JPH0458022A - Automatic transmission and control device for engine - Google Patents

Abstract

PURPOSE:To shorten the time required for starting of engagement of frictional engaging elements by changing a target idle engine speed to a large value when an engine is shifted from a stopping range to a travelling range, and returning the target idle engine speed after the change to a value before the change when the engagement of the frictional engaging elements is started. CONSTITUTION:When an engine is shifted from N or P range at a point P1, an oil passage through which oil pressure is supplied to frictional engaging elements of an automatic transmission 3, is opened. Time T0 is the mechanical operation lag time. On the other hand, when control for changing a target engine speed to 7000rpm is started to increase the engine speed NE, the delivery of a pump is increased to fill the oil passage in a short time. After the time T2 required to fill the oil passage has elapsed, the engagement of the frictional engaging elements is commenced, the turbine rotating speed NT of a torque converter 4 begins to reduce, and as a result, control for changing the target idle engine speed is stopped at a point P2 to return the target idle engine speed to 500rpm.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an automatic transmission and an engine control device.

(Prior Art) There is a tendency for modern vehicles to be equipped with automatic transmissions. This automatic transmission has a frictional engagement element such as a clutch in its transmission mechanism, and this frictional engagement element is operated by hydraulic pressure to perform a gearshift operation. For this reason, a pump is provided in the hydraulic circuit of the automatic transmission, and this oil pump is generally driven by the engine. On the other hand, JP-A-62-
As seen in Japanese Patent No. 63145, there is known an automatic transmission and engine control device that changes a target idle rotation speed during idling operation depending on the operating state of the automatic transmission.

By the way, in order to reduce fuel consumption, it is desirable to reduce the engine speed as much as possible during idling operation, which does not require driving force, as one method.

However, when the idle speed is lowered, the discharge amount of the oil pump of the automatic transmission is reduced. 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 frictional engagement element is engaged,
This means that it takes a long time for the oil passage leading to the frictional engagement element to be filled with hydraulic oil, which means that the time until the frictional engagement element starts to be engaged becomes longer.

One possible solution to this problem is to increase the capacity of the oil pump, but using a pump with a large capacity requires a large driving force, which is disadvantageous to improving fuel efficiency.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an automatic transmission and an engine control device that shorten the time required to start engaging frictional engagement elements without increasing the capacity of the automatic transmission. be.

(Means for Solving the Problems) In order to achieve this technical problem, the present invention provides an automatic transmission that performs a gear change operation by engaging and releasing a frictional engagement element operated by hydraulic pressure, Detecting the shift position of the shift lever of the automatic transmission, assuming an automatic transmission and engine control device including an engine whose target idle rotation speed during idling operation is changed according to the operating state of the transmission. a first detection means for detecting a start of engagement of the frictional engagement element; and a second detection means for detecting a start of engagement of the frictional engagement element; and upon receiving a signal from the first detection means, the shift lever is shifted from a stop range to a drive range. sometimes,
Upon receiving signals from the target idle rotation speed changing means for changing the target idle rotation speed to a large value and the second detection means, and the engagement of the frictional engagement element described in ii7 is started, the deformed This configuration includes target idle rotation speed change canceling means for returning the target idle rotation speed to the target idle rotation speed before the change.

(Operation, Effect) With the above configuration, the engine speed is increased until the frictional engagement element is engaged or started, so the pump discharge amount is increased, and the oil passage leading to the frictional engagement element is quickly filled. It will be. Therefore, it is possible to shorten the time required to start fastening the frictional engagement elements. As a result, during idling operation, it is possible to lower the idling speed to improve fuel efficiency, and to ensure the fastening response of the frictional engagement element when the vehicle is shifted to the driving range.

(Example) Hereinafter, an example of the present invention will be described based on the accompanying drawings.

In FIG. 2, reference numeral 1 indicates a drive system of an automobile, and the drive system 1 includes an engine 2, an automatic transmission 3 equipped with a multi-stage transmission mechanism, and an engine 2 and an automatic transmission 3 interposed between the engine 2 and the automatic transmission 3. The output shaft 3a of the automatic transmission 3 is connected to the drive shaft 5.

