression (4) corresponds to the above (complement 5) expression.

BESTTRACE1 = BESTTRACE1 + TRACEERR1
... (4)
Equation (4) corresponds to an operation for obtaining the characteristics of the broken line within a predetermined correction range centered on the VTC angle of the matching point as shown in FIG. The calculation of the basic trace ignition timing estimation basic value BBESTTRACE1 and the trace ignition timing error correction amount TRACEERR1 on the right side of the equation (4) will be described later.

  FIG. 9 is a subroutine for calculating the basic trace ignition timing estimation basic value BBESTTRACE1, which is a subroutine of step 023 in FIG.

  In step 0231, the engine rotational speed NRPM and the charging efficiency ITAC are referred to, and the operation angle sensitivity center angle sensitivity EVSLTIMSL of the basic trace ignition timing estimation basic value is referred to by referring to the map shown in FIG. 12, and in step 0232, the engine rotational speed NRPM and charging are performed. The operation angle sensitivity central angle intercept EVSLTIMIN of the basic trace ignition timing estimation basic value is calculated from the efficiency ITAC by referring to the map having the contents shown in FIG. 13, and the basic trace ignition timing estimation basic value is calculated by the following equation in step 0233. Calculate angular sensitivity. The expression (5) is the same as the above (complement 7).

EVSL = EVSLTIMSL × RETIMING + EVSLTIMIN
... (5)
However, EVSL: Operating angle sensitivity,
EVSLTIMSL: Operating angle sensitivity Center angle sensitivity,
RETIMING: Center angle of intake valve,
EVSLTIMIN: working angle sensitivity central angle intercept,
In step 0234, the engine rotational speed NRPM and charging efficiency ITAC are referred to, and the operating angle intercept center angle sensitivity EVINTIMSL of the basic trace ignition timing estimation basic value is referred to by referring to the map shown in FIG. The operating angle intercept center angle intercept EVINTIMIN of the basic trace ignition timing estimation basic value is calculated from the efficiency ITAC by referring to the map having the contents shown in FIG. 15, and the basic trace ignition timing estimation basic value is calculated by the following equation in step 0236. Calculate the angular intercept. The expression (6) is the same as the above (complement 8) expression.

EVIN = EVINTIMSL × RETIMING + EVINTIMIN
(6)
Where EVIN: working angle intercept,
EVINTIMSL: Operating angle intercept center angle sensitivity,
RETIMING: Center angle of intake valve,
EVINTIMIN: working angle intercept central angle intercept,
In step 0237, a basic trace ignition timing estimation basic value is calculated by the following equation. The expression (7) is the same as the above (complement 6).

BBESTTRACE1 = EVSL × REEVENT + EVIN
... (7)
However, BBESTRACE1: Basic trace ignition timing estimation basic value,
EVSL: Operating angle sensitivity,
REEVENT: The operating angle of the intake valve,
EVIN: Working angle intercept,
Here, the operating angle sensitivity center angle sensitivity EVSLTIMSL shown in FIG. 12, the operating angle sensitivity center angle intercept EVSLTIMIN shown in FIG. 13, the operating angle intercept center angle sensitivity EVINTIMSL shown in FIG. 14, and the operating angle intercept shown in FIG. Each map characteristic of the central angle intercept EVINTIMIN is pre-adapted so that the basic trace ignition timing estimated basic value BBESTTRACE is equal to or retarded to the actual trace knock ignition timing when the engine speed NRPM, charging efficiency ITAC, VEL angle, and VTC angle change. Keep it.

  FIG. 10 is for calculating the trace ignition timing error correction amount TRACEERR1, and is a subroutine of step 024 in FIG.

  In step 0241, the target operating angle TGEVENT of the intake valve 15 is referred to by referring to the engine speed NRPM and charging efficiency ITAC in FIG. 16. In step 0242, FIG. 17 is determined from the engine speed NRPM and charging efficiency ITAC. The target center angle TGTIMING of the intake valve 15 is calculated by referring to the map. The map characteristics of the target operating angle TGEVENT shown in FIG. 16 and the target center angle TGTIMING shown in FIG. 17 are preliminarily adapted so as to be the best in the state of the suitable engine speed NRPM and charging efficiency ITAC. Here, the best state is determined by demand. For example, the target operating angle TGEVENT and the target center angle TGTIMING are determined so that the fuel consumption (or engine output) is optimized.

  In step 0243, the error (TGEVENT-REEVENT) of the actual operating angle REEVENT of the intake valve 15 at that time from the target operating angle TGEVENT and the error of the actual central angle RETIMING of the intake valve 15 from the target central angle TGTIMING ( TGTIMING-RETIMING) is used to calculate an error EVTIMERR between the operating angle and the central angle according to the following equation.

EVTIMERR = ((TGEVENT−REEVENT) / a) ^ 2
+ ((TGTIMING-RETIMING) / b) ^ 2
(8)
Where a and b are constants,
The constants a and b are adjusted in advance so that the basic trace ignition timing estimated value BESTTRACE 1 calculated in step 025 is equal to or retarded from the actual trace knock ignition timing.

