JPH09287655A - Shift control device for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform a shift reflected by the shift intention of a driver as an opportunity to execute deceleration fuel cut through shift control is enlarged. SOLUTION: In a deceleration operation state wherein an idle switch is turned ON, a shift is controlled (shift control for deceleration) at S5 so that the increase of a rotation speed exceeds an engine rotation speed NC, which is a condition on which injection of fuel to an engine is stopped. During the deceleration operation, a driver operates a select lever to vary a range at S7, S12, and S17. When a speed selected through ordinary shift control at a range after variation is higher than a speed selected through the shift control foe deceleration at S8, S13, and S18, a shift is effected to a speed corresponding to operation of a driver at S9, S14, and S19 and thereafter a return to ordinary shift control is effected at S10, S15, and S20.

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, and more particularly to a shift control device provided with a shift characteristic that is applied only in a specific operating condition in addition to a regular shift characteristic.

[0002]

2. Description of the Related Art Conventionally, there has been known an electronically controlled fuel injection device which performs a so-called deceleration fuel cut in which fuel supply to an engine is stopped in a deceleration operation state in which an engine rotation speed is equal to or higher than a predetermined value. On the other hand, in the automatic transmission connected to the engine in which the deceleration fuel cut is performed, during deceleration operation, a function of controlling the shift speed so as to be equal to or higher than the engine rotation speed in which the deceleration fuel cut is performed (hereinafter,
A shift control device including a deceleration shift control has been proposed (see Japanese Patent Laid-Open No. 4-203559).

[0003]

By the way, in an automatic transmission for a vehicle, a range can generally be selected by a select lever operated by a driver. As the selectable range, for example, P, R, N,
There are D, 3, 2, and 1 ranges. Here, when the “3” range is selected, the gear stage is selected from the first speed, the second speed, and the third speed, and in the deceleration operation state, the fuel cut is executed at the third speed, for example. If the obtained engine rotation speed is ensured, the third speed is controlled by the deceleration shift control. Then, in this state, when the driver operates the select lever to change to the "D" range in which automatic shifting is performed in the 1st to 4th speeds, the condition in which it is normally upshifted to the 4th speed However, if the engine speed at which the fuel can be cut is not reached at the 4th speed, it is maintained at the 3rd speed as it is (see FIG. 5).

The shift operation from the "3" range to the "D" range by the driver can be generally regarded as the driver's request for upshifting. As described above, even if the driver performs the range change operation corresponding to the upshift request from the state in which the gear is shifted to the highest speed that can execute the fuel cut, the upshift is not actually executed and the driver feels uncomfortable. There was a problem of giving.

The present invention has been made in view of the above problems, and an object of the present invention is to make it possible to execute shift control that reflects the driver's shift intention even during deceleration shift control.

[0006]

Therefore, the invention according to claim 1 is constructed as shown in FIG. In FIG. 1, the regular shift control means controls the shift of the automatic transmission according to a preset shift pattern. Further, the specific drive shift control means controls the shift of the automatic transmission based on a shift characteristic different from the shift characteristic of the normal shift control means in a specific operating state.

Here, the operation prioritizing means performs the operation when the driver gives an instruction to change the gear shift characteristic in the normal gear shift control means during the gear shift control by the specific driving gear shift control means. The corresponding shift control is preferentially executed. According to this configuration, when the driver performs a gear change characteristic change operation, for example, an operation intended for an upshift, when the gear change is controlled based on a characteristic different from the normal gear change characteristic in a specific driving state, The shift control corresponding to the operation is executed with priority over the shift characteristic corresponding to the specific driving state, and the driver's intention is reflected in the shift speed.

According to a second aspect of the present invention, the operation prioritizing means preferentially executes the shift control corresponding to the operation when the selection range is changed by the operation of the select lever by the driver. . According to this configuration, for example, when the driver operates the “3” range to the “D” range to request an upshift, it is possible to shift to a shift speed that corresponds to the upshift request.

