JP2002227993A - Shift range change control device of automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shift range change control device of an automatic trans mission which is possible to avoid a sudden start of vehicle even when an engine speed increases too much by a misoperation of a driver. SOLUTION: This device provides a shift range change mechanism 10 to change a shift range of an automatic transmission to each driving range including parking, an actuator 100 to constitute a driving source of the shift range change mechanism 10, a driving circuit 20b to drive the actuator 100 and a control means 20a to control the shift range of the automatic transmission to the shift range corresponding to the change instruction by driving the actuator through the driving circuit according to the shifting instruction which is inputted by an external operation. When the control means 20a decides that an engine is a overspeed, it prohibits the control to the shift range which is brought into the driving condition of vehicles in spite of changing instruction when the vehicle is in a stop condition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a shift range switching control device for an automatic transmission.

[0002]

2. Description of the Related Art As a shift range switching device for an automatic transmission, there is known a shift range switching device which operates a position of a spool valve for controlling a hydraulic pressure of a hydraulic circuit inside the automatic transmission.

In this apparatus, a neutral start switch is provided outside the automatic transmission as means for detecting the position of the spool valve. Also, this spool valve is mechanically linked to the shift lever selection device,
The driver switches to each shift lever by operating this shift lever selection device.

[0004]

In the conventional configuration, switching to each shift range, in particular, switching to parking (hereinafter, referred to as P), neutral (hereinafter, referred to as N), and reverse (hereinafter, referred to as R) ranges. Switching is possible only by the driver's operation. However, when the vehicle is stopped and the brake pedal and the accelerator pedal are mistakenly depressed, the shift range is switched to the drive (hereinafter, referred to as D) range or the R range while the engine speed is high. The vehicle may start suddenly.

The present invention has been made in view of such circumstances, and has as its object to reduce the possibility that the engine speed will increase due to a driver's erroneous operation such as a wrong pedal depressed when the vehicle stops. Another object of the present invention is to provide a shift range switching control device for an automatic transmission that can avoid sudden start of a vehicle.

[0006]

According to a first aspect of the present invention, a shift range switching mechanism for switching a shift range of an automatic transmission to various traveling ranges including parking, and a drive source of the shift range switching mechanism are provided. The shift range of the automatic transmission is controlled to the shift range corresponding to the switching command by driving the actuator via the driving circuit according to the actuator to be formed, the driving circuit for driving the actuator, and the switching command input by an external operation. Control means, the automatic transmission being connected to an engine for transmitting propulsion to the vehicle, wherein the control means detects that the engine speed exceeds a predetermined speed when the vehicle is stopped. When it is determined that
The control to the shift range in which the vehicle runs is prohibited.

[0007] Thus, when the engine overruns beyond a predetermined speed due to a driver's erroneous operation such as a wrong pedal depressing when the vehicle is stopped, the shift range is controlled to a state in which the vehicle runs. Since the prohibition, the sudden start of the vehicle can be prevented.

According to claim 2 of the present invention, the control means includes:
After the control to the shift range is prohibited, when the driver continues the switching command corresponding to the shift range, the driver is notified that the switching command is abnormal.

[0009] As a result, by prohibiting the control of the shift range in which the vehicle is driven to run, the driver is prompted to be alerted while preventing the vehicle from suddenly starting. The operation returns to normal.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of an automatic transmission control apparatus according to an embodiment of the present invention.

FIG. 1 is a block diagram showing the overall configuration of a shift range switching control device for an automatic transmission according to an embodiment of the present invention. FIG. 2 is an electrical configuration diagram showing an electrical configuration for controlling the shift range by driving the actuator unit in FIG. FIG. 3 is a flowchart showing a shift range automatic switching control process performed at the time of engine overspeed, which is executed by the control circuit in FIG.

As shown in FIG. 1, a shift range switching control device 1 for an automatic transmission includes a shift range selection device 10.
, A control circuit 20a, a display unit 30, and a drive circuit 20b.
And a shift range switching mechanism 40 incorporated in the automatic transmission 50 for switching a shift range, an actuator unit 100 for driving the shift range mechanism 40, a vehicle speed sensor 70, and a brake switch 80. I have.

