JPH04129842A - Integrated control device for engine and automatic transmission - Google Patents

Abstract

PURPOSE:To reduce a speed change shock under all conditions by making feedback control, in which an engine speed is made to conform to an engine speed target value decided in response to a vehicle speed detected value, during a speed change by accelerator foot-separation up shifting. CONSTITUTION:When a speed changing condition by accelerator footseparation up shifting is detected with an acceleration operation detection means (c) and an in-speed-changing detection means (d), an engine speed target value, by which a speed change shock is restrained in a low degree in an engine speed target value deciding means (g), is decided in response to at least a vehicle speed detected value from an vehicle speed detection means (e). Then a feedback control command, by which an engine speed detected value at the time of idling from an engine speed detection means (a) is made to conform to the engine speed target value, is outputted to an idling engine speed control means (f) in an integrated control means (h). This can control an idling engine speed of an engine to retain the engine speed target value, by which the speed change shock is restrained in a low degree, during a speed change by accelerator foot- separation up shifting.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a comprehensive control device for an engine and an automatic transmission that performs idle speed control.

(Conventional technology) The shift shock caused by upshifting when the accelerator foot is released puts the power train in a neutral state at the same time as the shift, and when the torque converter output shaft rotation reaches a predetermined rotation determined by the transmission output shaft rotation and the gear ratio, the shift shock occurs after the shift. It is known that if the gear shifting elements of the two gears are engaged in synchronization, it is possible to shift gears without shock.

On the other hand, in conventional automatic transmissions, a device is known that performs shift timing control by detecting the rotation of a torque converter input shaft during an upshift when the accelerator foot is released.

Further, since detecting the rotation of the input shaft and output shaft of a torque converter increases costs, devices are known in which the shift timing (time) is set at a fixed time assuming ideal conditions.

(Problem to be Solved by the Invention) However, in the former of the above-mentioned conventional transmission control devices, the responsiveness of the transmission element on the automatic transmission side and the rotational fall speed of the engine change depending on the warm-up condition of the engine. Therefore, it is not possible to always perform shift timing control that suppresses shift shock.

In the latter of the above conventional speed change control devices,
Because the shift timing control is based on a fixed time assuming ideal conditions, variations occur depending on the vehicle, and if the engine warm-up condition deviates from the assumed ideal conditions, a shift shock may occur.

The present invention has been made with attention to the above-mentioned problems, and is a comprehensive control device for an engine and an automatic transmission that performs idle speed control. The objective is to reduce shift shock under all conditions, regardless of whether the vehicle is warmed up or not.

(Means for Solving the Problems) In order to solve the above problems, the integrated control device for an engine and an automatic transmission of the present invention adjusts the engine rotational speed at least according to the detected vehicle speed value during a gear shift in which the accelerator foot is released and the upshift is performed. This is a means for performing feedback control to match the engine speed target value determined by the following steps.

That is, as shown in the complaint correspondence diagram of FIG. Operation detection means C
, a shift detecting means d for detecting whether the automatic transmission is shifting, a vehicle speed detecting means e for detecting the vehicle speed, and an idling speed detecting means for controlling the idle speed back in accordance with the detected value of the engine cooling water temperature. The engine speed target value determining means 9 determines the engine speed target value at least according to the vehicle speed detection value, and the engine speed target value determining means 9 determines the engine speed target value at which the shift shock can be suppressed to a low level. The present invention is characterized by comprising a general control means for outputting a feedback control command to the idle rotation speed control means f to make the detected value coincide with the engine rotation speed target value.

(Function) When it is detected by the accelerator operation detecting means C and the shifting detecting means d that the gear is being shifted by upshifting with the foot off the accelerator, the engine rotational speed target value determining means 9 determines the engine speed at which the shift shock can be suppressed to a low level. The numerical target value is determined in accordance with at least the vehicle speed detection value from the vehicle speed detection means e.

Then, in the general control means, a feedback control command is outputted to the idle speed control means f to cause the engine speed detection value during idling from the engine speed detection means a to match the engine speed target value.

As a result, during a shift by upshifting by releasing the accelerator foot, the idle speed of the engine is controlled so as to maintain the engine speed target value, which suppresses the shift shock to a low level.

(Example) Embodiments of the present invention will be described below based on the drawings.

First, the configuration will be explained.

FIG. 2 is an overall system diagram showing a comprehensive control device for an engine and an automatic transmission according to an embodiment of the present invention.

The engine 1 employs a centralized electronic control system that centrally performs various controls, and one of the control systems, the idle speed control system, controls the amount of auxiliary intake air based on the engine cooling water temperature, etc. The optimal amount of intake air is sent to the engine 1 when the throttle valve is fully closed, depending on the warm-up condition and operating condition of the engine.

This idle rotation speed control system (idle rotation speed control means) includes an idle switch 2 (accelerator operation detection means), a vehicle speed sensor 3 (vehicle speed detection means), and an engine rotation sensor 4 (engine rotation speed detection means) as means for obtaining input information. means), an engine cooling water temperature sensor 5 (engine cooling water temperature detection means), and other sensors/switches 6, and an ECC5 control unit 7 as a means for inputting and processing these sensor signals and switch signals.
An AAC valve 8 is provided as an actuator operated by an idle rotation speed control command from a C5 control unit.

