JPH05163996A - Control device for engine - Google Patents

Abstract

PURPOSE:To prevent the deterioration of fuel consumption and emission and moreover to properly control engine torque in a device to control the engine torque so as to fit with desired torque at specified time. CONSTITUTION:A engine control device (c) has a means (a) to adjust intake air quantity and a means (b) to adjust igniting timing or the like, and is provided with a means (d) to compute supposed torque corresponding to engine torque in the case where the ignition timing is set up on the basis of predetermined characteristic, a means (e) to execute the feedback control of the intake air quantity so as to make the supposed torque correspond with desired torque, and a means (f) to correct the ignition timing according to the deviation of the engine torque at the time of the above feedback control from the desired torque.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine control device having means for controlling an engine torque to a required torque at a specific time.

[0002]

2. Description of the Related Art Heretofore, various engine control devices have been known which are provided with means for controlling an engine torque to meet a request at a specific time, in addition to torque adjustment by a driver's accelerator operation.

For example, in the device disclosed in Japanese Patent Laid-Open No. 55-46905, a torque shock due to a change in gear ratio is generated at the time of gear shifting of a vehicle in which a multi-stage automatic transmission is connected to an engine. In order to suppress the engine torque, the engine torque is reduced by controlling the ignition timing and the fuel supply amount.

In the device disclosed in the above publication, torque control parameters such as ignition timing are changed according to a preset time function during gear shifting. It is also considered that the required torque is set and the torque control parameter is changed so that the required torque is obtained by the feedback control. According to this feedback control, the engine torque can be accurately adapted to the required.

[0005]

In this type of device, as the torque control at the time of gear shifting, the ignition timing control and the fuel cut control are generally adopted because of their excellent responsiveness. However, according to the control of the ignition timing,
When the torque is reduced, the ignition timing is retarded, which may cause deterioration of fuel efficiency and emission.Furthermore, the fuel cut control causes the torque reduction to be gradual and the fine control cannot be performed. It is easy to cause deterioration of

Therefore, as torque control which does not cause such a harmful effect, the intake air amount is controlled, and, for example, the throttle valve in the intake passage is operated by an actuator in response to a control signal, and the throttle valve in response to an accelerator operation. It is conceivable to control the throttle valve so as to reduce the intake air amount during gear shifting, separately from the operation of. But,
In the control of the intake air amount, the response delay becomes larger than that in the control of the ignition timing.

From the above, it is effective to combine the control of the intake air amount and the control of the ignition timing and the like with good responsiveness as the control of the engine torque at the time of shifting. However, in this case, if the change of the engine torque due to the control of the ignition timing or the like affects the feedback control of the intake air amount, the ratio of the torque control by the intake air amount becomes small, and the advantages of the intake air amount control are fully exerted. Disappear.

In view of the above circumstances, the present invention combines the control of the intake air amount and the control of other torque control parameters,
Moreover, it is an object of the present invention to provide an engine control device capable of sufficiently controlling the intake air amount and appropriately controlling the engine torque without deteriorating the fuel consumption and the emission.

[0009]

To achieve the above object, the present invention controls the torque adjusting means for adjusting the torque of the engine 1 and the torque adjusting means so that the engine torque becomes a required torque at a specific time. In an engine control device including control means c, an intake air amount adjusting means a for adjusting the intake air amount of the engine 1 as the torque adjusting means and a torque control parameter adjusting means for adjusting a torque control parameter other than the intake air amount. and a torque calculation for calculating an assumed torque corresponding to the engine torque when the control means c is provided with a torque control parameter other than the intake air amount based on a predetermined engine control characteristic. Means d and the control amount of the intake air amount adjusting means a so that the assumed torque converges to the required torque. Of the intake air amount feedback control means e, and the control amount of the torque control parameter adjusting means b according to the deviation between the engine torque and the required torque when the control by the intake air amount feedback control means e is performed. The correction means f for feedback correction is provided.

In this structure, the intake air amount adjusting means a
It is preferable that the actuator adjusts the opening degree of the throttle valve in the intake passage according to a control signal.

