JPH11148393A - Controller for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect failure of an automatic transmission using an existing sensor regardless of existence of a turbine sensor. SOLUTION: This controller is provided with a throttle sensor 8 for detecting a throttle opening, a means 20 for detecting driver's running intention based on a signal from an inhibitor switch 6, a means 22 for discriminating a vehicle speed based on a signal from a vehicle speed sensor 7, a comparative computing means 23 which compares a reference engine rotational speed corresponding to the throttle opening in a D-range condition, obtained from a reference engine rotational characteristic map 24 with actual engine rotational speed at the time of depressing an accelerator pedal, and discriminates that the automatic transmission is in a failed and inoperative condition if the driver's running intention is detected, the vehicle speed is discriminated as '0' and the reference engine rotational speed is the actual engine rotational speed or lower, and an warning lamp 12 for warning the driver according to the discrimination of a failure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission, when a driver selects a driving range other than the N range from the N range while the vehicle is stopped, in the event that the automatic transmission has some trouble. The present invention relates to a control device for an automatic transmission, comprising: means for detecting a failure of the vehicle and determining that the vehicle cannot travel.

[0002]

2. Description of the Related Art When a driver operates a select lever in a stopped state of a vehicle to select a driving range other than the N range from the N range, a clutch or the like of an automatic transmission breaks down and is in a neutral state. There are cases. In this case, although the vehicle must travel forward or backward, the vehicle cannot travel and is contrary to the driver's will. For this reason, when the automatic transmission is out of order, it is necessary to detect such an outage and take appropriate measures at an early stage. As a control device for an automatic transmission having a failure detecting means, for example, Japanese Patent Application Laid-Open
The one described in JP-A-174079 is known.

This automatic transmission control device is provided with means for detecting a failure of a forward clutch of the automatic transmission. The control device shifts the turbine rotational speed in the N range and shifts from the N range to the forward travel range. When the difference from the turbine rotation speed after a predetermined time after
It is determined that the forward clutch is out of order.

[0004]

However, in such a conventional control device for an automatic transmission, a turbine sensor for detecting the turbine speed of a torque converter is used for detecting a failure of the automatic transmission. Although a turbine sensor can be used for an existing automatic transmission as it is, an automatic transmission without a turbine sensor requires a new turbine sensor.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and a control device for an automatic transmission capable of detecting a failure of the automatic transmission using an existing sensor regardless of the presence or absence of a turbine sensor. The purpose is to provide.

[0006]

In order to achieve the above object, a control device for an automatic transmission according to a first aspect of the present invention includes a means for detecting a depression characteristic of an accelerator pedal and a means for detecting a driving intention of a driver. And means for determining the vehicle speed, and comparing the reference engine speed in the travel range state with the actual engine speed when the accelerator pedal is depressed in the transmission mechanism previously set according to the depressing characteristics, Further, when the driver's driving intention is detected, the vehicle speed is determined to be "0", and the reference engine speed when the accelerator pedal is depressed is lower than the actual engine speed, the automatic transmission Means for determining that the vehicle is in a state of being unable to travel due to failure, means for warning the driver in response to the failure determination, and suppressing an increase in engine speed in response to the failure determination Characterized by comprising at least one means of stages.

[0007] A control device for an automatic transmission according to claim 2 is
In claim 1, the means for suppressing an increase in the engine speed cuts fuel to a part or all of the cylinders of the engine.

[0008] A control device for an automatic transmission according to claim 3 is
According to a first aspect of the present invention, the means for suppressing an increase in the engine speed controls the throttle valve in a closing direction.

According to a fourth aspect of the present invention, a control device for an automatic transmission comprises:
4. The method according to claim 1, wherein the comparison operation unit performs a failure determination after a lapse of a predetermined time from the detection of the drive intention by the drive intention detection unit. 5.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a system configuration diagram of a control device of an automatic transmission according to an embodiment of the present invention, FIG. 2 is a block diagram for explaining the control device,
FIG. 3 is a graph showing the relationship between the engine speed (stall speed) and the throttle opening, and FIG. 4 is a graph showing the relationship between the torque capacity (when the vehicle is stopped), the stall speed and the throttle opening. FIG. 5 is a flowchart for explaining the operation of the control device.

In FIG. 1, reference numeral 1 denotes an engine, 2 denotes a torque converter for transmitting the power of the engine 1 to a transmission mechanism 3, and 4 denotes a pressure-regulated output from an oil pump (not shown) and supplies the output to the transmission mechanism 3. Hydraulic control valve, 5
Are hydraulic control solenoids (shift solenoid A, shift solenoid B,
Line pressure solenoid, backup pressure solenoid, etc.),
Reference numeral 6 denotes an inhibitor switch for detecting a selected position of a select lever (not shown), 7 a vehicle speed sensor for detecting the number of revolutions of the output shaft, 8 a throttle sensor (stepping characteristic detecting means) for detecting a throttle opening, 9 Denotes an engine speed sensor for detecting the engine speed, 10 denotes an ECCS (Engine Centralized Electronic Control System) control unit for controlling the engine 1 based on signals from the engine speed sensor 9 and the throttle sensor 8, and 11 denotes the engine speed. The hydraulic control solenoid is controlled based on signals from the number sensor 9, the throttle sensor 8, the inhibitor switch 6, the vehicle speed sensor 7, and the like. When the automatic transmission fails and the vehicle cannot run, the failure is determined. AT control unit for turning on a warning lamp (warning means) 12 Yes, AT control unit 1
Reference numeral 1 denotes a microcomputer including a predetermined drive circuit.