  In step 0244, the operating angle / center angle error EVTIMERR is compared with the threshold value TH1 of the operating angle / center angle error. Here, as shown in FIG. 6C, the threshold value TH1 is a value (a constant value) that determines whether the basic trace ignition timing estimated basic value BBESTTRACE1 is to be corrected in a range from the compatible point, and is preliminarily adapted. .

  Accordingly, when the operating angle / center angle error EVTIMERR is larger than the threshold value TH1, the correction range is not set, and therefore the process proceeds to step 0245 to set the trace ignition timing error correction amount TRACEERR1 = 0.

  On the other hand, when the operating angle / center angle error EVTIMEERR is equal to or less than the threshold value TH1, it is determined that it is within a predetermined correction range centered on the matching point, and the process proceeds to step 0246, and FIG. 18 is shown from the engine speed NRPM and the charging efficiency ITAC. By referring to the map, the trace ignition timing estimation error correction amount basic value BTRACERERR1 is calculated. This trace ignition timing estimation error correction amount basic value BTRACERR1 is used to obtain the value of the above (Supplement 4).

  In step 0247, the trace ignition timing error correction amount TRACEERR1 is calculated by the following equation.

TRACEERR1 = BTRACERR1
× (TH1-EVTIMERR) / TH1
... (9)
(EVTIMERR / TH1) on the right side of the equation (9) is a positive value of 1 or less. When the actual operating angle REEVENT of the intake valve 15 matches the target operating angle TGEVENT and the actual center angle RETIMING of the intake valve 15 also matches the target center angle TGTIMING, the operating angle / center angle error EVTIMERR = 0. ), The trace ignition timing error correction amount basic value BTRACERERR1 is directly used as the trace ignition timing error correction amount TRACEERR1. Further, as the actual operating angle REEVENT of the intake valve 15 is separated from the target operating angle TGEVENT and the actual center angle RETIMING of the intake valve 15 is separated from the target central angle TGTIMING, the operating angle / center angle error EVTIMERR increases and approaches the threshold value TH1. When the operating angle / center angle error EVTIMEERR coincides with the threshold value TH1, the trace ignition timing error correction amount TRACEERR1 becomes zero. That is, the equation (9) is an operation for obtaining a correction amount for shifting from the alternate long and short dash line characteristic to the broken line characteristic within a predetermined correction range centered on the matching point as shown in FIG. 6C. It is.

  The characteristic of the above-mentioned trace ignition timing estimation error correction amount basic value BTRACERR1 is calculated in step 025 as the actual operating angle REEVENT of the intake valve 15 approaches the operating angle of the intake valve 15 at the matching point (that is, the target operating angle TGEVENT). The basic trace ignition timing estimated value BESTTRACE 1 to be adjusted is adjusted in advance so as to approach the actual trace knock ignition timing of the matching point, that is, to obtain the characteristic of the broken line shown in FIG.

  Here, the effect of this embodiment is demonstrated.

According to the present embodiment (the invention described in claims 1 , 2 , 7, and 8), in an engine including the VTC mechanism 27 and the VEL mechanism 28, the engine rotational speed NRPM, the engine load, and the VTC mechanism 27 are given. Based on the command value and the command value given to the VEL mechanism 28, a basic trace ignition timing estimated basic value BBESTRTRACE1 (trace ignition timing basic value) is calculated (see step 023 and FIG. 9 in FIG. 8), and the calculated basic trace ignition is calculated. Since the spark ignition is performed at the timing estimated basic value BBESTRACE1 (trace ignition timing basic value), the VTC angle (command value given to the VTC mechanism 27) does not change, but the intake valve depends on the VEL angle (command value given to the VEL mechanism 28). Even if the opening or closing timing (opening / closing timing) of 15 is advanced or retarded, The race ignition timing estimation basic value BBESTTRACE1 (trace ignition timing basic value) can be accurately calculated, and the calculation (estimation) accuracy of the basic trace ignition timing estimation basic value BBESTTRACE1 (trace ignition timing basic value) is improved.

According to the present embodiment (inventions described in claims 1, 2, 7 , and 8 ), the basic trace ignition timing estimation basic value BBESTRTRACE1 (trace ignition timing basic value) is expressed by a linear expression of the operating angle REEVENT of the intake valve 15. Since they are approximated (see step 0237 in FIG. 9), even when the operating angle of the intake valve 15 and the VEL angle (command value given to the VEL mechanism 28) are different, the basic trace ignition timing estimated basic value BBESTTRACE1 (trace ignition timing basic value) ) Can be easily calculated.