The torque control parameter adjusting means b adjusts the ignition timing, and the torque calculating means d calculates the assumed torque from the charging efficiency, the engine speed and the preset ignition timing based on a predetermined ignition timing map. The correction means f is an intake air amount feedback control means e.
It is preferable that the ignition timing is feedback-corrected in accordance with the deviation between the actual engine torque or the assumed torque and the required torque when the control is performed.

Further, the control by the intake air amount feedback control means e and the correction means f of the control means c reduces the engine torque to the required torque at the time of gear shifting of the automatic transmission in the vehicle in which the automatic transmission is connected to the engine. Is preferred.

[0013]

According to the above construction, the control for making the engine torque the required torque at the specific time is mainly performed by the feedback control of the intake air amount. However, during the response delay of the feedback control of the intake air amount, The engine torque becomes the required torque by correcting the torque control parameter such as the ignition timing. Then, during the intake air amount feedback control after the response delay period, since the intake air amount such that the assumed torque matches the required torque is given, the torque control parameter is based on a predetermined engine control characteristic. It is returned to the set value.

[0014]

Embodiments of the present invention will be described with reference to the drawings.
FIG. 2 schematically shows the entire apparatus when the present invention is applied to control of engine torque during shifting of an automatic transmission. In the figure, 1 is an engine, 2 is an intake passage, and a throttle valve 4 driven by an electric actuator 3 such as a servomotor is provided in the intake passage 2. The throttle valve 4 and the actuator 3 constitute intake air amount adjusting means. An air flow meter 5 that detects the amount of intake air is provided upstream of the throttle valve 4.

A spark plug 6 is provided in each cylinder of the engine 1.
Is provided. The spark plug 6 is connected to an ignition circuit 7 composed of an ignition coil, a distributor and the like, and the ignition circuit 7 can adjust the ignition timing according to a control signal. The ignition circuit 7 constitutes torque control parameter adjusting means for adjusting the ignition timing as a torque control parameter other than the intake air amount.

Further, the engine 1 is equipped with an engine speed sensor 8 for detecting the engine speed, a throttle opening sensor 9 for detecting the opening of the throttle valve 4, and the like.

Reference numeral 10 denotes a multi-stage automatic transmission, which includes a torque converter 11 connected to the output shaft of the engine 1, a transmission mechanism 12 connected to the output side of the torque converter 11, and this transmission mechanism. Various friction elements (not shown) included in 12 and a hydraulic control circuit 13 that controls the hydraulic pressure supply to the torque converter 11. The hydraulic control circuit 13 is provided with a plurality of shift solenoid valves 14 for switching the hydraulic pressure supply / discharge state to the friction element of the speed change mechanism 12 and a duty solenoid valve 15 for controlling the line pressure. Further, the automatic transmission 10 has a rotation speed sensor 1 for detecting the rotation speed of the transmission mechanism on the input side (the turbine speed of the torque converter 11).
6. Rotation speed sensor 17 for detecting the rotation speed of the output side of the speed change mechanism
And so on.

Detection signals from the air flow meter 5 and each sensor are input to a control unit (ECU) 20. The ECU 20 performs shift control by outputting a control signal to the shift solenoid valve 14 according to the operating state of the vehicle (for example, accelerator operation amount and vehicle speed), while the ECU 3 of the throttle valve 4 receives the control signal. The output is controlled to control the throttle opening, the control signal is output to the ignition circuit 7 to control the ignition timing, and the engine torque is controlled by controlling the throttle opening and controlling the ignition timing.

The ECU 20 constitutes the control means c in FIG. 1, and the torque calculation means d, the intake air amount feedback control means e, and the correction means f are performed by performing control according to the flowchart described below. It is supposed to fulfill the function as.

A concrete example of control by the ECU 20 is shown in FIG.
It will be described with reference to the flowchart of FIG.

