JP4707894B2 - Shift range switching control device for automatic transmission - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shift range switching control device for an automatic transmission.
[0002]
[Prior art]
2. Description of the Related Art As a shift range switching device for an automatic transmission, a device that switches a shift range by operating the position of a spool valve that controls the hydraulic pressure of a hydraulic circuit inside the automatic transmission is known.
[0003]
In this type of device, a neutral start switch is provided outside the automatic transmission as means for detecting the position of the spool valve. The spool valve is mechanically linked to the shift lever selection device, and the driver switches to each shift lever by operating the shift lever selection device.
[0004]
[Problems to be solved by the invention]
In the conventional configuration, switching to each shift range, in particular, switching to the parking (hereinafter referred to as P) and neutral (hereinafter referred to as N) ranges is possible only by the operation of the driver. In other words, after the shift lever selection device is operated by the driver's will to switch to a predetermined shift range where the vehicle can travel, the drive is automatically stopped unless the shift lever selection device is operated again at the driver's discretion. There is no switch to the possible P or N range.
[0005]
For this reason, when driving backwards, such as in a garage, the driver mistakenly pressed the accelerator pedal and brake pedal and lost the vehicle's safe driving condition, or the vehicle was recognized by the back sonar warning that there was an obstacle in the blind spot of the vehicle. Nevertheless, the operation of applying the brake with the accelerator pedal fully closed may not be in time, and in some cases, rare cases such as contact with an obstacle may occur.
[0006]
The present invention has been made in consideration of such circumstances, and its purpose is to enable the vehicle to travel when there is a possibility of losing the safe traveling state of the vehicle due to a driver's misjudgment or erroneous operation. An object of the present invention is to provide a shift range switching control device for an automatic transmission capable of canceling the state.
[0007]
[Means for Solving the Problems]
According to the first aspect of the present invention, the shift range switching mechanism for switching the shift range of the automatic transmission to various travel ranges including parking, the actuator that forms the drive source of the shift range switching mechanism, and the drive that drives the actuator An automatic transmission comprising a circuit and a control means for controlling the shift range of the automatic transmission to a shift range corresponding to the switching command by driving the actuator through the drive circuit according to the switching command input by an external operation. Is connected to an engine that transmits a propulsive force to the vehicle, and the control means determines that the vehicle speed of the vehicle has exceeded a predetermined vehicle speed when the vehicle is in a reverse running state, and is associated with the switching command. First, the vehicle is allowed to travel.
[0008]
As a result, when an over-speed condition exceeding the specified vehicle speed occurs due to a driver's erroneous operation such as making a mistake in the pedal when reversing when entering the garage, etc., control to a shift range that cancels the vehicle's runnable state Therefore, it is possible to avoid a state of losing the safe driving state of the vehicle.
[0011]
And releasing the travelable state of the vehicle, as claimed in claim 1, the shift range of the automatic transmission is to switching control to the P digraph.
[0012]
That is, since the travel stop ready by switching control to the P digraphs can avoid a state where err safe driving condition of the vehicle.
[0013]
According to claim 2 of the present invention, the internal combustion engine includes fuel injection means for injecting fuel to be supplied to the combustion chamber of the internal combustion engine, and the control means cancels the vehicle travelable state, The fuel injection by the fuel injection means is stopped.
[0014]
That is, by stopping the fuel injection by the fuel injection means, it is possible to stop the operation of the internal combustion engine that transmits the propulsive force to the vehicle. Since the propulsive force can be lost, the vehicle can be stopped with certainty, and thus it is possible to reliably avoid the state in which the vehicle is in a safe driving state.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the automatic transmission control device according to the present invention will be described below with reference to the drawings.
[0020]
FIG. 1 is a configuration 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 at an excessive vehicle speed during backward running of the vehicle, which is executed by the control circuit in FIG.
[0021]
As shown in FIG. 1, a shift range switching control device 1 for an automatic transmission is incorporated into a shift range selection device 10, a control circuit 20a, a display unit 30, a drive circuit 20b, and an automatic transmission 50 to shift. A shift range switching mechanism 40 for switching the range, an actuator unit 100 that drives the shift range mechanism 40, a vehicle speed sensor 70, and a brake switch 80 are included.
[0022]
The shift range selection device 10 includes a position switch that is switched by operating a shift lever by the driver to select various travel ranges including parking of the automatic transmission 50, or an operation switch that is directly operated by the driver. .