According to the present embodiment (the invention described in claims 1, 2 , 7 , and 8 ), the basic trace ignition timing estimation basic value BESTTRACE1 (trace ignition timing basic value) is approximated by a linear expression of the operating angle REEVENT of the intake valve 15. In this case, the operating angle sensitivity EVSL (primary equation slope) of the basic trace ignition timing estimation basic value and the operating angle intercept EVIN (primary equation intercept) of the basic trace ignition timing estimation basic value are set to the central angle RETIMING of the intake valve 15. (See steps 0233 and 0236 in FIG. 9), even if the central angle of the intake valve 15 and the VTC angle (command values given to the VTC mechanism 27) are different, the basic trace ignition timing estimation basic value Operating angle sensitivity EVSL (slope of primary equation) and basic trace ignition timing estimation basic value operating angle intercept EVIN (primary equation intercept) It can be calculated.

The basic trace ignition timing estimated basic value operating angle sensitivity EVSL (primary equation slope) and the basic trace ignition timing estimated basic value operating angle intercept EVIN (primary equation intercept) are used as the basic trace ignition timing estimated basic value BESTTRACE1 (primary The first trace ignition timing basic value BBESTTRACE1 (first trace ignition timing basic value) is set so that the first trace ignition timing basic value approximated by the equation) matches the actual trace ignition timing at a predetermined fitting point. However, according to the present embodiment (the inventions described in claims 4 and 10 ), the basic trace ignition timing estimation basics may occur. Operating angle sensitivity EVSL (slope of primary expression) of value and operating angle intercept EVIN (intercept of primary expression) of basic trace ignition timing estimation basic value Basic trace ignition timing estimated basic value BBESTTRACE1 (first trace ignition timing basic value) is further set to a basic trace ignition timing estimated basic value BBESTTRACE1 (first trace ignition timing basic value) so that it does not advance from the actual trace ignition timing except at a compatible point. ) Is set by offsetting to the retarded angle side, so that it is possible to avoid occurrence of knocking at points other than the matching point.

According to the present embodiment (the inventions described in claims 5 and 11 ), the basic trace ignition timing estimation basic value BBESTRTRACE1 is set by being offset to the retard side so as not to advance from the actual trace ignition timing except at the matching point. 8 is calculated from the second trace ignition timing basic value) and the trace ignition timing error correction amount TRACEERR1 (trace ignition timing correction amount) (step 025 in FIG. 8). The basic trace ignition timing estimated value BESTTRACE1 (trace ignition timing estimated value) is replaced with the basic trace ignition timing estimated basic value BBESTRTRACE1 (second trace ignition timing basic value), and spark ignition is performed. Trace ignition timing estimated value BESTTRACE 1 (trace ignition Since the trace ignition timing estimation error correction amount basic value BTRACEERR1 (trace ignition timing correction amount) is set so that the actual trace ignition timing matches the actual trace ignition timing (see step 0246 in FIG. 10), the basic trace at the matching point It is possible to avoid the occurrence of an ignition timing error between the ignition timing estimated value BESTTRACE1 (trace ignition timing estimated value) and the actual trace ignition timing.

If the basic trace ignition timing estimated value BESTTRACE1 (trace ignition timing correction amount) is set so that the basic trace ignition timing estimated value BESTTRACE1 (trace ignition timing estimated value) and the actual trace ignition timing match only at the conforming point, There is a possibility that a difference in ignition timing occurs between the estimated value of the trace ignition timing and the actual trace ignition timing between the point and other points, and a torque step may be induced. In this embodiment (claims 6 and 12 ). In accordance with the present invention, a predetermined correction range is provided centering on the matching point, and in this correction range, the basic trace ignition timing estimated value BESTTRACE1 (trace ignition timing estimated value) is changed to the basic trace ignition timing estimated basic value BESTTRACE1 (second Trace ignition timing error so that the trace ignition timing basic value straight line Since calculates a correction amount TRACEERR1 (trace point timing correction amount other than compatible point) (see step 0247 in FIG. 10), is not to induce such torque difference.

  Next, FIGS. 20 to 23 are flowcharts of the second embodiment, and FIGS. 20, 21, 22, and 23 correspond to FIGS. 7, 8, 9, and 10, respectively.

  Here, differences from the first embodiment will be mainly described.

  In FIG. 20, the basic trace ignition timing estimated value BESTTRACE2 and the trace ignition timing estimated value ESTTRACE2 are calculated in steps 11 and 14, but the same values are calculated in terms of contents. However, in order to indicate that the value is calculated in the first embodiment, “1” is added to the end of the symbol in the first embodiment, so that the value is calculated in the second embodiment. In the second embodiment, “2” is appended instead of “1” at the end of the symbol. This “2” is also used in FIG. 21, FIG. 22, and FIG.

  In FIG. 21 (subroutine of step 12 in FIG. 20), in step 122, the lift RELIFT of the intake valve 15 is calculated from the actual VEL angle REVEL by referring to a table having the contents shown in FIG. The lift table characteristics in FIG. 24 are determined by the specifications of the VEL mechanism 28.