The shift range selection device 10 includes a position switch that is switched by operating a shift lever by a driver to select various traveling ranges including parking of the automatic transmission 50, or an operation switch that is directly operated by the driver. Be composed.

The control circuit 20a uses a microcomputer, a read-only memory (ROM) storing programs necessary for various software processes for switching the running range of the automatic transmission 50, and a central processing unit for executing the programs. Processing unit (CPU), writable memory (RA) for temporarily storing variables necessary for the program
M) and the like.

A switching command (hereinafter, referred to as a range signal) output by operating the range selection device 10 is input to the control circuit 20a.
00a (see FIG. 4) for detecting the rotation angle
3 is input.

The control circuit 20a drives the actuator unit 100 via a drive circuit 20b, which will be described later, in accordance with a range signal input by an external operation of the range selection device 10 or the like, so that a shift corresponding to the range signal is performed. Control means for controlling to a range.

The drive circuit 20b receives the drive signal output from the control circuit 20a in accordance with the range signal. The drive circuit 20b supplies a current according to the drive signal,
The driving range switching actuator unit 100 is driven.

The display unit 30 is a device for informing a vehicle occupant such as a driver, for example, a range indicator 30a on an instrument panel provided on the front of the driver's seat or a voice navigation control unit (not shown). Note that a warning lamp 30b may be used as a means for notifying the driver or the occupant of the state of the shift range switching control device 1. Further, signals output from the control circuit 20 to the range indicator 30a and the voice navigation control unit are input to the display unit 30, respectively. Range indicator 30
In a, basically, the current traveling range of the automatic transmission 50 is lit and displayed, and the voice navigation control unit outputs sound from a speaker (not shown) to notify the driver of an erroneous operation of the range selection device 10 and the like. It is possible to perform a function such as a warning.

Vehicle speed sensor 70 and brake switch 8
0 is a device for recognizing the driving state of the vehicle,
For example, in response to a range signal output from the shift range selection device 10 by a driver's operation of a shift lever or the like, a target travel range is corrected according to the driving state of the vehicle, or a shift range selection device by the driver. Signals of the vehicle speed sensor 70 and the brake switch 80 are input to the control circuit 20 so that the operation of the vehicle 10 can be restricted.

Here, the actuator section 100 is the same as that shown in FIG.
As shown in FIG.
2, the encoder 103, and the neutral start switch 108.

As the actuator 101, a DC motor or a synchronous motor is used.
One rotating shaft 100a is connected to a speed reduction mechanism 102 that increases output torque.

The output end of the speed reduction mechanism 102 is connected to a control output shaft 408 of the shift range switching mechanism 40 (see FIG. 4). Therefore, when the driver operates the range selection device 10 to switch to the P range, the reduction mechanism 102 uses the actuator 101 to park the parking mechanism 40p (FIG. 4).
A large output torque can be generated without increasing the size of the actuator 101 so as to operate the mechanical locking means (see (2)).

The encoder 103 includes the actuator 10
It detects the rotation angle of one rotation shaft 100a,
In order to operate the shift range switching mechanism by rotating the actuator 101 a plurality of times via the speed reduction mechanism 102, an absolute rotation angle can be detected.

The shift range switching mechanism 40 sets the shift range of the automatic transmission 50 to each of parking (P), reverse (R), neutral (N), drive (D), second (2), and low (L). This is for sequentially switching to the driving range.

The shift range switching mechanism 40 includes, as shown in FIG.
0p. The range switching valve 40h is connected to the automatic transmission 50.
The hydraulic pressure is supplied from the internal hydraulic circuit, and the spool valve 401
The friction engagement device (not shown) for setting the travel range by controlling the position of the exhaust port by switching the discharge port
Is controlled to be engaged and disengaged. Further, the parking mechanism 40p is a mechanical locking means interlocked with the position of the spool valve 401, and switches to the P range.