When the routine of FIG. 3 is started, various signals from sensors etc. are first inputted in step S1, and it is judged in step S2 whether or not the shift signal is ON. You can check whether or not. When the determination in step S2 is NO, normal throttle valve control and ignition timing control are performed in step S3. That is, the throttle opening corresponding to the accelerator operation amount at that time is calculated on the basis of the characteristics set in advance in the throttle opening map and the throttle valve is controlled to the opening, and the ignition timing map and the like are set in advance. The ignition timing is set according to the operating state at that time on the basis of the characteristics defined in (3), and the ignition timing is controlled to that value.

When it is determined in step S2 that the shift signal is ON, a torque down routine by throttle valve control is executed in step S4, and then a torque down routine by ignition timing control is executed in step S5. Then, in step S6, it is determined whether or not the gear shift has ended by checking whether the gear ratio or the like has reached a gear shift end equivalent state, and it is determined in step S6 until the gear shift ends.
The process of 4 and step S5 is repeated.

The torque reduction routine by the throttle valve control (step S4) is as shown in FIG.
In this routine, various signals are input in step S41, and subsequently, in step S42, the gear ratio G checked from the input side rotation speed and the output side rotation speed of the speed change mechanism 12 is the reference value Ga for starting determination of the torque down control. It is determined whether or not it is between the end determination reference value Gb. That is, when a shift is performed, for example, in the case of upshifting, as shown in FIG. 9, the gear ratio G gradually decreases from a value corresponding to the shift stage before the shift to a value corresponding to the shift stage after the shift. , A reference value Ga corresponding to the gear ratio at the beginning of the gear shift and a reference value Gb corresponding to the gear ratio at a timing slightly before the end of the gear shift are set according to the gear stages before and after the gear shift, and Ga ≧ G ≧ Gb Is determined. It should be noted that although the figure illustrates the case of upshifting, in the case of downshifting, the magnitude relationship of the gear ratios is reversed in the determinations of step S42 and step S51 described below.

During the period when the determination in step S42 is YES, the processing as the torque calculating means and the intake air amount feedback control means is performed in steps S43 to S48. That is, in step S43, the required torque Tt is read from the map or the like in accordance with the operating state, gear position, elapsed time, etc. at that time, and the assumed torque Te is calculated in step S44 as described later. And
Based on the comparison of the assumed torque Te with the required torque Tt in steps S45 and S46, the throttle opening TVO is reduced by a certain amount ΔTVO when the required torque Tt is larger than the required torque Tt, and the throttle opening T is smaller than the required torque Tt.
VO is increased by a certain amount ΔTVO, and the required torque Tt
And the throttle opening TVO is left unchanged. If the determination in step S42 is NO, step S49 controls the throttle opening based on the predetermined characteristics (normal throttle opening control).
Is done.

The above assumed torque Te is the air charging efficiency C.
It is determined as follows from e, the engine speed Ne, and the set ignition timing I _GO based on the ignition timing map. That is, the engine torque T can be approximated as a quadratic function of the ignition timing I _G as shown in FIG.
If Shimese this formula, T = the ^{_{-A (I G -B) 2 +}} C ...... (1). A, B, and C in this equation are shown in FIGS.
As shown in (c), it is a coefficient that changes according to the operating state of the engine 1, and is preset as a map having the engine speed Ne and the air charging efficiency Ce as parameters.
Then, the current air charging efficiency Ce ₁ is obtained from the engine speed and the intake air amount, and the map is changed to the current operating state from each map according to the air charging efficiency Ce ₁ and the current engine speed Ne _1. The corresponding coefficients A ₁ , B ₁ ,
C ₁ is obtained, and the engine torque T is obtained by substituting these coefficients A ₁ , B ₁ , C ₁ and the ignition timing into the above equation (1). In particular, in the calculation in step S44, even if the actual ignition timing is corrected by the processing of the routine shown in FIG. 5, which will be described later, the set ignition timing I corresponding to the operating state is determined from the predetermined ignition timing map. _GO is sought, and this and A ₁ , B ₁ , C ₁ are (1)
The estimated torque Te is obtained by substituting in the equation. The ignition timing map is such that the ignition timing I _GO is defined in advance in a predetermined correspondence relationship with the operating state (air filling efficiency and engine speed).