According to a third aspect of the present invention, the engine coupled to the automatic transmission includes deceleration fuel cut means for stopping fuel supply in a deceleration operation state at a predetermined engine rotation speed or more, and the special operation gear shift. The control means controls the shift of the automatic transmission so that the engine rotation speed becomes equal to or higher than the predetermined engine rotation speed at which the fuel supply is stopped by the deceleration fuel cut means in the deceleration operation state.

According to this structure, when the engine rotation speed is low, the engine rotation speed can be maintained in the rotation range where the fuel cut is performed by downshifting, so that the opportunities for the deceleration fuel cut can be expanded, and the gear shift can be performed. When an operation is performed by the driver during the control, the gear shift is performed by giving priority to the operation of the driver rather than maintaining the engine rotation speed.

According to a fourth aspect of the invention, in the configuration for performing the shift control corresponding to the deceleration fuel cut means according to the third aspect, the operation priority means is the shift stage selected by the specific drive shift control means. Rather, the shift control to the shift speed selected by the normal shift control means is performed when the shift speed to be selected by the normal shift control means is a higher speed according to the driver's instruction to change the shift characteristics. It was set to give priority.

According to this structure, even when the shift control is performed to obtain the engine rotation speed at which the deceleration fuel cut is executed, the engine rotation speed is changed when the driver requests an upshift. This is executed even in the case of a downshift, and the driver's intention is reflected in the actual shift speed. According to a fifth aspect of the invention, the operation prioritizing means forcibly returns to the shift control by the normal shift control means.

According to this structure, even if the shift control is executed in a specific operating condition and with a characteristic corresponding to the specific operating condition, the normal control is restored when the driver operates, and the normal control is performed. The gear can be controlled according to the driver's operation.

[0014]

Embodiments of the present invention will be described below. In FIG. 2 showing the system configuration of the embodiment, an automatic transmission 2 is connected to an engine 1. A control unit 10 is provided to solenoid valves 2A to 2E for controlling hydraulic pressures to various transmission elements of the automatic transmission 2.
Outputs a control signal, whereby the speed change operation is controlled.

On the other hand, in the intake passage of the engine 1, the throttle sensor 3 including an idle switch 3A which detects the opening degree θ of a throttle valve (not shown) and is turned on at the fully closed position of the throttle valve, and the engine 1 An air flow meter 4 for detecting the intake air flow rate Q of is provided. Also,
A rotation sensor (crank angle sensor) 5 for detecting the engine rotation speed N is provided in the distributor or the like. Further, the vehicle speed sensor 6 for detecting the vehicle speed VSP, the automatic transmission 2
A gear position sensor 7 for detecting the gear position (gear position) is provided. In addition, there are provided a brake switch 8 which is turned on when the foot brake is operated, and an inhibitor switch 9 which detects a range selected by an A / T select lever operated by the driver.

Incidentally, by the A / T select lever,
For example, of each range of P, R, N, D, 3, 2, 1
Any one of them can be arbitrarily selected. Before
The detection signals from various sensors and switches are controlled by
Input to the unit 10. Control unit 10
Is the detection result of the intake air flow rate Q and the engine speed N.
One for controlling the fuel supply amount to the engine 1 based on the result
, The throttle valve is fully closed (Idle switch 3A is O
N) and the engine speed N (rpm) is the set speed N _CLess than
In the above deceleration operation state, stop the fuel supply (
Function corresponds to deceleration fuel cut means), set speed
Degree N_RIn the following cases, the so-called deceleration fuel power
Control.

Further, the control unit 10 normally carries out shift control according to a preset shift pattern based on the vehicle speed VSP and the throttle valve opening θ (accelerator opening) (this function corresponds to the normal shift control means). But)
During a predetermined deceleration operation (specific operation state), instead of the normal shift control, the engine rotation speed is maintained at a speed equal to or higher than the set rotation speed N _C in the deceleration fuel cut control to promote execution of deceleration fuel cut. The deceleration shift control for controlling the shift is executed (this function corresponds to the specific operation shift control means), and the state of the shift control during deceleration is shown in the flowcharts of FIGS. 3 and 4. Follow the instructions below.

