JP2007032381A - Control device for vehicle engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid giving a driver a feeling of idling or being pushed out by rotation synchronous control at the time of shifting when a deceleration request is strong.
SOLUTION: At the time of downshift, a target throttle opening TVOt that obtains a synchronous rotational speed is calculated. On the other hand, the acceleration and braking force of the vehicle are detected, and a larger correction value TVOh is set as the negative acceleration increases and the braking force increases. The final target throttle opening TVOs is obtained by subtracting the correction value TVOh from the target throttle opening TVOt.
[Selection] Figure 2

Description

  The present invention relates to a control device for a vehicle engine that performs rotation synchronization control that adjusts an engine rotation speed to a synchronization rotation speed during a shift in a transmission that transmits engine output to drive wheels.

In Patent Document 1, in an internal combustion engine equipped with an automatic transmission, the throttle valve is opened so that the rotational speeds of the input side and the output side of the clutch of the next stage gear shift substantially coincide with each other during the shift in the automatic transmission. A control device is disclosed that controls the degree of rotation and detects that the rotational speeds of the input side and the output side substantially coincide with each other and then connects the clutch of the next speed stage.
JP 09-295528 A

  By the way, as described above, after detecting that the rotational speeds of the input side and the output side substantially coincide with each other and then performing the rotation synchronization control to connect the clutch of the next speed stage, the occurrence of the shift shock can be prevented. However, when downshifting with a strong deceleration request, a shift without shift shock due to rotation synchronization control may give the driver a feeling of idling or being pushed against the strong deceleration request. was there.

  The present invention has been made in view of the above problems, and controls a vehicle engine that can avoid giving a driver a feeling of idling or being pushed by rotation synchronous control during a shift when a deceleration request is strong. An object is to provide an apparatus.

  Therefore, the vehicular engine control apparatus according to the present invention is characterized in that correction is applied to the rotation synchronization control for adjusting the engine rotation speed to the synchronization rotation speed in accordance with the strength of the deceleration request during downshifting.

  According to this configuration, when the deceleration request is weak, a shift in the rotation synchronization control inherent in the rotation synchronization state is realized to prevent the occurrence of a shift shock, and when the deceleration request is strong, the rotation synchronization control is corrected. By restricting the adjustment of the engine rotation speed, it is possible to prevent the driver from feeling idle or pushed out.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram showing a power train of a vehicle according to the embodiment together with its control system. The output of an engine (gasoline internal combustion engine) 1 is input to an automatic transmission 2, and the output shaft of the automatic transmission 2 The drive wheel 3 is rotationally driven.
The automatic transmission 2 switches a gear stage by combining a planetary gear transmission 5 with a torque converter 4 and controlling engagement / release of friction engagement elements such as clutches and brakes by hydraulic pressure.

For the hydraulic control, the automatic transmission 2 is provided with a control valve 9 having shift solenoids 6-8.
The shift solenoids 6 to 8 are controlled by a transmission controller 10 incorporating a microcomputer.
The transmission controller 10 receives detection signals from an output rotation sensor 11 that detects the rotation speed No of the output shaft of the automatic transmission 2 and a turbine sensor 12 that detects the turbine rotation speed Nt of the torque converter 3. At the same time, the engine controller 13 receives signals of the engine speed Ne and the accelerator opening APO.

The transmission controller 10 determines a target shift stage by referring to a shift map based on the output shaft rotational speed No (vehicle speed equivalent value) and the accelerator opening APO, If the shift speed is different, the shift solenoids 6 to 8 are controlled to switch between release and engagement of the friction engagement elements, and the shift speed is shifted to the target shift speed.
The intake air amount Q of the engine 1 is adjusted by the electric throttle device 14.

The electric throttle device 14 is a device that adjusts the opening of a butterfly throttle valve 16 by a throttle actuator 15 such as a motor.
An engine controller 13 incorporating a microcomputer inputs detection signals from various sensors, controls the electric throttle device 14 (throttle actuator 15) based on these signals, and controls the fuel injection amount and ignition timing in the engine 1. It has a function to control.

