JPS63135636A - Speed change control device of automatic transmission - Google Patents

Abstract

PURPOSE:To prevent up-shift shock when an engine brake is operated by predicting a gear ratio after the lapse of a designated time since a frictional engagement element for low speed stage is released and connecting a frictional engagement for high speed stage at a point of time the predicted gear ratio reaches a gear ratio for the high speed stage. CONSTITUTION:When an up-shift signal from low speed stage to high speed stage is output with an engine brake operated, a signal for releasing a band brake B1 is output to the second solenoid valve 32. Subsequently a change rate of a rotational frequency ratio between input and output shafts 16, 18 is calculated to predict a gear ratio which will be attained after the lapse of a designated time. When the predicted gear ratio reaches a preset gear ratio for the high speed stage, a connection signal for a clutch C is output to the first solenoid valve 30. Therefore when the clutch C is connected to set at the high speed stage, the apparent gear ratio substantially agrees with a gear ratio set by a gear train 12 so as to prevent a speed change shock.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a shift control device for an automatic transmission that includes at least two frictional engagement elements that are alternately engaged and released between a low gear and a high gear.

Conventional automatic transmissions for vehicles supply fluid pressure such as hydraulic oil to frictional engagement elements such as clutches and brakes to appropriately select the rotating fluorine of rotating drums, gears, etc. =9. The ratio change (speed change) is performed automatically according to the driving condition of the vehicle. In order to maintain riding comfort, the hydraulic pressure supplied to the frictional engagement elements is appropriately controlled.

As a conventional automatic transmission, for example, the automatic transmission with two forward speeds is shown in pages 1-19 of Automotive Engineering Handbook No. 5 Silk published by the Society of Automotive Engineers of Japan (published June 20, 1981). There is. This automatic transmission is equipped with one set of clutches and two sets of band brakes as frictional engagement elements, with the clutch being used as a frictional engagement element for high-speed gears, and one band brake used as a frictional engagement element for low-speed gears. It has become. The other band brake is used as a frictional engagement element for reversing.

Therefore, when shifting from a low gear to a high gear when moving forward, the shift shock can be reduced by gradually releasing the band brake on the low gear while engaging the clutch on the high gear. It has become.

Problems to be Solved by the Invention However, in such conventional automatic transmissions, a one-way clutch is not provided in the power transmission path of the gear train. The problem is that when the amplifier is shifted from a high gear to a high gear, the input rotation speed is forcibly reduced as the clutch is engaged, resulting in extremely large gear shift shock and rattling noise in the drive system. was there.

Therefore, in the present invention, when the engine brake is used to shift up to a high speed gear, the frictional engagement element for the low gear is first released to put the gear train in a idling state, and then the gear ratio becomes the set value for high speed gear. By predicting the timing and controlling the high-speed gear engagement element to be completely engaged at the next gear ratio set point, upshift shock when engine braking is applied is prevented or significantly reduced. The overall object of the present invention is to provide a speed change control device for an automatic transmission that does the following.

Means for Solving All Problems In order to achieve the above object, the shift control device of the automatic transmission of the present invention is hydraulically operated as shown in FIG. 1, and is engaged in a low gear and released in a high gear. It is fully equipped with #frictional engagement element a for low speed gear and friction engagement element for high speed gear that is released in low gear and fastened in high gear.

Hydraulic pressure actuators c for low speed and high speed, where the hydraulic pressure of each of these frictional engagement elements a and b is driven by an output signal.
, d, in an automatic transmission, the input and output speeds of the gear train e are detected, respectively.
Output rotation speed detection means f.

g, the input and output rotational speed detection means f1g'''C Gear ratio detection that detects the apparent gear ratio from the ratio of the obtained input and output rotational speeds; and the detection of the gear ratio detection means. A change rate detecting means i detects the entire change rate of the gear ratio based on the value, and when shifting up from a low speed gear to a high speed gear to an engine braking state, the change rate detecting means i detects the change rate of the gear ratio gear ratio prediction means j for predicting the gear ratio after a predetermined time based on the gear ratio, and a release signal for the low speed friction retention element a to the low speed hydraulic actuator C in response to a shift command from the low gear to the high gear. full output, and the gear ratio prediction means j
is provided in the control means for receiving a signal predicting the gear ratio of the high speed stage and outputting an engagement signal for the high speed hydraulic actuator dK high speed frictional engagement element.
It is made up of m.

