JP2932585B2 - Control device for automatic transmission - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a control device for an automatic transmission for a vehicle.

(Prior Art) An automatic transmission (AT) uses a fluid as a power transmission medium, and thus cannot avoid a significant reduction in transmission efficiency.

Although most automatic transmissions have three speeds, there have been times when fuel efficiency was improved with the advent of transmissions with overdrive.

Next up was the lock-up AT, which transmitted power mechanically during high-speed cruising when fluid transmission was not required.

On the other hand, with the rapid progress of electronic technology in recent years, the optimal shift according to the driving conditions of the vehicle and the driver's intention is controlled by electronic technology, and practical fuel consumption, driving force during acceleration and engine braking are improved. Electronically controlled ATs that improve performance have been announced.

Therefore, electronically controlled automatic transmissions have AT control
The microcomputer incorporated in the unit finely selects the shift characteristics and gear position according to the running conditions such as the accelerator opening and the vehicle speed, thereby increasing the acceleration force and smoothly transmitting power.

On the other hand, in order to ensure safety, a fail-safe mechanism is provided so that drivability is not impaired even if a failure occurs in the signal system input to the AT control unit by detecting the vehicle speed and throttle state. ing.

Further, in this automatic transmission, since the self-diagnosis mechanism is provided, the work of diagnosing a failure can be speeded up, so that the serviceability can be greatly improved.

FIG. 4 is a block diagram of a control device used in such a conventional automatic transmission.

In this figure, reference numeral 50 denotes the inside of the electronic control unit. The electronic control unit 50 mainly includes a CPU 51, a power supply circuit 52, a runaway detection reset IC 53, and a solenoid driver IC 54.

A driving voltage of 5 V is supplied from the power supply 55 to the _Vcc input port of the CPU 51 via the power supply circuit 52 to the CPU 51, and the CPU 51 operates.

The power supply circuit 52 is connected to a terminal on the input side of the runaway detection reset IC 53.

The output port V _po of the CPU 51 is connected to the input terminal of the runaway detection reset IC 53, and a pumping signal is input from the CPU 51 to the runaway detection reset IC 53. The output terminal of the runaway detection reset IC 53 is connected to the input port V _{rst of the} CPU 51.

When the CPU 51 is abnormal, the runaway detection reset IC 53
Supplies a reset signal to the input port _Vrst .

The output side of the CPU 51 is connected to the solenoid driver IC 54, and drives the solenoid driver 15 based on the output signal of the CPU 51.

On the other hand, the solenoid valve 56 is a solenoid driver IC 54
And the solenoid valve 56 is operated.

Figure 5 (a) ~ (c) is a timing chart showing the operation of the control device of the conventional automatic transmission, FIG. 5 (a) is outputted to the input port V _ps of CPU51 from runaway detection reset IC53 pumping signal, FIG. 5 (b) is a reset signal input from runaway detection reset IC53 to CPU51 input port V _rst.

FIG. 5 (c) is a timing explanatory diagram showing the state of the solenoid signal before and after the CPU 51 runs out or malfunctions. When the CPU 51 is normal before the runaway or malfunctions, the CPU 51 runs out or malfunctions. Later, when the reset signal in FIG. 5 (b) is at a high level, FIG. 5 (c) becomes undefined, and when the reset signal in FIG. 5 (b) is at a low level, the solenoid current is turned off.

(Problems to be Solved by the Invention) However, in the above control device, when the CPU 51 goes out of control and the pumping signal disappears, the reset signal becomes a high level signal (shown in FIG. (FIG. 5 (b)) becomes indefinite, and the CPU 51 remains in a malfunctioning state, so that the operation state of the shift solenoid 56 cannot be guaranteed reliably.

For this reason, in the conventional automatic transmission control device, the CPU 51
As a result, the shift operation of each shift solenoid 56 is no longer guaranteed, and there is a possibility that running stability and running safety cannot be ensured.

In a conventional control device having a fail-safe mechanism, the power supply of the control unit and the fail-safe power supply unit are the same. Therefore, when an abnormal voltage occurs, a microcomputer or a gate array of the control unit or the fail-safe mechanism is used. And the like may be destroyed, so that the controlled object cannot be maintained in a safe state.

