JPH03121364A - Speed change controller for automatic transmission - Google Patents

Abstract

PURPOSE:To surely satisfy acceleration demand of a driver by setting a temporary shift down line on higher speed side till a first shift down is carried out after a change to a high speed transmission line and by returning it to the high speed transmission line after transmission. CONSTITUTION:Signals from sensors 21 and 22 of a throttle opening degree and a car speed and a transmission characteristic selection switch 23 are put into a control unit U, and solenoids 5 and 6 are magnetized or demagnetized so as to carry out transmission of a multi-stage transmission gear mechanism 4. In this control unit U, if an automatic mode is selected by a switch 23, it is switched to a power mode when a throttle opening degree change rate becomes more than a predetermined reference value, and immediately after that, a temporary shift down line on the higher speed side than this is set. After shift down by this is carried out, returning transmission is executed to a predetermined high speed transmission line. Thus, acceleration demand of a driver can be surely satisfied.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a shift control device for an automatic transmission that appropriately changes shift characteristics.

(Prior Art) In recent automatic transmissions, it has become common to have transmission characteristics that can be changed as appropriate. In such automatic transmissions, two shift characteristics are normally prepared in advance, for example, an economy mode shift characteristic and a power mode in which the shift line is set on the higher vehicle speed side than the economy mode, and for example, manual selection is possible. Therefore, the speed change control is performed with any desired speed change characteristics.

As mentioned above, among those having a plurality of shift characteristics, there have also been proposed ones in which the shift characteristics are automatically changed according to the engine load. Japanese Patent Publication No. 57-8983 states that while gear change control is normally performed based on the economy mode, when the engine load exceeds a predetermined reference value, for example when the throttle opening is 3/4 or more, the power A system has been disclosed that performs speed change control based on the code. That is, when the engine negative value η is less than a certain reference value, it is assumed that a large engine output (torque) is required, and the power mode is automatically selected.

Furthermore, Japanese Patent Publication No. 51-22698 discloses a system that switches to power mode when the accelerator is suddenly depressed, that is, when the rate of change in engine load reaches a predetermined reference value or higher. Proposed.

Furthermore, Japanese Patent Publication No. 58-27421 discloses a device in which the period during which the power mode is maintained is set as a predetermined time.

(Problem to be solved by the invention) However, as mentioned above, even if the mode is changed to power mode when the preset conditions are met, a downshift is not necessarily performed, and the driver requests acceleration. There will be cases where it is not possible to fully satisfy these requirements. In other words, the shifting characteristics are usually
Although the vehicle speed and engine load are set as parameters, for example, even if the engine load or the rate of change in the engine load falls below a reference value, it does not necessarily mean that the shift down line will be crossed. .

Therefore, an object of the present invention is to more reliably satisfy the driver's acceleration request, assuming that the shift line is changed to a higher vehicle speed side when a preset condition is met. An object of the present invention is to provide a shift control device for an automatic transmission.

(Structure 1 of the Invention) In order to achieve the above-mentioned object, the present invention has the following structure. In other words, in an automatic transmission that changes the shift line to a high speed shift line on the high vehicle speed side when a preset condition is met, one downshift after changing the shift line to the high speed shift line listed in 17iI. a temporary downshift line setting means for setting a temporary downshift line on a higher speed side than the downshift in the high speed shift line; and after the downshift is performed based on the temporary downshift line. , and a return means for returning to the high-speed shift line.

With this configuration, the first downshift immediately after changing the shift line to the high speed shift line is performed based on the temporary downshift line set to the higher speed side, so the downshift is performed faster. This will be done even more reliably. After the first downshift is performed after changing to the high-speed shift line, the normal high-speed shift line is returned to, so that no equal support is caused in subsequent shift control.

(Effects of the Invention) As described above, according to one aspect of the present invention, downshifting immediately after changing the shift line to the high speed side is made easier to perform, which is effective in satisfying acceleration demands.

(Example) Examples of the present invention will be described below based on the attached drawings.