The automatic transmission 3 is equipped with a plurality of frictional engagement elements (not shown) operated by hydraulic pressure, that is, a brake and a clutch, and a gear shift operation is performed by engaging and disengaging these frictional engagement elements. A plurality of solenoid valves 6 to 8 are incorporated in the hydraulic circuit, and hydraulic pressure is supplied to or discharged from the frictional engagement element by the ON/OFF combination of the solenoid valves 6 to 8. A plurality of gears are generated. The hydraulic pressure in the hydraulic circuit is generated by a pump (not shown) driven by the engine 2. Shift signals for the solenoid valves 6 to 8 are output from the control unit U, and the control unit U forms the shift signals based on a predetermined map. In Figure 2, 9
is a shift lever, and this shift lever 9 is arranged on the side of the driver's seat, and can be manually operated by the driver to shift to P range (stopping), R range (reverse), and N range. ), D range (automatic shifting from 1st to 4th speed), 2 range (
2nd speed fixed), ■ range (1st speed fixed). Since the above configuration has been known since ancient times, further explanation 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, a crankshaft 14, an intake boat 15 and an intake valve 16, an exhaust boat 17 and an exhaust valve 18, and a valve mechanism. 19,
Intake passage 20. The exhaust passage 21, the dot plug 23, etc. are the same as those of a normal one, so detailed explanations will be omitted.

In the intake passage 20, there are air conditioners 2 and 2 in order from the upstream side.
5. An air flow meter 26, a throttle valve 27, and an injector 28 are interposed, and the throttle valve 27 includes a throttle opening sensor 30 that detects the throttle opening, and an idle switch 31 that turns 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 is installed in the cylinder block 10 to detect the temperature of the cooling water in the water jacket 10a. A crank angle sensor 35 for detecting the crank angle of the crankshaft 14 is provided in conjunction with the crankshaft 14.

The above control unit U includes an air flow meter 2.
6, throttle opening sensor 30 and idle switch 3
1, a crank angle sensor 35, a water temperature sensor 34, and a sensor 36 for detecting the turbine rotation speed NA of the torque converter 4.
, detection signals from sensors and switches such as a sensor 37 that detects the position of the shift lever 9 are input, and control signals are output from the control unit U to the injector 28, ignition unit 35, and ISCSC2O3, respectively.

The control unit U is composed of, for example, a microcomputer, and includes an A/D converter that converts detection signals from sensors into A/D, a waveform shaping circuit that shapes the waveform of the detection signal from the crank angle sensor 35, and a human output interface. , an injector 28, and a plurality of drive circuits for SCSC2O3. The RON (read-only memo) of the microcomputer of the control unit U contains a control program for idle rotation speed control, various maps necessary for this control, and control programs and maps necessary for shift control of the automatic transmission 3, which will be described later. is input and stored in advance.

Control 1 - The idle speed control performed by the roll unit U will be briefly described as follows: Target idle speed N according to engine cooling water temperature. is set, and this target idle rotation speed N.

The basic bypass air amount G8 corresponding to , that is, the opening amount of the ISO valve 33 is set. Then, corrections such as external loads are added to this basic bypass air amount G.
The final bypass air amount GA is set. In other words, ISC
The SC2O3 valve amount is adjusted depending on the presence or absence of an external load.

Based on the above, an example of idle rotation speed control will be explained in detail based on the flowchart (FIG. 4).

In the figure, Si (i=1.2.3...) indicates each step.

When this control is started when the engine is started, necessary initial settings are performed, and then various signals are read from sensors and switches (Sl).

Next, the engine rotation speed N8 is calculated using the crank angle signal from the crank angle sensor 35 (S2), and the next 83
In step 84, the target idle rotation speed No. corresponding to the cooling water temperature is set based on the map shown in FIG. 5, and in the next step 84, the basic bypass air amount GB is set based on the map shown in FIG. .

Next, it is determined whether or not the engine is idling based on the signal from the idle switch 31 (S6), and if the engine is idling, the engine rotational speed N, and the target idle N are set. Which rotational speed deviation ΔN is ΔN=N.

(S7), and then using the map shown in FIG. 7 to calculate the increase in feedback correction amount (hereinafter referred to as F/B correction amount) △G FB from the rotational speed deviation △N. is calculated (S8), and then the previously calculated memo' is stored in the RAM.
The previous F/B correction amount GF stored in /, the F/B correction amount stored in l
Increase in B sleeve amount △G FB is added to this F/B
Correction amount G FB ('?i) is calculated (S9). If not in idle, F/B sleeve correct amount G FB is GFB;
Set to 0 (SIO).

In the next Sll, it is determined whether or not these external loads are operating based on the switch signals of the power steering, air conditioner, etc., and if they are operating, the load correction amount G according to the external load is displayed on the map. It is calculated based on the table (S12), and if it is not operating, the load correction i
GL is set to G,,=0 (313).

Next, it is determined whether or not deceleration is occurring based on the signal from the throttle opening sensor 30 (S14). If deceleration is occurring, the dashpot air correction amount G . P is calculated (S15)
[If not, use Dashbot air correction amount G. P
or G. It is set to p-O (S16).