The inhibitor switch 6 has a plurality of range switches corresponding to the selected position of the select lever. The state of the range switch at each selected position is detected, and the range switch is turned ON and selected at the selected position. When there is no position, the range switch is turned off, and a combination pattern of the ON / OFF state of each select position can be obtained.

As shown in FIG. 2, the microcomputer of the AT control unit 11 detects a driver's willingness to travel based on a signal from the inhibitor switch 6 and a signal from the vehicle speed sensor 7. determining means 22 whether the vehicle speed is "0" (in this embodiment, D-range state) previously running range state, which is set according to the throttle opening Tv ₀ reference engine speed N _e and the accelerator in The actual engine speed N _e0 when the pedal is depressed is compared with the reference engine when the driver's intention to drive is detected, the vehicle speed is determined to be “0”, and the accelerator pedal is depressed. speed N _e is the actual engine speed N _e0 automatic transmission is in a state that can not be run in failure when at most a determined comparison operation means 23 and the timer It includes a stage 21.

[0014] The driving intention detecting means 20 changes the range from N range to N
If a signal indicating that the vehicle has been switched to a driving range other than the range, in this embodiment, a signal indicating that the vehicle has been switched to the D range, is received from the inhibitor switch 6, it is determined that there is an intention to travel.

The comparing means 23 counts a predetermined time by the timer means 21 after the driving intention detecting means 20 detects the driving intention of the driver, and the vehicle speed determining means 22 determines that the vehicle speed is "0". When it is determined, the throttle opening Tv ₀ and the actual engine speed N _e0 are read from the throttle sensor 8 and the engine speed sensor 9, and then the reference engine speed characteristic shown in FIG. by referring to the map 24, in a region a exceeds the reference engine speed N _e of the actual D-range when the engine rotational speed N _e0 is set in advance according to the throttle opening Tv ₀ when depression of the accelerator pedal It is determined whether or not there is.

If the actual engine speed N _e0 is within the range A, the clutch (forward clutch) of the automatic transmission fails and it is determined that the vehicle cannot travel in spite of the D range. Warning lamp 1 to call attention
2 is turned on.

Here, the reference engine speed N _e according to the throttle opening Tv ₀ is set as follows. That is, the torque t required to rotate the pump impeller, which is the input shaft of the torque converter 2, is determined by the rotation speed (=
Engine speed). This proportional constant is defined as a torque capacity τ, and the engine speed in each running state is determined by the torque capacity τ.

In particular, when the vehicle is stopped, the rotation of the turbine runner, which is the output shaft of the torque converter 2, is stopped, and the speed ratio (output shaft rotation speed / input shaft rotation speed) becomes zero. The torque capacity τ at this time is called a stall capacity, and the engine speed in the stopped state is determined by this.

For example, as shown in FIG. 4, the brake is depressed in the D range, and the throttle opening Tv _{0 is set} to 8/8 (fully open).
The engine speed at 7/8 and 6/8 is determined by the intersection of the engine torque characteristic corresponding to the throttle opening Tv ₀ and a parabola indicating stall capacity.

Then, this parabola and each throttle opening Tv
The intersection with the engine torque at ₀ is the engine speed corresponding to the D range + the throttle opening Tv ₀ when the brake pedal is depressed (during stall), and each throttle opening at this time
That organize the relationship between the engine speed and Tv ₀ corresponding to the throttle opening Tv ₀ is the reference engine speed characteristics map criterion line shown in FIG.

Next, the operation of the control device for the automatic transmission will be described with reference to FIG. Here, step S10 corresponds to the driving intention detecting means of the present invention, step S12 corresponds to the vehicle speed determining means, steps S13 to S15 correspond to the comparison calculating means, and step S16 corresponds to the warning means.

First, in step S10, it is determined based on a signal from the inhibitor switch 6 whether or not the shift range has been switched from the N range to the D range. When the shift range has been switched, the process proceeds to step S11. In step S11, it is determined whether or not the counting of the predetermined time by the timer unit 21 has timed out. If the time has elapsed, the process proceeds to step S12.

In step S12, it is determined whether the vehicle speed is "0" based on a signal from the vehicle speed sensor 7. If the vehicle speed is "0", the throttle sensor 8 and the engine speed sensor are determined in steps S13 and S14. From 9, the throttle opening Tv ₀ and the actual engine speed Ne ₀ are read, and then the process _proceeds to step S 15.

In step S15, referring to the reference engine speed characteristic map 24, the actual engine speed N _e0 when the accelerator pedal is depressed is calculated as the reference engine speed N _e.
It is determined whether or not the engine speed N _e0 is within the area A exceeding the range A. If the actual engine speed N _e0 is within the area A, the process _proceeds to step S1.
Then, the process goes to step S6 to turn on the warning lamp 12.

