JPH05231515A - Controller of automatic transmission - Google Patents

Abstract

PURPOSE:To prevent downshifting if an accelerator pedal is operated suddenly even though an accelerated state that a driver requires has been realized by the current speed. CONSTITUTION:Acceleration that a driver presumably requires is calculated according to the speed at which an accelerator pedal is operated. After a first predetermined period of time has elapsed from a sudden operation, the actual acceleration is calculated, and the acceleration after a second predetermined period of time is anticipated according to the actual acceleration. The acceleration thus anticipated is compared with the required acceleration, and when the anticipated acceleration does not reach the required acceleration, downshifting is performed to increase driving forces. If the anticipated acceleration has reached the required acceleration, downshifting is not performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an automatic transmission.

[0002]

2. Description of the Related Art As a conventional control device for an automatic transmission, there is, for example, the one disclosed in Japanese Patent Application Laid-Open No. 57-195951. This is configured such that the vehicle speed at which gear shifting is to be performed is increased as the accelerator pedal depression speed increases. That is, when the accelerator pedal is depressed rapidly, more rapid acceleration is expected, so that downshifting is facilitated. In addition, JP-A-55-1
Japanese Patent Publication No. 29648 discloses that the shift pattern is changed according to the changing speed of the engine load (accelerator pedal depression amount). This also makes downshifting easier as the accelerator pedal is depressed more rapidly. Further, JP-A-58-146750 discloses that when the accelerator pedal is depressed rapidly, the overdrive state (4th speed) is released and the gear is downshifted to 3rd speed.

[0003]

However, in any of the above publications, when the accelerator pedal depression speed is higher than a predetermined value, the gear shifts down regardless of other conditions. However, there is a problem that the downshift may be performed even when it is not necessary. That is, when traveling downhill or when the loaded weight is small, the pedaling speed can be reduced even if the acceleration state required by the driver is realized even at the gear stage before the accelerator pedal is rapidly depressed. If the value is equal to or greater than the predetermined value, the downshift will occur. The present invention aims to solve such problems.

[0004]

According to the present invention, the acceleration state required by the driver is obtained from the stepping speed of the accelerator pedal, and if the acceleration state can be realized without downshifting, the downshift is not performed. , To solve the above problems. That is, the control device for an automatic transmission according to the present invention, as shown in FIG. 1, includes a sudden depression determination means for determining a rapid depression start of an accelerator pedal, an accelerator pedal depression speed detection means for obtaining an accelerator pedal depression speed, and Demanded acceleration state detection means for obtaining the required acceleration state from the accelerator pedal depression speed obtained by the acceleration, and acceleration for predicting the acceleration state after the second predetermined time from the driving state after the first predetermined time has elapsed after the sudden depression determination. State prediction means and downshift command means for instructing downshift only when it is determined that the acceleration state predicted thereby does not reach the required acceleration state obtained by the required acceleration state detection means. There is.

[0005]

