JP2945515B2 - Transmission control device for automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art A conventional shift control device for an automatic transmission is disclosed in Japanese Patent Application Laid-Open No. 2-72263. The shift control device of the automatic transmission shown therein has two types of shift lines as downshift shift lines when the select device is at the engine braking position. That is, the first downshift line and the second downshift line on the lower vehicle speed side. The first downshift line is selected until a predetermined time elapses after operating the selector device to the engine braking position, and the second downshift line is selected after the predetermined time elapses. By doing so, at a relatively low vehicle speed where there is no possibility that the engine will overrun, downshifting is performed immediately after the operation of the select device by the first downshift line, while at a high vehicle speed where there is a possibility that the engine will overrun, Immediately after the operation of the selecting device, the actual vehicle speed is on the higher vehicle speed side than the first downshift line, so that no shift is performed, and after a predetermined time has elapsed, the shift is performed based on the second downshift line.

[0003]

However, in the conventional shift control device for an automatic transmission as described above, the shift is always performed by the second downshift line when the select device is operated on the high vehicle speed side. Therefore, there is a problem that this shift line is not sufficient depending on the operating conditions. That is, even when the brake is operated at a high vehicle speed and the selection device is operated to the position for engine braking and rapid deceleration is required, if the selection operation is performed at a high vehicle speed, the second downshift line Therefore, it takes time to actually downshift, and the driver's intention does not match the actual control. An object of the present invention is to solve such a problem.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problem by ensuring that when a brake is actuated, a shift is performed by a downshift line on the high vehicle speed side. That is, the shift control device for the automatic transmission according to the present invention includes the first downshift line and the second downshift line on the lower vehicle speed side as the downshift shift lines when the select device is at the engine braking position. The type is set, and the first downshift line is selected until a predetermined time elapses from the operation of the select device to the engine braking position, and the second downshift line is selected after the predetermined time elapses. that is obtained by assuming the shift control apparatus for an automatic transmission, a brake actuation determining means for determining the operation of the brake, if the brake <br/> key is determined to be actuated by the brake actuation determining means Is characterized in that a brake downshift line selecting means for selecting the first downshift line is provided.

[0005]

When the selector is operated to the position for engine braking and the brake is operated, the first downshift line is selected regardless of the elapsed time from the operation. Therefore, when the above operation is performed at a high vehicle speed, when the vehicle speed decreases to the first downshift line, a downshift is performed, and the engine brake is applied from an early stage. On the other hand, when the brake is not actuated, the first downshift line is selected for a predetermined time from the operation of the selection device, and the second downshift line is selected after the lapse of the predetermined time, as in the related art.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
Description will be made based on 0. FIG. 2 is a skeleton diagram showing the power transmission mechanism of the automatic transmission with four forward speeds and one reverse speed with overdrive. This power transmission mechanism includes a torque converter 10
, An input shaft 13 to which torque from an engine output shaft 12 is transmitted, an output shaft 14 to transmit driving force to a final drive, a first planetary gear set 15, and a second planetary gear set 1
6, reverse clutch 18, high clutch 20, forward clutch 22, overrunning clutch 24, low and reverse brake 26, band brake 28,
It has a low one-way clutch 29 and a forward one-way clutch 30. The torque converter 10 has a lock-up clutch 11 built therein. First
The planetary gear set 15 includes a sun gear S1, an internal gear R1, and a carrier PC1 that supports a pinion gear P1 that meshes with the two gears S1 and R1 simultaneously. The planetary gear set 16 includes a sun gear S2, an internal gear And a carrier PC2 that supports a pinion gear P2 that meshes with both gears S2 and R2 at the same time. The carrier PC1 can be connected to the input shaft 13 via the high clutch 20, and the sun gear S1 is
The input shaft 13 can be connected via a reverse clutch 18. The carrier PC1 includes a forward clutch 22 and a forward one-way clutch 3 connected in series with the forward clutch 22.
0, or via an overrunning clutch 24 arranged in parallel with the forward clutch 22 and the forward one-way clutch 30. 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 be a sun gear S1.
Can be fixed. The low one-way clutch 29 is arranged in such a direction that the forward rotation (rotation in the same direction as the engine output shaft 12) of the carrier PC1 is allowed but the reverse rotation (rotation in the opposite direction to the forward rotation) is not allowed.