In step 123, the basic trace ignition timing estimated basic value BBESTRACE2 [degBTDC] is calculated, and in step 124, the trace ignition timing error correction amount TRACEERR2 [deg] is calculated. In step 125, the basic trace ignition timing estimated basic value BBESTRTRACE2 is trace-ignited. The value obtained by adding the timing error correction amount TRACEERR2 (the value on the advance side by the trace ignition timing error correction amount TRACEERR2) is used as the basic trace ignition timing estimated value BESTTRACE2 [degBTDC], that is, the basic trace ignition timing estimated value BESTTRACE2 is calculated by the following equation: To do. The expression (10) corresponds to the above (complement 5) expression.
BESTTRACE2 = BESTTRACE2 + TRACEERR2
(10)
Equation (10) corresponds to an operation for obtaining a broken line within a predetermined correction range centered on the VTC angle of the matching point as shown in FIG. The calculation of the basic trace ignition timing estimation basic value BBESTTRACE2 and the trace ignition timing error correction amount TRACEERR2 on the right side of the equation (10) will be described later.

  In FIG. 22 (subroutine of step 123 in FIG. 21), in step 1231, the lift sensitivity central angle sensitivity of the basic trace ignition timing estimation basic value is obtained by referring to the map containing FIG. 25 from the engine speed NRPM and the charging efficiency ITAC. In step 1232, the lift sensitivity central angle intercept LISLTIMIN of the basic trace ignition timing estimation basic value is calculated by referring to the map containing the contents of FIG. 26 from the engine speed NRPM and the charging efficiency ITAC in step 1232. The lift sensitivity of the basic value for estimating the basic trace ignition timing is calculated from the equation. The expression (11) is the same as the above (complement 7 ') expression.

LISL = LISLTIMSL × RETIMING + LISLTIMIN
... (11)
Where LISL: lift sensitivity,
LISLTIMSL: Lift sensitivity center angle sensitivity,
RETIMING: Center angle of intake valve,
LISLTIMIN: lift sensitivity central angle intercept,
In step 1234, the lift intercept center angle sensitivity LINTIMSL of the basic trace ignition timing estimation basic value is referred to by referring to a map containing the contents of FIG. 27 from the engine speed NRPM and charging efficiency ITAC, and in step 1235, the engine speed NRPM and charging efficiency. The lift intercept center angle intercept LIINITIMIN of the basic trace ignition timing estimation basic value is calculated from the ITAC by referring to the map having the contents shown in FIG. 28. In step 1236, the lift intercept of the basic trace ignition timing estimation basic value is calculated by the following equation. calculate. The expression (12) is the same as the above (complement 8 ′) expression.

LIIN = LIINITIMSL × RETIMING + LITINTIMIN
(12)
Where LIIN: lift intercept,
LIIMSIMS: Lift intercept center angle sensitivity,
RETIMING: Center angle of intake valve,
LIMINTIM: Lift intercept central angle intercept,
In step 1237, a basic trace ignition timing estimation basic value is calculated by the following equation. The expression (13) is the same as the above (complement 6 ′) expression.

BBESTTRACE2 = LISL × RELIFT + LIIN
... (13)
Where BBESTRACE2: Basic value of basic trace ignition timing estimation,
LISL: lift sensitivity,
RELIFT: Intake valve lift,
LIIN: lift operating angle intercept,
Here, the lift sensitivity center angle sensitivity LISLTIMSL shown in FIG. 25, the lift sensitivity center angle intercept LISLTIMIN shown in FIG. 26, the lift intercept center angle sensitivity LIINITIMSL shown in FIG. 27, and the lift intercept center angle intercept LIINITIMIN shown in FIG. Each map characteristic is adjusted in advance so that the basic trace ignition timing estimated basic value BBESTTRACE is equal to or retards the actual trace knock ignition timing when the engine speed NRPM, the charging efficiency ITAC, the VEL angle, and the VTC angle change.

  In FIG. 23 (subroutine of step 124 of FIG. 21), in step 1241, the target lift TGLIFT of the intake valve 15 is referred to by referring to a map containing FIG. 29 from the engine speed NRPM and charging efficiency ITAC, and in step 1242, the engine The target center angle TGTIMING of the intake valve 15 is calculated from the rotational speed NRPM and the charging efficiency ITAC by referring to a map having the contents shown in FIG. Each map characteristic of the target lift TGLIFT shown in FIG. 29 and the target center angle TGTIMING shown in FIG. 17 is adapted in advance so as to be the best in the state of the adapted engine rotational speed NRPM and charging efficiency ITAC. Here, the best state is determined by demand. For example, the target lift TGLIFT and the target center angle TGTIMING are determined so that the fuel consumption (or engine output) is optimized.

  In step 1243, the error (TGLIFT-RELIFT) of the actual lift RELIFT of the intake valve 15 at that time from the target lift TGLIFT and the error (TGTIMING−) of the actual center angle RETIMING of the intake valve 15 at that time from the target center angle TGTIMING The error LITIMERR of the lift and the central angle is calculated by the following equation using RETIMING).

LITIMERR = ((TGLIFT-RELIFT) / c) ^ 2
+ ((TGTIMING-RETIMING) / d) ^ 2
... (14)
Where c and d are constants,
The constants c and d are preliminarily adapted so that the basic trace ignition timing estimated value BESTTRACE2 calculated in step 125 is equal to or retarded from the actual trace knock ignition timing.

