JPH0958429A - Auxiliary device for starting on uphill and downhill road - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent a vehicle from moving when a slope start auxiliary control is carried out. SOLUTION: In the case where a brake pedal 1 is stepped on during stopping of a vehicle, and a clutch pedal is stepped on or a speed change stage is set at a neutral position, namely in the case where driving force is in a cut off state, a magnet valve 9 is actuated to maintain braking force, and when the movement of the vehicle is detected in the case where the braking force is kept by the actuation of the magnet valve 9, a solenoid valve 23 is actuated to increase the braking force, and the movement of the vehicle can therefore be surely prevented when a slope start auxiliary control is carried out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake assist device provided to ensure the safety of a stopped vehicle.

[0002]

2. Description of the Related Art For vehicles such as automobiles, a brake assisting device (hill start assisting device) has been developed which can reduce the troublesomeness of a driver's brake operation. A conventional hill start assist device is a device that detects that a vehicle has stopped due to a brake operation by a control device and that holds the brake fluid pressure when the driver depresses the brake pedal even when the driver releases the brake pedal. As a result, the driver can maintain the stopped state of the vehicle without continuously depressing the brake pedal (see, for example, JP-A-6156224).

Specifically, an actuator for holding the brake fluid pressure is provided on the hydraulic oil supply path of the brake, and the vehicle is kept stopped for a predetermined time while the brake pedal is being depressed, after which the driver brakes. When it is detected that the foot is released from the pedal, the fluid pressure is supplied to the actuator to hold the braking force. Further, when the driver puts the clutch in the connected state, the brake control device is released, and normal traveling can be performed.

By using such a hill start assisting device, it is not necessary to continue to step on the brake pedal due to traffic congestion or waiting for a signal, and physical and mental fatigue can be reduced. Further, by using the slope start assist device, it is possible to easily start the slope, and further, it is possible to minimize damage even when a rear-end collision occurs and prevent an accident from spreading.

[0005]

The conventional hill-start assisting device is constructed so as to keep the brake fluid pressure constant during operation according to the operating force of the brake pedal of the driver. When the stopped vehicle starts moving, the braking force is not positively increased to stop the movement of the vehicle. Therefore, in the conventional hill start assist device, when the driver's brake pedal operation force is insufficient, the vehicle is stopped on an extremely steep slope, or when the vehicle has a large load, There was a risk that it would start to move.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a hill-start assisting device for increasing the braking force when the vehicle starts to move while the hill-start assisting device is operating. And

[0007]

The structure of the present invention for achieving the above object is a movement detecting means for detecting movement of a vehicle, and a braking for detecting that a service brake is operated by operating a brake pedal. An operation detecting means, a driving force cutoff detecting means for detecting that the driving force output of the engine is in a cutoff state, and a braking fluid which is interposed in the working fluid passage of the service brake and holds the braking force. A control valve, a pressurizing unit that increases the braking fluid independently of the operation of the brake pedal, and a braking operation detecting unit that detects that the service brake is being operated when the vehicle is stopped, and When the driving force cutoff detection unit detects that the driving force output of the engine is in the cutoff state, the control valve is closed and the control valve is closed. Characterized in that said that said vehicle by the movement detection unit is moved and a control means for actuating said pressurizing means to be detected when being dynamic.

Further, there is provided parking brake state detecting means for detecting the operating state of the parking brake, and the control means includes:
When the movement detecting means detects the movement of the vehicle in spite of the fact that the parking brake state detecting means detects that the parking brake is in an operating state, it has a function of operating the pressurizing means. It is characterized by being provided. Further, the control means activates the pressurizing means when it is detected that the vehicle has moved a first predetermined distance or more while the control valve is being closed, and the parking brake state detecting means. Has a function of activating the pressurizing unit when it is detected that the vehicle has moved a second predetermined distance longer than the first predetermined distance while it is detected that the parking brake is in operation. It is characterized by being.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a slope starting assistance device of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration showing the whole of a slope starting assistance device according to an embodiment of the present invention, and FIGS. 2 to 6 are flowcharts for explaining the operation of the slope starting assist device. The slope starting assist device shown in the figure has a function of increasing the braking force when the vehicle starts moving on a slope or the like, in addition to the function of holding the braking force while the vehicle is stopped (a slope starting assist function).