The power transmission mechanism includes clutches 18, 2
0, 22 and 24, and brakes 26 and 28 in various combinations to operate planetary gear sets 15 and 1
6 (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 a combination as shown in FIG. 3, four forward speeds and one reverse speed can be obtained. In FIG. 3, the symbols .DELTA. Indicate operating clutches and brakes, and .alpha.1 and .alpha.2 are 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. 14 is a ratio of the rotation speed of the input shaft 13 to the rotation speed of the input shaft 14.

FIGS. 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, lock-up 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, first reducing valve 76, second shuttle valve 78, overrunning clutch control valve 80, overrunning clutch solenoid 8
2. Overrunning clutch reducing valve 8
4, a 1-2 accumulator 88, a 2-3 accumulator 88, a 3-4 accumulator 90, an ND accumulator 92, an accumulator control valve 94, a filter 96, etc., which are connected to each other as shown in the drawing. And the torque converter 10 described above.
(In this, an apply chamber 11a and a release chamber 11b of the lock-up clutch 11 are formed), a forward clutch 22, a high clutch 20, and a band brake 28 (this includes the second-speed apply chambers 28a,
A speed release chamber 28b and a fourth-speed apply chamber 28c are formed), the reverse clutch 18, the low-and-reverse brake 26, and the overrunning clutch 24 are also connected as shown, and the feedback accumulator 32 is Equipped with variable capacity vane type oil pump 34, oil cooler 36, front lubrication circuit 3
7 and the rear lubrication circuit 38 are also connected as shown. A detailed description of these valves will be omitted. The parts whose description is omitted are described in JP-A-63-251.
It is the same as that described in No. 6521.

FIGS. 7, 8 and 9 show 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 includes:
Engine 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 speed sensor 309, overdrive switch 310, signals from the brake switch 399, and the like. On the other hand, shift solenoids 64 and 66, overrunning clutch solenoid 82, lock-up solenoid 56, and line pressure solenoid 4
4 is output. In the control unit 300, control is performed according to a flowchart shown in FIG. 10 during a select operation. First, it is determined whether or not the gear is being shifted (step 500). If the gear is not being shifted, it is determined which range the selector lever is in (step 502). In the case of the D range, it is determined whether or not the overdrive switch 310 is off (504), and if it is off, it is determined from the signal of the brake switch 399 whether or not the brake is operating (505). If the timer has not been activated, it is determined whether or not the timer has exceeded the time T1 (506). Step 502
If the range is two or one, the process proceeds to step 505. Note that the timer of step 506 starts counting after the overdrive switch 310 is switched from on to off or after the select lever is operated to select between two ranges or one range. If the timer has not reached time T1, the first downshift line is selected (508). On the other hand, if the timer has exceeded the time T1,
R> Selects second downshift line (510). If the brake is operating in step 505, the process immediately proceeds to step 508 to select the first downshift line.
If the gear is being shifted in step 500, P,
In the case of the R or N range, and in the case where the overdrive switch 310 is turned on in step 504, the process ends immediately. As the first downshift line and the second downshift line, those shown in FIGS. 11, 12, and 13 are set for the 4-3 shift, the 3-2 shift, and the 2-1 shift, respectively. The 4-3 shift line shown in FIG. 11 is a shift line generated when the overdrive switch 310 is turned off. The first downshift line corresponds to the vehicle speed (136 km /
In h), the engine is set to have the maximum permissible rotational speed when the third speed is reached. The second downshift line is the first
It is set on the lower vehicle speed side (114 Km / h) than the downshift line. The 3-2 shift line shown in FIG. 12 is a shift line generated when the select lever is set to two ranges. Again, the first downshift line indicates that the vehicle speed (93K
m / h), the engine speed is set to the maximum allowable speed when the second speed is reached, and the second downshift line is set to a lower vehicle speed side (76 Km / h). It is. The 2-1 shift line shown in FIG. 13 is a shift line generated when the select lever is set to one range. First
The downshift line is set so that the engine speed becomes the maximum permissible speed when the first speed is reached at this vehicle speed (53 Km / h), and the second downshift line is a lower vehicle speed side. (39 km / h). For example, an operation when the select lever is operated to select the second range while driving in the third speed in the D range will be described.
The first downshift line of the 3-2 shift is a vehicle speed of 93 km / h.
And the second downshift line has a vehicle speed of 76
Km / h. When the select lever is selected to two ranges at a vehicle speed of 93 Km / h or less and the brake is not operated, the first downshift line is selected for the time T1 after the selection, so that the second shift is performed simultaneously with the select operation.
A shift to a high speed is performed. As described above, since the 3-2 shift is performed simultaneously with the select operation, the shift feeling is good and the engine braking effect can be obtained immediately. On the other hand, when the select lever is operated in two ranges with the brake inactive at a vehicle speed higher than 93 km / h,
The first downshift line is selected for the time T1 from the select operation, but the time T1 elapses before the vehicle speed decreases to 93 Km / h, and the second downshift line is selected after the time T1. become. Therefore, the vehicle speed is 76 km /
Only when the speed decreases to h, the 3-2 shift is performed. This allows for smooth 3-
Two shifts are performed. Next, when the brake is operating, the first downshift line is always selected. Therefore, when the select lever is selected to two ranges at a vehicle speed of 93 Km / h or less, the shift to the second speed is performed simultaneously with the selection operation. This operation is similar to the case where the brake is not operated. On the other hand, 93 km / h
When the select lever is operated to the two ranges at a higher vehicle speed, the shift is not immediately performed, and when the vehicle speed decreases to 93 Km / h, the 3-2 shift is performed. At the time of this shift, the engine rotation speed increases to the maximum allowable rotation speed, and a sufficient engine braking effect can be obtained. If the driver steps on the brakes and operates the select lever in two ranges, the driver intends to downshift quickly in this state intended for rapid deceleration. Therefore, the effect of the increase in the engine rotation speed is small. The above description relates to the 3-2 shift when selecting to two ranges.
The same operation as described above can be obtained with respect to the 4-3 shift when the switch is turned off and the 2-1 shift when the range is selected. In the above embodiment, the operation of the brake is detected by the brake switch 399, but may be detected by the deceleration of the vehicle, a brake fluid pressure sensor, or the like.

