JP2008115755A - Internal combustion engine control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively prevent torque steering in accelerating operation in an internal combustion engine for a front wheel drive vehicle or a four-wheel drive vehicle performing output control by making a valve lift amount of an intake valve continuously variable. <P>SOLUTION: When a steering angle θh and an accelerator opening ACCP are determined as being in a torque steering restraining region (S152; yes), a feedback gain Kp smaller than usual is set in accordance with the steering angle θh and the accelerator opening ACCP (S156). Accordingly, responsiveness of valve lift amount control of the intake valve in accordance with accelerating operation is deteriorated, and a valve lift amount increase speed is lowered. Thus, raid increase of output of the internal combustion engine is restrained, and increase of torque steering can be prevented. When the steering angle θh and the accelerator opening ACCP are determined as being out of the torque steering restraining region (S152; no), the feedback gain Kp is large, and the valve lift amount increase speed is not restrained, and the valve lift amount of the intake valve is adjusted with high responsiveness, and acceleration efficiency of the vehicle is not deteriorated than required. Thus, the problem can be solved. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an internal combustion engine that performs internal combustion engine output control by continuously adjusting a valve lift amount of an intake valve by a variable valve mechanism according to an accelerator opening in a vehicle internal combustion engine that transmits driving force to a steered wheel. The present invention relates to a control device.

  When turning a vehicle equipped with an internal combustion engine that transmits driving force to the steering wheel, such as a front-wheel drive vehicle or a four-wheel drive vehicle, a torque steer phenomenon occurs during sudden acceleration operation, and the steering wheel is taken to the left or right Sometimes. For the internal combustion engine that transmits the driving force to the steering wheel in this way, a variable valve mechanism that adjusts the valve lift amount of the intake valve according to the accelerator opening is provided, and the internal combustion engine is adjusted by adjusting the valve lift amount of the intake valve. It is conceivable to combine a configuration for controlling the engine output. In the internal combustion engine having such a configuration, the response at the time of adjusting the output of the internal combustion engine by the driver's accelerator operation is higher than that of adjusting the output by the throttle valve. This makes it possible to achieve a rapid acceleration as compared with the case where the output control of the internal combustion engine is performed by a throttle valve, but due to the high response, a countermeasure for torque steer has become more important.

As a conventional technique for solving a problem at the time of turning a front-wheel drive vehicle equipped with an internal combustion engine with a variable valve lift amount, an internal combustion engine equipped with a variable valve mechanism that can switch the valve lift amount in two stages is used. A technique for stopping switching and preventing understeer during vehicle turning is known (see, for example, Patent Document 1).
Japanese Patent Publication No. 7-15268 (page 3-4, FIG. 7)

  However, in Patent Document 1, the output adjustment of the internal combustion engine is performed by a throttle valve, the output responsiveness is lower than that of the internal combustion engine by the variable valve mechanism, and it is a countermeasure against understeer. Therefore, the technique of Patent Document 1 cannot be applied as a technique for solving torque steer in an internal combustion engine in which output control is performed by a variable valve mechanism.

  An object of the present invention is to effectively prevent torque steer during acceleration operation in a vehicle internal combustion engine that performs output control by continuously varying the valve lift amount of the intake valve described above. .

In the following, means for achieving the above object and its effects are described.
The internal combustion engine control apparatus according to claim 1 is a vehicle internal combustion engine including a variable valve mechanism that transmits a driving force to a steering wheel of a vehicle and continuously varies a valve lift amount of an intake valve. An internal combustion engine control device that performs internal combustion engine output control by adjusting a valve lift amount of an intake valve by the variable valve mechanism according to an accelerator opening detected by an opening detection means, the steering steering angle being Steering angle detection means for detecting, and internal combustion engine output increase suppression means for suppressing the valve lift amount increase speed of the intake valve by the variable valve mechanism based on the magnitude of the steering angle detected by the steering angle detection means; It is provided with.

  Even during the same vehicle acceleration operation, the magnitude of the torque steer varies depending on the steering angle. Therefore, the internal combustion engine output increase suppression means suppresses the valve lift increase rate of the intake valve by the variable valve mechanism based on the size of the steering angle in order to suppress the valve lift increase rate of the intake valve. . By suppressing the valve lift amount increasing speed, a rapid increase in the driving force of the internal combustion engine is suppressed to prevent the torque steer from becoming large.