The torque reduction routine by ignition timing control (step S5) is as shown in FIG. In this routine, in step S51, the gear ratio G, which is checked from the input rotation speed and the output rotation speed of the transmission mechanism 12, is between the start determination reference value Ga and the end determination reference value Gc of the torque down control. It is determined whether or not there is. in this case,
Considering the response delay of the intake air amount change, the end Gb of the torque down control by the throttle opening is set to some extent before the end of the shift, while the end Gc of the torque down control by the ignition timing is approached at the end of the shift. like,
In the case of upshifting, Gb> Gc is set (see FIG. 9).

During the period when the determination in step S51 is YES, the processing as the correction means is performed in steps S52 and S53. That is, in step S52, the coefficients A ₁ , B ₁ , C ₁ according to the air charging efficiency Ce ₁ and the engine speed Ne ₁ after the processing in steps S42 to S48 of the routine of FIG. 4 are obtained. The engine torque Tq at the present time is calculated by substituting these and the ignition timing I _G1 at the present time into the above equation (1). Then, in step S53, the ignition timing correction amount is obtained from the deviation between the engine torque Tq and the required torque Tt, and the ignition timing is retarded by the correction amount from the previous time. The contents of steps S52 and S53 are shown in FIG.

Incidentally, the engine torque Tq calculated in step S52 is set ignition based on the above-mentioned coefficients A ₁ , B ₁ and C ₁ obtained after the processing in steps S42 to S48 and a predetermined ignition timing map. It may be an assumed torque calculated using the time I _GO and in this case,
In step S53, the set ignition timing I _GO may be retarded by the correction amount obtained from the torque deviation.

When the determination in step S51 is NO, in step S54, ignition timing control based on predetermined characteristics, that is, the set ignition timing determined from the ignition timing map according to the operating state is set. Normal ignition timing control for controlling is performed.

According to the apparatus of the present embodiment as described above, changes in the intake air amount, ignition timing and engine torque during gear shifting are as shown in FIG. That is, during shift, the required torque Tt is set to a value lower than that at the time of non-shift in order to suppress shift shock and the like, and is set to a value according to the operating state and the like. Then, in the processes of steps S43 to S48, while the assumed torque Te is larger than the required torque Tt, the throttle opening TVO is reduced, whereby the intake air amount is reduced and the required torque Tt is reached. Be down. However, since there is a response delay in the change of the intake air amount, the change of the engine torque is shown by the broken line if only by controlling the throttle opening.
The required torque deviates during the response delay period.

On the other hand, in steps S52 and S5 described above.
By the ignition timing correction process in 3, the ignition timing is retarded (reference numeral I1) during the response delay period, and the actual engine torque is corrected to match the required torque Tt.

Further, the throttle opening is controlled so that the assumed torque Te, which is a torque when the ignition timing is assumed to be the set ignition timing I _GO , converges to the required torque Tt, so that the response delay is caused. After the period, the torque is reduced by controlling the throttle opening and the ignition timing returns to the set ignition timing (reference I2). Therefore, the torque reduction at the time of shifting is mainly performed by the reduction of the intake air amount by the throttle valve control, and is compensated by the retard correction of the ignition timing only during the period when the response delay occurs. In this embodiment, the ignition timing is retarded during the period in which the gear ratio G is between Gb and Gc near the end of the shift in addition to the above-mentioned response delay period at the beginning of the shift (reference I3).

In the above embodiment, the torque down control during the shift of the automatic transmission is shown as the control at the specific time performed by the intake air amount feedback control means and the correction means. The present invention can be applied to regulation of engine torque when changing the range of a transmission, regulation of engine torque for traction control, and the like.

As means for adjusting the intake air amount, in addition to the adjustment of the throttle valve by the actuator as in the above-mentioned embodiment, the adjustment by the ISC valve or the like can be considered. Further, the torque control parameter other than the intake air amount is not limited to the ignition timing, but may be any parameter that is related to the engine torque and has better response than the intake air amount.

