JP5531924B2 - Vehicle stop assist device - Google Patents

Description

  The present invention relates to a vehicle stop assist device.

  In a vehicle that performs idling stop that stops the engine when the vehicle is stopped, the driver applies a foot brake at the time of idling stop to maintain the stopped state of the vehicle. Patent Document 1 describes a vehicle stop assist device that maintains brake braking pressure and restricts movement of a vehicle when a brake pedal is depressed to a predetermined position when the vehicle is stopped.

JP 2008-239034 A

  However, in the vehicle stop auxiliary device described in Patent Document 1, an electromagnetic valve for maintaining the brake braking pressure is separately required. In addition, a separate control circuit for controlling the solenoid valve is required. As a result, the apparatus configuration becomes complicated.

  An object of the present invention is to provide a vehicle stop assist device that maintains a stop state of a vehicle when idling is stopped.

According to the first aspect of the present invention, the control means included in the vehicle stop auxiliary device determines that the vehicle is stopped when the vehicle speed detecting means detects that the vehicle speed is zero. At this time, when the operation amount of the brake pedal detected by the brake operation amount detection means is equal to or greater than a predetermined threshold value, and the operation amount of the accelerator pedal detected by the accelerator operation amount detection means is equal to or less than the first threshold value, The control means executes a parking range switching process for switching the mechanical shift range, which is the shift range of the manual valve, to the parking range by the shift-by-wire actuator. Thereby, even if a driver does not apply a foot brake, the vehicle maintains a stopped state.
Further, when it is detected by the range detection means that the operation shift range that is the shift range selected by the driver is a range that allows the vehicle to move forward, the control means stops the operation of the internal combustion engine. The process, i.e. idling stop, is executed. Thereby, even if the driver does not apply the foot brake at the time of idling stop, the vehicle can maintain the stopped state. Therefore, the burden on the driver at the time of idling stop can be reduced. Moreover, since the vehicle stop state during idling stop is maintained using the existing parking range switching process, the vehicle stop can be assisted with a simple configuration.

  According to the second aspect of the present invention, the vehicle stop auxiliary device according to the first aspect includes the parking brake detection means. When the control unit detects that the parking brake is released by the parking brake detection unit, the control unit executes a parking range switching process for switching the mechanical shift range to the parking range. Thereby, when the parking brake is applied, the vehicle stop assist device does not perform the switching process to the parking range. Therefore, two types of brakes are not applied simultaneously, and it is possible to prevent an erroneous operation of the driver when restarting from an idling stop.

According to the third aspect of the present invention, when the operation amount of the accelerator pedal detected by the accelerator operation amount detection means becomes equal to or larger than the second threshold value which is smaller than the first threshold value after executing the internal combustion engine stop process described above, The control means executes an internal combustion engine operation process for starting the operation of the internal combustion engine.
According to a fourth aspect of the present invention, there is provided storage means for storing an operation shift range when executing the parking switching process , and the accelerator detected by the accelerator operation amount detecting means after executing the aforementioned internal combustion engine stop process. When the operation amount of the pedal becomes equal to or more than the first threshold value, a range return process for changing the mechanical shift range from the parking range to the operation shift range stored in the storage unit is executed.
After the internal combustion engine is stopped due to idling stop, the driver starts the internal combustion engine by operating the accelerator. At this time, the operation amount of the accelerator pedal is based on a second threshold value that is smaller than the first threshold value that switches the mechanical shift range from the parking range to a range that allows the vehicle to move. As a result, when the driver operates the accelerator pedal to the second threshold value or higher, the internal combustion engine is started while the mechanical shift range is maintained in the parking range state. Thereafter, when the accelerator operation amount by the driver becomes equal to or greater than the first threshold, the mechanical shift range is changed to the range of the operation shift range stored in the storage means , and the vehicle can move. Thereby, the sudden start of the vehicle at the time of internal combustion engine starting can be prevented. Further, the driver can restart from the idling stop state only by the accelerator operation.

  According to the fifth aspect of the present invention, the program causes the computer to function as each means included in the vehicle stop auxiliary device according to any one of the first to fourth aspects.

It is a mimetic diagram showing composition of a vehicle stop auxiliary device by an embodiment of the present invention. It is a flowchart regarding the vehicle stop control of the vehicle stop auxiliary device by embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the vehicle stop assist device 1 includes an ECU 10, a vehicle speed sensor 20, a parking brake switch 30, a brake pedal sensor 40, an accelerator pedal sensor 50, a range sensor 60, and a shift-by-wire actuator 70. The vehicle stop assist device 1 is attached to an idling stop vehicle that stops an engine when an idling state is detected when the vehicle is stopped.