  If it can be determined that the torque steer is at a level that is no problem or small based on the size of the steering angle, the speed of increase of the valve lift is not suppressed, or it can be suppressed to a small level, so that the acceleration performance is reduced more than necessary. There is no.

Thus, torque steer during acceleration operation can be effectively prevented in the vehicle internal combustion engine that performs output control by continuously changing the valve lift amount of the intake valve.
The internal combustion engine control apparatus according to claim 2, wherein the internal combustion engine output increase suppression means according to claim 1, wherein the steering angle detected by the steering angle detection means is larger than a reference angle. It is characterized by suppressing the rate of increase of the valve lift amount of the intake valve by the variable valve mechanism.

  Since the torque steer increases as the steering angle increases, a reference angle may be set, and when the steering angle is larger than this reference angle, the valve lift increase rate of the intake valve may be suppressed. Thus, torque steer during acceleration operation can be effectively prevented in the vehicle internal combustion engine that performs output control by continuously changing the valve lift amount of the intake valve.

  The internal combustion engine control apparatus according to claim 3, wherein the internal combustion engine output increase suppression means according to claim 1, wherein the steering angle detected by the steering angle detection means is larger than a reference angle, and the accelerator When the accelerator opening detected by the opening detection means is larger than the reference opening, the valve lift amount increase rate of the intake valve by the variable valve mechanism is suppressed.

  When the steering angle is increased, the torque steer is increased, and when the valve lift amount is increased in accordance with the increase of the accelerator opening degree under the situation where the torque steer is generated at such a steering angle, the torque steer is further increased. From this, the reference opening is set together with the reference angle, and when the steering angle is larger than the reference angle and the accelerator opening is larger than the reference opening, the valve lift increase rate of the intake valve is suppressed. It is also good. This makes it possible to more effectively prevent torque steer during acceleration operation in a vehicle internal combustion engine that performs output control by continuously changing the valve lift amount of the intake valve.

  The internal combustion engine controller according to claim 4, wherein the internal combustion engine output increase suppression means is detected by the steering angle detected by the steering angle detection means and the accelerator opening detection means in claim 1. When the state of the accelerator opening belongs to the torque steer suppression region set on the side where the torque steer increases on the two-dimensional space composed of the steering angle and the accelerator opening, the intake valve by the variable valve mechanism It is characterized in that the rate of increase in the valve lift is suppressed.

  As described above, the torque steer increases when the steering angle is large and the accelerator opening is large. Therefore, when the torque steer suppression region as described above is set on the two-dimensional space composed of the steering angle and the accelerator opening, and the engine is in a state belonging to this torque steer suppression region, the intake by the variable valve mechanism is changed. The increase rate of the valve lift amount of the valve may be suppressed. This makes it possible to more effectively prevent torque steer during acceleration operation in a vehicle internal combustion engine that performs output control by continuously changing the valve lift amount of the intake valve.

  The internal combustion engine control apparatus according to claim 5, wherein the internal combustion engine output increase suppression unit suppresses the valve lift amount increase speed by providing a limit to the valve lift amount increase speed. It is characterized by that.

In order to suppress the valve lift amount increase speed of the intake valve by the variable valve mechanism, a limit may be set on the valve lift amount increase speed.
The internal combustion engine control apparatus according to claim 6, wherein the internal combustion engine output increase suppression means corresponds to the acceleration opening increase speed detected by the accelerator opening detection means in any of claims 1 to 4. The valve lift increase rate is suppressed by lowering the valve lift increase rate than the increasing rate.

  In order to suppress the increase speed of the valve lift amount of the intake valve by the variable valve mechanism, the valve lift amount increase speed may be made lower than the increase speed corresponding to the increase speed of the accelerator opening.

  The internal combustion engine control apparatus according to claim 7, wherein the internal combustion engine output increase suppression means increases the suppression of the valve lift amount increase rate as the steering angle increases. It is characterized by that.

  Torque steer increases as the steering angle increases, so it is possible to more effectively prevent torque steer during acceleration by increasing the suppression of the valve lift amount increasing speed as the steering angle increases. It becomes.

  In the internal combustion engine control apparatus according to claim 8, in any one of claims 1 to 7, the internal combustion engine output increase suppression means suppresses the valve lift amount increase speed as the accelerator opening increases. It is characterized by strengthening.