When the accelerator pedal is rapidly depressed, the required acceleration state, which is considered to be required by the driver, is required from the stepping speed. An actual acceleration state of the vehicle is detected after a first predetermined time which is a relatively short time after the accelerator pedal is suddenly depressed, and an acceleration state after a second predetermined time is predicted from this. If the predicted acceleration state has not reached the required acceleration state, a downshift command is issued. As a result, the gear ratio increases, the engine speed increases, and the acceleration force increases. On the other hand, when the predicted acceleration state is the required acceleration state or higher, the downshift is not performed. This is because the acceleration state required by the driver can be realized without downshifting. This prevents unnecessary downshifting.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.
It will be described based on 2. FIG. 2 is a skeleton view of a power transmission mechanism of an automatic transmission with four forward speeds and one reverse speed with overdrive. This power transmission mechanism is the torque converter 10
An input shaft 13 to which a rotational force is transmitted from an engine output shaft 12 via an output shaft 14, an output shaft 14 to transmit a driving force to a final drive device, a first planetary gear set 15, and a second planetary gear set 1
6, a reverse clutch 18, a front clutch 20, a rear clutch 22, an overrunning clutch 24, a low and reverse brake 26, a band brake 28, a low one-way clutch 29, and a forward one-way clutch 30. The torque converter 1
0 has a lock-up clutch 11 built-in. The first planetary gear set 15 includes a sun gear S1 and an internal gear R.
1 and a carrier PC1 that supports a pinion gear P1 that meshes with both gears S1 and R1 at the same time, and the planetary gear set 16 meshes with a sun gear S2, an internal gear R2, and both gears S2 and R2 at the same time. The carrier PC2 supports the pinion gear P2. The carrier PC1 can be connected to the input shaft 13 via the front clutch 20, and the sun gear S1
Can be connected to the input shaft 13 via a reverse clutch 18. The carrier PC1 includes a rear clutch 22 and a forward one-way clutch 30 connected in series to the rear clutch 22.
Can be connected to the internal gear R2 via a rear clutch 22 and a forward one-way clutch 30 via an overrunning clutch 24 arranged in parallel. The sun gear S2 is always connected to the input shaft 13, and the internal gear R1 and the carrier PC2 are always connected to the output shaft 14. The low and reverse brake 26 can fix the carrier PC1, and the band brake 28 can fix the sun gear S1. The low one-way clutch 29
The carrier PC1 is arranged in a direction that allows normal rotation (rotation in the same direction as the engine output shaft 12) but does not allow reverse rotation (rotation in the opposite direction to normal rotation).

The power transmission mechanism includes clutches 18, 2
0, 22 and 24, and brakes 26 and 28 in various combinations to operate the planetary gear sets 15 and 1
6 elements (S1, S2, R1, R2, PC1, and P
The rotation state of C2) can be changed, whereby the rotation speed of the output shaft 14 with respect to the rotation speed of the input shaft 13 can be variously changed. By operating the clutches 18, 20, 22 and 24 and the brakes 26 and 28 in the combination as shown in FIG. 3, the fourth forward speed and the first reverse speed can be obtained. Note that in FIG. 3, the circles indicate operating clutches and brakes, α1 and α2 are the ratios of the number of teeth of the sun gears S1 and S2 to the number of teeth of the internal gears R1 and R2, respectively, and the gear ratio is the output shaft. It is the ratio of the rotation speed of the input shaft 13 to the rotation speed of 14.

4, 5 and 6 show a hydraulic control device for controlling the operation of the power transmission mechanism. This hydraulic control device
Pressure regulator valve 40, pressure modifier valve 42, line pressure solenoid 44, modifier pressure accumulator 46, pilot valve 4
8, torque converter relief valve 50, lockup control valve 52, first shuttle valve 54,
Lock-up solenoid 56, manual valve 58, first shift valve 60, second shift valve 62, first shift solenoid 64, second shift solenoid 66, servo charger valve 68, 3-2 timing valve 70,
4-2 relay valve 72, 4-2 sequence valve 7
4, fast reducing valve 76, second shuttle valve 78, overrunning clutch control valve 80, overrunning clutch solenoid 8
2, overrunning clutch reducing valve 8
4, 1-2 accumulator 86, 2-3 accumulator 88, 3-4 accumulator 90, ND accumulator 92, accumulator control valve 94, filter 96, etc., and these are mutually connected as shown in the drawing. And the torque converter 10 described above.
(In addition, the apply chamber 11a and the release chamber 11b of the lockup clutch 11 are formed in this.), The rear clutch 22, the front clutch 20, the band brake 28 (Here, the apply chamber 28a for 2nd speed, 3rd. A speed release chamber 28b and a fourth speed apply chamber 28c are formed), a reverse clutch 18, a low and reverse brake 26, and an overrunning clutch 2
4 is also connected as shown in the drawing, and further has a variable capacity vane type oil pump 34 equipped with a feedback accumulator 32, an oil cooler 36, a front lubrication circuit 37,
Also, the rear lubrication circuit 38 is connected as shown. Detailed description of these valves is omitted.
Regarding the part of which description is omitted, it is disclosed in JP-A-63-25165.
21.