  The ECU 10 controls the entire vehicle stop assist device 1. The ECU 10 is configured as a so-called microcomputer system, and includes a CPU, a ROM, a RAM, an I / O, a bus line, and the like. The ECU 10 is electrically connected to a vehicle speed sensor 20, a parking brake switch 30, a brake pedal sensor 40, an accelerator pedal sensor 50, a range sensor 60, and a shift-by-wire actuator 70, which will be described later. The ECU 10 makes a determination based on signals input from the sensors. The ECU 10 corresponds to “control means” described in the claims.

  The vehicle speed sensor 20 detects the speed of the vehicle, and is attached to, for example, the outer periphery of the drive shaft. The vehicle speed sensor 20 inputs a pulse signal indicating the vehicle speed to the ECU 10. The vehicle speed sensor 20 corresponds to “vehicle speed detection means” described in the claims.

  The parking brake switch 30 is disposed on the lever portion of the parking brake system. The parking brake switch 30 outputs an ON signal to the ECU 10 when the parking brake is operated, and outputs an OFF signal to the ECU 10 when the parking brake is not operated, that is, when the parking brake is released. The parking brake switch 30 corresponds to “parking brake detecting means” described in the claims.

  The brake pedal sensor 40 is connected to the brake pedal. The brake pedal sensor 40 detects a brake pressure operated by the brake pedal, and outputs the brake pressure to the ECU 10 as an electric signal. The brake pedal sensor 40 corresponds to “brake operation amount detection means” described in the claims.

  The accelerator pedal sensor 50 is connected to an accelerator pedal. The accelerator pedal sensor 50 that detects the accelerator opening is a rotation angle sensor, and outputs a linear voltage signal according to the rotation position corresponding to the accelerator opening. The output voltage signal is input to the ECU 10. The accelerator pedal sensor 50 corresponds to “accelerator operation amount detection means” described in the claims.

  The range sensor 60 connects the shift-by-wire actuator 70 and the ECU 10. The range sensor 60 detects the shift range of the manual valve 86 via the shift-by-wire actuator 70 and outputs it to the ECU 10. On the other hand, the shift range selected by the driver is input to the ECU 10 via a range switch (not shown). The range sensor 60 and the ECU 10 correspond to “range detection means” recited in the claims.

  The shift-by-wire actuator 70 is connected to the drive shaft member 81 of the transmission mechanism unit 80 that constitutes the automatic transmission. When the shift range selected by the driver is input to the ECU 10, the shift-by-wire actuator 70 electrically connected to the ECU 10 rotates the drive shaft member 81 to change the shift range.

  As shown in FIG. 1, the transmission mechanism 80 includes a drive shaft member 81, a detent plate 82, a roller 83, and the like. The drive shaft member 81 is connected to the shift-by-wire actuator 70 and is rotationally driven by the shift-by-wire actuator 70. The detent plate 82 extends radially outward from the drive shaft member 81 and is attached so as to be rotatable integrally with the drive shaft member 81. Thereby, the detent plate 82 is rotationally driven by the shift-by-wire actuator 70. The detent plate 82 has a pin 84 that protrudes in parallel with the drive shaft member 81. The pin 84 is connected to the manual valve 86. As a result, when the detent plate 82 rotates together with the drive shaft member 81, the manual valve 86 reciprocates in the axial direction. That is, the transmission mechanism 80 converts the rotational driving force of the shift-by-wire actuator 70 into a linear motion and transmits it to the manual valve 86.

  The detent plate 82 has a plurality of detent plate recesses 831 at the end opposite to the drive shaft member 81 in the radial direction. Each of the detent plate recesses 831 corresponds to the shift range of the automatic transmission. The roller 83 is supported at the tip of the leaf spring 85. The roller 83 is engaged with one of the detent plate recesses 831 of the detent plate 82, whereby the axial position of the manual valve 86 is determined. When a rotational force is applied to the detent plate 82 via the drive shaft member 81, the roller 83 moves to another adjacent detent plate recess 831. As a result, when the drive shaft member 81 is rotated by the shift-by-wire actuator 70, the axial position of the manual valve 86 changes, and the shift range of the automatic transmission is changed.