[0023]
The control circuit 20a uses a microcomputer, a read-only memory (ROM) that stores programs necessary for various software processes for switching the running range of the automatic transmission 50, and a central processing unit ( CPU), a writable memory (RAM) for temporarily storing variables necessary for the program, and the like.
[0024]
The control circuit 20a receives a switching command (hereinafter referred to as a range signal) that is output by operating the range selection device 10, and is provided in the actuator unit 100 to provide a rotating shaft 100a of the actuator unit 100 (FIG. 4). The detection signal detected from the encoder 103 that detects the rotation angle (see FIG. 2) is input.
[0025]
The control circuit 20a controls the shift range corresponding to the range signal by driving the actuator unit 100 via a drive circuit 20b described later in accordance with a range signal input by an external operation of the range selection device 10 or the like. Control means.
[0026]
The drive circuit 20b receives the drive signal output from the control circuit 20a according to the range signal. In response to the drive signal, the drive circuit 20b supplies current to drive the travel range switching actuator unit 100.
[0027]
The display unit 30 is a device that notifies a vehicle occupant such as a driver, such as a range indicator 30a on an instrument panel provided in front of the driver's seat, or a voice navigation control unit (not shown). Note that the warning lamp 30b may be used as means for notifying the driver and the occupant of the state of the shift range switching control device 1. The display unit 30 receives signals output from the control circuit 20 to the range indicator 30a and the voice navigation control unit. The range indicator 30a basically lights up and displays the current travel range of the automatic transmission 50, and the voice navigation control unit outputs a sound from a speaker (not shown) to notify the driver of an erroneous operation of the range selection device 10 or the like. It is possible to perform functions such as warning.
[0028]
The vehicle speed sensor 70 and the brake switch 80 are devices 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 operating a shift lever, the vehicle The signals of the vehicle speed sensor 70 and the brake switch 80 are input to the control circuit 20 so that the target travel range can be corrected according to the driving state of the vehicle or the operation of the shift range selection device 10 by the driver can be regulated. ing.
[0029]
Here, as shown in FIG. 2, the actuator unit 100 includes an actuator 101, a speed reduction mechanism 102, an encoder 103, and a neutral start switch 108.
[0030]
As the actuator 101, a DC motor, a synchronous motor, or the like is used, and a rotating shaft 100a of the actuator 101 is connected to a speed reduction mechanism 102 that increases output torque.
[0031]
The output end of the speed reduction mechanism 102 is connected to the 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 speed reduction mechanism 102 causes the actuator 101 to operate the mechanical locking means of the parking mechanism 40p (see FIG. 4). A large output torque can be generated without increasing the size.
[0032]
The encoder 103 detects the rotation angle of the rotation shaft 100a of the actuator 101. The encoder 103 rotates the actuator 101 a plurality of times via the speed reduction mechanism 102 to operate the shift range switching mechanism. Can be detected.
[0033]
The shift range switching mechanism 40 changes the shift range of the automatic transmission 50 to each travel range of parking (P), reverse (R), neutral (N), drive (D), second (2), and low (L). It is for switching in order.
[0034]
As shown in FIG. 4, the shift range switching mechanism 40 includes a range switching valve 40h and a parking mechanism 40p. The range switching valve 40h is supplied with hydraulic pressure from a hydraulic circuit inside the automatic transmission 50, and controls the position of the spool valve 401 so that the discharge port is switched and a friction engagement device for setting each traveling range ( Engagement and disengagement (not shown) are controlled. The parking mechanism 40p is a mechanical locking means that is linked to the position of the spool valve 401, and switches to the P range.
[0035]
Specifically, the automatic transmission 50 is a spool valve 401, which is a range switching valve 40h, a valve body 402, a detent spring 403 for holding each travel range, a detent lever 404, and a parking mechanism 40p. The parking gear 405 provided on the output shaft (not shown), the parking king pole 406 fitted to the parking gear 405, the parking rod 407 for stopping the rotation of the control output shaft 408, and the detent lever 404 are fixed. Output shaft 408.
[0036]
The parking mechanism 40p transmits the rotation of the control output shaft 408 through the detent lever 404 and the parking rod 407 as a link operation in the arrow directions A and B, and the parking king pole 406 is fitted to the parking gear 405. Let Accordingly, the control output shaft 408 coupled to the output shaft 100a of the actuator unit 100 is switched to the P range by the rotation.