The structure of the slope start assist device will be described with reference to FIG. The illustrated hill start assist device includes a service brake that uses air pressure as a control pressure according to the operation of a brake pedal, and a parking brake (not shown). The service brake is provided with an air supply system 2 for supplying brake operating air of a required pressure in accordance with the operation of the brake pedal 1. The brake operating air from the air supply system 2 supplies the brake fluid pressure on the front wheel side. The hydraulic pressure boosters (air masters) 3 and 4 connected to the system and the brake hydraulic pressure supply system on the rear wheel side are operated to generate a braking force on the vehicle.

A brake valve 5 and an air tank 6 are connected to the air supply system 2, and when the driver depresses the brake pedal 1, the brake valve 5 opens and the high pressure air in the air tank 6 is released. When the high pressure air in the air tank 6 is released, the high pressure air is supplied to the hydraulic boosters 3 and 4 via the air supply passages 7 and 8 and a magnet valve 9 as a control valve described later. When the hydraulic boosters 3 and 4 are activated by the high-pressure air, the hydraulic pressure of the brake oil in the brake fluid pressure supply systems on the front and rear wheels is increased, and the service brake is activated to generate a braking force on the vehicle. . This hill start assist device has a hill start assist control that executes the function of holding the braking force while the vehicle is stopped and a parking assist control that executes the function of increasing the brake force when the vehicle starts moving on a hill. Since the slope start assist control and the parking assist control interact with each other, it is possible to easily start the slope start of the vehicle and ensure the safety of the parked vehicle.

First, the hill start assist control will be described.
The slope start assist control is executed when the vehicle is stopped by depressing the brake pedal 1. That is, when the driver depresses the brake pedal 1 and the stop of the vehicle is detected for a predetermined time or more, the magnet valve 9 of the air supply system 2 is switched to generate high pressure air in the air supply system 2 downstream of the magnet valve 9. It is intended to retain the braking force even if the driver releases his / her foot from the brake pedal 1 by containing it.

The magnet valve 9 is controlled by a controller (ECU) 10 as a control means. ECU
Reference numeral 10 denotes an operation switch 11, an adjustment switch 12, a clutch pedal stroke sensor (clutch sensor) 13 as a driving force cutoff detection means, a vehicle speed sensor 14 as a movement detection means, a neutral switch 15, and a stop lamp as a braking operation detection means. A switch 16, a parking switch 17 as a parking brake detection means, a door switch 18, and a key switch 19 are connected. The detection information of the sensors is input to the ECU 10, and the operation of the magnet valve 9 is controlled based on the detection information of the sensors.

The actuation switch 11 is an on / off switch arranged around the driver, and when the actuation switch 11 is turned on, the slope starting device is activated. The adjustment switch 12 adjusts the operation of the slope start assist device, and adjusts the timing at which the operation of the magnet valve 9 is released. The clutch sensor 13 is a sensor that outputs an ON signal when the driver depresses the clutch pedal,
The vehicle speed sensor 14 is a sensor that detects a moving distance by the number of pulses when a vehicle speed is generated. The neutral switch 15 is a sensor that outputs an ON signal only when the gear stage of the transmission is in neutral.

The stop lamp switch 16 is for detecting the operating state of the brake pedal 1, and is a sensor that outputs an ON signal when the driver depresses the brake pedal 1. The parking switch 17 is a switch for detecting the operating state of the parking brake lever. The door switch 18 is a switch that detects the open / closed state of the door on the driver's side of the vehicle. The key switch 19 is a switch that detects whether the engine is operating or not operating.

Warning means 20 is connected to the ECU 10,
When the hill start assist control and the state of the vehicle meet predetermined conditions, a warning is issued to the driver. ECU
At 10, the control signal of the magnet valve 9 is set based on the detection information of the above-mentioned sensors and output to the magnet valve 9.