In the flow chart of FIG. 3, first, in step 1 (denoted as S1 in the figure; the same applies hereinafter), it is determined whether the idle switch 3A is ON or OFF.
When the vehicle is in the predetermined deceleration operation state on condition that the idle switch 3A is ON, the routine proceeds to step 2. Note that the predetermined deceleration operation state may be a state in which the idle switch 3A is ON and the brake switch 8 is ON.

In step 2, the flag F indicating the canceled state of the deceleration shift control is determined. The flag is reset to 0 in step 3 when it is determined in step 1 that the idle switch 3A is off, that is, when it is determined that the vehicle is not in a predetermined deceleration operation state and normal gear shift control is performed. As described above, the routine proceeds to step 4 after step 3, and shift control (normal shift control) is normally performed according to the vehicle speed VSP and the throttle valve opening θ. The function of step 4 corresponds to the normal shift control means.

Therefore, at the first time after shifting to the deceleration operation, it is determined in step 2 that the flag F is 0, and the process proceeds to step 5 deceleration shift control. Deceleration shift control of step 5 (shift control means for specific operation)
This situation is shown in detail in the flowchart of FIG.
In the flowchart of FIG. 4, in step 51, the engine rotational speed N ₄ when the gear position G is controlled to the 4th speed from the current operating state is calculated by the following equation. However, if the present condition is the fourth speed, N ₄ = N may be set (the same applies to steps 54 and 57 described later).

N ₄ = VSP · K 1 · I ₄ · E where K 1 is a constant for converting the vehicle speed VSP (km / h) into the rotational speed (rpm) of the output shaft of the transmission, and I ₄ is 4 Gear ratios of speed (similarly, I ₃ , I ₂ and I ₁ are the third speed, the second speed and the first speed, respectively.
And E is the speed ratio of the torque converter (assuming constant).

Next, the routine proceeds to step 52, where the prediction engine for the fourth speed is used.
Gin rotation speed N_FourIn the deceleration fuel cut control
Set rotation speed N_CCompare with And N_Four≧ N_CIn
If it is determined that the deceleration change
The gear position G when performing the speed control is determined to be the fourth speed, and_X=
I_FourAnd set. On the other hand, at step 52, N_Four<N_CAnd judgment
When it is determined, the process proceeds to step 54, where the same arithmetic expression
 (I_FourTo I_Three3 speed prediction engine
Rotation speed N _Three, And then proceeds to step 55 where N_ThreeTo
N_CCompare with

If it is determined that N ₃ ≧ N _C , the process proceeds to step 56 in the same manner as described above, and the gear position G for deceleration shift control is determined to be the third speed, and I _X = I
₃ is set, and when it is determined that N ₃ <N _C , the process proceeds to step 57. Hereinafter, as compared to the set rotation speed N _C deceleration fuel cut control while seeking a predicted engine speed N _2, N ₁ in the same manner as in Step 57 to Step 62, N ₂ ≧ N _C,
When it is determined that N ₁ ≧ N _C , I _X = I ₂ , I _X
= I to ₁ and the set.

Also, N₁<N_CWhen it is determined that
Depending on the shift control, the set rotation speed N _CMore than
Since it is not possible, go to step 4 above
Executes shift control according to a pattern (normal shift control means)
You. In this way, when shifting gears from the high speed side
Predict engine speed N_CHighest of the above
Determine the gear position on the high speed side as the gear position for deceleration shift control.
To step 63.

In step 63, the deceleration when the gear is shifted to the determined gear position is calculated. This vehicle speed VSP _X after shifting _{(VSP X = K2 · I X} · N X: K2 is a constant)
Is calculated as the deviation ΔVSP from the current vehicle speed VSP. In step 64, the deviation ΔVSP is compared with a predetermined value, and when it is larger than the predetermined value, it is determined that deceleration due to engine braking becomes too large and a deceleration shock is felt when the gear shift is performed, and the gear shift is stopped and step 4 is executed. Then, the normal shift control (normal shift control) is performed.