  In step 1244, the lift / center angle error LITIMERR is compared with the lift / center angle error threshold value TH2. Here, as shown in FIG. 6C, the threshold TH2 is a value (a constant value) that determines whether the basic trace ignition timing estimated basic value BBESTRTRACE2 is to be corrected in a range from the compatible point, and is preliminarily adapted. .

  Accordingly, when the lift / center angle error LITIMERR is larger than the threshold value TH2, it is not within the correction range, so the routine proceeds to step 1245, where the trace ignition timing error correction amount TRACEERR2 = 0 is set.

  On the other hand, when the lift / center angle error LITIMERR is less than or equal to the threshold value TH2, it is determined that it is within a predetermined correction range centered on the matching point, and the routine proceeds to step 1246, where FIG. 30 is calculated from the engine speed NRPM and the charging efficiency ITAC. By referring to the map, the trace ignition timing estimation error correction amount basic value BTRACERERR2 is calculated. This trace ignition timing estimation error correction amount basic value BTRACERERR2 is used to obtain the value of the above (Supplement 4).

  In step 1247, the trace ignition timing error correction amount TRACEERR2 is calculated by the following equation.

TRACEERR2 = BTRACERR2 × (LITIMERR / TH2)
... (15)
(LIEVTIMERR / TH2) on the right side of the equation (15) is a positive value of 1 or less. When the actual lift RELIFT of the intake valve 15 coincides with the target lift TGLIFT and the actual center angle RETIMING of the intake valve 15 also coincides with the target center angle TGTIMING, the lift operating angle / center angle error LITIMERR = 0, and (15) From the equation, the trace ignition timing estimation error correction amount basic value BTRACERERR2 becomes the trace ignition timing error correction amount TRACERR2 as it is. Further, as the actual lift RELIFT of the intake valve 15 moves away from the target lift TGLIFT and the actual center angle RETIMING of the intake valve 15 moves away from the target center angle TGTIMING, the lift operation angle / center angle error LITIMERR increases and approaches the threshold value TH1. When the lift operating angle / center angle error LITIMERR coincides with the threshold value TH1, the trace ignition timing error correction amount TRACEERR2 becomes zero. That is, the equation (15) is an operation for obtaining a correction amount for shifting from the alternate long and short dash line characteristic to the broken line characteristic within a predetermined correction range centered on the matching point as shown in FIG. 6C. It is.

  The characteristic of the above-mentioned trace ignition timing estimation error correction amount basic value BTRACEERR2 is the basic trace calculated in step 125 as the actual lift RELIFT of the intake valve 15 approaches the lift of the intake valve 15 at the matching point (that is, the target lift TGLIFT). The ignition timing estimated value BESTTRACE2 is preliminarily adapted so as to approach the actual trace knock ignition timing of the suitable point, that is, to obtain the characteristic of the broken line shown in FIG.

  Here, the effect of 2nd Embodiment is demonstrated.

According to the second embodiment (the invention described in claims 1 , 2 , 7, 8), in an engine including the VTC mechanism 27 and the VEL mechanism 28, the engine rotational speed NRPM, the engine load, and the VTC angle (VTC) Based on the command value given to the mechanism 27) and the VEL angle (command value given to the VEL mechanism 28), a basic trace ignition timing estimated basic value BBESTTRACE2 (trace ignition timing basic value) is calculated (see step 123 in FIG. 21, FIG. 22). ) Since the spark ignition is performed with the calculated basic trace ignition timing estimation basic value BESTTRACE1 (trace ignition timing basic value), the VTC angle (command value given to the VTC mechanism 27) does not change, but the VEL angle (VEL mechanism). 28), the opening timing and closing timing (opening / closing timing) of the intake valve 15 are advanced. The basic trace ignition timing estimated basic value BBESTTRACE2 (trace ignition timing basic value) can be accurately calculated even when the angle is retarded, or the basic trace ignition timing estimated basic value BBESTTRACE2 (trace ignition timing basic value) is calculated. (Estimation) Accuracy is improved.

According to the second embodiment (the inventions described in claims 1, 2, 7 , and 8 ), the basic trace ignition timing estimation basic value BBESTRTRACE2 (trace ignition timing basic value) is expressed by a linear expression of the lift RELIFT of the intake valve 15. Since the approximation (see step 1237 in FIG. 22), even if the lift of the intake valve 15 and the VEL angle (command value given to the VEL mechanism 28) are different, the basic trace ignition timing estimation basic value BBESTRACE2 (trace ignition timing basic value) Can be easily calculated.