The AAC valve 8 is provided in an auxiliary intake pipe 24 that bypasses a throttle valve 23 provided in the middle of the intake pipe 22, and is driven ON-OFF at a predetermined frequency. increases, and the amount of auxiliary air is controlled by changing this ON time.

The basic idle speed control content is controlled such that the lower the engine cooling water temperature Tw is, the higher the idle speed target value l10rev is obtained.

The automatic transmission 10 employs a centralized electronic control system that centrally performs various controls such as gear shifting and lock-up, and one of the control systems, the gear shift control system, has a gear shift schedule set in advance. The system provides good driving performance by responsively shifting gears to the optimal gear position for the vehicle condition.

This shift control system uses the following methods as a means of obtaining input information:
Accelerator opening sensor 11. Vehicle speed sensor 3゜Other sensors・
It is equipped with switches 12, and an A/T control unit 13 is provided as a means for inputting and calculating these sensor signals and switch signals, and a plurality of shift control units are provided as actuators operated by shift control commands from the A/T control unit 13. It is equipped with a solenoid 14.

In this shift control system, shift control is performed based on a shift schedule as shown in FIG. 7, for example.

The ECC5 control unit 7 and A/T control unit 13 are each provided with communication ICs 7a and 13a connected by communication lines 20 and 21, and real-time signal conversion is performed between both control units 7 and 13. , comprehensive control is performed to reduce shift shock.

As this comprehensive control, the A/T control unit 13
A shifting signal and a gear position signal are input from the communication IC 13a, and during shifting by upshifting when the accelerator foot is released, the idle rotation speed (engine rotation speed detection value Erev) is input.
A comprehensive control program for performing feedback control to make F/Brev coincide with the idle rotation speed target value F/Brev determined according to the gear position and vehicle speed V is incorporated in the idle rotation speed control section of the ECC5 control unit γ.

Next, the effect will be explained.

3 and 6 are flowcharts showing the flow of control operations carried out by the idle speed control section of the ECC5 control unit 7. FIG.

First, the idle rotation speed target value setting process will be described with reference to FIG.

In step 30, the engine coolant temperature Tw is read.

In step 31, the idle rotation speed target value I/Drev is determined based on the engine coolant temperature Tw.

As shown in FIG. 4, this idle rotation speed target value l10rev is set to be higher as the engine cooling water temperature Tw becomes lower.

In step 32, the idle rotation speed target value F/Brev is determined based on the vehicle speed V and the gear position.

This idle rotation speed target value F/Brev is set as a target value that suppresses shift shock to a low level even when the shift timing is not actively performed, and as shown in FIG. The higher the vehicle speed, the higher the rotational speed target value, and the lower the gear position, the higher the rotational speed target value.

The idle rotation speed control process will be described with reference to FIG.

In step 40, it is determined whether the throttle is fully closed based on the switch signal from the idle switch 2, and if it is determined YES due to the release of the accelerator foot, step 41
Subsequent idle rotation speed control processing is performed.

In step 41, the detected engine speed value Erev is read.

In step 42, it is determined whether the detected engine speed value Erev exceeds the target idle speed value l10rev.

If Erev≦l10rev, the process proceeds to step 43, where the idle rotation is set to the idle rotation speed target value l10rev.
A control command is output.

If Erev>l10rev, the process proceeds to step 44, where it is determined whether or not the gear is being changed based on the gear change information from the A/T control unit 13.

If the gear is not being shifted, the process proceeds to step 43, where the engine idle speed is set to the idle speed target value l10.
If the control command to rev is output and the gear is being changed, the process advances to step 45, where the detected engine speed value Ere
It is determined whether v exceeds the idle rotation speed target value F/Brev.

If Erev>F/Brev, the process returns to step 40 and idle rotation speed control is not performed.

If Erev≦F/Brev, the process proceeds to step 46, where the idle rotation is set to the idle rotation speed target value F/Brev.
A control command is output.

FIG. 7 is a diagram showing an example of a shift schedule set in the A/T control unit 13, and FIG.
2 is a flowchart showing the flow of signal processing operations performed by the control unit 13 during gear shifting.

The A/T control unit 13 performs shift control by upshifting or downshifting based on input information such as vehicle speed V and accelerator opening A, and comparison with a shift schedule as shown in FIG.

Then, as shown in FIG. 8, it is determined whether or not the gear is being shifted (step 80), and if the gear is being shifted, a gear shifting signal is output to the ECC5 control unit 7 (
In step 81), if the gear is not being shifted, the gear shifting signal is canceled (step 82).

Part 9 is a timing chart for upshifting when the foot is released from the accelerator.