In FIGS. 7, 8 and 9, the solenoids 44, 56,
A control unit 300 for controlling the operation of 64, 66 and 82 is shown. The control unit 300 includes an input interface 311, a reference pulse generator 312,
CPU (Central Processing Unit) 313, ROM (Read Only Memory) 314, RAM (Random Access Memory) 1
5 and an output interface 316, which are connected by an address bus 319 and a data bus 320. This control unit 300 has
Engine rotation speed sensor 301, vehicle speed sensor 302, throttle opening sensor 303, select position switch 304, kick down switch 305, idle switch 306, full throttle switch 307, oil temperature sensor 308, input shaft rotation speed sensor 309, overdrive switch A signal from 310 or the like is input. On the other hand, shift solenoids 64 and 66, overrunning clutch solenoid 82, lockup solenoid 5
6, and a signal is output to the line pressure solenoid 44.

The control in the case of sudden depression of the accelerator pedal is performed according to the control flow shown in FIG. First, the current throttle opening TH and vehicle speed V are read (step 102), and then the accelerator pedal depression speed dT.
H is required (at 104). The depressing speed of the accelerator pedal is obtained from the amount of change in the throttle opening every predetermined time. Then, the reference value C set as a function of the read TH and V is read (106 of the same). The value of C is set to be larger as the throttle opening TH is larger and as the vehicle speed V is larger. Next, dTH and C are compared (108). If dTH is smaller than C, the process ends. If dTH is larger than C, it means that it is determined to be a sudden depression, and thus step 110
The required acceleration α0 which is considered to be required by the driver is calculated from the current throttle opening TH, the vehicle speed V and the stepping speed dTH. As α0, a larger value is set as the throttle opening TH is larger, the vehicle speed is larger, and the dTH is larger. Then, step 108
The actual acceleration α1 at this point is detected after the first predetermined time T1 from the judgment of the sudden depression (at 112), and the acceleration after the second predetermined time T2 from the sudden depression judgment based on the detected actual acceleration α1. Predict α2 (at 114). Next, the predicted acceleration α2 and the required acceleration α0 are compared (at 116). When α2 is smaller than α0, the downshift is instructed (at 118 in the same case), and in the opposite case, no downshift is instructed. Next, it is determined whether a release condition described later is satisfied (at step 120). If the cancellation condition is not satisfied, the process returns to step 114. When the release condition is satisfied, the normal control is restored (see the same 12).
2). That is, based on the vehicle speed and the throttle opening,
The shift speed is determined from the normal shift pattern. The determination of the cancellation condition is performed as follows. That is, if the accelerator pedal is returned to a predetermined value or more (or if the accelerator pedal is returned to a predetermined value or more and a predetermined time has elapsed after returning the accelerator pedal), it is determined that the release condition is satisfied, and When the current acceleration reaches the required acceleration α0, it is determined that the release condition is satisfied. It should be noted that step 108 constitutes a sudden depression determination means, step 104 constitutes an accelerator pedal depression speed detection means, step 110 constitutes a required acceleration detection means, and step 112.
And 114 constitute acceleration state prediction means, and step 118 constitutes downshift command means.

11 and 12 show how the vehicle speed changes by the above control. FIG. 11 shows the case of downshifting. That is, the actual acceleration increases after the sudden depression is determined at time 0, and reaches α1 at the first predetermined time T1. At the time of the first predetermined time T1, the acceleration of the second predetermined time T2 is predicted. The predicted acceleration is α2. This α2 is α
Since it is less than 0, the required acceleration α
0 cannot be realized. Therefore, the downshift is commanded at the time of the first predetermined time T1.