According to the second embodiment (the inventions described in claims 1, 2 , 7 , and 8 ), the basic trace ignition timing estimation basic value BESTTRACE2 (trace ignition timing basic value) is set to the lift RELIFT (maximum valve lift amount) of the intake valve 15. ) Is approximated by the lift sensitivity LISL (primary equation slope) of the basic trace ignition timing estimation basic value and the lift intercept LIIN (primary equation intercept) of the basic trace ignition timing estimation basic value. Since it is approximated by a linear expression of the center angle RETIMING (see steps 1233 and 1236 in FIG. 22), even when the center angle RETIMING and VTC angle (command values given to the VTC mechanism 27) of the intake valve 15 are different, the basic trace ignition timing Estimated basic value lift sensitivity LISL (primary slope) and basic trace ignition timing estimated basic value The Doo intercept LIIN (intercept of the linear equation) can be easily calculated.

The basic trace ignition timing estimation basic value lift sensitivity LISL (primary equation slope) and the basic trace ignition timing estimation basic value lift intercept LIIN (primary equation intercept) are expressed as the basic trace ignition timing estimation basic value BBESTTRACE2 (primary equation). When the approximate first trace ignition timing basic value) is set so as to coincide with the actual trace ignition timing at a predetermined adaptation point, the basic trace ignition timing estimated basic value BBESTTRACE2 (first trace ignition timing basic value) is compatible. Except for this point, there is a possibility that knocking may occur with an advance from the actual trace ignition timing. However, according to the second embodiment (the inventions according to claims 4 and 10 ), the basic value of the basic trace ignition timing is estimated. Lift sensitivity LISL (primary equation slope) and basic trace ignition timing estimation basic value lift intercept LIIN (primary equation intercept) The basic trace ignition timing estimation basic value BBESTTRACE2 (first trace ignition timing basic value) is set so that the basic trace ignition timing estimation basic value BBESTTRACE2 (first trace ignition timing basic value) does not advance from the actual trace ignition timing except at a compatible point. Value) is set by offsetting to the retarded angle side, so that it is possible to avoid occurrence of knocking at points other than the matching point.

According to the second embodiment (inventions described in claims 5 and 11 ), the basic trace ignition timing estimation basic value BESTTRACE2 is set by being offset to the retard side so as not to advance from the actual trace ignition timing except at the matching point. The basic trace ignition timing estimated value BESTTRACE2 (trace ignition timing estimated value) is calculated from the second trace ignition timing basic value) and the trace ignition timing error correction amount TRACEERR2 (trace ignition timing correction amount) (step of FIG. 21). 125), the basic trace ignition timing estimated value BESTTRACE2 (trace ignition timing estimated value) is replaced with the basic trace ignition timing estimated basic value BESTTRACE2 (second trace ignition timing basic value), and spark ignition is performed. Basic trace ignition timing estimate BESTTRACE2 (trace Since the trace ignition timing estimation error correction amount basic value BTRACERERR2 (trace ignition timing correction amount) is set so that the fire timing estimated value) matches the actual trace ignition timing (see step 1246 in FIG. 23), the basic point at the matching point is used. It is possible to avoid occurrence of an ignition timing error between the trace ignition timing estimated value BESTTRACE2 (trace ignition timing estimated value) and the actual trace ignition timing.

If the basic trace ignition timing estimated value BESTTRACE2 (trace ignition timing correction amount) is set so that the basic trace ignition timing estimated value BESTTRACE2 (trace ignition timing estimated value) and the actual trace ignition timing coincide with each other only at the conforming point, There is a possibility that a difference in ignition timing is generated between the estimated value of the trace ignition timing and the actual trace ignition timing between the point and other points, and a torque step may be induced, but the second embodiment (Claims 6 and 12 ). According to the present invention, a predetermined correction range is provided centering on the matching point, and in this correction range, the basic trace ignition timing estimated value BESTTRACE2 (trace ignition timing estimated value) is the basic trace ignition timing estimated basic value BBESTTRACE2 (second Trace ignition timing so that it is smoothly connected to the trace ignition timing basic value line) Since it calculates a difference correction amount TRACEERR2 (trace point timing correction amount other than compatible point) (see step 1247 of FIG. 23), is not to induce such torque difference.

In the first and second aspects of the invention, the trace ignition timing basic value calculation processing procedure is performed by Step 023 and FIG. 9 in FIG. 8 or Step 123 and FIG. 22 in FIG.

In the inventions according to claims 7 and 8, the function of the trace ignition timing basic value calculation means is performed by step 023 and FIG. 9 of FIG. 8 or by steps 123 and 22 of FIG.