As a specific configuration, the range switching valve 40
h, a spool valve 401, a valve body 402, and a detent spring 40 for holding each travel range.
3, a detent lever 404, a parking mechanism 405, a parking gear 405 provided on an output shaft (not shown) of the automatic transmission 50, and the parking gear 4
The parking lock pole 406 is fitted with a parking rod 405, a parking rod 407 for stopping the rotation of the control output shaft 408, and a control output shaft 408 to which the detent lever 404 is fixed.

The parking mechanism 40p transmits the rotation of the control output shaft 408 via the detent lever 404 and the parking rod 407 as a link operation in the directions indicated by arrows A and B, and causes the parking king pole 406 to move to the parking gear 405. To fit. Thereby, the range is switched to the P range by the rotation of the control output shaft 408 connected to the output shaft 100a of the actuator section 100.

The configuration of the shift range switching control device 1 for an automatic transmission has been described above. The electrical configuration for controlling the shift range by driving the actuator unit 100 is as shown in FIG. Here, the actuator control circuit 20 includes the control circuit 20a and the drive circuit 2 described above.
0b, and includes a control unit 201, a counter unit 202, a nonvolatile memory unit 203 built in the control unit 201, a signal input / output stage 204, and the like. The power supply to the actuator control circuit 20 is performed by a battery 600 charged by an alternator (not shown) when the engine is driven, and the power from the battery 600 to the actuator control circuit 20 is turned on and off by the ignition key 620. Is supplied and cut off via the relay 610.

In the shift range switching control device 1 of the automatic transmission having the above-described configuration, the control circuit 20a receives a range signal output from the shift range selecting device 10 by a driver operating a shift lever or the like. Next, the control circuit 20a controls the rotation shaft 100 detected by the encoder 103 provided in the actuator unit 100 to be in a target travel range (hereinafter, referred to as a target travel range).
A signal representing the rotation angle of a and a drive signal for switching from the current travel range to the target travel range are sent to the drive circuit 20b. As a result, the drive circuit 20b is connected to the actuator 1
01 is supplied to switch to the target travel range.

Here, means for avoiding a sudden start of the vehicle even when the engine overspeeds due to a driver's erroneous operation such as a wrong pedal depressing when the vehicle is stopped, which is a feature of the present invention, will be described with reference to FIGS. This will be described with reference to FIG.

As shown in FIG. 2, the actuator control circuit 20 is connected to a signal input / output stage 204 with a warning light 32 of the display unit 30 and a notification means such as a warning buzzer 92.

Next, a description will be given of a shift range automatic switching control process (hereinafter referred to as an overspeed automatic switching control process) shown in FIG.

As shown in FIG. 3, in the overspeed automatic switching control process, the vehicle speed signal transmitted from the vehicle speed sensor 70 is transmitted to the signal input / output stage 204 in S301 (S represents a step).
To read the vehicle speed. When this vehicle speed is read, in S302, it is determined whether or not the vehicle is in a stopped state (a state in which the vehicle speed is substantially zero). If the vehicle speed is substantially zero, the process proceeds to S303 where it is determined whether the current shift range of the automatic transmission 50 is the P or N range. On the other hand, if the vehicle speed is not substantially zero, the process returns to S301 and the process is set to a standby state.

At S303, the neutral switch 10
8 or the rotation angle signal transmitted from the encoder 103 to the signal input / output stage 20.
4 to determine whether it is in the P or N range. If it is in the P or N range, the engine speed is further detected to determine whether or not the engine speed is excessive S304, S3
Go to 05. Conversely, if it is a shift range other than the P or N range, the process returns to S301 to put this processing in a standby state.

In S305, a signal transmitted from an engine speed sensor (not shown) or a vehicle speed sensor 70
The engine speed is read by taking in the signal transmitted from the controller to the signal input / output stage 204. When this engine speed is read, in S305, it is determined whether or not the engine is overspeed exceeding a predetermined engine speed (specifically, for example, 1500 rpm). If it exceeds the predetermined engine speed (1500 rpm), the process proceeds to S306 in which control to the D or R range is prohibited. On the other hand, if the engine speed is equal to or lower than the predetermined engine speed (1500 rpm), the control prohibition to the D or R range is released in S307 (specifically, a flag for prohibiting the control to the D or R range is set). From the state where it is).

