JPH05248523A - Speed change controller of automatic transmission - Google Patents

Abstract

PURPOSE:To prevent sudden shock caused by the engine brake by preventing indiscreet shift down without spoiling operability for switching the shift range of an automatic transmission. CONSTITUTION:A range control section 20, which electrically control the selection of a shift range including a plural stage advance range in an automatic transmission AT, is provided with a shift limiting means to control the shift down of the advance range while a car is advancing at a specified speed or higher so as to limit the shift down of the advance range depending upon car speed.

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 in which selection of each shift range including a plurality of forward drive ranges is realized by electrical control.

[0002]

2. Description of the Related Art In an automatic transmission, a range switching valve (manual valve) is used to select a plurality of forward drive ranges (ranges of D, 3, 2, L, etc.), reverse range, shift range such as parking range and neutral range. ) Switching. Although the range switching valve is generally switched by manual operation, an automatic transmission having a configuration in which an actuator for driving the switching valve is electrically controlled to select a shift range has already been proposed.

The applicant of the present invention, for example, Japanese Patent Application No. 3-3
It proposes an operating device for an automatic transmission as shown in the specification and the drawings attached to the application No. 04181.
In this device, an electric signal is output from the range control unit to the drive circuit of the actuator in response to the contact signal of the range select switch that is switched by operating the shift lever, so that the shift range of the automatic transmission is selected. Is becoming

Specifically, the parking (P) range, the reverse (R) range, the neutral (N) range, and the drive (D) range are selected by the shift operation of the shift lever. By operating the shift lever up and down in the drive range position in the direction intersecting with the shift operation direction, the forward drive range such as the third (3) range including the D range, the second (2) range and the low (L) range is selected. It

[0005]

In this device, the up / down operation of the shift lever for selecting the forward drive range is performed by a light touch in order to improve the operability. Therefore, for example, the driver may inadvertently touch the shift lever during high-speed traveling, and the shift range of the automatic transmission may be shifted down from the D range. As a result, a large engine brake is applied, which causes an unexpected shock to the driver.

The technical problem of the present invention is to prevent downshifting without limiting the operability for shifting the shift range of the automatic transmission by limiting downshifting of the forward drive range depending on the vehicle speed. Is to avoid an unexpected shock due to engine braking.

[0007]

In order to solve the above problems, a shift control device for an automatic transmission according to the present invention is constructed as follows. That is, a range control unit that electrically controls selection of each shift range including a plurality of forward travel ranges in an automatic transmission according to a contact signal associated with operation of a range select switch, and a detection signal that detects a vehicle speed and outputs the detection signal. And a vehicle speed sensor for transmitting to the range control unit. The range control unit includes shift limiting means for limiting downshifting of the forward traveling range by operating the range select switch during forward traveling at a predetermined vehicle speed or higher.

[0008]

According to this structure, even if the range select switch is operated at a predetermined vehicle speed or higher and the control based on the contact signal is downshifting from the D range to the 3 range, for example, this is canceled and the automatic gear shift is performed. There are restrictions such as keeping the shift range of the machine in the D range.
This prevents downshifting of the forward drive range due to erroneous operation of the range select switch or careless operation.

[0009]

Embodiments of the present invention will now be described with reference to the drawings. Example 1 FIG. 2 is a perspective view showing a part of the front of a driver's seat of a vehicle. As can be seen in this drawing, the steering wheel 1
A shift lever 10 is arranged on the left side of the steering column portion 14 near the position 2. By operating the shift lever 10, the contacts of the range select switch SW for selecting the shift range of the automatic transmission AT, which will be described later, are switched. In FIG. 2, the automatic transmission AT is provided on the instrument panel 16 on the front side of the driver's seat.
A range indicator 25 for displaying the shift range of is provided.

FIG. 3 shows each range position of the shift lever 10 in a plan view. As is apparent from this drawing, an operation line C1 for operating the shift lever 10 at each range position P, R for selecting the parking (P) range and the reverse (R) range of the automatic transmission.
And the operation line C2 for operating the shift lever 10 to each range position N, D for selecting the neutral (N) range and the drive (D) range are offset in parallel by a certain amount.

At the position of the range position D, on the operation line C3 orthogonal to the operation line C2, a range position for selecting a forward traveling range (3, 2, L) other than the D range in the automatic transmission. UP and DW are set so as to be distributed to both sides centering on the range position D. The shift lever 10 is moved from the range position D to the range position UP, along the operation line C3.
If you operate the DW and release the operating force,
Shift lever 1 by the function of a detent mechanism (not shown)
0 is returned to the range position D each time.

As described above, the shift lever 10 has the structure shown in FIG.
A shift operation along the operation lines C1 and C2 or an up-down operation along the operation line C3 from the range position D is possible. The contacts of the range select switch SW are switched by these operations of the shift lever 10.

