JPH01266026A - Device for controlling speed change of automatic transmission - Google Patents

Abstract

PURPOSE:To get rid of carrying out the unnecessary operation of engine brake by releasing the operation of the down shift for engine brake when the gear stage by an ordinary speed change pattern becomes a lower gear than that of a down-shift gear stage. CONSTITUTION:A vehicle speed is detected by A means A while detecting a braking operation by a means B. Also, deceleration is detected by a means C and an idling condition is detected by a means D. Further, delay is set only at an idling-OFF time by a means I while determining a gear position by a means J. The down shift for engine brake is determined by a means F based on the outputs of the means A-C, I, J. On the other hand, based on the output of the means F, the speed change control of an automatic transmission H to a defined gear position is carried out by a means G. At this time, when the gear stage by an ordinary speed change pattern becomes a lower gear than that of the gear stage of down shift, the operation of down shift for engine brake is released.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a shift control device for an automatic transmission, and particularly relates to shift control during braking of a vehicle.

(Prior art) As a conventional shift control device for an automatic transmission, for example, the "Nissan Automatic Transmission L" published by Nissan Motor Co., Ltd. in November 1982
Maintenance instructions for 4N71B type and E4N71B type! (A261
C04) There are some listed in J.

(Problem to be Solved by the Invention) However, in such a conventional automatic transmission shift control device, the idle switch, vehicle speed and brake switch are detected, and the vehicle speed is within a preset range, and the idle switch is detected. When the switch is on and the brake switch is on, downshifting for engine braking is performed and engine braking is obtained by setting an upper limit on the gear stage, so if the vehicle speed decreases or the pattern changes, downshifting will occur. Even if you shift, engine braking continues to work, which can cause a strange feeling.

(Means for Solving the Problems) This invention improves such conventional techniques,
In an automatic transmission that performs a downshift for engine braking depending on the conditions during braking, when the downshift for engine braking is activated, the gear position determined by the normal shift pattern is changed by the downshift for engine braking. When the gear is shifted to a lower gear, the downshift for engine braking is released.

(Function) As described above, in the present invention, when a downshift for engine braking is activated, when the gear according to the normal shift pattern becomes a lower gear than the gear for the downshift, the downshift for engine braking is activated. Since it is configured to release the shift operation, engine braking does not work even when downshifting due to deceleration or changing the shift pattern, eliminating the sense of discomfort that was previously felt.

(Example) The present invention will be explained below based on the drawings.

FIG. 1 is a diagram showing an embodiment of the present invention.

First, to explain the configuration, the vehicle speed detecting means A calculates the vehicle speed by counting pulse signals from a vehicle speed sensor provided on the output shaft of the automatic transmission H for a predetermined period of time (for example, 354 m5 such as Looms). The braking operation detection means B detects a brake signal from a brake switch to determine whether or not a braking operation is performed. The deceleration detecting means C determines the deceleration from the change in the signal from the means A at a predetermined period, and can also be determined from the longitudinal G sensor of the vehicle.

The idle state detection means detects a signal from a throttle fully closed switch (idle switch) provided in a throttle chamber of the engine to determine whether or not the engine is in an idle state. Other information E is information necessary for conventional speed change control (throttle opening, temperature of hydraulic fluid in the automatic transmission, etc.).

Further, the downshift determining means F for engine braking is
Vehicle speed information from means A, brake information from means B, deceleration information from means C, idle information with off-delay from means I, and gear position information from means J are input to create downshift conditions for engine braking. It is determined whether or not the following is true, and the result is sent to the speed change control means G.

The gear change control means G basically controls the gear position determined by the means J, and when downshifting for engine braking,
Shift control is performed to the gear position of means F. Further, in response to a downshift request from the downshift determining means F for engine braking, shift control, control of the clutch for engine braking, and upshifting are prohibited.

Further, the off-delay setting means (2) sets a delay only when the idle is off for the idle information from the means (2).

Further, the gear position determination means J based on the shift pattern, as in the past, determines the gear position according to the shift pattern selected by the driver.
The present invention is configured to determine the gear position that should be present.

The explanation of this example is based on Nissan Motor Co., Ltd.
RHdROIA type (maintenance manual A2) issued in March 2016
61GO? ) is an example applied to an automatic transmission, and its specific configuration requires only adding a brake switch input circuit to the control circuit of the REdROIA type automatic transmission.