In FIG. 1, 1 is an engine, and the output of the engine 1 (
torque) is transmitted to drive wheels (not shown) via the automatic transmission 2.

In the embodiment, the automatic transmission 2 includes a lock-up clutch 3.
The torque converter 3 includes a torque converter 3 equipped with a Δ, and a multi-speed gear mechanism 4 with four forward speeds and one reverse speed. The automatic transmission 2 is hydraulically operated, and the lock-up clutch 3A is engaged and engaged by switching between energization and demagnetization of a solenoid 5 incorporated in the hydraulic circuit. Further, by changing the combination of excitation and demagnetization of the plurality of solenoids 6 incorporated in the hydraulic circuit, the speed of the multi-speed gear mechanism 4 is changed.

In FIG. 1, U is a control unit for speed change control configured using a microcomputer. Signals from sensors or switches 21 to 23 are input to the control unit U, while signals from the control unit U are input to the control unit U for speed change control. Said solenoid5.
6 is output.

The sensor 21 detects the throttle opening. The sensor 22 detects vehicle speed. switch 2
3 is for selecting the speed change characteristic, and in the embodiment, it is a manual operation type, and is used to select the economy mode shown in FIG. 2, the power mode shown in FIG. 3, and the selection of both modes. Four types of selections are made: an automatic (automatic switching) mode in which kana is automatically selected, and a hold mode. In the embodiment, when the economy mode or the power mode is selected by the switch 23, the selected speed change characteristics are fixed and are not changed. Further, as is known, the hold mode is fixed at 3rd speed when in the D range, fixed at 2nd speed when in the 2nd range, and fixed at 1st speed when in Lunge. The automatic mode is the object of the present invention, and while the economy mode is normally selected, when the rate of change in engine load becomes less than a predetermined reference value, a switch is made to select the power moto mode. Note that the present invention can also be applied when the economy mode is selected by the switch 23.

The outline of the control by the control unit [J is as follows.

First, on the premise that the automatic mode is selected by the switch 23, the economy mode shown in FIG. 2 is basically selected, and the speed change control is performed based on the economy mode.

When the throttle opening change rate ΔGOVO, which indicates the rate of change in engine load, reaches a predetermined reference value of 0 or more, the economy mode is switched to the power mode, and gear shift control is performed based on the power mode.

1- The reference value a for switching to the power mode is:
Basically, it is determined by a map value set using the throttle opening TVO and vehicle speed V8P as parameters. In Figures 4 and 5, the base L(+rt (map value)
a as a and throttle opening as a parameter, il
It shows the tendency of correspondence with j speed.

-1- After switching to the power mode as described above, the mode is returned to the economy mode when the throttle opening TVO becomes smaller than a predetermined reference value γ. In the embodiment, this reference value γ is set as a parameter such as vehicle speed as shown in FIG.

Immediately after switching to the power mode, the shift down line among the shift lines for the power mode shown in FIG. 3 is changed to a temporary shift down line on the higher speed side. However, this temporary downshift line is only changed to the 4th gear when acceleration is difficult to obtain, and therefore only the 4-3 downshift line is set as the temporary downshift line. In this embodiment, this temporary 4-3 shift down line is set to be the same as the 3-4 shift up line in the power mode, as shown by the dashed line in FIG. Here, the 3-4 shift up line and tentative 4-3 shift down line are drawn slightly shifted to clearly show them.) After such a temporary downshift line is set, when the first downshift is performed, that is, when the gear position is 3rd gear or lower in the embodiment, the regular downshift line (see Fig. 3) is set. power mode). However, when the operating condition is such that the downshift line is changed even based on the 4-3 downshift line for the regular power mode shown in FIG. 3, the provisional downshift line is not set.

For this reason, a reference value β (throttle opening degree) with vehicle speed as a parameter is used to determine whether or not to set a temporary downshift line.
This is how you set it. The 9th parameter for setting this reference value β
The characteristics shown in the figure are the same as those of a regular 4-3 shift down line for power mode.