Operation With the above-described configuration, in the shift control device for an automatic transmission of the present invention, when shifting up from a low gear to a high gear in an engine braking state, the control means first receives a gear shift command and supplies the low gear fluid to the control means. A full drive signal is output to the pressure actuator C to release the low speed frictional engagement element a. Then, the gear train e enters an inertia phase state, and an apparent gear ratio change occurs as the p input rotational speed decreases. This gear ratio change is detected by the gear ratio detection means, and the gear ratio prediction means i predicts the gear ratio after a predetermined period of time. The predetermined time for predicting the gear ratio at this time is
By outputting an engagement signal for the high-speed gear friction engagement element and setting the time at which the high-speed gear friction engagement element actually starts to engage, the gear ratio prediction means When the high speed gear ratio is predicted by j, the control means k sends the high speed hydraulic actuator d the high speed speed jI! Outputs a fastening signal for the friction element. Then, at the time when the high-speed friction engagement element starts to be engaged, the gear train e
Since the apparent gear ratio is set at or near the gear ratio of the high speed gear, torque is introduced smoothly during the actual upshift operation, and shift shock is prevented or significantly reduced. become.

Example Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

That is, FIG. 2 shows a transmission power control system [10'z] for an automatic transmission according to an embodiment of the present invention, and gear trains 12 and 9 of the automatic transmission in which this transmission control device 10 is used are shown in FIG.
The one shown in the figure is used. This gear train 12 uses, as a planetary gear set, a Ravigneau gear train 14 consisting of two sun gears S+ and St, two pinion gears P+, and one ring gear of Pt gear. The input shaft 16 of the gear train 12 and one sun gear SI are connected via a clutch C as a high-speed frictional engagement element, and
The one sun gear Si can be fixed via a band brake B+t- as a low-speed attack J[l engagement element.

In addition, the other sun gear S is connected to the input shaft 16 at 9; cv
i, the ring gear I can be fixed via a band brake horse for reverse, and one pinion gear P
K is meshed between one sun gear S and ring gear 1, and the other pinion gear P is meshed with said pinion gear P.
L and the other sun gear S1, and these two pinion gears P, , P, are connected to one pinion gear rear (,1
- is attached to the output shaft 18 via.

Such a gear train 12 has frictional engagement elements C, B1 . The horse is bound and released.

(Leaving space below) In the same table, the ○ mark indicates the engaged state, the × mark indicates the disengaged state, and the table also shows the reduction ratio of 4, 6 and 7 at each gear stage.
＞”, P+= ”/dm Pt= ”/d terror ri, a
, is the number of faces of the sun gear St, a is the number of teeth of the other sun gear St, and d is the number of teeth of the ring gear.

The power of the engine 20 is inputted to the input shaft 16 of the gear train 12 via the torque converter 22.

By the way, the one set of clutches C and the two sets of band brakes B, B, are respectively engaged when hydraulic pressure is supplied, and are released when the hydraulic pressure is removed. This hydraulic pressure is controlled by the first hydraulic actuator for high speed, low speed, and reversing. Second.
The work is performed by the third solenoid valve 30, 32, 34. In addition, an input shaft rotation speed sensor 36 and an output shaft rotation speed sensor 38 are provided on the input shaft 162 and output shaft 18 of the gear train 12, and the detection signals from each of these sensors 36 and 38 are It is designed to be output to the controller 40 of the speed change control device 10 shown in the figure.

