JP2862643B2 - Control device for automatic transmission and engine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an automatic transmission and an engine control device.

(Prior Art) Recently, vehicles with automatic transmissions tend to be heavily used. In this automatic transmission, the transmission mechanism has a friction engagement element such as a clutch, and the friction engagement element is operated by hydraulic pressure to perform a shift operation. Therefore, a pump is provided in a hydraulic circuit of the automatic transmission, and the oil pump is generally driven by an engine. On the other hand, JP
As disclosed in Japanese Patent No. 63145, there is known an automatic transmission and an engine control device in which a target idle speed during idling operation is changed according to an operation state of the automatic transmission.

Incidentally, in order to reduce the fuel consumption, as one of the methods, it is desirable to lower the engine speed as much as possible during idling operation which does not require a driving force.

However, when the idle speed is reduced, the discharge amount of the oil pump of the automatic transmission decreases.
This means that when the shift lever of the automatic transmission is shifted, for example, from the neutral range (N range) to the drive range (D range) and the friction engagement element is engaged, the oil passage leading to the friction engagement element is engaged. , It takes a long time to be filled with the hydraulic oil, which means that the time until the engagement of the friction engagement element is started becomes long.

To solve this problem, it is conceivable to increase the capacity of the oil pump. However, when a large capacity pump is used, a large driving force is required, which is disadvantageous for improving fuel efficiency.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an automatic transmission and an engine control device in which the time until the start of engagement of a friction engagement element is reduced without increasing the capacity of the automatic transmission. .

(Means for Solving the Problems) In order to achieve the above technical object, according to the present invention, there is provided an automatic transmission that performs a shifting operation by engaging and releasing a friction engagement element that is operated by hydraulic pressure, An engine in which a target idle speed during idle operation is changed in accordance with an operation state of the transmission; and an engine control device including the engine, and detects a shift position of a shift lever of the automatic transmission. First detecting means, a second detecting means for detecting the start of engagement of the frictional engagement element, and a signal from the first detecting means, the shift lever is shifted from a stop range to a traveling range. Receiving the signal from the target idle speed changing means for changing the target idle speed to a large value and the second detecting means, the fastening of the friction engagement element is started. To come, a configuration equipped with a target idle rotational speed change stop means for returning to the target idle speed before the change of the target idle rotation speed after the change.

(Operation and effect) With the above configuration, the engine speed is increased until the engagement of the friction engagement element is started, so that the discharge amount of the pump is increased, and the oil passage leading to the friction engagement element is quickly filled. Will be. Therefore, the time required until the start of the engagement of the friction engagement element can be reduced. This allows
At the time of idling, it is possible to secure the engagement responsiveness of the friction engagement element when shifting to the travel range while reducing the idling speed to improve fuel efficiency.

(Example) Hereinafter, an example of the present invention will be described with reference to the accompanying drawings.

In FIG. 2, reference numeral 1 denotes a driving system of an automobile.
The drive system 1 includes an engine 2, an automatic transmission 3 having a multi-stage transmission mechanism, and a torque converter 4 interposed between the engine 2 and the automatic transmission 3. The shaft 3a is connected to the drive wheel 5.

The automatic transmission 3 includes a plurality of frictionally engaging elements (not shown) operated by hydraulic pressure, that is, a brake and a clutch, and performs a shifting operation by fastening and releasing these frictionally engaging elements. A plurality of solenoid valves 6 to 8 are incorporated in the hydraulic circuit, and supply or discharge of hydraulic pressure to or from the friction engagement element is performed by a combination of ON and OFF of the solenoid valves 6 to 8, whereby a plurality of shift speeds are set. Is generated. The hydraulic pressure in the hydraulic circuit is generated by a pump (not shown) driven by the engine 2. The shift signals for the solenoid valves 6 to 8 are transmitted to the control unit U.
The control unit U forms a shift signal based on a predetermined map. In FIG. 2, reference numeral 9 denotes a shift lever. The shift lever 9 is disposed beside the driver's seat, and is manually operated by a driver to have a P range (stop), an R range (reverse), and an N range (neutral). ), D range (automatic shifting from 1st to 4th speed), 2 ranges (fixed at 2nd speed), and 1 range (fixed at 1st speed). Since the above configuration is conventionally known, further description will be omitted.