[0037]
The configuration of the shift range switching control device 1 of the automatic transmission has been described above. However, FIG. 2 shows an electrical configuration in which the actuator unit 100 is driven to control the shift range. Here, the actuator control circuit 20 is the control circuit 20a and the drive circuit 20b described above, 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. It is comprised including. The actuator control circuit 20 is supplied with power from a battery 600 that is 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 in an on / off state of the ignition key 620. Therefore, the supply and interruption are performed via the relay 610.
[0038]
In the shift range switching control device 1 for an automatic transmission having the above-described configuration, the control circuit 20a receives a range signal output from the shift range selection device 10 by a shift lever operation or the like by the driver. Next, the control circuit 20a includes a signal representing the rotation angle of the rotary shaft 100a detected by the encoder 103 provided in the actuator unit 100 so as to be a target travel range (hereinafter referred to as a target travel range). Then, a drive signal for switching from the current travel range to the target travel range is sent to the drive circuit 20b. As a result, the drive circuit 20b supplies current to the actuator 101 to switch to the target travel range.
[0039]
Here, according to FIG. 2 and FIG. 3, means for avoiding a sudden start of the vehicle even when the engine is over-rotated due to a driver's erroneous operation such as a mistake in pressing the pedal when the vehicle is stopped, which is a feature of the present invention. explain.
[0040]
As shown in FIG. 2, in the actuator control circuit 20, notification means such as a vehicle speed sensor 70, a brake switch 80, an alarm lamp 32 of the display unit 30, and an alarm buzzer 92 are connected to the signal input / output stage 204.
[0041]
Next, the shift range automatic switching control process at the time of over-vehicle speed in the reverse traveling state shown in FIG. 3 (hereinafter referred to as an over-vehicle speed automatic switching control process) will be described.
[0042]
As shown in FIG. 3, in the over-speed automatic switching control process, the current shift range of the automatic transmission 50 is read in S301 (S represents a step). In other words, the shift range, that is, the current travel range is read by fetching the range signal transmitted from the shift lever selector 10 or the rotation angle signal transmitted from the encoder 103 into the signal input / output stage 204. When this shift range is read, it is determined in S302 whether or not the read current travel range is the R range. If the current travel range is the R range, the process proceeds to S303. On the other hand, if it is not the R range, the process returns to S301 and the process is set in a standby state.
[0043]
In S303, the vehicle speed is read by taking the vehicle speed signal transmitted from the vehicle speed sensor 70 into the signal input / output stage 204. When this vehicle speed is read, in S304, it is determined whether or not the current vehicle speed exceeds a predetermined vehicle speed (for example, whether or not 30 km / h or more). If the current vehicle speed is 30 km / h or higher, the process proceeds to S305 in which the state in which the vehicle can travel automatically is released regardless of the switching command of the shift range selection device 10. On the other hand, if the current vehicle speed has not reached 30 km / h, the process returns to S301 and the process is set in a standby state.
[0044]
In S305, the shift control is forcibly controlled to a shift range (for example, N range) that can be stopped so as to automatically cancel the travelable state regardless of the switching command of the shift range selection device 10. Thereby, since it can be made the state which can stop driving | running | working by switching control to N range, the state which loses the safe driving state regarding the over-vehicle speed in the reverse driving | running | working state of a vehicle can be avoided.
[0045]
Specifically, when an excessive vehicle speed exceeding a predetermined vehicle speed occurs due to a driver's mistaken operation such as stepping on the pedal when reversing in a garage, etc., control to a shift range that cancels the vehicle's runnable state is performed. Since this is possible, it is possible to avoid a state in which the vehicle is in a safe driving state.
[0046]
In addition, as a shift range which can stop driving | running | working, it is good also as not only N range but P range. For the purpose of avoiding the state of losing the safe driving state of the vehicle due to the cause of the driver's erroneous operation, if the forced switching control to the P range is performed in consideration of the degree of urgency and the occurrence ratio, the automatic operation by maintaining the P range during driving As long as the strength function of the transmission 50 can be maintained, the vehicle can be instantly switched to the vehicle stop and hold state, so that it is possible to immediately avoid the state of losing the safe driving state of the vehicle.
[0047]
Further, in S305, by the fuel injection means for injecting the fuel to be supplied to the combustion chamber of the internal combustion engine while canceling the travelable state by forcibly switching to the shift range N range or P range where travel can be stopped. Stop fuel injection. As a result, the propulsive force of the internal combustion engine transmitted to the vehicle disappears, so that it is possible to reliably avoid the state of losing the safe traveling state of the vehicle.