  The parking lock unit 90 regulates the rotation of the output shaft of the automatic transmission by engaging the claw 94 of the lock arm 93 with the recess 92 formed on the outer periphery of the parking gear 91. The rod 95 of the parking lock portion 90 is formed in a substantially L shape. One end of the rod 95 is fixed to the detent plate 82 and the other end is connected to a cone head 96 having a tapered cone shape. The cone head 96 is pressed against the lock arm 93 by a spring 97 so as to be reciprocally movable in the axial direction. As the cone head 96 reciprocates in the axial direction by the rotation of the detent plate 82, the cone head 96 drives the lock arm 93 up and down in FIG. When the detent plate 82 rotates to an angle at which the detent plate recess 831 corresponding to the parking range of the detent plate 82 and the stopper 83 are engaged, the manual valve 86 is switched to the “parking range” and the cone head 96 presses the lock arm 93. The claw 94 of the lock arm 93 meshes with the recess 92 of the parking gear 91. As a result, the output shaft of the automatic transmission is mechanically restricted from rotating, and the parking range of the automatic transmission is achieved.

(Function)
Next, the vehicle stop assistance process in this embodiment will be described based on the flowchart of FIG. Note that the vehicle stop assistance process in this embodiment is repeatedly executed when it is determined that the vehicle speed detected by the vehicle speed sensor 20 is lower than a predetermined speed.

  In the first step (hereinafter, “step” is omitted and is simply indicated by symbol S) 101, the ECU 10 determines whether or not the vehicle speed detected by the vehicle speed sensor 20 is “0”. If it is determined that the vehicle speed is “0”, the process proceeds to S102. On the other hand, when it is determined that the vehicle speed is not “0”, that is, when the vehicle is running, the subsequent process is not executed and the vehicle stop assist process is terminated.

  In S102, it is determined from the signal output from the parking brake switch 30 whether or not the parking brake is released. As described above, since the ON signal is input while the parking brake is being used, an affirmative determination is made when the OFF signal is input. If it is determined that the parking brake is released, the process proceeds to S103. On the other hand, when it is determined that the parking brake has not been released, that is, when the parking brake is in operation, the following process is not executed and the vehicle stop assist process is terminated.

  In S103, it is determined whether or not the brake pressure is greater than or equal to a threshold value. When it is determined that the brake pressure operated by the brake pedal is equal to or higher than the threshold value, the process proceeds to S104. On the other hand, when it is determined that the brake pressure is smaller than the threshold value, the subsequent process is not executed and the vehicle stop assist process is terminated.

  In S104, it is determined whether or not the accelerator opening is equal to or smaller than a first threshold value. When the accelerator opening is equal to or smaller than the first threshold value, the process proceeds to S105. On the other hand, when the accelerator opening is larger than the first threshold, the subsequent process is not executed and the vehicle stop assist process is terminated.

  In S105, the shift range selected by the driver, for example, the drive range is stored. In subsequent S106, the shift range of the manual valve is switched to the parking range. In the parking range, the claw 94 of the lock arm 93 shown in FIG. 1 meshes with the recess 92 of the parking gear 91, so that the vehicle mechanically stops. At this time, the shift range selected by the driver remains the drive range. In subsequent S107, the engine is stopped. Thus, idling stop is executed to stop the operation of the engine with the manual valve range switched to the parking range. The shift range selected by the driver corresponds to the “operation shift range” described in the claims. The shift range of the manual valve corresponds to the “mechanical shift range” recited in the claims.

  In S108, it is determined whether or not the accelerator opening is equal to or greater than a second threshold value. Here, the second threshold value of the accelerator opening is set to a value smaller than the first threshold value. If the accelerator opening is smaller than the second threshold value, the process does not proceed to S109 and the determination process of S108 is repeated. On the other hand, when the accelerator opening is equal to or larger than the second threshold, the process proceeds to S109. In S109, the stopped engine is started.

In S110, it is determined whether or not the accelerator opening is equal to or greater than a first threshold value. When the accelerator opening is equal to or greater than the first threshold, the process proceeds to S111. On the other hand, when the accelerator opening is smaller than the first threshold, the determination process of S110 is repeated.
In S111, the shift range stored by the ECU 10 in S105, that is, the shift range of the manual valve is returned to the drive range.

(effect)
Next, the effect of the vehicle stop auxiliary device 1 of this embodiment will be described.
(1) The ECU 10 changes the shift range of the manual valve to the parking range via the shift-by-wire actuator 70 before the idling stop is executed. Thereafter, the engine is stopped and idling stop is executed. Thereby, even if the driver does not operate the brake pedal during the idling stop, the vehicle maintains the stopped state, so that the burden on the driver is reduced.

