JP2000205394A - Controller for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make control parameters for controlling shift and line pressure proper. SOLUTION: Whether a degree of opening of an accelerator APO detected by an accelerator opening degree sensor is fully closed or not is judged (S13). If the degree of opening of the accelerator is fully closed, whether a degree of opening of throttle TVO detected by a throttle opening degree sensor is fully closed or not is judged (S14). If the degree of opening of the accelerator APO is fully closed and the degree of opening of the throttle TVO is not fully closed, shift control and line pressure control are done by the degree of opening of the accelerator APO (S15). In a case other than this, the shift control is done by the degree of opening of the accelerator APO, and line pressure control is done by the degree of opening of the throttle TVO (S16).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an automatic transmission, which performs a shift control based on an accelerator opening and controls a line pressure based on a throttle opening.

[0002]

2. Description of the Related Art In a conventional control device for an automatic transmission, a shift control is generally performed based on an accelerator opening detected by an accelerator opening sensor, while a throttle opening detected by a throttle opening sensor is controlled. The line pressure is controlled based on the degree.

[0003]

However, in a control device for an automatic transmission in which the shift control is performed by the accelerator opening and the line pressure control is performed by the throttle opening, the throttle opening is performed while the accelerator opening is fully closed. When the degree is other than the fully closed state (when the idle speed control is performed by the throttle actuator), the torque actually input to the transmission becomes zero.
Even though it is near, the line pressure is determined by the throttle opening, so that the line pressure becomes higher than necessary. For this reason, the loss (load of the oil pump) due to the oil pump increases, and the operability also deteriorates.

The present invention has been made in view of the above-mentioned conventional problems, and has as its object to appropriately control the line pressure.

[0005]

Therefore, according to the present invention, as shown in FIG. 1, a shift control means for performing a shift control based on an accelerator opening detected by an accelerator opening sensor; Line pressure control means for performing line pressure control based on the throttle opening detected by the throttle opening sensor, the control device for an automatic transmission, wherein the accelerator opening detected by the accelerator opening sensor is fully closed. Throttle opening determining means for determining whether the throttle opening is fully closed, throttle opening determining means for determining whether the throttle opening detected by the throttle opening sensor is fully closed, and throttle opening when the accelerator opening is fully closed. Is not fully closed,
By the line pressure control means, instead of the throttle opening,
Control parameter changing means for performing line pressure control based on the accelerator opening.

That is, when the accelerator opening is fully closed and the throttle opening is other than fully closed, both the shift control and the line pressure control are performed at the accelerator opening.
The shift control is performed by the accelerator opening, and the line pressure control is performed by the throttle opening.

[0007] In the invention according to claim 2, the accelerator opening sensor failure diagnosing means for diagnosing the presence or absence of a failure of the accelerator opening sensor, and the throttle opening sensor failure diagnosing means for diagnosing the presence or absence of the throttle opening sensor failure. The accelerator opening determination unit, the throttle opening determination unit, and the control parameter changing unit function only when both the accelerator opening sensor and the throttle opening sensor do not fail. I do.

[0008]

According to the first aspect of the present invention, when the accelerator opening is fully closed and the throttle opening is other than fully closed, the line pressure control is performed at the accelerator opening, so that it is actually possible. Although the torque input to the transmission is near 0, the line pressure is prevented from becoming unnecessarily high,
Since the loss due to the oil pump (load on the oil pump) does not increase, the fuel efficiency is improved, and the optimal oil pressure is obtained, so that the operability does not deteriorate.

On the other hand, in other cases, by performing the line pressure control at the throttle opening, a line pressure suitable for the torque input to the transmission can be obtained. That is, when the accelerator opening is other than the fully closed state, if the line pressure control is performed based on the accelerator opening, the line pressure becomes insufficient when the throttle opening becomes larger than the accelerator opening,
In the case of a belt-type continuously variable transmission, belt slippage occurs, and in the case of a gear-type continuously variable transmission, frictional engagement elements (clutches, brakes) slip, and conversely, the throttle opening is smaller than the accelerator opening. When the pressure decreases, the line pressure becomes excessive and fuel consumption deteriorates.However, by performing the line pressure control at the throttle opening, a line pressure suitable for the torque input to the transmission can be obtained. It is done.

According to the second aspect of the invention, the failure is diagnosed for the accelerator opening sensor and the throttle opening sensor, and control is performed only when there is no failure, thereby improving reliability.