FIG. 1 shows a system diagram of electric control for selecting a shift range of the automatic transmission AT. In this drawing, a range control unit (SBW) 20 is a read-only memory (RO) in which a microcomputer is used and stores programs necessary for shift range switching of the automatic transmission AT and various software processing related thereto.
M), a central processing unit (C
PU), a writable memory (RAM) for temporarily storing variables necessary for a program, and the like.

A microcomputer is also used for the automatic shift control unit (ECT) 22 shown in FIG. 1, and as is well known, the control unit 22 automatically shifts gears based on vehicle speed and engine load (throttle opening). The switching control of the automatic shift solenoid valve 34 in the machine AT is possible. As a result, the automatic transmission AT is automatically switched to each gear.

Further, in FIG. 1, an actuator (DC motor) 30 provided on the automatic transmission AT side can switch a range switching valve (not shown) of the automatic transmission AT by driving the actuator. The line hydraulic pressure of the automatic transmission AT is supplied to the range switching valve, and the engagement and disengagement of a friction engagement device (not shown) for setting each shift range is controlled by the switching.

The range control unit 20 includes a contact signal associated with the switching of the range select switch SW, a detection signal of the valve position sensor 24 for detecting the range position of the range switching valve, and a vehicle speed sensor 28 for detecting the vehicle speed. The detection signal is also input. Further, the range control unit 20 outputs electric signals to the automatic shift control unit 22, the range indicator 25, and the drive circuit 32 of the actuator 30, respectively.

When the shift lever 10 is shifted along the operation lines C1 and C2 shown in FIG. 3, the contacts of the range select switch SW shown in FIG. 1 are changed according to the range positions P, R, N and D at that time. Are switched, and the electric signal from each contact is input to the range control unit 20.
Further, by operating the shift lever 10 from the range position D to the range position UP or DW side along the operation line C3, a count signal is transmitted from the switch SW to the range control unit 20.

The range control section 20 outputs a control signal corresponding to the contact signal of the range select switch SW to the drive circuit 32 of the actuator 30.
By driving the actuator 30 based on this, the shift range of the automatic transmission AT is selected as described above.
By operating the shift lever 10 down from the range position D to the range position DW, the forward drive range of the automatic transmission AT is changed to D according to the number of operations.
→ 3 → 2 → L Shift down one range at a time. Conversely, if the shift lever 10 is operated to move up to the range position UP, the forward traveling range is changed from L → 2 according to the number of times of operation.
→ 3 → D One range is shifted up.

When the shift range of the automatic transmission AT is switched and controlled in this manner, the automatic transmission AT is displayed on the range indicator 25 shown in FIGS. 1 and 2 based on the signal output from the range control section 20. The display portion corresponding to the shift range of is lit and displayed with a green background color, for example. However, there are 3 forward driving ranges, 2 ranges and L
The display units (“3”, “2”, and “L”) corresponding to the ranges are displayed such that the red background color is lit or the yellow background color is blinking during the shift-down restriction control described later.

4 and 5 are flow charts showing the contents of the shift control of the forward travel range by the range control unit 20. Further, FIG. 6 shows an operation identification region for each shift speed of the forward travel range with respect to the vehicle speed V. First, in step S1 of FIG. 4, it is determined whether or not the vehicle is traveling forward, and if the result of this determination is YES, then the next step S1.
Then, the routine proceeds to step 2, where it is determined whether or not the shift range of the automatic transmission AT is the D range based on the detection signal of the valve position sensor 24. If the result of this determination is no, the process further proceeds to the next step S3, and it is determined whether or not the shift range of the automatic transmission AT is three ranges.

If the result of the determination in step S3 is YES, the process proceeds to step S4, where the vehicle speed V based on the detection signal of the vehicle speed sensor 28 and the vehicle speed V4 shown in FIG. 6 (V> V4). Or not. If the result of this determination is NO, the process proceeds to step S5, and it is further determined whether or not (V> V3). If the result of the determination is YES, the current vehicle speed region is in region a of FIG. There will be. Therefore, in this case, the process proceeds to step S6 where the contact signal (down signal) of the range select switch SW caused by the down operation of the shift lever 10 is canceled once. That is, in this vehicle speed range, shifting from the 3rd range to the 2nd range is not possible unless the shift lever 10 is operated twice continuously.

In addition, in step S6, the background of the display portion of "3" in the range indicator 25 is made to blink in yellow to notify the driver that the down signal has been canceled once, and the circulation processing is continued. As a means for canceling the down signal once in step S6, a flag is set when the first down signal is input and the down signal is counted, and the first signal is counted unless the next down signal is counted. It is possible to cancel. In addition to this means, the shift down may be held for a predetermined time even when the first down signal is input, and the shift down may be executed by the next down signal.

If the result of the determination in step S1 is NO or if the result of the determination in step S2 is YES,
That is, when the vehicle is stopped or traveling backward, or when the shift range of the automatic transmission AT is the D range, the processing of this time is ended and the processing shifts to normal processing. If the result of the determination in step S3 is NO, that is, if the shift range of the automatic transmission AT is not 3 ranges, the process proceeds to step S10 in FIG.