Accordingly, the present invention has been made in view of the above situation, and when a CPU malfunctions, a solenoid power supply circuit with a timer, which is a power supply source for the solenoid drive circuit, allows a power supply circuit to be connected between the power supply circuit and the solenoid drive circuit. A control device for an automatic transmission that can switch the shift operation of the automatic transmission from computer control to manual shift using only the shift lever position and the mechanism of the automatic transmission main body by disconnecting the connection and deenergizing the solenoid output. The purpose is to provide.

(Means for Solving the Problems) As means for solving the above-mentioned objects, the present invention provides a driven information detecting means for detecting driven information and an actuator based on a detection output from the driven information detecting means. Main control means for controlling the operation; actuator driving means for driving the actuator by a control signal from the main control means; operation monitoring means for monitoring the operation of the main control means; and a monitoring signal from the operation monitoring means And a driving operation signal transmitting means for transmitting a driving operation signal to the actuator driving means based on the following. The driving operation signal transmitting means is driven for a predetermined time in response to an input of a monitoring signal indicating an abnormality of the main control means. The transmission of the operation signal is stopped.

(Operation) The driven information detection means detects driven information such as a vehicle speed, a shift position, and a throttle opening.

The main control means controls the operation of the shift solenoid, which is an actuator, based on the detection output from the operated information detection means.

On the other hand, the actuator driving means drives the actuator according to a control signal from the main control means.

The operation monitoring means monitors whether the operation of the main control means is normal or abnormal.

Further, the driving operation signal transmitting means transmits a driving operation signal to the actuator driving means based on the monitoring signal from the operation monitoring means.

When there is an abnormality in the main control means, the transmission of the drive operation signal is stopped for a predetermined time in response to the input of the monitoring signal indicating the abnormality of the main control means. As a result, the drive operation signal is not sent to the actuator drive means, so that the actuator does not operate, and the shift operation is performed not by the automatic shift operation but by the manual shift operation.

Next, a control device for an automatic transmission according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a block diagram showing the overall configuration of one embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes an electronic control unit, and the electronic control unit 1 is a main control unit serving as a main control unit.
U2, runaway detection reset IC 3 as operation monitoring means, power supply circuit 4, timer and solenoid power supply circuit 5 as driving operation signal sending means, solenoid driver circuit 6 as actuator driving means, inverters 7 to 9, and amplifiers 10 to
It is mainly composed of 12.

The input port _Vcc of the main CPU 2 is connected to the main C
The drive voltage (5V) of PU2 is supplied via the power supply circuit 4.

The power supply circuit 4 is connected to a terminal on the input side of the runaway detection reset IC3.

Runaway detection reset IC3 input pin to CPU51 output port
V _po is connected, and a pumping signal is input from CPU2 to runaway detection reset IC3. The output terminal of runaway detection reset IC3 is connected to input port _Vrst of _CPU2 .

Then, when the main CPU 2 is abnormal, the runaway detection reset
A reset signal is supplied from IC3 to input port _Vrst .

The runaway detection reset IC 3 detects whether or not the main CPU 2 is operating abnormally based on the pumping output. When the main CPU 2 is operating normally, the reset signal is held at a high level.

On the other hand, a vehicle speed sensor 25, a shift position sensor 26, and a throttle opening
Is V _vs , V _ps , V _{so of the} main CPU 2 through the amplifiers 10 to 12.
Connected to each input port, each sensor output is
Input to CPU2.

Based on each sensor output, the main CPU 2 selects energization or non-energization of shift solenoids 22 to 24, which will be described later, and performs control such that an appropriate gear position is established.

The output side of the main CPU 2 is connected to the solenoid driver circuit 6 and drives the solenoid driver circuit 6 based on the output signal of the main CPU 2.

The output side of the solenoid driver circuit 6 is connected to an inverter 7
Through 9 are connected to shift solenoids 22 to 24 of the transmission 21, respectively.

On the other hand, the timer and the solenoid power supply circuit 5 are connected to the main CP.
Connected to the _Vcc input port, _Vrst input port of U2 and the input terminal of the solenoid driver circuit 6, respectively,
When U2 runs out of control or malfunctions, a signal is not supplied from the timer and solenoid power supply circuit 5 to the solenoid driver circuit 6.

FIG. 2 is a specific circuit diagram around the timer and solenoid power supply circuit 5, which is a main part of one embodiment of the present invention.