The controller 40 includes an input shaft rotation speed detection means 42 which inputs the detection signals from the input and output shaft rotation speed sensors 34 and 38, respectively, and calculates the input shaft rotation speed (NT) and the output shaft rotation speed INo. A built-in output shaft rotation speed detection means 44 is built-in. These input and output shaft rotation speed detection means 42
．． Each rotation speed calculated in step 44 is output to gear ratio detection means 46, and this means 46 calculates the ratio of each rotation speed (NT/N
, ) to calculate the apparent gear ratio (R). Next, this calculated gear ratio signal is outputted from the change rate detection means 481C, and the change rate (ΔR) of the gear ratio (R) is outputted.
) and outputs the result to the gear ratio prediction means 50,
This gear ratio prediction means 50 is designed to determine the apparent predicted gear ratio Ref after a predetermined period of time. The judgment signal of this gear ratio predicting means 50 is the first one. A drive signal is output to the @2 solenoid valve 30.52 to the control means 52, and the control means 52 controls the timing of engagement and release of the clutch C and the band brake B (7).

That is, a shift command signal is input to the control means 52, and when an amplifier shift signal from a low gear to a high gear is input while the engine is braking and the foot is off the accelerator pedal, first The band brake B1 is released to the second solenoid valve 32, and No. 3 full output is applied, and then, when the predicted gear ratio Re becomes equal to or higher than the gear ratio of the high speed gear by the gear ratio prediction means 50, the first solenoid valve 30 is applied to the clutch C. It is designed to output a signal.

The operation of the speed change control device 10 of this embodiment will be explained based on the flowchart of FIG. 4 using the above groove bottom. Incidentally, this flowchart is executed at a predetermined time ratio, for example, every 5 m5ec, and shows the processing after a shift-up signal from a low speed gear to a high speed gear is outputted in an engine braking state.

Therefore, in such a Florchart, first step 100
A release signal for the band brake B is output to all second solenoid valves 32. At this time, gear train 12
Since the motor is in an idling state and the throttle opening is zero, the rotational speed ratio between the input and output shafts 16 and 18 and the apparent gear ratio change as shown in FIG. In the next step 101, the changing gear ratio tR=NT/N,
)', and in the next step 102, the gear ratio change rate (
Calculate ΔRJ. This rate of change (ΔR) is calculated by storing the previously determined gear ratio and calculating the difference between this gear ratio and the current gear ratio. Next step 10
6, the gear ratio R13k that will be reached after a predetermined time is predicted using the rate of change (ΔR) t-. This predicted gear ratio Re is determined by taking into account the hardware delay time (the time when clutch C is actually engaged after hydraulic pressure is supplied) and the program processing timing, and a constant t is determined by taking into account these time lags. −, then I Re = current gear ratio −△R−K
).

Note that the time lag constant may include, for example, a hardware delay of 1
00m5ec, the program processing timing is 5m5ec [= 100, 15=20
Therefore, it is desirable that the temperature of the working fluid be taken into account in the delay time of the .

In the next step 104, it is determined whether the predicted gear ratio (Re) has become equal to or less than the gear ratio (Ro) at a preset station speed. If Re has not yet reached Ro (NO), the process proceeds to step 105, where the current gear ratio is stored as the previous gear ratio, and then this flow is temporarily terminated. On the other hand, if it is determined in step 104 that Re has reached RO (YES), step 106
Then, the entire engagement signal for the clutch C is outputted to the first solenoid pulp 30, and the flow is temporarily terminated.

Therefore, in this embodiment, at the time when the clutch C engagement signal is output, the actual gear ratio (R) is still the high gear ratio (R).
o) is not reached (point Po in Figure 5),
When clutch C is securely engaged, the gear ratio [Re]
Predict the predetermined gear ratio (Ro) of the high speed gear.
(Point Po in Fig. 5). Therefore, when the clutch C is engaged and the high speed gear is set, the apparent gear ratio and the gear ratio set by the gear train match or substantially match. Therefore, shift shock can be prevented or reduced even during upshifts under engine braking conditions.

