JPH06107141A - Automatic braking device for vehicle - Google Patents

Abstract

PURPOSE:To provide an automatic braking device for a vehicle which detects trouble in a usual automatic braking device to surely carry out braking through preliminary braking, and an automatic brake is also actuated in the case of failure, and moreover a troubled portion is distinguished for giving an alarm corresponding to the troubled portion to a driver. CONSTITUTION:An automatic braking device for a vehicle which automatically actuates a brake under fixed conditions to brake a vehicle has a pressurizing means to actuate the brake under the fixed conditions, judging means 7, 20 to judge failure in the pressurizing means 4, and a preparatory pressurizing means 5 to pressurize instead of the pressurizing means 4 for actuating the brake when the failure in the pressurizing means 4 is judged, and in addition, an alarm means 21 to inform of the failure in the pressurizing means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle automatic braking device, and more particularly to a vehicle automatic braking device having a fail-safe function.

[0002]

2. Description of the Related Art Recently, in order to ensure the safety of a driver and passengers, it is automatically braked (brake) on the basis of a distance to an obstacle, a relative speed, etc., and a risk of collision under certain conditions. ) Has been considered an automatic braking device.
As a method of automatic braking (brake), it is considered that a braking pressure path different from the braking pressure path from the regular brake pedal to the braking device is created, and this braking pressure path is switched by a plurality of valves when a collision risk occurs. There is.

For example, in Japanese Patent Laid-Open No. 54-40432,
In automatic braking, a technique is disclosed in which preliminary braking is performed before the sudden braking to notify the occupant of the sudden braking to avoid danger due to the sudden braking.

[0004]

However, in these conventional techniques, the failure of the automatic braking device has not been taken into consideration. The present invention eliminates the above-mentioned conventional drawbacks, detects a failure in the conventional automatic braking device, and surely performs braking by preliminary braking, so that the automatic braking can be operated even at the time of failure. An automatic braking device for a vehicle is provided.

Further, the present invention provides an automatic braking device for a vehicle, which further informs a driver of an alarm according to a failure part by identifying the failure part.

[0006]

In order to solve this problem, an automatic braking device for a vehicle according to the present invention is an automatic braking device for a vehicle which automatically actuates a brake under a predetermined condition to brake the vehicle. The pressurizing means for operating the brake under a predetermined condition, the determining means for determining the failure of the pressurizing means, and the brake by substituting the pressurization when the failure of the pressurizing means is determined. And a pre-pressurizing means for operating. Here, the determination means determines that the brake pressure is a failure when the brake pressure is not a predetermined value when the pressurizing means is activated,
The pre-pressurizing means has a fail-safe accumulator, which activates a brake by the fail-safe accumulator, and further comprises alarm means for notifying a failure of the pressurizing means.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, referring to FIG. 4, the structure and operation of a conventional braking mechanism of an automatic braking device will be briefly described. In FIG. 4, reference numeral 1 is a master back for increasing the pedaling force of the brake pedal 2 by the driver, and 3 is a master cylinder for generating a braking pressure according to the pedaling force increased by the master back 1. The braking pressure generated in 3 is first supplied to the automatic braking valve unit 4 and then supplied to the brake device 6 of each wheel.

The automatic braking valve unit 4 has a shutter valve 11 for shutting off the communication between the master cylinder 3 and the brake device 6 side, a pressurizing valve 12 and a depressurizing valve 13, and these three are provided. Valves 11-13
Both are electromagnetic 2-port 2-position switching valves. Between the pressurizing valve 12 and the master cylinder 3, a motor-driven oil pump 14 and an accumulator 15 for storing the pressure oil discharged from the oil pump 14 and maintaining it at a constant pressure are interposed. It is set up.

When the shutter valve 11 is in the open position, braking is applied by the brake device 6 of each wheel according to the depression force of the brake pedal 2. On the other hand, when the shutter valve 11 is in the closed position and the pressure valve 12 is switched to the open position and the pressure reducing valve 13 is switched to the closed position, the pressure oil from the accumulator 15 is supplied to the brake device 6 of each wheel. Braking, pressurizing valve 12
Is switched to the closed position and the pressure reducing valve 13 is switched to the open position, the pressure oil is returned from the brake device 6 to weaken the braking.

Switching of the three valves 11 to 13 is as follows.
The actuator is composed of a voltage source or the like for applying a voltage to each of them, and the actuator is controlled by receiving a signal from the control box.
The brake device 6 for each wheel includes a disk 26 that rotates integrally with the wheel, and a caliper 27 that receives the braking pressure from the master cylinder 3 side to sandwich the steam disk 26.

In practice, an ABS (anti-skid brake device) valve unit is provided between the automatic braking mechanism 4 and the braking device 6 so that the braking pressure is controlled during braking so that the wheels are not locked. There is. In such a conventional automatic braking device, the oil pump 14 and the pressurizing valve 12 are used.
Alternatively, when a failure of the pressure reducing valve 13 or the like occurs, automatic braking is not normally performed, which in turn increases the risk.

<Automatic Braking Device of the Present Embodiment> FIG. 1 is a schematic diagram of the automatic braking device of the present embodiment. In this figure, the same functional parts as those in FIG. 4 are designated by the same reference numerals. Also in this figure, the ABS valve unit is actually provided. 5
Is a fail-safe unit added in this embodiment, and includes an actuator 17 and a fail-safe valve 16. Sufficient oil is accumulated in the actuator 17 for almost one braking, and when the automatic control valve unit 4 has a failure, the fail-safe valve 16 is opened to substitute braking. Whether to substitute the braking is judged from the pressure value from the pressure sensor 7, and the substitution is performed when the pressure is not a predetermined value.