On the other hand, when it is determined in step 64 that the deviation ΔVSP is less than or equal to the predetermined value, the routine proceeds to step 65, and shift control is performed to the determined gear position I _X. By such deceleration shift control, a gear position is selected such that the engine rotation speed N becomes equal to or higher than the set rotation speed N _C during the deceleration operation. Therefore, the opportunity for performing the deceleration fuel cut is expanded, and the fuel efficiency is improved. Etc. can be achieved. Step 51 ~
The function of step 65 corresponds to deceleration shift control means.

Now, returning to the flow chart of FIG. 3 and continuing the description, when the deceleration shift control is executed according to the above-described flow chart of FIG. 4, the routine proceeds to step 6, where the third speed is set as a result of the deceleration shift control. It is determined whether or not the gear is shifted to. If it is the third speed, the routine proceeds to step 7, where it is determined whether or not the driver has operated the A / T select lever to select a range indicating an upshift request (an operation for instructing to change the shift characteristic in the normal control). Determine whether. The selection of the range indicating the upshift request is, for example, from the "3" range in which the shift control is performed in the first speed to the third speed to the "D" range in which the shift control is performed in the first speed to the fourth speed. The change to the range in which the higher speed stage is selected is indicated as in the operation of.

When the range indicating the upshift request is selected in step 7, the process proceeds to step 8 and the condition that the fourth speed is selected by the normal shift control in the changed range (vehicle speed and throttle Valve opening). Then, if it is under the condition that the speed is changed to the fourth speed in the normal control, the process proceeds to step 9, and the speed change control corresponding to the A / T select lever is prioritized over the speed change control for the deceleration and the fourth speed is set. Force an upshift to.

Therefore, even if the engine speed N is such that the deceleration fuel cut is stopped by upshifting to the 4th speed, the A / T select lever is operated to shift to the 4th speed. Upshifting will be performed, and gear shifting that reflects the driver's intention can be performed. That is, if it is possible to execute the deceleration fuel cut by maintaining the third speed, it is required that the third speed is maintained even if the operation from the “3” range to the “D” range is performed. However, in general, the operation from the “3” range to the “D” range is intended for upshifting from the 3rd speed to the 4th speed, and the shift operation causes the 4th speed, which is a higher speed stage in the normal shift control. If the vehicle is not upshifted to the 4th speed under the condition that the vehicle is upshifted to, the driver will feel uncomfortable.

Therefore, during the deceleration shift control, the driver
When the T select lever is operated and the upshift is performed under the normal control according to the lever operation, the driver's request should be satisfied rather than the shift control for executing the deceleration fuel cut. Is prioritized to perform shift control according to normal characteristics. When the upshift is executed in step 9 in preference to the deceleration shift control, the flag F is set to 1 in step 10 so that from the next time onward, the routine proceeds from step 2 to step 4 so that normal shift control ( Forcibly return to normal shift control). Therefore, after the shift control corresponding to the lever operation of the driver is executed during the deceleration shift control, the deceleration shift control is not executed until the deceleration operation state is exited and the deceleration operation state is resumed. Will be performed.

The above-mentioned steps 7 to 10 and the below-mentioned steps 12 to 15 and 17 to 20 having similar functions correspond to the operation priority means. On the other hand, if the driver does not perform the lever operation indicating the upshift request, or if the operation of the lever is not a condition for upshifting due to the characteristics of normal shift control, step 9, By bypassing 10, the third speed selected in the deceleration shift control is maintained as it is, and the deceleration shift control is continued.

If it is determined in step 6 that the gear position selected by the deceleration shift control is not the third speed, the process proceeds to step 11 to determine whether the gear position selected by the deceleration shift control is the second speed. Determine whether or not. Even when the gear position is the second speed, the presence / absence of the lever operation corresponding to the upshift request by the driver is discriminated as described above, the lever operation is performed (step 12), and the normal lever operation corresponding to the lever operation is performed. When the condition is such that the upshift to the third speed or the fourth speed is performed by the control of (step 13),
The upshift corresponding to the normal control is executed (step 14), and then the flag F is set to 1 (step).
15) Return to normal control.

When the gear position selected in the deceleration shift control is the first speed (step 16), there is a lever operation corresponding to an upshift request by the driver (step 17). When it is a condition that the upshift to any of the second speed to the fourth speed is performed by the corresponding normal control (step 18), the upshift corresponding to the normal control is executed (step 1).
9) Return to normal control (step 20).

