JPH01229143A - Speed change control device for automatic transmission - Google Patents

Abstract

PURPOSE:To enable braking downshift to be canceled by providing a vehicle deceleration detecting means, and determining whether or not braking downshift is to be carried out, by the detected deceleration. CONSTITUTION:A deceleration detecting means C obtains the deceleration by the variation in the specified period of the signal from a vehicle speed detecting means A. A vehicle speed information from the vehicle speed detecting means A, braking information from a braking operating detecting means B, deceleration information from the deceleration detecting means C, idling information from an idle condition detecting means D, and gear position information from a speed change control means G are input into an engine brake downshift determining means F. And it is judged whether or not engine brake downshift conditions are satisfied, and the result is sent to the speed change control means G. Thus, braking downshift can be canceled.

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
4N71B type, E 4 N71B type maintenance manual (A26
1 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. The system was designed to downshift for engine braking when the switch is on and the brake pedal is engaged, so this is combined with the driver's feeling that the downshift will occur even when the brake pedal is lightly pressed. There was a possibility that no control would be exercised.

(Means for Solving the Problems) This invention improves such conventional techniques,
In addition to the conventional conditions, the deceleration of the vehicle is also detected, and when the detected deceleration is smaller than a predetermined value, downshifting for engine braking is not performed.

(Function) As described above, in this invention, the downshift conditions for the engine brake of the automatic transmission include not only the states of the idle switch and the brake switch and the vehicle speed condition, but also the condition that the deceleration is at least a predetermined value. Because I added it, because I put my foot lightly on the brake pedal,
This eliminates the need for a downshift for engine braking.

(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 detection 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, 100 m5 or 354 m5). 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 detection 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 fully open throttle switch (idle switch) provided on a throttle converter 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
The downshift conditions for engine braking are established by inputting the vehicle speed information from the means B, the deceleration information from the means C, the idle information from the means G, and the gear position information from the means G. It is determined whether or not the transmission is being carried out, and the result is sent to the speed change control means G. The shift control means G basically controls the shift of the automatic transmission H depending on the operating state. Further, in response to a downshift request from the downshift determining means F for engine braking, the gear change control and the clutch for engine braking are controlled.

Note that the description of this example is based on the RE4ROIA type (
Maintenance instructions band A261CD? ) is applied to an automatic transmission, and its specific configuration is RE 4 ROIA
It is only necessary to add a brake switch input circuit to the control circuit of the type automatic transmission.

Next, the effect will be explained.

Here, the deceleration detection means C, the downshift determination means F for engine braking, and the shift control means G 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.), △ is proportional to the deceleration 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,
Of course, it is also possible to determine the deceleration from the output of the longitudinal G sensor, etc.

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

The downshift request flag FO8 for engine braking is as follows: - FDS=0 when (selector "D" range) or (IOLH off) - (selector "D" range) (IDLε on) and (brake on) (VL<VSP<VH)
When (ΔC≧ΔC5et), FDS=1. Note that VLLi is the lower limit vehicle speed, vSP is the vehicle speed, VH is the upper limit vehicle speed, ΔC is the deceleration, and ΔC5et is the set deceleration.

Then, first check whether it is a D parenge or not.
”If it is not in the range, it ends as FDS=O.

Next, it is checked whether it is 10LE, and if it is not 10LE, the process ends with FDS=0.

Next, the state of F[]S is checked, and if FDS=1, the process ends.

Next, check the brake switch and turn it off. If so, just exit.

Next, data corresponding to the gear stage currently in use (Vll,
VL, △C5et).

Next, if it is not checked whether the vehicle speed vSP is within the set vehicle speed range (between VL and VH), the process ends.

Next, it is checked whether the deceleration ΔC is equal to or greater than the set deceleration ΔCset, and if it is less than the set deceleration ΔCset, the process is terminated, and when the above conditions are met, FDS is set to 1.

Next, the speed change control means G will be explained with reference to FIG.

First, as usual, the gear stage GP is determined based on the operating condition and the shift pattern.

Next, the result FDS of the engine brake downsoft determining means F is checked, and if FDS=O, the necessary shift processing is performed as before and the process ends.

When FDS=1, the gear stage GP is lowered by one step and GP-
It is called GP-1.

Next, a gear change process is performed and a clutch for engine braking is engaged.

(Effects of the Invention) As explained above, in this invention, downshift conditions for engine braking of an automatic transmission include not only the states of the idle switch and brake switch and the vehicle speed condition, but also the deceleration exceeding a predetermined value. By adding this condition, it is possible to obtain the effect that it is possible to eliminate the problem of a downshift for engine braking being performed simply because the foot is lightly placed on the brake pedal.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the present invention, and FIGS. 2 to 4 are flowcharts explaining the present invention in detail. 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

Claims (1)

[Claims] 1. The system includes a means for controlling the gear used, a means for detecting the idle state of the engine, a means for detecting braking of the vehicle, and a means for detecting the speed of the vehicle, and detects a braking operation within a preset vehicle speed range. In a vehicle that performs a downshift for engine braking in a vehicle, a means for detecting the deceleration of the vehicle is provided, and it is determined whether or not to perform a downshift for engine braking based on the detected deceleration. Characteristics of the automatic transmission shift control device.