By the way, in conventional engines, as disclosed in Japanese Patent Laid-Open No. 56-50232, under certain conditions, 7 yuel is cut off during deceleration to improve exhaust purification performance and fuel efficiency. There is something. When the engine 20 equipped with the fuel cut function is used in this embodiment, step 104 in the flowchart described above
Now, the pre-IT+gear ratio (Re) has reached the high speed gear ratio (RO)! After determining YES), all changes to the fuel cut control are prohibited.For example, if 7 fuel is cut during upshifting, recovery of 7 fuel is prohibited and fuel cut control is disabled. -Make sure it continues. By prohibiting the change in the seven-wheel cut control in this way, it is possible to prevent the predicted gear ratio (Re) from being changed after the clutch C engagement is instructed.

Incidentally, the gear train of an automatic transmission in which the speed change control device 10 of the above-described embodiment is used is not limited to the one shown in FIG.

Detailed Description of the Invention As shown in Section 7'C, in the shift control device for an automatic transmission of the present invention, when upshifting is performed under engine braking, the frictional engagement element for a low gear is first released, and then a predetermined shift is performed. The gear ratio of the gear train after a certain period of time is predicted, and when this predicted gear ratio reaches the gear ratio of the high speed gear, the engagement instruction for the frictional engagement element for the high speed gear is performed. The apparent gear ratio of the gear train is set to the high speed, by setting the time to the time at which the frictional engagement element for the high speed gear is engaged just after receiving the engagement instruction. When the value is reached, the high-speed stage frictional engagement element is substantially engaged. Therefore, when the gear train is set to the high speed gear, the apparent gear ratio also becomes the set value for the high speed gear, and the difference in gear ratio between the two becomes zero or extremely small. Therefore, the torque is introduced smoothly, and the ultimate effect of completely preventing or greatly reducing the shift shock when the gear is shifted up to a high speed gear to an engine braking state is achieved.

[Brief explanation of the drawing]

Figure 1 shows the speed change of the variable transmission according to the present invention. ! A block diagram showing the concept of the ILI control device, FIG. 2 is a schematic configuration diagram showing an embodiment of the speed change control device of the present invention, and FIG. FIG. 4 is a flowchart showing an example of the next process for executing the restriction program of the transmission control device of the present invention, and FIG. 5 is a schematic diagram showing an embodiment of the transmission control device of the invention. FIG. 10... Speed change control device, 12... Gear train, 1
6... Input shaft, 18... Blade shaft, 20... Engine, 22... Torque converter, 6o... First solenoid valve (hydraulic actuator for high speed stage), 32...
・・1st/l//id pulp (hydraulic actuator for low speed stage), 40 ・・controller, 42 ・・input shaft rotation speed detection means, 44 ・・output shaft rotation speed detection means, 46
...Gear ratio detection means, 48...Change rate detection means, 5
゜... Gear ratio prediction means %52... Control means. Fig. 2 1 o i! Glaze 1 Finishing Figure 4 Figure 5

Claims (1)

[Claims] (1) Equipped with a low-speed friction engagement element that is hydraulically operated and engaged in a low-speed gear and released in a high-speed gear, and a high-speed friction engagement element that is released in a low gear and engaged in a high gear. In automatic transmissions in which the working hydraulic pressure of each of these frictional engagement elements is controlled by hydraulic actuators for low and high gears driven by output signals, the input and output rotational speeds of the gear train are controlled. Input and output rotational speed detection means detecting the respective input and output rotational speeds, gear ratio detection means that detects an apparent gear ratio from the ratio of the input and output rotational speed obtained by the input and output rotational speed detection means, and the gear ratio detection means. a change rate detection means for detecting a gear ratio change rate based on a detected value of the means; and a gear ratio change rate detected by the change rate detection means when shifting up from a high speed gear to a high speed gear to an engine braking state. a gear ratio prediction means for predicting a gear ratio after a predetermined time based on the gear ratio, and outputting a release signal for a low-speed frictional engagement element to the low-speed hydraulic actuator upon receiving a shift command from a low-speed to a high-speed. and a control means for outputting an engagement signal for a high-speed frictional engagement element to the high-speed hydraulic actuator in response to a signal from which the gear ratio prediction means predicted a high-speed gear ratio. A speed change control device for an automatic transmission characterized by: