JP2004150464A - Controller for automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a controller for an automatic transmission capable of smoothly decelerating and stopping a vehicle even under idle-up control, with respect to the vehicle comprising an idle-up device. <P>SOLUTION: A gear of a transmission is shifted to a neutral stage (S7, S8) when the fuel injection amount is more than a specific value (S6), under a condition that a gear stage of the transmission is not neutral (S1), and a brake pedal is pressed or an accelerator opening is less than a specific value (S2, S3), as a result, a car speed becomes less than a specific value (S4), and an engine rotating speed is within a specific range (S5). Whereby as the gear is shifted to neutral when a vehicle is stopped from a travelling state even when an idle-up rotating speed is determined to be higher than a neutral gear shift rotating speed, the vehicle can be smoothly stopped without operating the brake by excessively pressing the brake pedal. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a control device for an automatic transmission of a vehicle, and more particularly to a technique for smoothly stopping a vehicle during idle-up control.
[0002]
[Prior art]
2. Description of the Related Art In recent years, mechanical automatic transmissions that automatically change the speed according to the traveling state by electronically controlling a friction clutch and a gear-type transmission have been put to practical use. In a mechanical automatic transmission, since a fluid clutch (torque converter) is not interposed in a driving force transmission system from an engine to a driving wheel, driving force transmission efficiency is high and fuel efficiency can be improved. Also, since there is no slip feeling specific to the fluid clutch, drivability is also improved.
[0003]
Note that, in the speed change control of the mechanical automatic transmission, as disclosed in Patent Document 1 or the prior application (Japanese Patent Application No. 2001-92119), in order to re-accelerate the gear type transmission immediately before the vehicle is stopped after being shifted to neutral. A technique has been proposed in which, when an accelerator operation is performed, the gear is shifted to an optimal gear according to the vehicle speed. In such a mechanical automatic transmission, in order to prevent the engine from stopping when the vehicle is stopped from a running state, when the brake operation and the engine rotation speed become equal to or less than a predetermined value (neutral transmission rotation speed), a gear-type automatic transmission is automatically provided. Control for setting the transmission to neutral is generally performed.
[0004]
[Patent Document 1]
JP 2001-227630 A
[Problems to be solved by the invention]
On the other hand, the engine is provided with an idle-up device, for example, in order to stabilize engine rotation at low water temperature and to quickly complete warm air. This idle-up device has a manual idle-up device that increases the engine speed during idling by the driver operating the idle volume, and automatically sets the engine speed during idling to a predetermined value according to the coolant temperature. There is an automatic idle-up device for raising the rotation speed to (idle-up rotation speed). With these idle-up devices, the fuel supply amount is controlled so as to be maintained at the idle-up rotation speed, and the engine rotation speed is kept substantially constant with respect to load fluctuations.
[0006]
Therefore, in a vehicle provided with such an idle-up device and a mechanical automatic transmission, if the idle-up rotation speed is set to be higher than the neutral shift rotation speed, the idle-up control is performed. However, even if the driver performs a brake operation to stop the vehicle from the running state, the engine rotation speed does not become lower than the neutral shift rotation speed, and the gear transmission does not become neutral.
[0007]
Therefore, the driver needs to depress the brake pedal more than necessary and forcibly reduce the engine rotation speed, thereby lowering the engine rotation speed to a value equal to or lower than the neutral shift rotation speed, and setting the gear type transmission to neutral. was there. In this case, the operation feeling of the brake is deteriorated. Also, the load on the brake may increase more than necessary.
[0008]
Accordingly, the present invention has been made in view of the above-described conventional problems, and when a vehicle provided with an idle-up device is stopped from a running state, it is determined that the vehicle is in an idle-up state based on engine torque, and a neutral state is determined. It is an object of the present invention to provide a control device for a mechanical automatic transmission that smoothly stops by shifting gears.
[0009]
[Means for Solving the Problems]
For this reason, the invention according to claim 1 is a gear position detecting means for detecting the gear position of the transmission, a deceleration intention determining means for determining whether the driver has a deceleration intention, and a vehicle speed detection for detecting the vehicle speed. Means, an idle-up determining means for determining whether or not the engine is in an idle-up state based on engine torque, a gear position detected by the gear position detecting means is a traveling speed, and the deceleration intention determining means When the vehicle speed detected by the vehicle speed detecting means is less than a first predetermined value and the idle-up determining means determines that the vehicle is in an idle-up state, And shift control means for shifting the gear position to neutral.
[0010]
According to this configuration, it is determined whether or not the engine is in the idle-up state based on the engine torque. When it is determined that the gear of the transmission is the traveling gear, the driver has a willingness to decelerate, the vehicle speed is less than the first predetermined value, and it is determined that the vehicle is in the idle-up state, the transmission is set to neutral. It is shifted. Thus, even when the idle-up rotation speed is set to be higher than the neutral shift rotation speed, the speed is shifted to neutral when the vehicle stops from the running state.