Further, when the result of the determination in step S4 is YES, that is, when the vehicle speed V is (V> V4), the current vehicle speed range is in the range b in FIG. 6, so in this case It progresses to step S7 of FIG. In this step S7, the down signal of the range select switch SW is canceled to set the shift range of the automatic transmission AT to 3
Hold the range. Subsequently, the process proceeds to step S8, the background of the display portion of "3" on the range indicator 25 is turned on in red, the driver is informed that the down signal has been canceled, and then the normal process is performed.

If the result of the determination in step S5 is NO, that is, if the vehicle speed V is slower than the vehicle speed V3 in FIG. 6,
There is no problem even if the shift range of the automatic transmission AT is downshifted from the 3rd range to the 2nd range.

Next, in step S10 of FIG. 5, it is determined whether or not the shift range of the automatic transmission AT is two ranges. If the result of the determination is YES, the process proceeds to step S11 and the vehicle speed V becomes (V> V4) is determined.
If the result of this determination is no, the process proceeds to step S12,
It is determined whether the relationship between the vehicle speed V and the vehicle speed V2 in FIG. 6 is (V> V2). If the result of the determination is NO, it is further determined in step S13 whether or not (V> V1). If the result of this determination is YES, the current vehicle speed region is in region c of FIG. Becomes Therefore, in this case, the process proceeds to step S14, where the down signal of the range select switch SW is canceled once as in the process of step S6, and the background of the display portion of "2" in the range indicator 25 is changed to yellow blinking. The circulation process is continued below.

If the result of the determination in step S10 is NO, that is, if the shift range of the automatic transmission AT is not two ranges, the current processing is ended and the circulation processing is continued.
If the result of determination in step S11 is YES, that is, if the vehicle speed region is in region b of FIG. 6, the process proceeds to step S15. In step S15, the shift range of the automatic transmission AT is forcibly shifted from the current 2 range to the 3 range, and the process is ended.

If the result of the determination in step S12 is YES, that is, if it is determined that the current vehicle speed region is in the region d of FIG. 6, the process proceeds to step S16. In step S16, the down signal of the range select switch SW is cancelled, and the shift range of the automatic transmission AT is maintained at 2 ranges. Then, the process proceeds to step S17, the background of the display portion of "2" on the range indicator 25 is turned on in red, the driver is informed that the down signal has been canceled, and the circulation process is continued.

When the result of the determination in step S13 is NO, that is, when the vehicle speed V is slower than the vehicle speed V1 in FIG. 6, the shift range of the automatic transmission AT is from 2 ranges to L range.
There is no problem even if the gear is shifted down to the range, so this processing ends and circulation processing continues.

Embodiment 2 FIG. 7 shows a part of a shift lever 10 adapted to Embodiment 2 in section. In this drawing, the shift lever 1
A switch knob 70 is attached to the end of the grip at 0 so that it can be pushed. This switch knob 7
If 0 is pushed against the force of the spring 74 built into the grip, the grip portion 11
The normally-open contact 76 of the switch 75 arranged inside is pushed by the protrusion 72 of the switch knob 70 to be turned on.
The ON / OFF signal of the normally open contact 76 is also input to the range controller 20.

Therefore, in the present embodiment, under the condition that the down signal of the range select switch SW described above is canceled once, the switch knob 70 is operated simultaneously with the down operation of the shift lever 10, and the normally open contact of the switch 75 is operated. It is set to permit downshifting only when 76 is turned on. As a result, the first embodiment
Compared with counting down operation of the shift lever 10 as described above, the processing in the range control unit 20 is simplified.

[0032]

As described above, according to the present invention, inadvertent shift down at a predetermined vehicle speed or higher can be prevented without impairing the operability for switching the shift range, thereby avoiding an unexpected shock due to engine braking.

[Brief description of drawings]

FIG. 1 is an electric control diagram showing an outline of a shift control device.

FIG. 2 is a perspective view showing a part in front of a driver's seat of a vehicle.

FIG. 3 is a plan view showing each range position of a shift lever.

FIG. 4 is a flowchart showing a part of control contents by a range control unit for limiting downshifting of a forward traveling range.

FIG. 5 is a flowchart showing the control content by the range control unit for limiting downshifting of the forward drive range together with FIG.

FIG. 6 is a graph showing an operation identification region for each shift speed of a forward travel range with respect to a vehicle speed.

FIG. 7 is a sectional view showing a part of a shift lever.

[Explanation of symbols]

 20 Range control unit 28 Vehicle speed sensor AT Automatic transmission SW Range select switch

Claims (1)

[Claims] 1. A range control section for electrically controlling selection of each shift range including a plurality of forward travel ranges in an automatic transmission according to a contact signal associated with operation of a range select switch, and a vehicle speed detected. A vehicle speed sensor that transmits the detection signal to the range control unit is provided, and this range control unit limits downshifting of the forward traveling range by operating the range select switch when traveling forward at a predetermined vehicle speed or higher. A shift control device for an automatic transmission characterized by comprising shift limiting means.