FIG. 2 is a diagram showing the control configuration of the automatic braking device of this embodiment. The ECU (engine control unit) 20 starts braking according to the danger determination signal and operates the braking valve groups 11 to 13. However, the pressure sensor 7
If the pressure value from is not a predetermined value, it is determined that there is some failure in the automatic control valve unit 4, and the fail-safe valve 16 is opened. However, it is devised to determine whether the subsequent driving is possible or should be stopped and to notify the driver through the alarm means 21 in a distinguishable manner.

In this example, the ECU 20 is described as starting braking according to the danger judgment signal.
20. The risk determination may be made by the person 20 based on the input from various sensors. This determination procedure will not be described in detail. <Automatic Braking Procedure of this Embodiment> FIG. 3 is a flow chart showing the braking procedure of this embodiment. It should be noted that FIG. 3 shows a procedure after the automatic braking conditions have already been established and the automatic braking is started.

First, in step S31, it is determined whether or not the automatic brake is in operation. If not running, exit the flow. If it is in operation, the pressurizing valve 12 should have already been opened and the braking pressure should have been released, so step S3
In step 2, it is determined from the signal from the pressure sensor 7 whether or not the braking pressure has a predetermined pressure value. If the pressure is the predetermined pressure, it is determined that the automatic control valve unit 4 is normal, and the process returns with the fail-safe valve 16 kept at 0N (closed) in step S33.

If the braking pressure is not the predetermined pressure value, the fail-safe valve 16 is turned off (open) in step S34, and the emergency hydraulic pressure is supplied as the braking pressure in place of the automatic control valve unit 4. Although the vehicle is basically braked by this, it is unknown whether or not the automatic braking system can be operated thereafter, and the dealer will be called. In the present embodiment, the driver is informed of whether or not the vehicle can be driven normally thereafter and whether or not the automatic braking system cannot be used, by determining the faulty part.

In step S35, it is determined whether the pressure can be maintained or the pressure can be controlled. If not possible, it is determined that the pressure reducing valve 13 is defective, and in step S36, the vehicle is stopped suddenly while watching the wheel speed so as to avoid the wheel lock as much as possible (not to exceed the ABS control limit). In this case, the subsequent driving is dangerous, so
In step S39, the driver is notified that the automatic braking system cannot be used after stopping.

On the other hand, when the pressure reducing valve 13 is normal, the routine proceeds to step S37, where it is determined whether or not the accumulator is being repressurized during braking. If it is not repressurized, it is determined that the oil pump 14 is defective, and step S38 is performed.
Continue normal braking with and continue braking until the car stops completely. Also in this case, the subsequent automatic braking system cannot be used, and the driver is notified of this fact in step S39.

If the oil pump 14 is normal in step S37, it is determined that the pressurizing valve 12 is defective.
The failure of the pressurizing valve 12 can be replaced by the fail-safe valve 16 and automatic braking can be used thereafter. Therefore, after the braking is performed by the normal control in step S40, the driver is notified of the abnormality of the automatic braking system, Tell the dealer to go.

The above-mentioned method of identifying a failed portion is one example, and the gist of the present invention is to judge the degree of failure of the automatic braking system and issue a different alarm.

[0021]

As described above, according to the present invention, by detecting a failure in the automatic braking device and reliably performing the braking by the preliminary braking, the automatic braking of the vehicle can be operated even at the time of failure. A device can be provided. or,
The present invention can further provide an automatic braking device for a vehicle, which notifies a driver of an alarm corresponding to a failure part by identifying the failure part.

According to the present invention, it is possible to secure at least one automatic brake operation when a failure is detected.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an automatic braking system of the present embodiment.

FIG. 2 is a diagram showing a configuration of automatic braking control according to the present embodiment.

FIG. 3 is a flowchart showing a control procedure of automatic braking according to the present embodiment.

FIG. 4 is a diagram showing a configuration of a conventional automatic braking system.

[Explanation of symbols]

1 is a master back, 2 is a brake pedal, 3 is a master cylinder, 4 is an automatic braking valve unit, 5 is a fail-safe unit, 6 is a brake device, 7 is a pressure sensor, 1
1 is a shutter valve, 12 is a pressure valve, 13 is a pressure reducing valve, 14 is an oil pump, 15 is an accumulator, 16
Is a fail-safe valve, 17 is an actuator, 20
Is an ECU, 21 is an alarm means, 26 is a disk, and 27 is a caliper.

Claims (2)

[Claims] 1. An automatic braking device for a vehicle, which automatically actuates a brake under a predetermined condition to brake a vehicle, and a pressurizing means for operating the brake under a predetermined condition, and the pressurizing means. An automatic braking device for a vehicle, comprising: determination means for determining a failure; and preliminary pressurization means for activating the brake in place of pressurization when the failure of the pressurizing means is determined. 2. The determining means determines a failure when the brake pressure is not a predetermined value when the pressurizing means is activated, and the preliminary pressurizing means has a failsafe accumulator and brakes by the failsafe accumulator. 2. The automatic braking device for a vehicle according to claim 1, further comprising alarm means that is activated and that notifies the failure of the pressurizing means.