  Torque steer increases as the valve lift increases in response to the accelerator opening, so by increasing the suppression of the valve lift increase rate as the accelerator opening increases, the torque steer during acceleration is increased. This can be prevented more effectively.

[Embodiment 1]
FIG. 1 is a block diagram showing a schematic configuration of an internal combustion engine control apparatus to which the above-described invention is applied. Here, the internal combustion engine 2 is an in-cylinder injection spark ignition type four-cylinder gasoline engine mounted on an automobile. FIG. 1 shows the first cylinder # 1 portion among the four cylinders # 1 to # 4 from the first cylinder # 1 to the fourth cylinder # 4. The vehicle on which the internal combustion engine 2 is mounted is a four-wheel drive vehicle, and the driving force of the internal combustion engine 2 is transmitted to the front wheels that are the steering wheels together with the rear wheels.

  Outside air is sucked into the combustion chambers 4 of the four cylinders # 1 to # 4 through an intake passage 6 having an air filter at the tip, and fuel is directly injected from a fuel injection valve 8. The fuel may be injected into the intake port. When the air / fuel mixture is ignited by the spark plug 10, the air / fuel mixture burns, the piston 12 reciprocates, and the crankshaft 14 that is the output shaft of the internal combustion engine 2 rotates. . The air-fuel mixture after combustion is sent out from each combustion chamber 4 to the exhaust passage 16 as exhaust.

  The combustion chamber 4 and the intake passage 6 are connected and cut off by the opening / closing operation of the intake valve 22, and the combustion chamber 4 and the exhaust passage 16 are connected and cut off by the opening / closing operation of the exhaust valve 24. The intake valve 22 and the exhaust valve 24 open and close in accordance with the rotation of the intake camshaft 26 and the exhaust camshaft 28 to which the rotation of the crankshaft 14 is transmitted.

  The intake camshaft 26 is provided with a variable valve timing mechanism 30 that adjusts the relative rotational phase of the intake camshaft 26 with respect to the crankshaft 14 to advance or retard the valve timing of the intake valve 22. Between the intake camshaft 26 and the intake valve 22, the lift amount variable mechanism 32 that makes the operating angle (opening period) of the intake valve 22 variable by continuously changing the valve lift amount of the intake valve 22. Is provided. Note that the valve timing adjustment of the intake valve 22 by the variable valve timing mechanism 30 and the valve lift adjustment of the intake valve 22 by the variable lift amount mechanism 32 are performed by intakes of all cylinders # 1 to # 4 by actuators such as hydraulics and electric motors. The same applies to the valve 22.

  An electronic control device (hereinafter abbreviated as “ECU”) 34 that controls the operation of the internal combustion engine 2 is mounted on the vehicle. Through the ECU 34, fuel injection control, ignition timing control, throttle opening control, valve timing control of the intake valve 22 and valve lift amount variable control are performed. The ECU 34 receives detection signals from various sensors shown below. That is, the crank angle sensor 36 that detects the rotation of the crankshaft 14, the cam angle sensor 38 that detects the rotation (cam angle) of the intake camshaft 26, and the accelerator opening ACCP (%) that is the depression amount of the accelerator pedal 39 are detected. An accelerator opening sensor 40 (corresponding to accelerator opening detecting means) is provided. Further, a throttle position sensor 42 for detecting the throttle opening degree TA (%), an air flow meter 44 for detecting the intake air amount GA (g / s) passing through the intake passage 6, and the combustion chambers 4 of all cylinders # 1 to # 4. An air-fuel ratio sensor 46 for detecting the air-fuel ratio AF of the exhaust gas to be discharged is provided. Further, a steering angle sensor 50 (corresponding to a steering angle detection means) for detecting the steering angle θh by the handle 48 and a valve lift amount sensor 52 for detecting the valve lift amount of the intake valve 22 are provided. The valve lift amount sensor 52 does not directly detect the valve lift amount, but detects the amount of movement of the control shaft driven by the actuator for adjusting the valve lift amount provided in the variable lift amount mechanism 32. Thus, the control shaft movement amount is detected as the valve lift amount.