Next, the parking assist control will be described. The parking assist control operates to stop the vehicle when the vehicle starts moving after the vehicle has been stopped under a predetermined condition and the driver has not performed any operation. For example, when the vehicle starts to move naturally when parked on a slope, the brake fluid pressure is increased to mechanically operate the brake on the rear wheel side.

As shown in FIG. 1, the air supply passage 8 on the rear wheel side.
An auxiliary air supply passage 21 to which high-pressure air is supplied from the air tank 6 is provided between the downstream side of the magnet valve 9 and the master cylinder 4. The auxiliary air supply passage 21 is provided with a check valve 22 and a solenoid valve 23 from the upstream side, and by controlling the operating state of the solenoid valve 23, the braking force of the vehicle is increased independently of the operation of the brake pedal 1. It is like this.
That is, the auxiliary air supply passage 21 and the solenoid valve 23
The pressurizing means is constituted by.

In the above-mentioned ECU 10, the solenoid valve 23 is controlled based on the detection information of the above-mentioned sensors, and the brake on the rear wheel side is mechanically operated independently of the operation of the brake pedal 1. There is. In addition, when the parking assist control and the state of the vehicle meet predetermined conditions,
It gives an alarm to the driver.

The slope start assist control and the parking assist control are E
The operation is executed by the CU 10.

In the hill start assist control, the stop lamp switch 16 detects that the brake pedal 1 is depressed for a predetermined time or longer, the vehicle speed sensor 14 detects that the vehicle is stopped, and the clutch sensor 13 depresses the clutch pedal. When the neutral position is detected by the neutral switch 15, the control signal is output to the magnet valve 9. As a result, the magnet valve 9 is turned on, and the high-pressure air from the air tank 6 is enclosed between the hydraulic boosters 3 and 4 and the magnet valve 9. Therefore, the hydraulic boosters 3 and 4 are kept in operation regardless of whether the brake valve 5 is turned on or off, the braking force is held, and the vehicle is stopped.

In the parking assist control, the parking switch 1
7 detects that the parking brake is in operation, the vehicle speed sensor 14 detects a predetermined vehicle speed, the key switch 19 detects that the engine is in operation, and the neutral speed is neutral. When it is detected by the switch 15 that the shift position is the neutral position, or the parking switch 17
When the vehicle speed sensor 14 detects a predetermined vehicle speed and the key switch 19 detects that the engine is in operation, even though the parking brake is detected by the solenoid valve. Two
A control signal is output to 3. By the operation of the solenoid valve 23, the high pressure air from the air tank 6 is supplied to the hydraulic booster 4 via the auxiliary air supply passage 21. Therefore,
The braking force of the vehicle is increased and the vehicle is automatically stopped, ensuring the safety of the vehicle when the vehicle starts to move naturally during parking.

The operation of the slope starting assist device will be described in detail with reference to the flowcharts shown in FIGS.

The overall flow will be described with reference to FIG. As shown in FIG. 2, after the outputs of the respective sensors and switches are read, the slope start assist control is executed in step S1.
Parking assist control is executed in step S2. Thereafter, in step S3, it is determined whether or not the slope start safety flag (details will be described later) is 1, and when it is determined that the slope start safety flag is 1, the solenoid valve 23 is activated in step S4 and the vehicle Increase braking power. Step S
If it is determined in 3 that the slope start safety flag is not 1, the parking safety flag is set in step S5 (details will be described later).
Is determined to be 1 or not. When it is determined that the parking safety flag is 1 in step S5, the solenoid valve 23 is activated to increase the braking force of the vehicle in step S4, and when it is determined that the parking safety flag is not 1 in step S5, step S6 Therefore, the solenoid valve 23 is deactivated and the braking force of the vehicle is not increased.

The slope starting assist control in step S1 will be described with reference to FIGS. As shown in FIG. 3, in step S11, it is determined whether or not the operation switch 11 is on, and when it is determined that the operation switch 11 is not on (off), the slope start safety flag is set to 0 in step S12,
In step S13, the magnet valve 9 is deactivated. When it is determined in step S11 that the operation switch 11 is on, it is determined in step S14 whether or not the slope start assist control is being executed. When it is determined in step S14 that the hill start assist control is not being executed, it is determined in step S15 whether the brake pedal 1 is depressed for a predetermined time or longer.