[0048]
In addition, although the predetermined vehicle speed as the excess vehicle speed is set to 30 km / h, it may be set to a value lower than this in order to make it safer.
[0049]
In the above-described embodiment, the determination of the state of losing the safe driving state related to the excessive vehicle speed has been described based on the configuration for determining based on the current vehicle speed. However, the accelerator is not limited to the vehicle speed, and represents an acceleration change of the vehicle speed. Any change in the amount of pedal depression, etc., or the number of revolutions of the internal combustion engine that transmits the propulsive force to the vehicle, with a judgment value that can predict that a safe running state will be lost Good.
[0050]
In the above-described automatic switching control process at the time of overspeed, if the driver forcibly switches to the N or P range in S305, and the driver continues to depress the accelerator pedal related to the excessive vehicle speed, You may add the control process which alert | reports the warning of the state which loses what is called a safe driving | running | working state which tells a driver | operator that the driving | running | working possible state was cancelled | released using the warning light 32 or the warning buzzer 92.
[0051]
As a result, the state of losing the safe traveling state related to the excessive vehicle speed in the backward traveling state of the vehicle is avoided and the driver is warned, so that the operation of the driver can be quickly returned to the normal state.
[0052]
(Modification)
A modification will be described with reference to FIGS. 5 and 6 below. FIG. 5 is a block diagram showing the overall configuration of a shift range switching control device for an automatic transmission according to a modification. FIG. 6 is a flowchart showing a shift range automatic switching control process at an excessive vehicle speed during backward running of the vehicle, which is executed by the control circuit in FIG.
[0053]
As shown in FIG. 5, in the modified example, an obstacle alarm device 90 for detecting an obstacle and notifying the driver is added to the configuration so that the obstacle does not contact the blind spot of the vehicle. Except for this, the configuration is the same as that of the above embodiment. The obstacle alarm device 90 is provided at the front and rear corners of the vehicle, and the obstacle alarm device 90 transmits an approach signal indicating an approach distance of an obstacle approaching the vehicle, and a signal from the control circuit 20. The input / output stage 204 is connected.
[0054]
Next, shift range automatic switching control processing (hereinafter referred to as excessive approach automatic switching control processing) when an obstacle is excessively approached in the vehicle traveling state shown in FIG. 6 will be described.
[0055]
As shown in FIG. 6, the over-close automatic switching control process reads the current travel range, that is, the shift range, of the automatic transmission 50 in S501. When this shift range is read, it is determined in S502 whether or not the read current travel range is the D or R range. If the current travel range is the D or R range, the process proceeds to S503. On the other hand, if it is other than the D and R ranges, the process returns to S301 to put the process into a standby state.
[0056]
In S503, an approach signal transmitted from the obstacle alarm device 90 is taken into the signal input / output stage 204, thereby reading an approach distance of an obstacle approaching the vehicle (hereinafter referred to as an obstacle approach distance). When this obstacle approach distance is read, in S504, it is determined whether the obstacle approach distance is narrower than a predetermined approach distance (for example, whether the vehicle speed is 50 cm or less, which is the limit near distance when traveling at 10 km / h or less). to decide. If the obstacle approaching distance is 50 cm or less, the process proceeds to S505 for canceling the state in which the vehicle can automatically travel regardless of the switching command of the shift range selection device 10. On the other hand, if the obstacle approaching distance exceeds 50 cm, the process returns to S301 and the process is set in a standby state.
[0057]
In S505, switching control is forcibly controlled to a shift range (for example, N range) that can stop traveling so that the state in which traveling is possible is automatically canceled regardless of the switching command of the shift range selection device 10. Thereby, since it can be made the state which can stop driving | running | working by switching to N range, the state which loses the safe driving | running | working state related to the excessive approach in a vehicle driving | running state can be avoided.
[0058]
Specifically, despite the fact that the obstacle approaching device 90 recognizes an obstacle approaching the vehicle, the operation delay etc. that cancels the vehicle travelable state such as full closure of the accelerator pedal with sufficient agility The vehicle can be controlled to a shift range that cancels the vehicle's runnable state when an overapproaching state in which an obstacle approaching the vehicle is narrower than a predetermined approaching distance due to a driver's misjudgment cause. It is possible to avoid the state of losing the safe driving state.