  In the internal combustion engine 2, the intake air amount adjustment into the combustion chamber 4 of each of the cylinders # 1 to # 4 is executed by adjusting the valve lift amount of the intake valve 22 by the lift amount variable mechanism 32. For example, as shown in FIG. 2, the intake air amount is smoothly adjusted by continuously adjusting the valve operating angle between the maximum valve lift amount and the minimum valve lift amount.

  A throttle valve 6b is disposed upstream of the surge tank 6a formed in the intake passage 6. The throttle valve 6b is fully opened when the internal combustion engine 2 is started, and fully closed when the internal combustion engine 2 is stopped. It is said. If it is difficult to adjust the valve lift amount of the intake valve 22 due to the failure of the variable lift amount mechanism 32, the intake amount is adjusted by the independent operation of the throttle valve 6b.

Next, an intake air amount control process executed by the ECU 34 will be described. FIG. 3 shows a flowchart of the intake air amount control process. This process is repeatedly executed at regular time intervals.
When this process is started, it is first determined whether or not the intake air amount control process by adjusting the valve lift amount of the intake valve 22 can be executed (S100). For example, in the case where the intake air amount adjustment is executed by the throttle valve 6b due to the failure of the lift amount variable mechanism 32 as described above, and the valve lift amount adjustment is prohibited (No in S100), the state is kept as it is. Exit this process once. In this state, control of maintaining the valve lift amount of the intake valve 22 at the maximum valve lift state (FIG. 2) is performed by the intake air amount control separately performed by the ECU 34, and the throttle opening corresponding to the accelerator opening ACCP is performed. TA is adjusted.

  When the intake air amount control process by adjusting the valve lift amount can be executed (yes in S100), the accelerator opening amount ACCP detected by the accelerator opening amount sensor 40 and the valve lift amount sensor 52 are detected. The valve lift amount VL is read into the work area in the memory in the ECU 34 (S102).

  Next, the target valve lift amount VLt is calculated based on the value of the accelerator opening ACCP read in step S102 by using a map MAPaccp shown by a solid line in FIG. 4 showing the relationship between the accelerator opening ACCP and the target valve lift amount VLt. (S104). This map MAPaccp is set in advance so as to match the performance required for the internal combustion engine 2 in design.

  Next, the gain Kp in the PID calculation (control amount calculation for PID control) performed in the feedback control of the valve lift amount is set by the feedback gain setting process of FIG. 5 described later (S106). This gain Kp is the gain of the P term (proportional term), and this adjusts the responsiveness of the feedback control. The gains Ki and Kd of the I term and D term are set as fixed values in advance.

  When the gain Kp is set, based on the difference between the target valve lift amount VLt and the valve lift amount VL, the power supply amount to the drive motor and the rotation direction of the drive motor in the lift amount variable mechanism 32 are set by PID calculation. (S108). This power supply amount determines the responsiveness in adjusting the valve lift amount of the intake valve 22 to the adjustment speed of the valve lift amount VL, that is, the change in the accelerator opening ACCP.

Then, power supply control in the power supply amount and rotation direction set in step S108 is executed (S110).
The feedback gain setting process (FIG. 5) will be described. In this process, it is first determined whether or not the accelerator opening ACCP is increasing (S148). Here, whether or not the accelerator opening ACCP is increasing is determined as an increase if the value of the accelerator opening ACCP at the current control cycle is larger than the value at the previous control cycle.

  If the accelerator opening ACCP is increased (yes in S148), the steering angle θh detected by the steering angle sensor 50 is read (S150). Then, it is determined whether or not the steering angle θh and the accelerator opening ACCP are within the torque steer suppression region indicated by the map MAPθh in FIG. 6 (S152). Here, FIG. 6 represents a two-dimensional space composed of the absolute value (| θh |) of the steering angle θh and the accelerator opening ACCP. Note that the straight traveling is the steering angle θh = 0 °.

  During vehicle acceleration, the torque steer increases as the absolute value of the steering angle θh increases, that is, as the turning angle of the handle 48 to the left (θh> 0 °) or right (θh <0 °) increases, resulting in acceleration operation. The torque steer increases as the driving force of the internal combustion engine 2 increases. Therefore, the torque steer suppression region is set on the side where the accelerator opening ACCP and | steering angle θh | are larger in the two-dimensional space of FIG.