[0035]

As described above, the present invention is provided with the intake air amount adjusting means and the torque control parameter adjusting means other than the intake air amount, and the torque control parameter other than the intake air amount is predetermined. Means for feedback-controlling the intake air so as to converge the assumed torque corresponding to the engine torque when set based on the control characteristic of the control torque, and the engine torque and the above-mentioned required torque when this control is performed. And means for correcting the torque control parameter in accordance with the deviation from Therefore, the control for making the engine torque the required torque is mainly performed by the intake air amount to improve the fuel consumption and the emission, and the response delay of the intake air amount control is compensated by the correction of the torque control parameter to ensure the proper operation. The engine torque can be controlled.

When the intake air amount adjusting means adjusts the opening degree of the throttle valve by the actuator, the feedback control of the intake air amount can be easily performed.

Further, the ignition timing is used as a torque control parameter, and the assumed torque is calculated from the charging efficiency, the engine speed, and the set ignition timing based on a predetermined ignition timing map. When the control is performed, the effects of improving fuel efficiency and emission and ensuring responsiveness are enhanced.

When the control for reducing the engine torque to the required torque at the time of shifting the automatic transmission is performed by the above feedback control of the intake air amount and the correction of the torque control parameter such as the ignition timing, the fuel consumption and the emission are improved. At the same time, it is possible to properly perform control for suppressing shift shock and the like.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing a configuration of the present invention.

FIG. 2 is a schematic view of an entire apparatus according to an embodiment of the present invention.

FIG. 3 is a flowchart showing a main routine of control by an ECU.

FIG. 4 is a flowchart of a torque reduction routine by throttle valve control.

FIG. 5 is a flowchart of a torque reduction routine by ignition timing control.

FIG. 6 is a characteristic diagram of engine torque with respect to ignition timing.

7 (a), (b) and (c) are maps for obtaining respective coefficients in an approximate expression of engine torque.

FIG. 8 is an explanatory diagram showing how to determine an ignition timing correction amount in a characteristic diagram of engine torque with respect to ignition timing.

FIG. 9 is a time chart showing changes in gear ratio, engine torque, throttle opening, and ignition timing during gear shifting.

[Explanation of symbols]

 a intake air amount adjustment means b torque control parameter adjustment means c control means d torque calculation means e intake air amount feedback control means f correction means 1 engine 3 actuator 4 throttle valve 7 ignition circuit 20 ECU

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location F02D 45/00 320 A 7536-3G 330 7536-3G F02P 5/15 B 9150-3G

Claims (4)

[Claims] 1. A control device for an engine, comprising: a torque adjusting means for adjusting an engine torque; and a controlling means for controlling the torque adjusting means so that the engine torque becomes a required torque at a specific time. In addition to the intake air amount adjusting means for adjusting the intake air amount of the engine and the torque control parameter adjusting means for adjusting the torque control parameter other than the intake air amount, the control means previously stores the torque control parameter other than the intake air amount. A torque calculation means for calculating an assumed torque corresponding to the engine torque when set based on a predetermined engine control characteristic, and an intake air amount adjusting means for converging the assumed torque to the required torque. Intake air amount feedback control means for changing the control amount and this intake air amount feed Control of the engine, characterized in that correction means for feedback-correcting the control amount of the torque control parameter adjusting means in accordance with the deviation between the engine torque and the required torque when the control by the back control means is performed are provided. apparatus. 2. The engine control device according to claim 1, wherein the intake air amount adjusting means adjusts the opening of the throttle valve in the intake passage by an actuator according to a control signal. 3. The torque control parameter adjusting means adjusts the ignition timing, and the torque calculating means calculates the assumed torque from the charging efficiency, the engine speed and the preset ignition timing based on a predetermined ignition timing map. The correction means feedback-corrects the ignition timing in accordance with a deviation between an actual engine torque or an assumed torque when the intake air amount feedback control means is controlled and the required torque. Or 2
The engine control device described. 4. The control by the intake air amount feedback control means and the correction means of the control means is to reduce the engine torque to the required torque when shifting the automatic transmission in a vehicle in which the engine is connected to the automatic transmission. 4. The engine control device according to any one of Items 1 to 3.