As shown in FIG. 3, the engine 2 includes a cylinder block 10, a cylinder head 11, a piston 12, a connecting rod
13, the crankshaft 14, the intake port 15 and the intake valve 16, the exhaust port 17 and the exhaust valve 18, the valve train 19, the intake passage 20, the exhaust passage 21, the dot plug 23, etc. are the same as ordinary ones, so detailed explanations Is omitted.

In the intake passage 20, the air cleaner 2 is sequentially arranged from the upstream side.
5, an air flow meter 26, a throttle valve 27, and an injector 28 are provided. The throttle valve 27 is provided with a throttle opening sensor 30 for detecting the throttle opening and an idle switch 31 that is turned on when the throttle valve 27 is fully closed. An ISC valve (idle speed control valve) 33 is interposed in a bypass passage 32 that bypasses the throttle valve 27, and a water temperature sensor 34 for detecting the temperature of cooling water in the water jacket 10a is provided in the cylinder block 10. A crank angle sensor 35 for detecting a crank angle of the crank shaft 14 is provided in association with the crank shaft 14.

The control unit U includes an air flow meter
26, a throttle opening sensor 30, and idle sensors 31, a crank angle sensor 35, a water temperature sensor 34, a sensor 36 for detecting the turbine speed _NT of the torque converter 4, a sensor 37 for detecting the position of the shift lever 9, and the like. And detection signals from switches and the like, the control unit U sends the injector 28 and the ignition unit 35
And a control signal is output to the ISC valve 33 and the like.

The control unit U is formed of, for example, a microcomputer, and includes an A / D converter for A / D converting a detection signal from sensors, a waveform shaping circuit for shaping a detection signal from the crank angle sensor 35, and an input / output interface. ,
A plurality of drive circuits for the injector 28 and the ISC valve 33 are also provided. In the RON (read only memory) of the microcomputer of the control unit U, a control program for idle speed control, which will be described later, various maps required for this control, and control programs and maps required for speed control of the automatic transmission 3 are provided. Is input and stored in advance.

For idle speed control performed by the control unit U, will be described the outline, set the target idle speed N _O according to the engine coolant temperature, basic bypass air amount corresponding to the target idle speed N _O
G _B, i.e., the amount of opening of the ISC valve 33 is set. And
For this basic bypass air amount G _B, it is added to correct the external load or the like, the final bypass air amount G _A is set. That is, the opening amount of the ISC valve 33 is adjusted according to the presence or absence of the external load.

On the premise of the above, a detailed description will be given based on a flowchart (FIG. 4) of an example of idle speed control. In the drawing, Si (i = 1, 2, 3,...) Indicates each step.

When this control is started when the engine is started, various signals are read from sensors and switches after necessary initial settings are executed (S1).

Next, the engine speed _Ne is calculated using the crank angle signal from the crank angle sensor 35 (S2). In the next S3, based on the map shown in FIG. the number N _O is set, in the next S4, based on the map shown in FIG. 6, it is set basic bypass air quantity G _B.

Next, whether or not idle based on a signal from the idle switch 31 is determined (S6), when in the idle rotational speed deviation △ N of the engine speed N _e and the target idle N _O is, It is calculated based on the equation of ΔN = N _e −N _O (S
7) Then, using the map shown in FIG.
From the above, the increment △ G _{FB of} the feedback correction amount (hereinafter referred to as “F / B correction amount”) is calculated (S8), and then the previous F / B correction amount G _FB calculated next time and stored in the RAM memory. F / B correction amount increment △ G _FB is the current are added F / B correction amount G _FB is calculated in (S9). If the engine is not idling, the F / B correction amount G _FB is set to G _FB = 0 (S10).

In the next 11 based on the switch signals such as power steering and air conditioning it is determined whether these external loads is operating, when operating load correction amount G ₁ corresponding to the external load map Ya is It is calculated based on the table (S12), and when it is not operating, the load correction amount _GL becomes _GL =
It is set to 0 (S13).

Next, it is determined whether or not the vehicle is decelerating based on a signal from the throttle opening sensor 30 (S14).
The dashpot air correction amount _GDP is calculated from a map (not shown) using the water temperature _TW as a parameter (S15). If the vehicle is not decelerating, the dashpot air correction amount _GDP is set to _GDP = 0 (S16). ).