[0011]
According to a second aspect of the present invention, the deceleration intention determining means determines that the driver has a deceleration intention when the brake is operating or the accelerator opening is less than a second predetermined value. Features.
[0012]
According to such a configuration, when the vehicle stops from the traveling state, the brake operation is performed or the operation of stopping the depression of the accelerator pedal is performed. Therefore, when these conditions are satisfied, the driver has an intention to decelerate. Is determined.
[0013]
According to a third aspect of the present invention, the idle-up determining means determines that the engine is in an idle-up state when a fuel supply amount to the engine that is substantially proportional to the engine torque is equal to or greater than a third predetermined value. It is characterized by.
[0014]
According to this configuration, when the fuel supply amount to the engine is equal to or more than the third predetermined value, it is determined that the engine is in the idle-up state, so that an increase in the control load can be suppressed.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
[0016]
FIG. 1 shows a vehicle configuration including a control device for an automatic transmission according to the present invention.
[0017]
A gear type transmission (hereinafter referred to as “transmission”) 3 is attached to the engine 1 via a friction clutch (hereinafter referred to as “clutch”) 2. Further, the engine 1 is provided with a fuel injection pump 5 capable of controlling a fuel injection amount by an engine control unit 4 having a built-in microcomputer, and an engine speed sensor 6 for detecting an engine speed. The output shaft of a clutch booster 7 as a clutch driving actuator is connected to the clutch 2.
[0018]
On the other hand, the transmission 3 is provided with an actuator 10 for switching its gear position by air pressure via an electromagnetic valve 9 that is opened and closed by an automatic transmission control unit 8 containing a microcomputer. Further, the transmission 3 is provided with a position sensor 11 (gear position detecting means) for detecting a gear position, and a vehicle speed sensor 12 (vehicle speed detecting means) for detecting a vehicle speed from the rotation speed of the output shaft.
[0019]
In the driver's cab, an accelerator opening sensor 14 for detecting an accelerator opening through an amount of depression of an accelerator pedal 13, a brake operation switch 16 for detecting that a brake pedal 15 is depressed, and a shift instruction of the transmission 3 And a shift lever 17 for inputting the command.
[0020]
Then, a signal from the accelerator opening sensor 14 is input to the engine control unit 4, and the fuel injection pump 5 is controlled according to the accelerator opening.
[0021]
On the other hand, the automatic transmission control unit 8 receives the signals of the engine rotation speed sensor 6, the position sensor 11, the vehicle speed sensor 12, the brake operation switch 16, and the shift lever 17, and communicates with the engine control unit 4 to automatically transmit the signals. The clutch booster 7 and the solenoid valve 9 are controlled to perform the shift control.
[0022]
The automatic transmission control unit 8 controls according to a flowchart shown in FIG. The control according to the illustrated flowchart is repeatedly performed at predetermined time intervals.
[0023]
After START, in step 1 (abbreviated as “S1” in the figure, the same applies hereinafter), it is determined whether the gear position of the transmission 3 detected by the position sensor 11 is other than neutral (whether it is a traveling position). Is determined. If it is determined that it is other than neutral, the process proceeds to step 2. If it is determined that it is not neutral, step 1 is repeated.
[0024]
In step 2, it is determined whether or not the brake pedal 15 is depressed (whether the brake is being operated) based on a signal from the brake operation switch 16. If it is determined that the brake pedal 15 is depressed, the process proceeds to step 4. If it is determined that the brake pedal 15 has not been depressed, the routine proceeds to step 3.
[0025]
In step 3, it is determined whether or not the accelerator opening detected by the accelerator opening sensor 14 is less than a predetermined value (a second predetermined value). Here, the predetermined value is set to 10% of the accelerator opening when the accelerator is fully opened. If it is determined that the accelerator opening is smaller than the predetermined value, the process proceeds to step 4. If it is determined that the accelerator opening is not less than the predetermined value, the process returns to step 1. Note that a series of processes in steps 2 and 3 correspond to a deceleration intention determination unit. This is because, when the vehicle is stopped from the traveling state, a brake operation is performed or an operation of stopping the depression of the accelerator pedal is performed. Therefore, by satisfying these conditions, it is possible to determine that the driver has a deceleration intention. Because.
[0026]
In step 4, it is determined whether the vehicle speed detected by the vehicle speed sensor 12 is less than a predetermined value (first predetermined value). When it is determined that the vehicle speed is lower than the predetermined value, the process proceeds to step S5. If it is determined that the vehicle speed is not less than the predetermined value, the process returns to step 1.
[0027]
In step 5, it is determined whether or not the engine speed detected by the engine speed sensor 6 is within a predetermined range. Here, the predetermined range is set to an engine speed at which idling is stabilized, for example, from 650 rpm to 950 rpm. If it is determined that the engine speed is within the predetermined range, the process proceeds to step 6. If it is determined that the engine speed is not within the predetermined range, the process returns to step 1.