The schematic block diagram of the ignition timing control apparatus of the engine of 1st Embodiment of this invention. The valve lift characteristic figure in the case of providing a VEL mechanism and a VTC mechanism. The characteristic view which shows the relationship between a VTC angle, a VEL angle, and trace ignition timing basic value. The characteristic figure of the approximate type inclination with respect to a VEL angle. The characteristic figure of the approximate expression intercept with respect to a VEL angle. The characteristic view which shows the relationship between the VTC angle and VEL angle which were used in order to examine whether the linear approximation method of trace ignition timing basic value is appropriate, and trace ignition timing. The characteristic view which shows the relationship between the VTC angle and VEL angle which were used in order to examine whether the linear approximation method of trace ignition timing basic value is appropriate, and trace ignition timing. The characteristic view which shows the relationship between the VTC angle and VEL angle which were used in order to examine whether the linear approximation method of trace ignition timing basic value is appropriate, and trace ignition timing. The flowchart for demonstrating calculation of the trace ignition timing estimated value of 1st Embodiment. The flowchart for demonstrating calculation of the basic trace ignition timing estimated value of 1st Embodiment. The flowchart for demonstrating calculation of the basic trace ignition timing estimation basic value of 1st Embodiment. The flowchart for demonstrating calculation of the trace ignition timing error correction amount of 1st Embodiment. The characteristic view of the intake valve operating angle of the first embodiment. The characteristic figure of the working angle sensitivity center angle sensitivity of 1st Embodiment. The characteristic view of the working angle sensitivity central angle intercept of 1st Embodiment. The characteristic view of the working angle intercept center angle sensitivity of 1st Embodiment. The characteristic view of the working angle intercept center angle intercept of 1st Embodiment. The characteristic view of the target operating angle of the first embodiment. The characteristic figure of the target center angle of 1st, 2nd embodiment. The characteristic figure of the estimation error correction amount basic value of 1st Embodiment. The valve lift characteristic figure of an intake valve. The flowchart for demonstrating calculation of the trace ignition timing estimated value of 2nd Embodiment. The flowchart for demonstrating calculation of the basic trace ignition timing estimated value of 2nd Embodiment. The flowchart for demonstrating calculation of the basic trace ignition timing estimation basic value of 2nd Embodiment. The flowchart for demonstrating calculation of the trace ignition timing error correction amount of 2nd Embodiment. The characteristic figure of the lift of 2nd Embodiment. The characteristic figure of the lift sensitivity center angle sensitivity of 2nd Embodiment. The characteristic figure of the lift sensitivity central angle intercept of 2nd Embodiment. The characteristic figure of the lift intercept center angle sensitivity of 2nd Embodiment. The characteristic figure of the lift intercept center angle intercept of 2nd Embodiment. The characteristic figure of the target lift of a 2nd embodiment. The characteristic figure of the estimation error correction amount basic value of 2nd Embodiment.

Explanation of symbols

11 Ignition device 27 VTC mechanism (variable valve timing mechanism)
28 VEL mechanism (variable valve mechanism)
31 Engine controller 34 Cam angle sensor 37 Knock sensor 43 VEL angle sensor

Claims (12)