  (2) By using a parking range, an accelerator pedal sensor, a brake pedal sensor, and the like that are already mounted on the vehicle, the vehicle can be kept stopped when idling is stopped. Thereby, the structure for assisting the stop of a vehicle can be simplified.

  (3) The manual valve shift range is changed to the parking range on condition that the parking brake is released. As a result, the two types of brakes, that is, the parking brake and the parking range brake, are not applied simultaneously. Therefore, the engine can be restarted and started without erroneous operation by the driver when restarting from the idling stop.

  (4) To restart the vehicle after the engine has stopped, the driver operates the accelerator pedal. At this time, a first threshold value for restarting the engine and a second threshold value for the range return process are provided as threshold values for the accelerator opening. At this time, a value smaller than the first threshold is set as the second threshold. As a result, the engine is restarted with the parking brake applied by the driver's accelerator operation. Therefore, when the engine is restarted, it is possible to prevent a sudden start due to a sudden increase in the engine speed.

  (5) After the engine is stopped, the driver can restart the vehicle only by operating the accelerator pedal from the restart of the engine to the change to the drive range by returning the shift range. As a result, the burden on the driver at the time of restart is reduced.

(Other embodiments)
(A) In the above-described embodiment, the shift range selected by the driver is the drive range. However, the shift range selected by the driver may not be limited to this. Any range that moves the vehicle forward, such as a low range or a second range, may be used.

  As mentioned above, this invention is not limited to such embodiment, It can implement with a various form in the range which does not deviate from the summary.

10 ... ECU (control means, range detection means),
20 ... Vehicle speed sensor (vehicle speed detection means),
30 ... Parking brake switch (parking brake detection means),
40 ... Brake pedal sensor (brake operation amount detection means),
50 ... Accelerator pedal sensor (accelerator operation amount detection means),
60 ・ ・ ・ Range sensor (range detection means),
70 ・ ・ ・ Shift-by-wire actuator,
86: Manual valve.

Claims (5)

Vehicle speed detecting means for detecting the vehicle speed;
Brake operation amount detection means for detecting the operation amount of the brake pedal;
An accelerator operation amount detecting means for detecting an operation amount of the accelerator pedal;
Range detection means for detecting an operation shift range that is a shift range selected by the driver and a mechanical shift range that is a shift range of a manual valve;
A shift-by-wire actuator for switching the mechanical shift range;
Control means for controlling the shift-by-wire actuator to switch the mechanical shift range;
With
The control means detects that the vehicle speed is zero by the vehicle speed detection means, and the operation amount of the brake pedal detected by the brake operation amount detection means is equal to or greater than a predetermined threshold; and When the operation amount of the accelerator pedal detected by the accelerator operation amount detection means is equal to or less than a first threshold value,
A parking range switching process for switching the mechanical shift range to a parking range in which movement of the vehicle is restricted by the shift-by-wire actuator;
When the control means detects that the operation shift range detected by the range detection means is a range that allows the vehicle to move forward after executing the parking range switching process, the operation of the internal combustion engine is performed. A vehicle stop auxiliary device that executes an internal combustion engine stop process for stopping the engine. In the vehicle stop auxiliary device according to claim 1,
Parking brake detecting means for detecting whether the parking brake is released,
The vehicle stop assisting device, wherein the control means executes the parking range switching process when the parking brake detecting means detects that the parking brake is released. In the vehicle stop auxiliary device according to claim 1 or 2,
The control means performs the internal combustion engine when the operation amount of the accelerator pedal detected by the accelerator operation amount detection means becomes equal to or larger than a second threshold value smaller than the first threshold value after executing the internal combustion engine stop process. A vehicle stop auxiliary device that executes an internal combustion engine operation process for starting the operation of the vehicle. In the vehicle stop auxiliary device according to claim 3,
Comprising storage means for storing the operation shift range when executing the parking switching process;
The control means stores the storage means from the parking range when the operation amount of the accelerator pedal detected by the accelerator operation amount detection means becomes equal to or greater than the first threshold after executing the internal combustion engine operation process. A vehicle stop assistance device that executes a range return process for changing the mechanical shift range to the range of the operation shift range .
  The program which makes a computer function as each means with which the vehicle stop assistance apparatus as described in any one of Claim 1 to 4 is provided.

Images