[0011]

Embodiments of the present invention will be described below. FIG. 2 is a system diagram of one embodiment of the present invention.

The throttle valve 2 of the intake system of the engine 1
The motor 3 is connected to a step motor (or servo motor) 3 as a throttle actuator. The motor 3 is driven by a signal from an engine control unit (not shown).

Here, a target drive torque of the vehicle is determined from the accelerator opening and the vehicle speed, a target engine torque is determined from the target drive torque and the gear ratio of the automatic transmission, and a target throttle opening is determined based on the target engine torque. Motor 3 so that the target throttle opening is reached.
, The opening of the throttle valve 2 is controlled.

In the idle operation, when the target throttle opening is calculated, an idle speed control component based on a result of comparison between the actual idle speed and the target idle speed is included, so that the idle speed is calculated. It has a control function at the same time.

A belt-type continuously variable transmission (CVT) 4 is connected to the output side of the engine 1 as an automatic transmission. FIG. 3 is a system diagram on the transmission side.

The belt type continuously variable transmission (CVT) 4 has an input shaft 6 connected to an output shaft of the engine via a clutch 5.
Primary pulley 7 whose effective diameter on the side can be continuously changed
, A secondary pulley 9 whose effective diameter on the output shaft 8 side (differential side) can be continuously changed, a belt 10 wound between these pulleys 7 and 9, and a primary pressure (shift pressure) are input. A primary cylinder 11 acting on the primary pulley 7 in the radially expanding direction, and a secondary cylinder 12 receiving a line pressure and acting on the secondary pulley 9 in the radially increasing direction.

Here, the line pressure input to the secondary side cylinder 12 is based on the oil pressure from an oil pump (not shown) as a source pressure, and the line pressure control valve 1 having a relief function.
3 is generated.

The primary pressure input to the primary cylinder 11 is generated by the shift control valve 14 having a relief function using the line pressure as the original pressure. Therefore, the primary pressure is always lower than the line pressure, but the pressure receiving area of the primary cylinder 11 is
Since the pressure receiving area is set to be larger than the pressure receiving area of No. 2, by controlling the ratio of the primary pressure to the line pressure (primary pressure / line pressure), the pulley ratio can be changed and the speed ratio can be changed steplessly. .

Line pressure control valve 13 and shift control valve 14
Is duty-controlled by the transmission control unit 15. For this control, the transmission control unit 15 includes an accelerator opening sensor 16 for detecting an accelerator opening (depression amount of an accelerator pedal) APO, a throttle opening (opening of the throttle valve 2) TV.
Signals are input from a throttle opening sensor 17 for detecting O, a vehicle speed sensor 18 for detecting a vehicle speed VSP, and the like. The accelerator opening APO and the throttle opening TVO may be input from a control unit for engine control via a communication line.

Transmission control control unit 15
Based on these signals, the built-in microcomputer controls the transmission control valve 14 and the line pressure control valve 13 in accordance with the transmission control routine of FIG. 4 to control the transmission ratio and the line pressure.

The transmission control routine of FIG. 4 will be described. In step 1 (referred to as S1 in the figure, the same applies hereinafter)
Based on the accelerator opening APO and the vehicle speed VSP, a target gear ratio is calculated with reference to a shift map.

In step 2, duty control of the shift control valve 14 is performed so as to obtain the target gear ratio to control the primary pressure. Steps 1 and 2 correspond to shift control means.

In step 3, the throttle opening TVO
The target line pressure is calculated by referring to a predetermined table based on (or the accelerator opening APO). Here, whether to use the throttle opening TVO or the accelerator opening APO is determined according to a control parameter determination routine of FIG. 5 described later.

In step 4, the line pressure is controlled by controlling the duty of the line pressure control valve 13 so as to obtain the target line pressure. Steps 3 and 4 correspond to line pressure control means.

The control parameter determination routine shown in FIG. 5 will be described. In step 11, it is determined whether or not the accelerator opening sensor has failed. That is, in another routine, the output voltage of the accelerator opening sensor is compared with a predetermined upper limit value and a lower limit value, and when it is out of the predetermined range, it is diagnosed that there is a failure, and the diagnosis result is referred to. This part corresponds to the accelerator opening sensor failure diagnosis means.