After the warning lamp is turned on, and when NO is determined in steps S10 to S12 and S15, another control by the AT control unit 11, for example, a normal hydraulic control is performed.

As is apparent from the above description, in this embodiment, regardless of the presence or absence of the turbine sensor, most of the engines use the existing throttle sensor 8 and engine speed sensor 9 to detect the failure of the automatic transmission. Since it is possible to detect the failure of the automatic transmission, it is not necessary to provide a new sensor when detecting a failure of the automatic transmission, and both the AT control unit and the ECCS can have failure detection means using an existing sensor.

Also, if a racing select is performed in which the engine speed is sufficiently increased in the N range state and the D range is selected, slippage occurs in the torque converter 2 and it takes time for the engine speed to follow. , From the N range to the D range, it may be erroneously determined that the failure is immediately determined by the comparison calculation means 23. However, in this embodiment, the comparison is performed after a predetermined time has elapsed since the switching from the N range to the D range. Since the failure determination is performed by the calculating means 23, the failure determination can be made more reliably.

In the above-described embodiment, when a signal indicating that the range has been switched from the N range to the D range is received from the inhibitor switch 6, it is determined that the driver has the intention to travel. , May be determined to have the intention to travel when a signal indicating that the range has been switched from the N range to another travel range, for example, the R range. In this case, the reference engine speed _Ne (judgment reference line) of the reference engine speed characteristic map is set in accordance with the R range.

In the above-described embodiment, when the failure is judged by the comparing and calculating means 23, the warning lamp 1 is activated.
2 lights up to alert the driver,
Alternatively, or additionally, for example, the engine speed may be increased by cutting fuel to some or all of the cylinders of the engine 1 or controlling the throttle valve to close in response to a failure determination. May be suppressed. This makes it possible to prevent over-rev at the time of failure. Means for suppressing an increase in the engine speed can be provided in the ECCS control unit 10, and when provided in the ECCS control unit, the increase in the engine speed can be more easily suppressed.

[0030]

As is apparent from the above description, according to the first to third aspects of the present invention, regardless of the presence or absence of the turbine sensor, the automatic transmission uses the existing throttle sensor and engine speed sensor for most engines. Can detect the failure of the automatic transmission, so there is no need to provide a new sensor when detecting the failure of the automatic transmission. Both the AT control unit and the ECCS control unit have failure detection means using existing sensors. The effect of being able to do is obtained.

If the fuel is cut off to some or all of the cylinders of the engine or the throttle valve is closed in response to the failure judgment to suppress the increase in the engine speed, the failure may occur. The effect that over rev at the time can be satisfactorily prevented can be obtained.

According to a fourth aspect of the present invention, in addition to any one of the first to third aspects of the present invention, the failure determination is performed after a predetermined time has elapsed since the detection of the drive intention, thereby performing the reliable failure determination. The effect that it can be obtained is obtained.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a control device for an automatic transmission according to an embodiment of the present invention.

FIG. 2 is a block diagram for explaining the control device.

FIG. 3 is a graph showing a relationship between an engine speed (stall speed) and a throttle opening.

FIG. 4 is a graph showing a relationship among a torque capacity, a stall rotation speed, and a throttle opening.

FIG. 5 is a flowchart for explaining the operation of the control device.

[Explanation of symbols]

 6 Inhibitor switch 7 Vehicle speed sensor 8 Throttle sensor (stepping characteristic detecting means) 9 Engine speed sensor 12 Warning lamp (warning means) 20 Running intention detecting means 21 Timer means 22 Vehicle speed determining means 23 Comparison Arithmetic means 24: Engine rotation characteristic map

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI F16H 61/12 F16H 61/12 // F16H 59/44 59/44 63/12 63/12

Claims (4)

[Claims] 1. A means for detecting a depression characteristic of an accelerator pedal, a means for detecting a driving intention of a driver, a means for judging a vehicle speed, and a traveling range set in advance in accordance with the depression characteristic in a transmission mechanism. Comparing the reference engine speed in the state with the actual engine speed when the accelerator pedal is depressed, further detecting the driving intention of the driver, determining that the vehicle speed is "0", and A comparison operation means for determining that the automatic transmission has failed and cannot be driven when the reference engine speed when the accelerator pedal is depressed is equal to or lower than the actual engine speed;
A control device for an automatic transmission, comprising: at least one of a means for warning a driver in response to a failure determination and a means for suppressing an increase in engine speed in response to a failure determination. 2. The control device for an automatic transmission according to claim 1, wherein said means for suppressing an increase in the engine speed cuts off fuel to a part or all of cylinders of the engine. 3. The control device for an automatic transmission according to claim 1, wherein said means for suppressing an increase in the engine speed controls a direction in which a throttle valve is closed. 4. The apparatus according to claim 1, wherein the comparison operation means performs a failure determination after a lapse of a predetermined time from the detection of the drive intention by the drive intention detection means. Automatic transmission control device.