When it is determined in step S15 that the depression of the brake pedal 1 is less than the predetermined time, step S1
When it is determined in step S15 that the brake pedal 1 has been stepped on for more than the predetermined time, the process proceeds to step S1.
At 6, it is judged from the detection signal of the vehicle speed sensor 14 whether or not the vehicle is stopped. When it is determined that the vehicle is not stopped in step S16, the process proceeds to step S12, and when it is determined that the vehicle is stopped in step S16, it is determined in step S17 whether or not the clutch pedal is depressed by the detection signal of the clutch sensor 13. To be judged.

When it is determined in step S17 that the clutch pedal is depressed, the magnet valve 9 is activated in step S18, and when it is determined that the clutch pedal is not depressed in step S17, the neutral switch 15 shifts the gear in step S19. It is determined whether the position is a neutral position. When it is determined in step S19 that the shift position is the neutral position, step S1
8, the magnet valve 9 is activated, and if it is determined in step S19 that the shift position is not the neutral position, the process proceeds to step S13 to deactivate the magnet valve 9.

On the other hand, if it is determined in step S14 that the hill start assist control is being executed, as shown in FIG.
In step S20, it is determined by the neutral switch 15 whether or not the shift position is the neutral position. When it is determined in step S20 that the shift position is not the neutral position, it is determined in step S21 based on the detection signal of the clutch sensor 13 whether or not the clutch pedal is released, and in step S20 the shift position is determined to be the neutral position. If so, it is determined in step S22 based on the detection signal from the parking switch 17 whether the parking brake lever is pulled.

If it is determined in step S21 that the clutch pedal is released, the process proceeds to step S12 (FIG. 3) to set the slope start safety flag to 0, and step S21
When it is determined that the clutch pedal is not released in step S22, it is determined in step S22 whether the parking brake lever is pulled. When it is determined in step S22 that the parking brake lever is pulled, the process proceeds to step S12 (FIG. 3) to set the slope start safety flag to 0, and in step S22 it is determined that the parking brake lever is not pulled. In step S23, it is determined whether or not the moving distance of the vehicle exceeds the first predetermined distance L1 based on the detection signal of the vehicle speed sensor 14.

In step S23, the travel distance of the vehicle exceeds L1, that is, the shift position is other than the neutral position or the shift position is in the neutral position and the clutch pedal is depressed during execution of the hill start assist control, and the parking brake is applied. When it is determined that the moving distance of the vehicle exceeds L1 when the lever is not pulled, the slope start safety flag is set to 1 in step S24, the warning means 20 is activated in step S25, and step S18 (FIG. 3). Then, the magnet valve 9 is activated.

When it is determined in step S23 that the moving distance of the vehicle is less than or equal to L1, it is determined in step S26 based on the detection signal of the door switch 18 whether or not the door is open, and in step S26 that the door is open. If it is determined, the process proceeds to step S25 to activate the alarm means 20. If it is determined in step S26 that the door is not open, it is determined in step S27 whether or not there is an abnormality, and if it is determined in step S27 that there is abnormality, the alarm means 20 is activated in step S27 and step S18 (FIG. 3). Then, the magnet valve 9 is activated. When it is determined in step S27 that there is no abnormality, the process directly proceeds to step S18 (FIG. 3) to activate the magnet valve 9.

That is, while the vehicle is stopped (step S1
6) The service brake is operated (step S15),
Also, is the clutch pedal depressed (step S1)
7) Alternatively, when it is determined that the driving force is in the cutoff state due to the shift position being in the neutral position (step S19), the magnet valve 9 is operated (step S18) and the braking force is retained (sealing operation). . Also,
When the braking force is maintained by the operation of the magnet valve 9, that is, when it is detected that the vehicle has moved beyond the movement distance L1 while the hill start assist control is being executed (step S14) (step S23). Set the slope start safety flag to 1 (step S24) and solenoid valve 2
3 is operated (step S4) to increase the braking force (claims 1 and 3).