  If the steering angle θh and the accelerator opening ACCP do not exist in the torque steer suppression region (no in S152), the gain Kp is set to the initial gain Kp0 having the best response (S154). Note that step S154 is also executed when it is determined no in step S148. Then, PID calculation is performed using the gain Kp set in this way (FIG. 3: S108), and power feeding control is performed (FIG. 3: S110). In a state where there is no problem with this torque steer, the drive motor of the lift amount variable mechanism 32 rotates with sufficiently high responsiveness by the power supply control, and the valve lift amount VL corresponding to the accelerator operation is realized with high response.

  If the steering angle θh and the accelerator opening ACCP are present in the torque steer suppression region (yes in S152), then, based on the steering angle θh and the accelerator opening ACCP, gain from the map MAPkp shown in FIG. Kp is calculated (S156). This map MAPkp has a torque steer tendency as described above. In the upper right region (corresponding to the torque steer suppression region) from the solid line, the upper right portion (accelerator opening ACCP is large, | steering angle θh The smaller the value of | is, the smaller the gain Kp is set. The gain Kp is smaller than the initial gain Kp0 described above.

  PID calculation is performed using the gain Kp set in this way (FIG. 3: S108), and power feeding control is performed (FIG. 3: S110). In such a state where torque steer becomes a problem, the initial gain Kp0 is obtained. A smaller gain Kp will be used. As a result, the power feeding control with respect to the accelerator opening ACCP drives the drive motor of the variable lift amount mechanism 32 with a low response. Therefore, the responsiveness of the valve lift amount VL to the accelerator opening ACCP becomes low. That is, the time to reach the target valve lift amount VLt is delayed from the normal time (when determined to be no in step S152).

  An example of the control of the present embodiment is shown in the timing chart of FIG. Here, before the timing t0, the driver steers the handle 48 to the right (θh <0 °) and then depresses the accelerator pedal 39. Thus, the relationship between the absolute value of the steering angle θh and the accelerator opening ACCP belongs to the torque steer suppression region (t0: yes in S152). For this reason, the responsiveness of the valve lift amount VL decreases due to the reduction of the gain Kp, and the responsiveness to the accelerator opening ACCP decreases as shown by the solid line. If it is normal time (when it is determined as no in S152), the opening is higher than the solid line by the amount indicated by the broken line hatching and corresponds to the accelerator opening ACCP with high response.

  In the above-described configuration, the relationship with the claims is that the ECU 34 corresponds to the internal combustion engine output increase suppression means, and steps S152 and S156 of the feedback gain setting process (FIG. 5) in the processing of the ECU 34 are the internal combustion engine output increase suppression means. It corresponds to the processing as.

According to the first embodiment described above, the following effects can be obtained.
(I). Even during the same acceleration operation by the driver, the magnitude of the torque steer varies depending on the steering angle θh. Therefore, in the feedback gain setting process, it is determined whether or not the torque steer is within the torque steer suppression region where the torque steer increases and becomes a problem based on the steering angle θh (S152). Yes), torque steer is suppressed by reducing the gain Kp from normal (S156).

  As for the valve lift amount VL of the intake valve 22 driven by the accelerator operation, the torque steer becomes stronger when the value is larger. Therefore, in the present embodiment, the torque steering suppression region is set by adding the accelerator opening ACCP together with the steering angle θh, and determination is made by both the steering angle θh and the accelerator opening ACCP (S152: FIG. 6), and further gain The value of Kp is also set by both the steering angle θh and the accelerator opening ACCP (S156: FIG. 7).

  By reducing the gain Kp, the responsiveness of the feedback control with respect to the valve lift amount VL of the intake valve 22 based on the accelerator opening ACCP is lowered, and the valve lift amount increasing speed is lowered. In this way, a rapid increase in internal combustion engine output is suppressed, and torque steer is prevented from increasing.

  If the torque steer is at a level at which there is no problem based on the magnitudes of the steering angle θh and the accelerator opening ACCP (No in S152), the valve lift amount increasing speed need not be suppressed. Therefore, the acceleration performance of the vehicle is not reduced more than necessary.

  Thus, in the vehicle internal combustion engine 2 that performs output control by continuously changing the valve lift amount VL of the intake valve 22, torque steer during acceleration operation can be effectively prevented.