Target value F/Brev, l10rev is F/Brev
> When upshifting by releasing the accelerator after the engine has warmed up or when the engine is at a low temperature,
While the shift signal is being output, the idle speed target value is the target value l10rev corresponding to the engine coolant temperature Tw.
Instead, the target value F/Brev is used as a countermeasure against shift shock, and the upshift release transmission element that is released with an upshift and the upshift engagement transmission element that is engaged with an upshift are both in a released state. At the shift neutral time T2, the idle speed reaches the target value F/
Brev is kept at a constant rotational speed, and a shelf pressure is created that slowly engages the upshift engaging transmission element together with rotational synchronization of the transmission member, thereby suppressing shift shock to a small level.

Note that the upshift release shift element is released after a time T (=T3-72) has elapsed since the accelerator foot is released, and during this time T, the engine speed almost reaches the target value F/Brev. descend.

Target value F/F3rev, l10rev is F/Brev
< When the accelerator pedal is upshifted when the engine is at an extremely low temperature in the relationship of I/Drev, the idle rotation speed target value is set to the target value I/D corresponding to the engine coolant temperature Tw.
The system will remain in the rev state, and priority is given to preventing engine stalling and warming up the engine over countermeasures against gear shift shocks.

As explained above, the integrated control device for the engine and automatic transmission according to the embodiment provides the following effects.

■ During gear shifting when the accelerator foot is released, the device performs feedback control to match the engine speed to at least the idle speed target value F/Brev determined according to the vehicle speed V. , it is possible to reduce the shift shock under all conditions, regardless of the warm-up state of the engine, etc., without increasing costs.

In other words, the torque converter output shaft rotation is when the power train is neutral and there is little change in engine rotation.
It can be approximated as torque converter input shaft rotation (-engine rotation). By doing this, if the engine speed can be stably controlled around the shock-free rotation determined by the transmission output shaft rotation (= vehicle speed) (for a time that can sufficiently absorb variations in shift time), shock-free operation can be achieved under all conditions. can.

Furthermore, since the system does not control the shift timing using a turbine rotation speed sensor or the like, there is no increase in cost.

■ When determining the target idle speed value F/Brev, the gear position is included in addition to the vehicle speed V, so the shift shock can be effectively suppressed regardless of the gear position when the accelerator pedal is released and the upshift is started. can be reduced.

■ Feedback control to prevent shift shock is based on the idle speed target value I/, which is determined by the engine coolant temperature Tw.
Since the device is designed to operate only when Drev is below the idle speed target value F/Brev, engine stall can be prevented by always performing shift shock prevention control when the engine is at extremely low temperatures. Similar to the idler rotation speed control, the effect of warming up is obtained, and the two types of idle rotation speed control are harmonized with each other.

Although the embodiment has been described above based on the drawings, the specific configuration is not limited to this embodiment.

(Effects of the Invention) As described above, in the present invention, in a comprehensive control device for an engine and an automatic transmission that performs idle speed control, during an upshift when the accelerator foot is released,
Since this method performs feedback control to match the engine speed to at least the target engine speed determined according to the vehicle speed detection value, the engine warm-up condition can be maintained without increasing costs when upshifting when the accelerator foot is released. Regardless of the conditions, the effect of reducing shift shock can be obtained under all conditions.

[Brief explanation of drawings]

Fig. 1 is a complaint correspondence diagram showing an integrated control device for an engine and automatic transmission according to the present invention, Fig. 2 is an overall system diagram showing an integrated control device for an engine and automatic transmission according to an embodiment, and Fig. 3 is an embodiment. Flowchart showing the flow of the idle rotation speed Y target value setting process performed by the ECC5 control unit of the device, No. 4
The figure shows the idle speed target value characteristic diagram for the engine cooling water temperature. Figure 5 shows the idle rotation speed target value characteristic diagram for the vehicle speed and gear position. Figure 6 shows the flow of the idle rotation speed control processing operation performed by the ECC5 control unit. FIG. 7 is a diagram showing an example of the shift schedule of the automatic transmission in the embodiment device, and FIG. 8 is a flowchart showing the flow of the signal output processing operation during a shift performed by the A/T control unit of the embodiment device. The flowchart, FIG. 9, is a timing chart showing each operating state during a gear change when the accelerator foot is released for upshifting. a...Engine rotation speed detection means b...Engine cooling water temperature detection means C...Accelerator operation detection means d...During shift detection means e...Vehicle speed detection means f...Idle rotation speed control means 9...Engine speed target value determining means h...Comprehensive control means

Claims (1)

[Scope of Claims] 1) Engine rotation speed detection means for detecting engine rotation speed, engine cooling water temperature detection means for detecting water temperature for cooling the engine, accelerator operation detection means for detecting accelerator operation, and automatic transmission. A gear shifting detecting means for detecting whether or not the vehicle is shifting, a vehicle speed detecting means for detecting the vehicle speed, an idle rotation speed control means for feedback controlling the idle rotation speed according to a detected value of engine cooling water temperature, and a gear shift shock control means. Engine speed target value determination means that determines a target engine speed value that can be kept low in accordance with at least a detected vehicle speed value, and a device that matches the detected engine speed value to the target engine speed value during a shift by upshifting with the foot off the accelerator. A comprehensive control device for an engine and an automatic transmission, comprising: comprehensive control means for outputting a feedback control command to the idle rotation speed control means.