As the various sensors, there are provided an accelerator opening sensor 18 for detecting the depression amount of the accelerator pedal 17 (accelerator opening APO), an engine rotation sensor 19 for detecting the engine rotation speed Ne, and the like.
In the control of the electric throttle device 14 (throttle actuator 15), the engine controller 13 normally sets a target throttle opening mainly according to the accelerator opening APO, and according to the target throttle opening. Output a control signal.

On the other hand, at the time of downshift, a target throttle opening for obtaining the synchronous rotational speed transmitted from the transmission controller 10 is set based on the deviation between the synchronous rotational speed and the actual engine rotational speed Ne, and the target throttle By outputting a control signal corresponding to the opening, rotation synchronization control is performed to adjust the engine rotation speed corresponding to the requested synchronous rotation speed.
The rotation synchronization control is a control for making the rotational speeds of the input side and the output side of the friction engagement element newly engaged at the time of shifting substantially coincide with each other, and the transmission controller 10 controls the output shaft rotational speed at the time of shifting. Based on No and the gear ratio after the shift, the target of the engine speed for synchronizing the rotation is output as the requested synchronous speed.

  The transmission controller 10 is a friction engagement element that is fastened at a shift stage before a shift and should be released at a shift stage after a shift when a downshift request is generated as the accelerator pedal is released or the vehicle speed decreases. The hydraulic pressure of the (release side frictional engagement element) is reduced and released, and the requested synchronous rotational speed corresponding to the engine rotational speed after the shift is output to the engine controller 13 in the released state of the frictional engagement element.

When the actual engine rotational speed Ne substantially matches the required synchronous rotational speed by adjusting the throttle opening by the engine controller 13, the hydraulic pressure to the friction engagement element to be engaged at the shift stage after the shift is increased. Fasten and complete downshift control.
By the way, if the downshift is performed by synchronizing the rotation by the rotation synchronization control, the friction engagement element can be fastened without generating a large shift shock.

However, during a downshift with a strong deceleration request, the downshift without the shift shock may give the driver a feeling of running away or being pushed out (see FIG. 3).
Therefore, in this embodiment, the engine controller 13 corrects the target throttle opening calculated in order to obtain the synchronous rotation speed according to the strength of the deceleration request, and details of such correction control are shown in FIG. This will be described with reference to the flowchart of FIG.

In the flowchart of FIG. 2, first, in step S <b> 11, it is determined whether or not a downshift request is generated based on a signal from the transmission controller 10.
When a downshift request is generated, the process proceeds to step S12, and the synchronous rotational speed calculated by the transmission controller 10 is read.
In the next step S13, a target throttle opening TVOt for obtaining the synchronous rotation speed is calculated.

The target throttle opening TVOt is set by feedback-correcting the basic opening corresponding to the accelerator opening based on the deviation between the synchronous rotational speed and the actual engine rotational speed Ne.
In step S14, the acceleration of the vehicle is detected as a time differential value of the output shaft rotational speed No. An acceleration sensor can be provided to detect acceleration.

In step S15, the braking force is detected. The brake force is detected as the depression amount of the brake pedal 21 detected by the brake sensor 20, the depression force of the brake pedal 21, or the brake hydraulic pressure.
In step S16, a correction value TVOh for correcting the target throttle opening TVOt in the rotation synchronous control is calculated based on the acceleration and the braking force, which are variables indicating the strength of the deceleration request.

The correction value TVOh is set to 0 when the negative acceleration is equal to or less than a predetermined value and / or when the braking force is equal to or less than the predetermined value. The larger the negative acceleration is, the larger the braking force is. Indeed, it is set to a larger value.
Here, it is determined that the deceleration request is stronger as the negative acceleration is larger, and the deceleration request is determined to be stronger as the braking force is larger. Therefore, the correction value TVOh is set to 0 when the deceleration request is weak, The stronger the deceleration request, the larger the value is set.

  The correction value TVOh can be set based on either the acceleration or the braking force, and the addition result of the correction value set based on the acceleration and the correction value set based on the braking force is finally obtained. Or a basic correction value set based on one of acceleration and braking force can be corrected with a correction coefficient based on the other.