Next, details of the control by the control unit 1J will be explained with reference to the flowchart of FIG. 5. In addition, in the following explanation, P indicates a step.

First, when initializing the PI, the power mode is turned off.
F (economy mode selection).

In [)2, after the signals from the sensor order 21 to 23 are read, in P3, the slot/]nottle opening 'V
The rate of change △-FVO of VO is calculated (calculate the deviation between the previous throttle opening and the current throttle opening).
- It is determined whether or not. YES in this P4 judgment
In this case, the power mode is turned on (power mode selection) in P5.

After P5, at P6, the current throttle opening '■
It is determined whether or not 0 is smaller than the reference value β in FIG.

If the determination in I) 6 is YES, it is assumed that a downshift is not performed based on the regular 4-3 shift down line, and the process moves to P7, where a temporary 4-:3 shift down line is not performed.
A shift down line (equivalent to the 4-3 shift up line as described above) is set. After this, in P8, it is determined whether the gear position is 3rd gear or lower and whether a downshift has been performed.If the determination in P8 is NO, the process returns to P7 (temporary 4-3 downshift). maintain line settings).

If the determination in P8 is YES, the temporary 4-3 downshift line is returned to the regular 4-3 downshift line for power mode in P9.

After P9, at P I O, the throttle opening TV
0 (after speed vSP is read, throttle opening TV
It is determined whether or not O is smaller than the reset reference value γ shown in FIG. If the result of this pH determination is No, the process returns to PIO (power mode continues). Then, by determining the pH, YE
When it becomes S, it shifts to PI3 and the power mode turns OFF.
F and economy mode is selected.

When the determination in P4 is No, the process directly shifts to PI2 and is set to economy mode. Also, in the judgment of P6, N
When it is O, a transition is made to PIO without setting a temporary downshift line.

Although the embodiments have been described above, the engine load itself may be used instead of the rate of change in the engine load as the reference value for switching to the power mode. In this case, when setting the throttle opening as a reference value, it is preferable to set the throttle opening change rate △TVO and vehicle speed as parameters, and the correspondence trend between the reference value and the throttle opening change rate is shown in Figure 10. FIG. 11 shows the tendency of correspondence between the reference value and vehicle speed. The present invention can also be applied when switching to power mode by manual selection.

[Brief explanation of drawings]

FIG. 1 is an overall system diagram showing one embodiment of the present invention. Figure 2 shows an example of the speed change characteristics in economy mode. FIG. 3 is a diagram showing an example of shift characteristics in power mode. FIG. 4 is a diagram showing an example of setting a temporary shift down line. FIG. 5 is a flowchart showing a control example of the present invention. FIG. 6 and FIG. 7 are diagrams showing the tendency of correspondence between the throttle opening degree and vehicle speed and the reference value for power mode setting. FIG. 8 is a diagram showing an example of setting a reference value for power mode reset. FIG. 9 is a diagram showing an example of setting a reference value for determining whether to set a temporary downshift line. FIGS. 1O and 11 show other embodiments of the present invention, and correspond to FIGS. 6 and 7. 1 2 3 2 Control unit: Engine 2 Automatic transmission: Torque converter: Multi-speed gear mechanism: Solenoid (for shifting): Sensor (throttle opening): Sensor (vehicle speed): Switch (for selecting shifting characteristics) Kushi 4th section Figure 2 Figure 3 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 1I

Claims (1)

[Claims] (1) In an automatic transmission that changes the shift line to a high speed shift line on the high vehicle speed side when a preset predetermined condition is met, the first shift after changing the shift line to the high speed shift line. Until a downshift is performed, a temporary downshift line setting means is configured to set a temporary downshift line on a higher speed side than the downshift line in the high speed shift line, and a downshift is performed based on the temporary downshift line. A shift control device for an automatic transmission, comprising: a return means for returning the high-speed shift line to the high-speed shift line.