A variable valve timing mechanism that advances and retards the opening and closing timing of the intake valve according to the command value while the operating angle of the intake valve remains constant;
In an engine equipped with a variable valve mechanism that variably controls the valve lift maximum amount of the intake valve and the operating angle of the intake valve according to the command value,
The trace ignition timing basic value is approximated by a first primary expression of any one of a command value given to the variable valve timing mechanism and an intake valve central angle, and any one of the command value given to the variable valve timing mechanism and the intake valve central angle is determined. Trace ignition timing basic value calculation processing procedure for calculating this trace ignition timing basic value based on one,
Spark ignition execution processing procedure for performing spark ignition with the calculated trace ignition timing basic value,
A command given to the variable valve mechanism by approximating the inclination and intercept of the first primary formula to the variable valve mechanism by any one of the second primary expressions of the command value, intake valve operating angle, and intake valve lift maximum amount. An ignition / ignition calculation procedure for calculating an inclination and an intercept of the first linear expression based on any one of a value, an intake valve operating angle, and an intake valve lift maximum amount Timing control method. A variable valve timing mechanism that advances and retards the opening and closing timing of the intake valve according to the command value while the operating angle of the intake valve remains constant;
In an engine equipped with a variable valve mechanism that variably controls the valve lift maximum amount of the intake valve and the operating angle of the intake valve according to the command value,
The trace ignition timing basic value is approximated by a third primary expression of any one of a command value given to the variable valve mechanism, an intake valve operating angle, and an intake valve lift maximum amount, and the trace ignition timing basic value is set to the variable valve Trace ignition timing basic value calculation processing procedure for calculating this trace ignition timing basic value based on any one of a command value given to the mechanism, an intake valve operating angle, and an intake valve lift maximum amount,
Spark ignition execution processing procedure for performing spark ignition with the calculated trace ignition timing basic value,
The command value to be given to the variable valve timing mechanism is approximated by the fourth value of any one of the command value given to the variable valve timing mechanism and the central angle of the intake valve, and the inclination and intercept of the third primary formula are given to the variable valve timing mechanism. An ignition timing control method for an engine, comprising: an inclination / intercept calculation processing procedure for calculating an inclination and an intercept of the third linear expression based on any one of the central angles.   The first trace ignition timing basic value approximated by the first linear expression is the actual trace ignition timing and a predetermined matching point, and the slope and intercept of the third linear expression 3 is set so that the first trace ignition timing basic value approximated by the third linear expression coincides with the actual trace ignition timing at a predetermined matching point. Ignition timing control method. The slope and intercept of the first linear expression, before Symbol retard the first trace ignition timing basic value so as not to advance from the actual trace ignition timing other than the first trace ignition timing basic value more the compatible point The first trace ignition timing is set so that the slope and intercept of the third linear expression are not advanced from the actual trace ignition timing at a point other than the adaptation point. 4. The engine ignition timing control method according to claim 3, wherein the basic value is set by being offset to the retard side . A trace for calculating the estimated value of the trace ignition timing from the second trace ignition timing basic value that is offset and set to the retarded angle side so as not to advance from the actual trace ignition timing except at the above-mentioned conforming point. Ignition timing estimated value calculation processing procedure,
A spark ignition execution processing procedure for performing spark ignition instead of the trace ignition timing estimated value instead of the second trace ignition timing basic value;
5. The engine ignition timing control method according to claim 4, wherein the trace ignition timing correction amount is set so that the trace ignition timing estimated value and the actual trace ignition timing coincide with each other at the matching point.   A predetermined correction range is provided centering on the adaptation point, and the trace ignition timing estimated value other than the adaptation point is smoothly connected to the straight line of the second trace ignition timing basic value in the correction range. 6. The engine ignition timing control method according to claim 5, wherein a point timing correction amount is calculated. A variable valve timing mechanism that advances and retards the opening and closing timing of the intake valve according to the command value while the operating angle of the intake valve remains constant;
In an engine equipped with a variable valve mechanism that variably controls the valve lift maximum amount of the intake valve and the operating angle of the intake valve according to the command value,
The trace ignition timing basic value is approximated by a first primary expression of any one of a command value given to the variable valve timing mechanism and an intake valve central angle, and any one of the command value given to the variable valve timing mechanism and the intake valve central angle is determined. Trace ignition timing basic value calculating means for calculating the trace ignition timing basic value based on
Spark ignition execution means for performing spark ignition at the calculated trace ignition timing basic value;
A command given to the variable valve mechanism by approximating the inclination and intercept of the first primary formula to the variable valve mechanism by any one of the second primary expressions of the command value, intake valve operating angle, and intake valve lift maximum amount. And an inclination / intercept calculating means for calculating an inclination and an intercept of the first linear expression based on any one of a value, an intake valve operating angle, and an intake valve lift maximum amount. Control device. A variable valve timing mechanism that advances and retards the opening and closing timing of the intake valve according to the command value while the operating angle of the intake valve remains constant
In an engine equipped with a variable valve mechanism that variably controls the valve lift maximum amount of the intake valve and the operating angle of the intake valve according to the command value,
The trace ignition timing basic value is approximated by a third primary expression of any one of a command value given to the variable valve mechanism, an intake valve operating angle, and an intake valve lift maximum amount, and the trace ignition timing basic value is set to the variable valve Trace ignition timing basic value calculation means for calculating this trace ignition timing basic value based on any one of a command value given to the mechanism, an intake valve operating angle, and an intake valve lift maximum amount;
Spark ignition execution means for performing spark ignition at the calculated trace ignition timing basic value;
The command value to be given to the variable valve timing mechanism is approximated by the fourth value of any one of the command value given to the variable valve timing mechanism and the central angle of the intake valve, and the inclination and intercept of the third primary formula are given to the variable valve timing mechanism. An engine ignition timing control device comprising: an inclination / intercept calculating means for calculating an inclination and an intercept of the third linear expression based on any one of the central angles.   The first trace ignition timing basic value approximated by the first linear expression is the actual trace ignition timing and a predetermined matching point, and the slope and intercept of the third linear expression 9 is set so that the first trace ignition timing basic value approximated by the third linear expression coincides with the actual trace ignition timing at a predetermined adaptation point. Ignition timing control device. The slope and intercept of the first linear expression, before Symbol retard the first trace ignition timing basic value so as not to advance from the actual trace ignition timing other than the first trace ignition timing basic value more the compatible point The first trace ignition timing is set so that the slope and intercept of the third linear expression are not advanced from the actual trace ignition timing at a point other than the adaptation point. 10. The engine ignition timing control device according to claim 9, wherein the basic value is set by being offset to the retard side . A trace for calculating the estimated value of the trace ignition timing from the second trace ignition timing basic value that is offset and set to the retarded angle side so as not to advance from the actual trace ignition timing except at the above-mentioned conforming point. Ignition timing estimated value calculation means;
Spark ignition execution means for performing spark ignition instead of the trace ignition timing estimated value instead of the second trace ignition timing basic value;
11. The engine ignition timing control device according to claim 10, wherein the trace ignition timing correction amount is set so that the trace ignition timing estimated value and the actual trace ignition timing coincide with each other at the matching point.   A predetermined correction range is provided centering on the adaptation point, and the trace ignition timing estimated value other than the adaptation point is smoothly connected to the straight line of the second trace ignition timing basic value in the correction range. 12. The engine ignition timing control apparatus according to claim 11, wherein a point timing correction amount is calculated.

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