In step S17, a result obtained by subtracting the correction value TVOh from the target throttle opening TVOt is set as a final target throttle opening TVOs.
In step S18, the throttle actuator 15 is driven and controlled based on the target throttle opening TVOs.
According to the above configuration, when the deceleration request is strong and further deceleration is desired in accordance with the downshift, the throttle opening by the rotation synchronous control is corrected to be smaller and the engine rotation is limited to a low value. A feeling of free running or a feeling of being pushed out is not given to the driver, and a feeling of deceleration corresponding to the deceleration request can be given to the driver (see FIG. 3).

On the other hand, when the deceleration request is weak, rapid deceleration accompanying shift down can be avoided by rotation synchronous control, and smooth deceleration traveling can be realized.
In addition to the normal normal pattern, as a shift pattern, a power pattern having a wide low speed range is set, and in an automatic transmission in which switching between the normal pattern and the power pattern is performed automatically or manually. For example, only when the power pattern is selected, the correction according to the deceleration request can be executed, or the correction degree of the power pattern can be increased as compared with the normal pattern.

In other words, the state in which the power pattern is selected can be determined as a state in which the deceleration request is strong.
Even if the shift pattern is not switched, the tendency of the driver to perform smooth driving or sudden acceleration / deceleration based on the driving history such as the amount of depression of the accelerator pedal or brake pedal When the tendency to perform rapid acceleration / deceleration is strong, it can be determined that the deceleration request is strong, and correction can be applied to the rotation synchronization control.

Further, as a parameter for determining the strength of the deceleration request, it is also possible to detect a road condition such as a downward slope.
In the above embodiment, the target throttle opening for obtaining the synchronous rotational speed is corrected according to the strength of the deceleration request. However, the synchronous rotational speed (target value of the engine rotational speed) is adjusted according to the strength of the deceleration request. It can be configured to correct.

Furthermore, the correction of the rotation synchronization control according to the strength of the deceleration request may be a correction for canceling the rotation synchronization control when the deceleration request is large.
Also, in a vehicle equipped with a manual transmission, when performing shift determination based on the shift lever position and performing rotation synchronization control, the rotation synchronization control is performed according to the strength of the deceleration request during downshifting, as in the above embodiment. Corrections can be added.

The figure which shows the power train of the vehicle in embodiment with the control system. The flowchart which shows the rotation synchronous control in embodiment same as the above. The time chart which shows the throttle control characteristic at the time of downshift in embodiment same as the above.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Automatic transmission, 3 ... Drive wheel, 4 ... Torque converter, 5 ... Planetary gear transmission, 6-8 ... Shift solenoid, 9 ... Control valve, 10 ... Transmission controller, 11 ... Output rotation sensor , 12 ... Turbine sensor, 13 ... Engine controller, 14 ... Electric throttle device, 15 ... Throttle actuator, 16 ... Throttle valve, 17 ... Accelerator pedal, 18 ... Accelerator opening sensor, 19 ... Engine rotation sensor, 20 ... Brake sensor , 21 ... Brake pedal

Claims (5)

A control device for a vehicle engine that performs rotation synchronous control for adjusting an engine rotation speed to a synchronous rotation speed during a shift in a transmission that transmits engine output to driving wheels,
A control device for a vehicle engine, wherein correction is applied to the rotation synchronization control according to the strength of deceleration request during downshifting. The vehicle engine control device according to claim 1, wherein the strength of the deceleration request is detected based on vehicle acceleration and / or braking force. 3. The vehicle engine control device according to claim 1, wherein the stronger the deceleration request, the lower the engine speed during the rotation synchronization control. 4. A target throttle opening for obtaining the synchronous rotation speed is calculated, and a throttle actuator is controlled based on the target throttle opening,
The control device for a vehicle engine according to any one of claims 1 to 3, wherein the target throttle opening is corrected according to the strength of the deceleration request. 5. The control device for a vehicle engine according to claim 4, wherein the target throttle opening is corrected to be smaller as the deceleration request is stronger.

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