In S306, control to the D and R ranges where the vehicle may suddenly start is prohibited (for details, see D, R).
Alternatively, the control unit 20 sets a flag for prohibiting the control to the R range.
1 is stored in the memory unit 203 provided in the microcomputer.

When the control prohibition to the D or R range is started, the process returns to S304 and continues until the overspeed condition is eliminated, and the predetermined engine speed (1500 rpm) is reached.
If it is below, release is performed in S307, and this processing ends.

Thus, when the engine is overrunning beyond a predetermined speed due to a driver's erroneous operation such as a wrong pedal depressing when the vehicle is stopped, the shift range is controlled to a state in which the vehicle runs. Since the prohibition, the sudden start of the vehicle can be prevented.

In the above-described automatic switching control process at the time of overspeed, if the control to the D and R ranges is prohibited in S306 and the switching command corresponding to the shift range prohibited by the driver is continued, Using the warning light 32 or the warning buzzer 92, a control process that informs the driver that control to the D and R ranges has been prohibited, that is, notifies the driver that the switching command is abnormal is added. Good.

In addition, using the voice navigation control unit, "switching to the D / R range has been canceled."
May be announced.

Thus, the control of the shift range in which the vehicle is driven is prohibited, thereby preventing the sudden start of the vehicle or the like, and prompting the driver to be warned. It can be returned to a normal state.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an overall configuration of a shift range switching control device for an automatic transmission according to an embodiment of the present invention.

FIG. 2 is an electrical configuration diagram illustrating an electrical configuration for controlling a shift range by driving an actuator unit in FIG. 1;

FIG. 3 is a flowchart illustrating a shift range automatic switching control process performed by the control circuit in FIG. 1 at the time of engine overspeed.

FIG. 4 is a configuration diagram illustrating a schematic configuration of a shift range switching mechanism in FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Shift range switching control device of automatic transmission 10 Shift range selection device 20a Control means (control circuit) 20b Drive circuit 30 Display unit 30a Range indicator 30b Warning light (warning lamp) 40 Shift range switching mechanism 50 Automatic transmission 70 Vehicle speed sensor 80 Brake switch 92 Alarm buzzer 100 Actuator section 101 Actuator 102 Reduction gear 103 Encoder S301 to S307 Automatic shift range switching control processing when engine overspeeds

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hirochi Asa 14 Iwatani, Shimowasumi-cho, Nishio-shi, Aichi Japan Automobile Parts Research Institute, Inc. (72) Inventor Hitoshi Tanaka 1-1-1 Showa-cho, Kariya-shi, Aichi Stock F term in company Denso (reference) 3J552 MA01 NA01 NB01 PB01 RB02 SB14 VA62Z VB01W VB01Z VB16Z VC01X VC01Z VD11Z

Claims (2)

[Claims] 1. A shift range switching mechanism for switching a shift range of an automatic transmission to various traveling ranges including parking, an actuator serving as a drive source of the shift range switching mechanism, and a drive circuit for driving the actuator. By driving the actuator via the drive circuit according to a switching command input by an external operation,
Control means for controlling a shift range of the automatic transmission to a shift range corresponding to the switching command, wherein the automatic transmission is connected to an engine that transmits propulsive force to a vehicle, and the control means includes: When the vehicle is in a stopped state, if it is determined that the engine speed has exceeded a predetermined speed, the control to a shift range in which the vehicle is driven regardless of the switching command is performed. A shift range switching control device for an automatic transmission, wherein the control is prohibited. 2. The control means according to claim 1, wherein, after prohibiting the control to the shift range, when the driver continues the switching command corresponding to the shift range, the driver informs the driver of the abnormality of the switching command. The shift range switching control apparatus for an automatic transmission according to claim 1, wherein