[0028]
In step 6, it is determined whether the fuel injection amount to the engine 1 controlled by the engine control unit 4 is equal to or more than a predetermined value (third predetermined value). Here, the predetermined value is set to a fuel injection amount at which the torque of engine 1 becomes 30% of the maximum torque. If it is determined that the fuel injection amount is equal to or more than the predetermined value, the process proceeds to step S7. If it is determined that the fuel injection amount is not equal to or more than the predetermined value, the process returns to step 1. Note that the processing in step 6 corresponds to idle-up determination means. This is because, when the driver has the intention to decelerate and the vehicle speed is lower than the first predetermined value, and the fuel injection amount is equal to or more than the third predetermined value, the engine torque during normal idling. Because it is larger, it can be determined that the idle-up control is being performed.
[0029]
In step 7, a control signal is sent to the clutch booster 7 to disconnect the clutch 2. Then, the process proceeds to Step 8.
[0030]
In step 8, a control signal is sent to the electromagnetic valve 9 to control the operation of the actuator 10 to shift the gear of the transmission 3 to neutral. After that, the process proceeds to END and ends the control. Note that a series of processes in steps 7 and 8 correspond to a shift control unit.
[0031]
First, whether the control according to the present invention is necessary is determined by the automatic transmission control unit 8 having the above-described configuration based on whether the gear position is other than neutral. When the control according to the present invention is necessary, when the brake pedal is depressed or the accelerator opening is smaller than the second predetermined value, it is determined that the driver has the intention to decelerate. At this time, if the vehicle speed is less than the first predetermined value, the engine speed is within the predetermined range, and the fuel injection amount is equal to or more than the third predetermined value, it is determined that the vehicle is in the idle-up state. Then, the transmission 3 is automatically shifted to neutral.
[0032]
Thus, in the idle-up state, the control for automatically shifting to the neutral state is performed even if the engine rotational speed is equal to or higher than the neutral shift rotational speed. Therefore, when stopping from the running state, it is not necessary to depress the brake pedal 15 more strongly than necessary to forcibly reduce the engine rotation speed, so that the engine can be stopped smoothly.
[0033]
FIG. 3 shows a time chart when the vehicle provided with the present embodiment is experimentally driven. Here, the idle-up rotation speed is set to 900 rpm, and the neutral shift rotation speed is set to 690 rpm. As shown in FIG. 3, the operation of the brake lowers the engine rotation speed. However, before the engine rotation speed reaches the neutral shift rotation speed, when the engine torque exceeds 30% of the maximum torque, the neutral rotation is started. The speed is changed.
[0034]
【The invention's effect】
As described above, according to the first aspect of the invention, even when the idle-up rotation speed is set to be higher than the neutral shift rotation speed, the speed is shifted to neutral when the vehicle stops from the running state. Thus, there is no need to depress the brake pedal more than necessary to operate the brake, and the brake can be stopped smoothly. In addition, the load on the brake can be reduced, and the stop of the engine due to a decrease in the engine speed can be prevented.
[0035]
According to the second aspect of the present invention, it is determined that there is an intention to decelerate based on the operation of the driver, so that accurate control reflecting the intention of the driver can be performed.
[0036]
According to the third aspect of the present invention, it is sufficient to determine whether or not the fuel supply amount to the engine is equal to or more than a predetermined value in order to determine whether or not the engine is in the idle-up state. Can be suppressed.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a vehicle provided with an automatic transmission control device of the present invention. FIG. 2 is a flowchart showing a control procedure in an automatic transmission control unit. FIG. 3 is a time chart showing a test running state of the vehicle. Description]
DESCRIPTION OF SYMBOLS 1 Engine 2 Mechanical clutch 3 Transmission 4 Engine control unit 6 Engine rotation speed sensor 8 Automatic transmission control unit 11 Position sensor 12 Vehicle speed sensor 14 Accelerator opening sensor 16 Brake operation switch

Claims (3)

Gear position detecting means for detecting the gear position of the transmission;
Deceleration intention determining means for determining whether the driver has a deceleration intention,
Vehicle speed detecting means for detecting a vehicle speed;
Idle-up determining means for determining whether the engine is in an idle-up state based on the engine torque;
The gear position detected by the gear position detecting means is a traveling speed, the deceleration intention determining means determines that there is a deceleration intention, and the vehicle speed detected by the vehicle speed detecting means is less than a first predetermined value; And a shift control unit that shifts the gear of the transmission to neutral when the idle-up determination unit determines that the vehicle is in an idle-up state;
A control device for an automatic transmission, comprising: The said deceleration intention determination means determines that a driver | operator has a deceleration intention, when a brake is operating or an accelerator opening is less than a 2nd predetermined value. Automatic transmission control device. 2. The engine according to claim 1, wherein the idle-up determining unit determines that the engine is in an idle-up state when a fuel supply amount to the engine that is substantially proportional to the engine torque is equal to or greater than a third predetermined value. 3. The control device for an automatic transmission according to claim 2.

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