[Embodiment 2]
In the first embodiment, two maps MAPθh (FIG. 6) and MAPkp (FIG. 7) are used. However, in this embodiment, one map MAPkpx is used as shown in FIG. In this map MAPkpx, the same Kp as in FIG. 7 is set in the region corresponding to the torque steer suppression region in FIG. Kp = Kp0 is set outside the region corresponding to the torque steer suppression region. Therefore, the feedback gain setting process can be performed as shown in FIG. 10 instead of FIG. Other configurations are the same as those of the first embodiment.

When the process of FIG. 10 is started, it is first determined whether or not the accelerator opening ACCP is increasing (S248). This process is the same as step S148 in FIG.
If the accelerator opening ACCP is increased (yes in S248), the steering angle θh detected by the steering angle sensor 50 is read (S250). Based on the steering angle θh and the accelerator opening ACCP, the gain Kp is calculated from the map MAPkpx shown in FIG. 9 (S252). As described above, the map MAPkpx is set to Kp = Kp0 outside the region corresponding to the torque steer suppression region. Therefore, when the steering angle θh and the accelerator opening ACCP are outside the region corresponding to the torque steer suppression region, the valve lift corresponding to the accelerator operation is the same as the case where it is determined no in step S152 of FIG. The quantity VL is realized with high response.

  Further, the map MAPkpx is set such that Kp <Kp0 in the region corresponding to the torque steer suppression region as described above, and a smaller gain Kp is set as it goes to the upper right as shown by the dashed contour line. As a result, the power supply control for the accelerator opening ACCP drives the drive motor of the variable lift amount mechanism 32 with a low response, and the responsiveness of the valve lift VL to the accelerator opening ACCP becomes low. That is, the time to reach the target valve lift amount VLt is delayed.

  When the accelerator opening ACCP is not increased (No in S248), the initial gain Kp0 is set as the gain Kp (S254), and the valve lift VL corresponding to the accelerator operation is realized with high response. Is done.

  In the configuration described above, the relationship with the claims corresponds to the processing as the internal combustion engine output increase suppression means in step S252 of the feedback gain setting processing (FIG. 10) in the processing of the ECU 34.

According to the second embodiment described above, the following effects can be obtained.
(I). The same effect as the first embodiment is produced.
[Embodiment 3]
In the map MAPkpx (FIG. 9) of the second embodiment, two data (steering angle θh, accelerator opening ACCP) are used, but in this embodiment, the gain Kp is calculated only from the steering angle θh as shown in FIG. Map MAPkpa is used. In this map MAPkpa, Kp = Kp0 when | θh | = 0 °, but Kp <Kp0 when | θh |> 0 °, and the gain Kp gradually decreases as | θh | increases.

Therefore, the feedback gain setting process can be performed as shown in FIG. 12 instead of FIG. Other configurations are the same as those of the second embodiment.
When the processing of FIG. 12 is started, it is first determined whether or not the accelerator opening ACCP is increasing (S348). This process is the same as step S148 in FIG.

  When the accelerator opening ACCP is not increased (no in S348), the initial gain Kp0 is set as the gain Kp (S354), and the valve lift VL corresponding to the accelerator operation is realized with a high response. .

  If the accelerator opening ACCP is increasing (yes in S348), the steering angle θh detected by the steering angle sensor 50 is read (S350). Based on the steering angle θh, the gain Kp is calculated from the map MAPkpa shown in FIG. 11 (S352). Since this map MAPkpa is as described above, when | θh | = 0 °, Kp = Kp0, and the drive motor of the variable lift amount mechanism 32 rotates with sufficient responsiveness by power supply control, and the accelerator The valve lift amount VL corresponding to the operation is realized with high response.

  When | θh |> 0 °, a smaller gain Kp is set as | θh | is larger. Accordingly, as | θh | is larger, the power supply control with respect to the accelerator opening ACCP drives the drive motor of the variable lift amount mechanism 32 with a low response, and the response of the valve lift VL to the accelerator opening ACCP is Lower. That is, the time to reach the target valve lift amount VLt is delayed.

  As shown in the timing chart of FIG. 13, since | θh | = 0 ° before the timing t10, the valve lift amount VL corresponds to the accelerator opening ACCP with a high response. Even when | θh |> 0 °, when the accelerator opening ACCP is not increased, or when the increase of the accelerator opening ACCP can be sufficiently handled with the gain Kp corresponding to | θh | (t10 to t11), There is no problem with responsiveness.

