JPH0650423A - Control device for automatic transmission of vehicle - Google Patents

Abstract

PURPOSE:To prevent careless release of a parking state. CONSTITUTION:When selection of a parking state by a range selection switch 1 is detected by a range detection means 6 and a parking state of an automatic transmission A is detected by a parking state detection means 7, in the case where operation of an actuator 2 is detected by an actuator operation detection means 5, a signal is outputted by a second electronic control device 8, so that supply of electric power to the actuator 3 is shut off by a shutoff means 9 on the basis of the outputted signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for controlling an automatic transmission of a vehicle, and more particularly to a control device for selecting and setting a plurality of ranges including a parking condition.

[0002]

As is well known, in automatic transmissions for vehicles,
When a traveling state such as forward, backward, or parking is selected by a shift lever, and for example, a forward range is selected, a predetermined shift speed is set based on input information such as vehicle speed and throttle opening, and, for example, When the parking state (parking range) is selected, the power to the gear train is shut off and the rotation of the output shaft is stopped by mechanical means. This shift lever is mainly for selecting the traveling state (traveling range) as described above, is connected to a manual valve in the hydraulic control device through a link mechanism and a cable, and is a floor type vehicle. In the case of a column shift type vehicle, it is mounted next to the driver's seat and is attached to the steering column.

Japanese Patent Application Laid-Open No. 59-45224 proposes a device in which the shift lever is eliminated by arranging the selection of the traveling range by operating a switch. That is, in this device, an actuator such as a motor is connected to the manual shift valve in place of the shift lever, and an electronic control device for controlling the actuator based on signals from switches and signals from various sensors is provided. . Therefore, when the parking range is selected by the switch operation and the driving state of the vehicle becomes the state in which the parking is allowed, the actuator operates to switch the manual shift valve to the parking range and also the lock mechanism that stops the rotation of the output shaft. Let Further, the device described in the above publication is provided with a second electronic control device that backs up the electronic control device, and a signal indicating that the vehicle speed is zero when the main electronic control device fails. And a signal indicating that the parking range has been selected are input to the backup second electronic control unit so that the second electronic control unit operates the actuator to set the parking range. Has become.

[0004]

In the above-mentioned conventional device,
If the main electronic control unit becomes unable to set the parking state, the second electronic control unit controls the actuator so as to set the parking state instead. Therefore, in this respect, it is ensured that the parking state is set. There is a nature. However, there are various failure modes of the electronic control device. In addition to the above-described failure in which the command signal for setting the parking state cannot be output, the parking state is canceled despite that the parking state should be set. It is conceivable that a failure may occur such that an erroneous signal for operating the actuator is output. In the case of such a failure, in the above-described conventional device, the main electronic control device is operating, so that the second electronic control device does not output the command signal for setting the parking range, and Even if it does, there is a possibility that the parking state is released by the parking release signal from the main electronic control unit.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a control device capable of preventing a situation in which a parking state is accidentally released. is there.

[0006]

The present invention is characterized in that it has the structure shown in FIG. 1 in order to achieve the above object. That is, according to the present invention, the actuator 3 that drives the range selection valve 2 is controlled by the first electronic control unit 4 based on the signal output from the range selection switch 1 that selects a plurality of vehicle states including the parking state. In a control device for an automatic transmission A for a vehicle, an actuator operation detecting means 5 for detecting an operating state of the actuator 3, a range detecting means 6 for detecting a vehicle state selected by the range selection switch 1,
The parking state detecting means 7 for detecting that the automatic transmission A is parked, and the range detecting means 6 detecting that the parking state is selected by the range selection switch 1 and the automatic transmission A A second electronic control unit 8 that outputs a signal when the actuator operation detecting unit 5 detects that the actuator 3 is operating when the parking state detecting unit 7 detects that the vehicle is in a parking state. And a shutoff means 9 for shutting off the supply of electric power to the actuator 3 in response to a signal output from the second electronic control unit 8.