Next, in the case shown in FIG. 12, similarly, the acceleration α2 at the second predetermined time T2 is predicted at the first predetermined time T1. This acceleration α2 is the required acceleration α0
Therefore, the acceleration state required by the driver can be realized even at the current gear position. Therefore, the downshift command is not issued and the current shift speed is maintained.

In this embodiment, the required acceleration state and the predicted acceleration state are indicated by the acceleration, but the vehicle speed, the engine speed, etc. may be used instead. That is, the required vehicle speed or the required engine rotation speed is obtained from the accelerator pedal depression speed, and the predicted vehicle speed and the predicted engine rotation speed at the second predetermined time T2 are obtained from the actual vehicle speed after the first predetermined time T1 or the actual engine rotation speed. ,
It is possible to determine whether to perform the downshift by comparing the required vehicle speed and the predicted vehicle speed, or by comparing the required engine rotation speed and the predicted engine rotation speed.

[0014]

As described above, according to the present invention, the required acceleration state obtained from the accelerator pedal depression speed is compared with the predicted acceleration state, and the downshift is performed only when the required acceleration state is not realized. As a result, the downshift can be prevented from being performed even if the driver does not request.

[Brief description of drawings]

FIG. 1 illustrates the relationship between the components of the present invention.

FIG. 2 shows a framework of an automatic transmission.

FIG. 3 shows a combination of elements that act at each shift speed.

FIG. 4 shows the left half of the hydraulic circuit of the automatic transmission.

FIG. 5 shows the right half of the hydraulic circuit of the automatic transmission.

FIG. 6 shows a positional relationship between FIG. 4 and FIG.

FIG. 7 shows the left half of the control unit.

FIG. 8 shows the right half of the control unit.

FIG. 9 shows a positional relationship between FIGS. 7 and 8.

FIG. 10 shows a control flow.

FIG. 11 shows a change in acceleration with respect to time when a downshift is performed.

FIG. 12 shows a change in acceleration with respect to time when no downshift is performed.

[Explanation of symbols]

 300 Control unit 303 Throttle opening sensor

Claims (8)

[Claims] 1. A control device for an automatic transmission in which a gear stage is determined according to operating conditions including a vehicle speed and an engine load, and a sudden depression determination means for determining a rapid depression start of an accelerator pedal and an accelerator pedal depression speed. A desired accelerator pedal depression speed detection means, a required acceleration state detection means for obtaining an acceleration state required from the accelerator pedal depression speed obtained thereby, and a driving state after a lapse of the first predetermined time after the sudden depression judgment Acceleration state prediction means for predicting the acceleration state after a predetermined time, and commanding a downshift only when it is determined that the predicted acceleration state does not reach the required acceleration state obtained by the required acceleration state detection means A downshift commanding means, and a control device for an automatic transmission, comprising: 2. The control device for an automatic transmission according to claim 1, wherein the required acceleration state and the predicted acceleration state are indicated by acceleration. 3. The control device for an automatic transmission according to claim 1, wherein the required acceleration state and the predicted acceleration state are indicated by the vehicle speed. 4. The control device for an automatic transmission according to claim 1, wherein the required acceleration state and the predicted acceleration state are indicated by the engine speed. 5. A downshift canceling means for canceling the operation of the downshift command means and returning to a normal gear ratio determination state based on the driving condition when a predetermined driving condition that does not require the downshift condition is realized. The control device for the automatic transmission according to claim 1, 2, 3, or 4, further comprising: 6. The control device for an automatic transmission according to claim 5, wherein the predetermined operating state is determined by realizing a required acceleration state. 7. The control device for an automatic transmission according to claim 5, wherein the predetermined operating condition is determined by returning the accelerator pedal by a predetermined amount or more. 8. The control device for an automatic transmission according to claim 5, wherein the predetermined operating state is determined by maintaining a state in which the accelerator pedal is returned for a predetermined period or more for a predetermined period of time.