Next, step S2 will be described with reference to FIGS.
The parking assist control will be described. As shown in FIG. 5, in step S31, it is determined whether or not the parking assist control is being executed, and when the parking assist control is not being executed, is the parking brake lever pulled by the detection signal of the parking switch 17 in step S32. It is determined whether or not. When it is determined in step S32 that the parking brake lever is not pulled, the parking safety flag is set to 0 in step S33, and when it is determined that the parking brake lever is pulled in step S32, the vehicle speed sensor 14 of the vehicle speed sensor 14 is checked in step S34. Based on the detection signal, it is determined whether or not the moving distance of the vehicle exceeds L2, which is the second predetermined distance set to a value larger than the above-described moving distance L1.

When it is determined in step S34 that the moving distance of the vehicle is less than or equal to L2, the process proceeds to step S33, the parking safety flag is set to 0, and it is determined in step S34 that the moving distance of the vehicle exceeds L2. Case Step S35
Then, it is determined whether or not the key switch 19 is turned on, and the process proceeds to the process of setting the parking safety flag to 1. That is, the solenoid valve 23 can be operated when it is detected that the parking brake is in the activated state and the vehicle has moved the second predetermined distance longer than the first predetermined distance. And claim 3).

If it is determined in step S35 that the key switch 19 is on, the neutral switch 15 determines in step S36 whether or not the shift position is the neutral position. When it is determined in step S35 that the key switch 19 is not on (off), step S37
In step S37, it is determined whether or not it is within one hour after the key switch 19 is turned off. If it is determined in step S37 that it is over one hour after the key switch 19 is turned off, the process proceeds to step S33 and parking is performed. Set the safety flag to 0.

When it is determined in step S36 that the shift position is the neutral position, the parking brake lamp is blinked in step S38, and when it is determined in step S36 that the shift position is not the neutral position, the process proceeds to step S33. Set the parking safety flag to 0.
If it is determined that it is within one hour after the key switch 19 is turned off in step S37, step S37
At 38, the parking brake lamp blinks. After blinking the parking brake lamp in step S38,
In step S39, the parking safety flag is set to 1 to enable the solenoid valve 23 to operate.

On the other hand, when it is determined in step S31 that the parking assist control is being executed, the process proceeds to step S41 in FIG. That is, in step S41, it is determined whether or not the parking brake lever is released based on the detection signal from the parking switch 17. When it is determined in step S41 that the parking brake lever has been released, it is determined in step S42 whether or not the number of releases is greater than or equal to a predetermined number of times, and when it is determined in step S41 that the parking brake lever has not been released step S38 (See FIG. 6) The parking brake lamp blinks.

If it is determined in step S42 that the number of cancellations is greater than or equal to the predetermined number, the blinking of the parking brake lamp is canceled in step S43, the process proceeds to step S33, and the parking safety flag is set to zero. When it is determined in step S42 that the number of times of release is less than the predetermined number of times, it is determined in step S44 whether or not the brake pedal 1 is stepped on by the detection signal of the stop lamp switch 16. When it is determined in step S44 that the brake pedal 1 is depressed, the process proceeds to step S43, the blinking of the parking brake lamp is released, and when it is determined in step S44 that the brake pedal 1 is not depressed, step S38 (FIG. 6). Go to and blink the parking brake lamp.

In the above-described hill start assist device, when the brake pedal 1 is depressed while the vehicle is stopped and the clutch pedal is depressed or the gear position is in the neutral position, that is, the driving force is in the cutoff state. If
The magnet valve 9 is operated to maintain the braking force. Further, when the movement of the vehicle is detected while the braking force is held by the operation of the magnet valve 9, the solenoid valve 23 is operated to increase the braking force. Therefore, it is possible to reliably prevent the vehicle from moving while the hill start assist control is being executed.

Further, when the movement of the vehicle is detected despite the parking brake being pulled, the solenoid valve 23 is operated. Therefore, the solenoid valve 23 is controlled by the slope start assist control and the parking assist control. It can be shared and cost can be reduced. Further, when it is detected that the vehicle has moved beyond the movement distance L1 while the braking force is being held by the operation of the magnet valve 9, the solenoid valve 23 is operated, and when the parking brake is applied, the vehicle is operated. The solenoid valve 23 is activated when it is detected that the solenoid valve 23 has moved beyond the movement distance L2 longer than the movement distance L1, so that the solenoid valve 23 is prevented from frequently operating when the parking brake is applied. However, it is possible to reliably prevent the vehicle from moving during the execution of the hill start assist control. The moving distances L1 and L2 are set by the number of detection pulses of the vehicle speed sensor 14, and for example, the moving distance L1 is a pulse 1 edge and the moving distance L2 is a pulse 6 edge.