[0007]

The first electronic control unit 4 according to the present invention outputs a command signal to the actuator 3 based on the signal output when the parking range is selected by the range selection switch 1, and the actuator 3 parks the range selection valve. By driving the automatic transmission A to the parking state, that is, the automatic transmission A is set to the parking state, that is, the parking range. The operating state of the range selection switch 1, that is, the range selected by the switch 1 is detected by the range detecting means 6, and whether the actuator 3 is operating or not is detected by the actuator operation detecting means 5 and further automatic. Whether or not the transmission A is in the parking state is detected by the parking state detecting means 7. Of these, the range detection means 6 detects that the parking state is selected by the range selection switch 1, and the parking state detection means 7
Detects that the vehicle state of the automatic transmission A is a parking state, and the actuator operation detecting means 5 detects that the actuator 3 is operating, the second electronic control unit 8 causes the shutoff means 9 to operate. Signal is output to. As a result, the breaking means 9 cuts off the power supply to the actuator 3, so that the operation of the actuator 3 is stopped and the automatic transmission A is maintained in the parking range.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 2 is a block diagram schematically showing an embodiment of the present invention.
Is a so-called shift-by-wire type automatic transmission that causes the hydraulic control device to perform a switching operation of the manual shift valve 11 in 10 by the motor 12. The on / off control of the motor 12, that is, the energization and interruption of the motor 12 is performed by the drive circuit 14 controlled by the electronic control unit (SBW-ECU) 13 for electrically selecting the range. Has become. This drive circuit 1
A relay 15 that functions as a power switch is connected to the switch 4. The relay 15 closes the contacts in the OFF state to energize it, and opens the contacts in the ON state to open the motor via the drive circuit 14. Power to 12 is cut off.

The electronic control unit 13 is mainly composed of a central processing unit (CPU), a storage device (ROM, RAM), and an input / output interface.
The electronic control unit 13 includes a signal from a range selection switch (not shown), a signal from a vehicle speed sensor (not shown), and a range position sensor 16 provided in the automatic transmission A.
Signals from various sensors and switches, such as signals from, are input. The electronic control unit 13 operates the motor 12 as appropriate by controlling the drive circuit 14 by performing an arithmetic operation based on the input signal and the stored data, thereby switching the manual shift valve 11. A predetermined driving range is selected.

The control unit shown in FIG. 2 is an electronic control unit (SUB-E) that backs up the electronic control unit 13.
CU) 17. This electronic control unit (hereinafter abbreviated as second electronic control unit) 17 is provided mainly for ensuring the parking state of the automatic transmission A when the electronic control unit 13 fails. The second electronic control unit 17 is also mainly composed of a central processing unit (CPU), a storage unit (ROM, RAM) and an input / output interface, and a signal similar to the signal to the electronic control unit 13 is 2 is input to the electronic control unit 17. Further, a neutral (N) solenoid valve 18 for putting the automatic transmission A into a neutral state is connected to the second electronic control unit 17, and a hydraulic pressure that outputs a signal when the automatic transmission A is in the neutral state. The sensor 19 is connected to the second electronic control unit 17. Then, the second electronic control unit 17 supplies the excitation signal Er to the relay 15 via the OR circuit 20 when the motor 12 is driven although the automatic transmission A should be maintained in the parking state. Is output.

Since the electronic control unit 13 drives the motor 12 to switch the traveling range, the electronic control unit 17 is provided so that the second electronic control unit 17 can detect the failure of the electronic control unit 12. The motor control signal Am from 13 is communicated to the second electronic control unit 17. Further, in order to give information to the electronic control devices 13 and 17 that the electronic control device 13 is actually driving the motor 12, it is necessary to output an instruction signal from the electronic control device 13 to the drive circuit 14. The signal Dm shown is input to each of the electronic control units 13 and 17 by the motor current detection circuit 21. And again the OR circuit 2
The excitation signal Er from the electronic control unit 13 is input to 0.

Next, the operation of the above device will be described. When the vehicle is traveling or when the ignition switch (not shown) is set to ACC-ON and the range selection switch is operated to select an appropriate traveling range, the electronic control unit 13 sets the selected traveling range. Is determined based on the input data, and if it is determined that the driving state is allowed, the instruction signal Dm is output to the drive circuit 14, and the output from the drive circuit 14 is output based on the instruction signal Dm. The motor 12 is operated by the electric current, and as a result, the manual shift valve 11 is switched to set a predetermined traveling range. When the electronic control unit 13 is functioning normally in this way, the relay 15 is turned on.
In the FF state, the drive circuit 14 is energized because the contact is closed. The second electronic control unit 1
By communicating the motor control signal Am to 7,
The second electronic control unit 17 does not perform the backup operation.