  However, when the accelerator opening ACCP is rapidly increased by the driver's accelerator operation at | θh |> 0 ° (after t11), the response is lowered by the gain Kp corresponding to | θh | t11-t12). Note that, at the timings t11 to t12, the hatched portion of the broken line indicates the high response when | θh | = 0 °.

  In the configuration described above, the relationship with the claims corresponds to the processing as the internal combustion engine output increase suppression means in step S352 of the feedback gain setting processing (FIG. 12) in the processing of the ECU 34.

According to the third embodiment described above, the following effects can be obtained.
(I). The gain Kp is reduced only by the steering angle θh. However, even in this configuration, when torque steer becomes a problem, the gain Kp is reduced to provide feedback to the valve lift amount VL of the intake valve 22 based on the accelerator opening ACCP. Control responsiveness decreases, and the rate of increase in valve lift decreases. In this way, a rapid increase in driving force of the internal combustion engine is suppressed, and torque steer is prevented from increasing.

If the steering angle θh = 0 °, the increase rate of the valve lift amount is not suppressed. Therefore, the acceleration performance of the vehicle is not reduced more than necessary.
Thus, in the vehicle internal combustion engine 2 that performs output control by continuously changing the valve lift amount VL of the intake valve 22, torque steer during acceleration operation can be effectively prevented.

[Embodiment 4]
In the present embodiment, the map MAPkpy shown in FIG. 14 is used instead of the map MAPkpx shown in FIG. 9 in the configuration of the second embodiment. In this map MAPkpy, when the accelerator opening ACCP is larger than the reference opening ACCPstd and | steering angle θh | is larger than the reference angle θstd, a fixed value smaller than the initial gain Kp0 is set for the gain Kp. In other areas, the initial gain Kp0 is set as the gain Kp.

As a result, when ACCP> ACCPstd and | θh |> θstd, the increasing speed of the valve lift amount VL of the intake valve 22 is suppressed.
As a result, substantially the same effect as in the second embodiment can be produced.

[Embodiment 5]
In the present embodiment, the map MAPkpb shown in FIG. 15 is used instead of the map MAPkpa shown in FIG. 11 in the configuration of the third embodiment. In this map MAPkpb, when | steering angle θh | is larger than reference angle θstdb, gain Kp is set to a value smaller than initial gain Kp0. In other areas, the initial gain Kp0 is set as the gain Kp.

As a result, when | θh |> θstdb, the increasing speed of the valve lift amount VL of the intake valve 22 is suppressed.
As a result, substantially the same effect as in the third embodiment can be produced.

[Other embodiments]
(A). In the fourth embodiment, in the region where ACCP> ACCPstd and | θh |> θstd, the gain Kp is set to a fixed value smaller than the initial gain Kp0. Instead, in the region where ACCP> ACCPstd and | θh |> θstd, the same gain Kp value as the map set in the torque steer suppression region of FIG. 7 may be arranged.

  (B). In the fifth embodiment, a fixed value smaller than the initial gain Kp0 is set for the gain Kp when | θh |> θstdb, but instead, the same as the map MAPkpa in FIG. 11 when | θh |> θstdb. A value of the gain Kp may be arranged.

  (C). As another method of suppressing the valve lift amount increase speed in each of the above embodiments, the increase speed of the target valve lift amount VLt is not set to the increase speed corresponding to the accelerator opening ACCP, but is increased from the increase speed of the accelerator opening ACCP. It is also possible to make the rate of increase low. In this case, the target valve lift amount VLt may be corrected by a certain amount of increase speed reduction correction with respect to the acceleration speed of the accelerator opening ACCP, or may be corrected by a certain ratio.

  Alternatively, instead of the target valve lift amount VLt, the actual valve lift amount VL is directly adjusted so as not to increase corresponding to the accelerator opening ACCP, but to an increase rate lower than the increase rate of the accelerator opening ACCP. good. In this case as well, the valve lift amount VL may be reduced by a certain amount with respect to the increasing speed of the accelerator opening ACCP, or may be reduced at a certain rate.

  (D). In each of the above embodiments, a four-wheel drive vehicle is assumed. However, any vehicle that transmits a driving force to a steered wheel can be applied to a front wheel drive vehicle. The number of cylinders is not limited to four, and can be applied to an internal combustion engine having other numbers of cylinders.