[0041]

The hill start assisting device of the present invention holds the braking force when the service brake is operated and the driving force is in the cutoff state when the vehicle is stopped.
Since the braking force is increased when it is detected that the vehicle has moved while the braking force is being held, it is possible to reliably prevent the vehicle from moving during execution of the hill start assist control. As a result, the vehicle does not start moving when the vehicle is stopped on a steep slope or in a state where the load is large.

Further, since the braking force is increased when the movement of the vehicle is detected despite the parking brake being in the operating state, the pressurizing means should be shared between the hill start control and the parking assist control. Therefore, the cost can be reduced. The braking force is increased when it is detected that the vehicle has moved more than a first predetermined distance while the braking force is being held, and the vehicle moves more than a second predetermined distance longer than the first predetermined distance while the parking brake is operating. The braking force is increased when it detects that the vehicle is moving, while it is possible to prevent the vehicle from moving during the execution of the hill start assist control while preventing the pressurizing means from frequently operating during the operation of the parking brake. Can be prevented.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a slope start assist device according to an embodiment of the present invention.

FIG. 2 is a flowchart for explaining the operation of the slope start assist device.

FIG. 3 is a flowchart for explaining the operation of the slope start assist device.

FIG. 4 is a flowchart illustrating the operation of a slope start assist device.

FIG. 5 is a flowchart for explaining the operation of the slope start assist device.

FIG. 6 is a flowchart for explaining the operation of the slope start assist device.

[Explanation of symbols]

1 Brake Pedal 2 Air Supply System 3 Hydraulic Booster 4 Hydraulic Booster 5 Brake Valve 6 Air Tank 7 Air Supply Path 8 Air Supply Path 9 Magnet Valve 10 ECU 11 Actuation Switch 12 Adjustment Switch 13 Clutch Pedal Stroke Sensor (Clutch) 14) Vehicle speed sensor 15 Neutral switch 16 Stop lamp switch 17 Parking switch 18 Door switch 19 Key switch 20 Alarm means 21 Auxiliary air supply path 22 Check valve 23 Solenoid valve

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ryoji Nishi 5-3-8 Shiba, Minato-ku, Tokyo Inside Mitsubishi Motors Corporation

Claims (3)

[Claims] 1. A movement detecting means for detecting movement of a vehicle,
A braking operation detecting means for detecting that the service brake is operated by operating the brake pedal, a driving force cutoff detecting means for detecting that the driving force output of the engine is in a cutoff state, and a working fluid passage for the service brake. A control valve interposed between the control valve and the brake fluid for sealing the brake fluid, pressurizing means for increasing the brake fluid independently of the operation of the brake pedal, and the braking operation when the vehicle is stopped. When the detecting means detects that the service brake is being operated and the driving force cutoff detecting means detects that the driving force output of the engine is in the cutoff state, the control valve is closed and the control valve is closed. Control for activating the pressurizing means when the movement detecting means detects that the vehicle has moved while the control valve is being sealed. Hill-start assist, characterized in that a stage. 2. A parking brake state detecting means for detecting an operating state of the parking brake is provided, and the control means detects that the parking brake is in an operating state by the parking brake state detecting means. The hill start assist device according to claim 1, further comprising a function of activating the pressurizing unit when the movement of the vehicle is detected by the movement detecting unit. 3. The control means activates the pressurizing means when it is detected that the vehicle has traveled a first predetermined distance or more while the control valve is being sealed, and the parking brake. In a state where the state detecting means detects that the parking brake is in the activated state, the pressurizing means is activated when it is detected that the vehicle has moved a second predetermined distance longer than the first predetermined distance. The slope start assist device according to claim 2, further comprising a function.