In step 12, it is determined whether or not the throttle opening sensor has failed. That is, in another routine, the output voltage of the throttle opening sensor is compared with a predetermined upper limit value and a lower limit value. When the output voltage is out of the predetermined range, it is diagnosed that there is a failure, and the diagnosis result is referred to. This portion corresponds to a throttle opening sensor failure diagnosis unit.

In these determinations, if both the accelerator opening sensor and the throttle opening sensor have not failed, the process proceeds to step 13, and if any of them has failed, the process ends.

In step 13, the accelerator opening APO detected by the accelerator opening sensor is fully closed (APO =
0) is determined. This part corresponds to the accelerator opening degree determining means.

If the accelerator opening APO is fully closed, the routine proceeds to step 14. In step 14, it is determined whether or not the throttle opening TVO detected by the throttle opening sensor is other than fully closed (TVO ≠ 0). This part corresponds to a throttle opening degree determining means.

If the throttle opening TVO is not fully closed (that is, the accelerator opening APO is fully closed and the throttle opening TVO is not fully closed), the routine proceeds to step 15. In step 15, both the shift control and the line pressure control are performed at the accelerator opening APO.

That is, when the throttle opening TVO is not fully closed while the accelerator opening APO is fully closed,
In step 1 of FIG. 4, the shift control is performed based on the accelerator opening APO and the vehicle speed VSP.
To control the line pressure based on the accelerator opening APO (= 0).

The accelerator opening AP is determined in step 13
If O is not completely closed, or if the throttle opening TVO is fully closed as determined in step 14, the process proceeds to step 16. In step 16, the shift control is performed with the accelerator opening APO
, The line pressure control is performed at the throttle opening TVO.

That is, in these cases, the shift control is performed based on the accelerator opening APO and the vehicle speed VSP in step 1 of FIG. 4, while the line pressure control is performed based on the throttle opening TVO in step 3 of FIG. Let it do.

Here, the steps 15 and 16 correspond to control parameter changing means. As described above, when the accelerator opening APO is fully closed and the throttle opening TVO is not fully closed, the line pressure control is performed by the accelerator opening APO.
(= 0), it is possible to prevent the line pressure from becoming unnecessarily high even though the torque actually input to the transmission is near 0, and to prevent the loss (oil Pump load) does not increase,
Fuel efficiency is improved. In addition, since the oil pressure is optimal, drivability does not deteriorate.

On the other hand, in other cases, by performing the line pressure control at the throttle opening TVO, a line pressure suitable for the torque input to the transmission can be obtained. In the present embodiment, the automatic transmission is an example of a belt-type continuously variable transmission. However, the present invention is also applicable to a gear-type stepped transmission and a shift control and a line pressure control.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing a configuration of the present invention.

FIG. 2 is a system diagram showing an embodiment of the present invention.

FIG. 3 is a system diagram of a transmission side.

FIG. 4 is a flowchart of a transmission control routine.

FIG. 5 is a flowchart of a control parameter determination routine.

[Explanation of symbols]

 Reference Signs List 1 engine 2 throttle valve 3 motor 4 automatic transmission (belt-type continuously variable transmission) 5 clutch 6 input shaft 7 primary pulley 8 output shaft 9 secondary pulley 10 belt 11 primary side cylinder 12 secondary side cylinder 13 line pressure control valve 14 speed change Control valve 15 Transmission control unit 16 Accelerator opening sensor 17 Throttle opening sensor 18 Vehicle speed sensor

Claims (2)

[Claims] 1. A shift control means for performing a shift control based on an accelerator opening detected by an accelerator opening sensor, and a line pressure control for performing a line pressure control based on a throttle opening detected by a throttle opening sensor. Control means for an automatic transmission, comprising: accelerator opening determining means for determining whether an accelerator opening detected by an accelerator opening sensor is fully closed; and throttle opening detected by a throttle opening sensor. Throttle opening determining means for determining whether the degree is fully closed, and when the accelerator opening is fully closed and the throttle opening is other than fully closed, the line pressure control means replaces the throttle opening with the throttle opening. A control device for an automatic transmission, comprising: control parameter changing means for performing line pressure control based on an opening degree. An accelerator opening sensor failure diagnosing means for diagnosing the presence or absence of a failure of the accelerator opening sensor; and a throttle opening sensor failure diagnosing means for diagnosing the presence of a failure of the throttle opening sensor. Only when both the degree sensor and the throttle opening sensor have not failed, the accelerator opening determination means,
2. The control device for an automatic transmission according to claim 1, wherein the throttle opening degree determining means and the control parameter changing means function.