Next, the final bypass air amount G _A is G _A = G _B + G _FB + G _L + G _DP
Is calculated by the formula (S17), the driving pulse corresponding to the final bypass air amount G _A is output to ISC valve (S18) Then the flow returns to S1.

While the above idle speed control is being performed,
When the shift lever 9 is shifted to the driving range,
The target idle speed No is changed immediately, for example, 500rpm
It is changed to a large value from 700rpm. An example of the control for changing the target idle speed No will be described in detail with reference to a flowchart shown in FIG.

First, in S20, it is determined whether or not the vehicle is in a range other than the travel range, that is, in the N range or the P range. If YES, the process proceeds to S21, where the engine speed is detected. Is determined whether or not the engine speed is smaller than a predetermined value α, for example, 700 rpm. In this S22, when the answer is YES, the process proceeds to S23, whether the shift lever 9 is shifted to the driving range determination is made, the target idle speed N ₀ in the case of YES is set changed to 700 rpm. Thus, the feedback control is performed so that the engine speed becomes 700 rpm. Then, in the next S25,
Based on a signal from a sensor 36 for detecting the turbine speed of the torque converter 4, a change in turbine speed _NT
NT is detected, and in S26, whether this △ _NT is smaller than a predetermined negative value (-β), that is, the turbine rotational speed _NT
It is determined whether the engine speed has shifted in a direction of decreasing.If the answer is YES, the process proceeds to S27, in which the target engine speed N ₀ is reduced to 700 rpm.
To 500rpm. That is, the control for changing the target engine speed is stopped.

The above control will be described with reference to the timing chart shown in FIG.

Now, assuming that the shift from the N range or P range at point P _1, so that the oil passage for supplying hydraulic pressure to the clutch or the like as friction engagement elements of the automatic transmission 3 is opened. In the figure, time T ₀ is a mechanical operation delay time. On the other hand, change control to 700rpm the target engine rotational speed at the point P ₁ is started, the engine speed along with this
_NE will rise. And this engine speed
With increasing N _E, the discharge amount of the pump for supplying hydraulic pressure to the hydraulic circuit of the automatic transmission 3 is increased, therefore the oil passage leading to the clutches and the like of the automatic transmission 3 that is filled in a short time become. The time it takes to fill this oilway
It is indicated by T _2. After passing through the time T _2, the frictional engagement elements such as clutch, the engagement begins to be initiated, and that the turbine speed N _T of the torque converter 4 begins to decrease accordingly. In response to this decrease in turbine speed N _T, the change control of the target idle speed is stopped at point P _2,
The target idle speed is returned from 700 rpm to 500 rpm.

According to the above change control, the start of engagement of the friction engagement element such as the clutch can be realized early by increasing the target idle speed. Incidentally, the time T ₁ shown in FIG. 1, when not changing the target idle speed is shown the time taken to the start clutch engagement.

[Brief description of the drawings]

1 is a timing chart showing the operation of the embodiment over time, FIG. 2 is a schematic diagram of a drive system of a vehicle to which the embodiment is applied, and FIG. 3 is an overall configuration diagram of an engine to which the embodiment is applied. Fig. 4 is a flowchart showing an example of feedback control of idling operation, Figs. 5 to 7 are diagrams showing various maps used for idling operation control, and Fig. 8 is an example of target idle speed change control. It is a floater. 2: Engine 3: Automatic transmission 9: Shift lever 20: Intake passage 32: Bypass intake passage 33: ISC valve U: Control unit N ₀ : Target idle speed

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F02D 29/00-29/06 F02D 41/00-41/40 B60K 41/00-41/28

Claims (1)

(57) [Claims] (1) fastening of a friction engagement element operated by hydraulic pressure;
An automatic transmission and an engine control device, comprising: an automatic transmission that performs a shift operation by opening, and an engine that changes a target idle speed during idle operation according to an operation state of the automatic transmission. A first detection unit for detecting a shift position of a shift lever of the automatic transmission, a second detection unit for detecting a start of engagement of the friction engagement element, and a signal from the first detection unit, When the shift lever is shifted from the stop range to the drive range,
Target idle speed changing means for changing the target idle speed to a large value; and a signal from the second detecting means, and when the engagement of the friction engagement element is started, the target after the change is changed. A control device for an automatic transmission and an engine, comprising: a target idle speed change stop means for returning the idle speed to the target idle speed before the change.