1 is a block diagram illustrating a schematic configuration of an internal combustion engine and an internal combustion engine control device according to Embodiment 1. FIG. The valve lift amount variable state explanatory drawing of the intake valve by the lift amount variable mechanism. 3 is a flowchart of intake air amount control processing according to the first embodiment. Structure explanatory drawing of map MAPaccp. 5 is a flowchart of feedback gain setting processing according to the first embodiment. The structure explanatory drawing of map MAPthetah. The structure explanatory drawing of map MAPkp. 4 is a timing chart illustrating an example of processing according to the first embodiment. The structure explanatory drawing of map MAPkpx. 10 is a flowchart of feedback gain setting processing according to the second embodiment. The structure explanatory drawing of map MAPkpa. 10 is a flowchart of feedback gain setting processing according to the third embodiment. 10 is a timing chart illustrating an example of processing according to the third embodiment. The structure explanatory drawing of map MAPkpy. The structure explanatory drawing of map MAPkpb.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 2 ... Internal combustion engine, 4 ... Combustion chamber, 6 ... Intake passage, 6a ... Surge tank, 6b ... Throttle valve, 8 ... Fuel injection valve, 10 ... Spark plug, 12 ... Piston, 14 ... Crankshaft, 16 ... Exhaust passage, 22 ... Intake valve, 24 ... Exhaust valve, 26 ... Intake camshaft, 28 ... Exhaust camshaft, 30 ... Variable valve timing mechanism, 32 ... Variable lift amount mechanism, 34 ... ECU, 36 ... Crank angle sensor, 38 ... Cam angle Sensor 39 Accelerator pedal 40 Accelerator opening sensor 42 Throttle position sensor 44 Air flow meter 46 Air-fuel ratio sensor 48 Steering wheel 50 Steering angle sensor 52 Valve lift sensor

Claims (8)

Accelerator opening detected by accelerator opening detecting means in an internal combustion engine for a vehicle having a variable valve mechanism that transmits a driving force to a steering wheel of a vehicle and continuously varies a valve lift amount of an intake valve An internal combustion engine control device that performs internal combustion engine output control by adjusting the valve lift amount of the intake valve according to the variable valve mechanism according to
Steering angle detection means for detecting the steering angle;
Internal combustion engine output increase suppression means for suppressing the valve lift amount increase rate of the intake valve by the variable valve mechanism based on the magnitude of the steering angle detected by the steering angle detection means;
An internal combustion engine control apparatus comprising: 2. The internal combustion engine output increase suppression means according to claim 1, wherein when the magnitude of the steering angle detected by the steering angle detection means is larger than a reference angle, the valve lift amount of the intake valve by the variable valve mechanism is increased. An internal combustion engine control apparatus characterized by suppressing speed. 2. The internal combustion engine output increase suppressing means according to claim 1, wherein the steering angle detected by the steering angle detecting means is larger than a reference angle and the accelerator opening detected by the accelerator opening detecting means. An internal combustion engine control device that suppresses the rate of increase in the valve lift amount of the intake valve by the variable valve mechanism when the valve opening is larger than a reference opening. 2. The internal combustion engine output increase suppressing means according to claim 1, wherein the steering angle detected by the steering angle detecting means and the accelerator opening detected by the accelerator opening detecting means are the steering angle and the state of the accelerator opening. In the two-dimensional space consisting of the accelerator opening, when the torque steer is within the torque steer suppression region set on the side where the torque steer increases, the valve lift increase rate of the intake valve by the variable valve mechanism is suppressed. An internal combustion engine control device. 5. The internal combustion engine control apparatus according to claim 1, wherein the internal combustion engine output increase suppression means suppresses the valve lift amount increase speed by providing a limit to the valve lift amount increase speed. 5. The internal combustion engine output increase suppression means according to claim 1, wherein the internal combustion engine output increase suppression means has a valve lift amount increase speed higher than an increase speed corresponding to the increase speed of the accelerator opening detected by the accelerator opening detection means. An internal combustion engine control apparatus characterized by suppressing a valve lift amount increasing speed by lowering. 7. The internal combustion engine control device according to claim 1, wherein the internal combustion engine output increase suppression means increases the suppression of the valve lift amount increase rate as the steering angle increases. 8. The internal combustion engine control device according to claim 1, wherein the internal combustion engine output increase suppression means increases the suppression of the valve lift increase rate as the accelerator opening increases.

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