[0059]
In addition, as a shift range which can stop driving | running | working, it is good also as not only N range but P range. For the purpose of avoiding the state of losing the safe driving state of the vehicle due to the cause of the driver's misjudgment, if the forced switching control to the P range is performed in consideration of the urgency and the occurrence ratio, the P range is maintained during the driving. As long as the strength function of the automatic transmission 50 can be maintained, the vehicle can be instantaneously switched to the vehicle stop holding state, so that the state of losing the safe driving state of the vehicle can be immediately avoided.
[0060]
Further, in S505, the fuel injection means for canceling the travelable state by forcibly switching to the shift range N range or P range where travel can be stopped and for injecting the fuel supplied to the combustion chamber of the internal combustion engine. Stop fuel injection. As a result, the propulsive force of the internal combustion engine transmitted to the vehicle disappears, so that it is possible to reliably avoid the state of losing the safe traveling state of the vehicle.
[0061]
In addition, although the predetermined approach distance as over-approaching, that is, the limit approach distance is set to 50 cm when traveling at 10 km / h or less, the vehicle contact determination condition may be set to the following limit approach distance.
[0062]
First, when it is determined that the approach distance of the obstacle detected by the obstacle alarm device 90 is narrower than the predetermined approach distance, the control circuit 20 has a vehicle contact determination condition including a two-dimensional map based on the vehicle speed and the limit approach distance. It is determined that the distance is shorter than the limit approach distance corresponding to the vehicle speed of the vehicle.
[0063]
That is, the control circuit 20 detects the obstacle and informs the driver that the vehicle contact is based on the information on the approach distance of the obstacle detected by the obstacle alarm device 90. An over-approach state narrower than the limit approach distance corresponding to the vehicle speed of the vehicle can be determined from the determination condition, that is, the two-dimensional map based on the vehicle speed and the limit approach distance.
[0064]
Next, when it is determined that the approach distance of the obstacle detected by the obstacle alarm device 90 is narrower than the predetermined approach distance, the control circuit 20 has a vehicle contact having a limit approach distance obtained by a calculation formula using the vehicle speed as a variable. It has a determination condition and is determined to be narrower than the limit approach distance corresponding to the vehicle speed of the vehicle.
[0065]
That is, the control circuit 20 detects the obstacle and informs the driver that the vehicle contact is based on the information on the approach distance of the obstacle detected by the obstacle alarm device 90. An over-approach state narrower than the limit approach distance corresponding to the vehicle speed of the vehicle can be determined from the limit approach distance obtained by the determination condition, that is, the calculation formula using the vehicle speed as a variable.
[Brief description of the drawings]
FIG. 1 is a configuration 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. 1;
FIG. 3 is a flowchart showing a shift range automatic switching control process at an excessive vehicle speed when the vehicle is traveling backward, which is executed by the control circuit in FIG. 1;
4 is a configuration diagram showing a schematic configuration of a shift range switching mechanism in FIG. 1. FIG.
FIG. 5 is a configuration diagram illustrating an overall configuration of a shift range switching control device for an automatic transmission according to a modification.
6 is a flowchart showing a shift range automatic switching control process at an excessive vehicle speed during backward running of the vehicle, which is executed by the control circuit in FIG. 5;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Shift range switching control apparatus 10 of automatic transmission Shift range selection apparatus 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 90 Obstacle alarm device 92 Alarm buzzer 100 Actuator unit 101 Actuator 102 Deceleration device 103 Encoders S301 to S305 Shift range automatic switching control processing at the time of excessive vehicle speed in the reverse traveling state S501 to S505 Shift range automatic switching control processing when an obstacle is over approaching in vehicle travel

Claims (2)

A shift range switching mechanism for switching the shift range of the automatic transmission to various travel ranges including parking;
An actuator as a drive source of the shift range switching mechanism;
A drive circuit for driving the actuator;
Control means for controlling the shift range of the automatic transmission to a shift range corresponding to the switching command by driving the actuator via the drive circuit in accordance with a switching command input by an external operation;
The automatic transmission is connected to an internal combustion engine that transmits propulsive force to the vehicle,
If the control means determines that the vehicle speed of the vehicle has exceeded a predetermined vehicle speed when the vehicle is in a reverse running state, the control means sets the shift range of the automatic transmission to the P range regardless of the switching command. A shift range switching control device for an automatic transmission that cancels the vehicle travelable state and stops the travel of the vehicle by switching control to. The internal combustion engine includes fuel injection means for injecting fuel to be supplied to the combustion chamber of the internal combustion engine,
2. The shift range switching control device for an automatic transmission according to claim 1, wherein the control unit cancels a state in which the vehicle can travel and stops fuel injection by the fuel injection unit.

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