When the vehicle is stopped and the parking range is selected by the range selection switch, and the manual shift valve 11 is switched by the motor 12 accordingly,
The automatic transmission A also enters a parking state in which the input torque to the gear train is shut off and the rotation of the output shaft is stopped by a lock mechanism (not shown). This state is detected by the range position sensor 16 and input to each electronic control unit 13, 17. When the ignition switch is turned off in this state, the electronic control unit 13 outputs the excitation signal Er, which is sent to the relay 15 via the OR circuit 20 and the relay 15
Turns off. That is, by selecting the parking range, when the automatic transmission A is switched to the parking state and the ignition switch is turned off, the power supply to the motor 12 is cut off to prevent the electric leakage.

On the other hand, when the electronic control unit 13 fails, the motor control signal Am is not input to the second electronic control unit 17, so that the second electronic control unit 17 performs the backup control for setting the parking state. Figure 3
Is a flow chart showing the control routine. First, at step 1, it is judged whether or not the range selection switch is at the parking position and the parking range is selected. This can be specifically determined by the second electronic control unit 17 whether or not the parking range selection signal is input from the range selection switch. If the determination result is "yes", the process proceeds to step 2 and it is determined whether or not the shift position set in the automatic transmission A is the parking position. This can be determined based on the detection result of the range position sensor 16. When the parking range is set in the automatic transmission A, the process proceeds to step 3 and the electronic control unit 13 releases the motor 12 in the direction to release the parking state.
Based on the signal input from the motor current detection circuit 21, the second electronic control unit 17 determines whether or not the instruction signal Dm for driving is output to the drive circuit 14. If this determination result is “yes”, even though the parking range is selected and the automatic transmission A is in the parking state,
The electronic control unit 13 outputs the instruction signal Dm for canceling this due to the failure, and then the second electronic control unit 17 outputs the excitation signal Er to the OR circuit 20 (step 4). In this case, since the hydraulic pressure state of the automatic transmission A must be the same as the neutral range state, the second electronic control unit 17 confirms the neutral state based on the output from the hydraulic pressure sensor 19,
If it is not in the neutral state, an ON signal is output to the neutral solenoid valve 18.

It should be noted that if the result of the determination in steps 1 to 3 is "no", the control process returns.

Therefore, when a situation in which the parking state is released due to a failure of the electronic control unit 13 occurs, the relay 15 is excited and its contact opens, so that the power supply to the drive circuit 14 is cut off. As a result, the electric current stops flowing to the motor 12, and the parking state of the automatic transmission A is maintained.

Incidentally, the present invention is not limited to the above-mentioned embodiment, and the breaking means in the present invention can employ an appropriate means other than the above-mentioned relay, and the point is to energize the motor and other actuators which are changed to this. Anything that can stop Further, the means for detecting the operation of the actuator may be configured to directly detect the operation of the actuator in addition to the means for detecting the instruction signal to the actuator.

[0018]

As described above, according to the device of the present invention, when a situation in which the parking state is released due to the failure of the electronic control unit occurs, the energization of the actuator for switching the manual shift valve can be stopped. Therefore, it is possible to prevent the parking state from being inadvertently released.

[Brief description of drawings]

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

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

FIG. 3 is a flowchart showing an example of a control routine by the second electronic control unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 range selection switch 2 range selection valve 3 actuator 4 first electronic control unit 5 actuator operation detection unit 6 range detection unit 7 parking state detection unit 8 second electronic control unit 9 shutoff unit A automatic transmission

Claims (1)

[Claims] 1. Based on a signal output from a range selection switch for selecting a plurality of vehicle states including a parking state,
In a control device for an automatic transmission for a vehicle, wherein an actuator for driving a range selection valve is controlled by a first electronic control unit, an actuator operation detecting means for detecting an operation state of the actuator, and the range selection switch are selected. The range detection means for detecting the vehicle state that is present, the parking state detection means for detecting that the automatic transmission is in the parking state, and the range selection detection means for detecting that the parking state is selected by the selection switch And a second electronic that outputs a signal when the actuator operation detecting means detects that the actuator is operating when the parking state detecting means detects that the automatic transmission is parked. The control device and a signal output from the second electronic control device enable the actuation. A controller for an automatic transmission for a vehicle, comprising: a cutoff unit that cuts off the supply of electric power to the user.