[0010]

As described above, according to the present invention, two types of downshift lines of the first downshift line and the second downshift line are provided according to the time from when the selector device is selected to the engine braking position. When the brake is activated when the shift line is set, the first downshift line set on the high vehicle speed side is always selected, so the driving conditions that require rapid deceleration Then
A downshift occurs early and a sufficient deceleration force can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing a relationship between components of the present invention.

FIG. 2 is a skeleton diagram of the automatic transmission.

FIG. 3 is a diagram showing combinations of elements acting at each shift speed.

FIG. 4 is a diagram showing a left half of a hydraulic control circuit.

FIG. 5 is a diagram illustrating a right half of a hydraulic control circuit.

FIG. 6 is a diagram showing a positional relationship between FIG. 4 and FIG. 5;

FIG. 7 is a diagram showing a left half of the control unit.

FIG. 8 is a diagram showing a right half of the control unit.

FIG. 9 is a diagram showing a positional relationship between FIGS. 7 and 8;

FIG. 10 is a diagram showing a flowchart.

FIG. 11 is a diagram showing a 4-3 shift line.

FIG. 12 is a diagram showing a 3-2 shift line.

FIG. 13 is a diagram showing a 2-1 shift line.

[Explanation of symbols]

 300 control unit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F16H 59/00-61/12 F16H 61/16-61/24 F16H 63/40-63/48

Claims (1)

(57) [Claims] 1. A first downshift line and a second downshift line on a lower vehicle speed side as a downshift shift line when the select device is at an engine braking position.
The type is set, and the first downshift line is selected until a predetermined time elapses from the operation of the select device to the engine braking position, and the second downshift line is selected after the predetermined time elapses. that the shift control device for an automatic transmission, a brake actuation determining means for determining the operation of the brake, when the brake is determined to be actuated by the brake actuation determining means, brake for selecting first downshift line A shift control device for an automatic transmission, comprising: an hour downshift line selecting means.