Next, the effect will be explained.

Here, the speed change control means G including the deceleration detection means C, the downshift determination means F for engine braking, and the off-delay setting means I will be explained. Other parts are similar to the conventional example.

First, the deceleration detection means C will be explained (see FIG. 2).

The counter C is incremented by 1 each time a pulse from the vehicle speed sensor is input. Also, a predetermined period (for example, 100
m5, or 354 m5, etc.), Δ proportional to the deceleration is calculated from the previous counter value C' and the current counter value C.
At the same time as computing C, C' is updated and the counter C is cleared. Thereby, the deceleration ΔC is detected at every predetermined period. Note that here we are looking for deceleration rather than vehicle speed,
Naturally, it is also possible to determine the deceleration from the output of a longitudinal G sensor or the like.

Next, the downshift determining means F for engine braking will be explained with reference to FIG.

Note that the downshift request flags FDS2 (downshift to 2nd speed) and FDS3 (downshift to 3rd speed) for engine braking also serve as an upshift prohibition request.

(FDS2...Prohibition of upshifting to 3rd gear or higher, FD
S3...Prohibition of upshifting to 4th gear) ■ First, “D
Checks whether it is in the "D" range or not, and if it is other than the "D" range, the process ends with FDS2=01FDS3=0.

■ Next, check the status of IDLH, and
If not E, go to ■.

■ Next, check the FIDL flag and
When = 0 (that is, idle off → on), FDS
2=01FDS3=O (reset of downshift for engine brake), PIDL=1.

■Next, the brake is checked, and if the brake is off, the process ends.

■ Next, FDS2. Check FDS3, and if either is 1 (engine brake is already in operation), the process ends.

■〜■ Next, check the vehicle speed (VSP) and deceleration (Δ) depending on the currently used gear (4th or 3rd gear).
Check C) and if the conditions are satisfied, F
DS2. Set PDS3 to 1.

■ In the case of idle off, first check the FIDL, and if FIDL = 1 (that is, idle on/off), set the delay time in timer T, and
Let L=O.

[Phase] Next, when T=O (that is, after idle-on → off-color delay time), FDS2=O, FDS3
= 0, and the downshift for engine braking is canceled.

Note that, as shown in FIG. 4, the timer T is decremented every predetermined time (for example, 10nrs).

Next, the gear position determining means J and the speed change control means G based on the speed change pattern will be explained with reference to FIGS. 5 and 6.

■ First, as usual, the operating condition (throttle opening TVθ
, vehicle speed vsp, etc.).

■Next, the gear position GP is determined based on the shift pattern.

■、■ Next, the engine brake request flag FDS2
．． Check FDS3, if FDS3=1,
When the gear position GP is 3rd speed or higher, GP is changed to 3rd speed, and when it is 2nd speed or lower, GP remains unchanged and FDS3=0. If FDS2=1, when GP is in 2nd gear or higher,
When in 2nd gear, change GP, and when in 1st gear, leave GP unchanged and set FDS2=O.

As for the engine brake clutch, basically FDS2. It is engaged when either FDS3 is 1, and released when both are O (when a downshift for engine braking is released).

(Effects of the Invention) As described above, in this invention, when a downshift for engine braking is performed, when the gear according to the normal shift and pattern becomes a lower gear than the downshift gear, the engine brake is activated. Since the system is configured to disable the downshift operation, engine braking does not work even when downshifting due to deceleration or changing the shift pattern, which eliminates the sense of discomfort that was previously felt. .

[Brief explanation of the drawing]

Figure 1 is a block diagram showing the configuration of the present invention, Figures 2 to 6
The figure is a flowchart for explaining the operation of the present invention. A...Vehicle speed detection means B...Braking operation detection means C-Deceleration detection means D.
... Idle state detection means E ... Other information F ... Downshift determination means G for engine braking
...Shift control means H...Automatic transmission■...
・Off-delay setting means J... Gear determining means based on shift pattern Patent applicant
Nissan Motor Co., Ltd. Figure 2

Claims (1)

[Claims] 1. In an automatic transmission that performs a downshift for engine braking depending on conditions when braking, when a downshift for engine braking is activated, the gear determined by the normal shift pattern is changed by the downshift for engine braking. A shift control device for an automatic transmission, characterized in that a downshift operation for engine braking is released when the gear becomes lower than the gear position.