In FIG. 2, 5a is a timer IC, and 5b, 5c, 5d are switching transistors. The operation of the switching transistors 5b, 5c, 5d is delayed by a predetermined time by the timer IC 5a, so that the main CPU 2 In case of runaway or malfunction, the timer and solenoid power supply circuit 5
A signal can be prevented from being supplied to the solenoid driver circuit 6.

Next, the operation of the embodiment of the present invention will be described with reference to the timing chart of FIG.

FIG. 3A is a diagram showing a pumping signal output from the CPU 2.

For example, when the CPU 2 runs away or malfunctions during the time T, the CPU 2 does not generate a pumping signal.

FIG. 3 (b) shows a reset signal, which corresponds to the main CPU 2 shown in FIG.
There reset signal after a predetermined time T ₁ elapses from the time of runaway and malfunction T is turned off from on, start the timer and the timer of the solenoid power source circuit 5.

Then, again the timer is started after a next predetermined time T _2, again and again starts the timer after a predetermined time T ₃ has elapsed, if necessary, so that the driver can smoothly shift to the manual shift operation from the automatic speed change operation I do.

FIG. 3 (c) shows a timer IC signal. When the timer is started, no signal is supplied from the timer and the solenoid power supply circuit 5 to the solenoid driver circuit 6 in FIG. 1, and each time the timer is restarted. This state is maintained.

At this time, since all the shift solenoids 22 to 24 of the shift solenoids 22 to 24 become non-conductive, the vehicle can perform manual shift traveling.

FIG. 3D shows a solenoid signal.
After a indeterminate time T ₄ of the main CPU2 shown in Figure 1 until the timer start of FIG. 3 (c) from the time of runaway, since the solenoid current is turned off, quickly to manual shift operation driver from the automatic speed change operation Be able to migrate.

Therefore, according to the present embodiment, the output to the solenoid driver circuit 6 can be prohibited in the state where the main CPU 2 is running out of control, and the abnormal state in which the main CPU 2 cannot be controlled at the time of overvoltage can be prevented. Since a situation in which the automatic shift is continued without change can be eliminated, the safety of the vehicle can be improved.

Further, in the present embodiment, when an overvoltage occurs, the timing for switching from automatic transmission to manual transmission can be smoothly given, so that the driver can respond quickly.

Further, according to the present embodiment, the output of the output signal from the CPU 2 can be inhibited with simple components, so that the cost can be prevented from increasing, and the components are generally made of highly reliable components. In addition, the frequency of failure can be reduced.

(Effect of the Invention) As described above, according to the present invention, it is possible to prohibit the output from the main control means to the actuator driving means when the CPU goes out of control, and it becomes impossible to control the main control means at abnormal output voltage It is possible to eliminate a situation in which the automatic shifting is continued in the abnormal state, and it is possible to quickly shift from the automatic shifting traveling to the manual shifting traveling.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an entire configuration of an embodiment of the present invention, and FIG. 2 is a diagram showing a specific part around a timer and a solenoid power supply circuit which are main parts of the embodiment of the present invention. FIG. 3 is a timing chart showing the operation of one embodiment of the present invention, FIG. 3 (a) is a diagram showing a pumping signal,
FIG. 3 (b) shows a reset signal, FIG. 3 (c) shows a timer IC signal, FIG. 3 (d) shows a solenoid signal, and FIG. 4 shows a conventional automatic transmission. 5 (a) to 5 (c) are timing charts showing the operation of a conventional control device for an automatic transmission, and FIG. 5 (a) is a diagram showing a pumping signal. FIG. 5B is a diagram showing a reset signal, and FIG. 5C is a timing explanatory diagram. In the figure, 2 is a main control means, 3 is an operation monitoring means, 5 is a driving operation signal sending means, 6 is an actuator driving means, and 25 to 27 are operated information detection means.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F16H 59/00-61/12 F16H 61/16-61/24 F16H 63/40-63/48

Claims (1)

(57) [Claims] 1. Operated information detecting means for detecting operated information, main control means for controlling operation of an actuator based on a detection output from the operated information detecting means, and a control signal from the main control means. Actuator driving means for driving the actuator, an operation monitoring means for monitoring the operation of the main control means, and a driving operation signal for sending a driving operation signal to the actuator driving means based on a monitoring signal from the operation monitoring means. Transmission means, wherein the drive operation signal transmission means stops transmission of the drive operation signal for a predetermined time in response to an input of a monitoring signal indicating an abnormality of the main control means. Control device.