In the above deceleration shift control, the engine speed N is controlled so as to be equal to or higher than the set speed N _C which is the fuel cut start condition. However, after the deceleration fuel cut is started, The configuration may be such that the shift speed is selected so as to be equal to or higher than the set rotation speed N _R for restarting the fuel supply. Further, in the above, during the deceleration shift control, A
Although only shown when the / T select lever is operated,
In addition to this, even when an operation of a mode switch or the like is performed, a configuration may be adopted in which gear shift control is executed with priority given to such operation.

[0035]

As described above, according to the first aspect of the present invention, when the shift control corresponding to the specific driving condition such as the decelerating driving condition is being executed, the driver changes the normal shift characteristic. When the operation for instructing is performed, the shift control corresponding to the operation is preferentially executed, so that it is possible to reliably reflect the driver's intention in the shift speed.

According to the second aspect of the invention, for example, the driver operates the select lever to change the range from "3" to "D".
When the range is changed, there is an effect that it is possible to shift to a shift stage that matches the upshift request. According to the invention described in claim 3, there is an effect that it is possible to perform the shift control that reflects the driver's shift intention while increasing the chances of the deceleration fuel cut being performed by the shift control during the deceleration operation.

According to the fourth aspect of the present invention, when the shift control is performed to obtain the engine rotation speed at which the deceleration fuel cut is executed, the deceleration fuel cut is stopped even if the shift is performed. There is an effect that the shift can be performed according to the request of the person. According to the fifth aspect of the invention, when the driver performs an operation during execution of the shift control corresponding to a specific driving state such as deceleration driving, the normal control is forcibly returned to the normal control. There is an effect that it is possible to control the shift speed obtained according to the operation of the person.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of the invention according to claim 1;

FIG. 2 is a system configuration diagram of the automatic transmission according to the embodiment.

FIG. 3 is a flowchart showing a state of shift control in the embodiment.

FIG. 4 is a flowchart showing a state of deceleration shift control in the embodiment.

FIG. 5 is a time chart for explaining conventional problems.

[Explanation of symbols]

 1 Engine 2 Automatic Transmission 3A Idle Switch 3 Throttle Sensor 5 Rotation Sensor 6 Vehicle Speed Sensor 7 Gear Position Sensor 9 Inhibitor Switch 10 Control Unit

Claims (5)

[Claims] 1. A normal shift control means for controlling a shift of an automatic transmission according to a preset shift pattern, and a shift characteristic of the normal shift control means in place of the normal shift control means in a specific operating condition. In a shift control device for an automatic transmission, the shift control device for a specific drive controlling a shift of an automatic transmission based on a shift characteristic, wherein the driver is controlled during the shift control by the shift control device for the specific drive. Is provided with operation prioritizing means for preferentially executing the speed change control corresponding to the operation when an operation for instructing a change of the speed change characteristic in the normal speed change control means is performed. Control device. 2. The operation prioritizing means preferentially executes the shift control corresponding to the operation when the selection range is changed by the operation of the select lever by the driver. Shift control device for automatic transmission. 3. An engine connected to the automatic transmission,
The deceleration fuel cut means for stopping the fuel supply in the deceleration operation state at a predetermined engine speed or more is provided, and the specific operation speed change control means has the engine rotation speed in the deceleration operation state, and the fuel supply is stopped by the deceleration fuel cut means. The shift of the automatic transmission is controlled so as to be equal to or higher than the predetermined engine rotation speed.
A shift control device for an automatic transmission as set forth in. 4. The gear shift stage to be selected by the normal gear shift control unit in accordance with an instruction to change the gear shift characteristic by the driver, rather than the gear shift stage selected by the specific drive gear shift control unit. 4. The shift control device for an automatic transmission according to claim 3, wherein the shift control to the shift stage selected by the regular shift control means is prioritized when the shift speed is higher. 5. The shift control device for an automatic transmission according to claim 1, wherein the operation priority means forcibly returns to the shift control by the normal shift control means. .