Next, the final bypass air amount G, 1 or Gs ” Gs +
The formula of G FB + G t + G op is used (S
17) A drive pulse corresponding to the final bypass air amount GA is output to the SC valve (318), and then the process returns to S1.

When the shift lever 9 is shifted to the driving range while the above idle speed control is being performed, the target idle speed No. is immediately changed, for example, to 500.
rpm is changed to a large value of 700 rpm. An example of such control for changing the target idle rotation speed No. will be explained in detail based on the flowchart shown in FIG.

First, in S20, it is determined whether the vehicle is in a range other than the travel range, that is, in the N range or P range. A determination is made as to whether or not the engine speed is smaller than a predetermined value α, for example, 700 rpm. In this S22,
When the determination is YES, the process proceeds to S23, where it is determined whether the shift lever 9 has been shifted to the driving range, and when the determination is YES, the target idle rotation speed N++ is set to 70.
The setting is changed to Orpm. As a result, the engine speed is feedback-controlled to 700 rpm. Then, in the next step 325, the turbine rotation speed N is determined based on the signal from the sensor 36 that detects the rotation speed of the turbine of the torque converter 4. A change in ΔN is detected, and in S26, it is determined whether or not this ΔNT is smaller than a predetermined negative value (-β), that is, whether or not the turbine rotational speed NT has shifted to a decreasing direction. Judgment: Y
In the case of ES, proceed to S27 and set the target engine speed 1.
1 No. was restored from 70 rpm to 500 rpm. In other words, the control to change the target engine speed is stopped.

The above control contents will be explained based on the timing chart shown in FIG.

Now, if the shift is made from the N range or the P range at point P1, an oil passage for supplying hydraulic pressure to the friction engagement elements of the automatic transmission 3, such as the clutch, will be opened. In the figure, time To is mechanical operation delay time,
It is. On the other hand, at point P, the target engine speed is set to 7.
The change control to set the engine speed to 00 rpm is started, and the engine rotational speed N is increased accordingly. and,
As the engine speed N increases, the automatic transmission 3
The discharge amount of the pump that supplies hydraulic pressure to the hydraulic circuit of the automatic transmission 3 is increased, so that the oil passage connected to the clutch, etc. of the automatic transmission 3 is filled in a short time. The time required to fill this oil passage is indicated by T2. This time T2
After passing through, the frictional engagement elements such as the clutches start to be engaged, and accordingly, the turbine rotational speed N1 of the torque converter 4 starts to decrease. In response to this decrease in the turbine rotation speed N'r, the control to change the target idle rotation speed is stopped at point P2, and the target idle rotation speed is returned from 700 rpm to 50 Orpm.

With the above-described modified control, the engagement of frictional engagement elements such as clutches can be started by increasing the target idle rotation speed.
This will be realized as soon as possible. By the way, the time T shown in Fig. 1 is when the target idle speed is not changed.
This shows the time required until clutch engagement starts.

[Brief Description of the Drawings] Fig. 1 is a timing chart showing the effects of the embodiment over time; Fig. 2 is a schematic diagram of the drive system of a vehicle to which the embodiment is applied; Fig. 3 is a diagram to which the embodiment is applied. Figure 4 is a flowchart showing an example of feedback control for idle operation, Figures 5 to 7 are diagrams showing various maps used for idle operation control, and Figure 8 is a diagram showing the target idle rotation. It is a flowchart which shows an example of number change control. 2: Engine 3: Automatic transmission 9: Shift lever 20: Intake passage 32: Bypass intake passage 33: ISC valve U: Control unit NO = Target idle speed (Figure 1, Figure 5)? nWednesday/Thursday iTW 6th figure Mokusuiku Tw 7th figure F book 8th figure

Claims (1)

[Claims] (1) an automatic transmission that performs gear shifting operations by engaging and releasing frictional engagement elements operated by hydraulic pressure, and an engine whose target idle speed during idle operation is changed according to the operating state of the automatic transmission; An automatic transmission and engine control device comprising: a first detection means for detecting a shift position of a shift lever of the automatic transmission; a second detection means for detecting a start of engagement of the frictional engagement element; , when the shift lever is shifted from the stop range to the drive range in response to a signal from the first detection means;
When receiving signals from the target idle rotation speed changing means for changing the target idle rotation speed to a large value and the second detection means, and the engagement of the frictional engagement element is started,
A control device for an automatic transmission and an engine, comprising: target idle rotation speed change canceling means for returning the changed target idle rotation speed to the pre-change target idle rotation speed.