JP2000238632A - Vehicular braking device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a delay of initial responsiveness of brake fluid pressure by impressing a bias current of a degree of not generating brake fluid pressure on a proportional control valve even at nonbraking time when a brake pedal is not stepped down. SOLUTION: A control current of a bias current value in a degree of not generating brake fluid pressure is impressed on a proportional control valve 9 at nonbraking time when a brake pedal 1 is not stepped down. That is, a braking current is set so that the proportional control valve 9 stops in a position just before starting operation such as generating brake fluid pressure while microscopically vibrating. Then, as soon as a brake command current value is generated since the brake pedal 1 is stepped down, a valve element in the proportional control valve 9 can smoothly transfer to brake fluid pressure generating operation by the microvibration. With such constitution, since a delay of initial responsiveness of the brake fluid pressure is improved, an effect delay feeling is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generates a brake control electric signal corresponding to the amount of depression of a brake pedal,
The present invention relates to a vehicular braking device that generates a braking force in a braking device based on the brake control electric signal, and more particularly to a vehicular braking device that brakes a vehicle using an electrically controllable control valve.

[0002]

2. Description of the Related Art In recent years, brake systems for vehicles are remarkably provided with intelligent brake functions including an anti-lock brake system. Among them, various types of vehicular braking devices have been developed which generate a brake control electric signal corresponding to the amount of depression of a brake pedal and generate a braking force on the brake device based on the brake control electric signal. For example, there is a vehicle that controls the current of a proportional control valve, such as a vehicular braking system described in Japanese Patent Application Laid-Open No. 10-86802.

[0003]

However, in the vehicle braking device described in Japanese Patent Application Laid-Open No. 10-86802, a triangular-wave dither current is applied to a brake control electric signal corresponding to the amount of depression of a brake pedal. Is superimposed to make the valve operation of the proportional control valve smooth, but since the proportional control is performed from 0 (A) (that is, the command current rises from 0 (A) from the time when the brake pedal is depressed). In addition, since an inertial member such as a valve or a brake fluid is moved, the initial response of the brake fluid pressure is not good, and there is a problem that the effect is delayed at the beginning of braking.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a vehicular braking apparatus that can improve the response delay at the beginning of braking.

[0005]

In order to achieve the above object, the present invention generates a brake control current corresponding to the amount of depression of a brake pedal, and generates a braking force in a brake device based on the brake control current. A brake control device for a vehicle, comprising: a proportional control valve for controlling a brake fluid pressure supplied to a brake device according to a supplied control current; and a brake command current value corresponding to an amount of depression of a brake pedal. Control current generating means for adding, to the current value, a bias current value that does not apply braking to the wheels, and applying the bias current value as a control current to the proportional control valve.

According to the above configuration, when the brake pedal is depressed, that is, during braking, a bias current value that does not generate brake fluid pressure is added to a brake command current value corresponding to the depression amount, and the control is performed. The current is applied to the proportional control valve. When the brake pedal is not depressed, that is, when the brake is not applied, only the control current having the bias current value is applied to the proportional control valve. In other words, even during non-braking when the brake pedal is not depressed, a control current with a bias current value that does not generate brake fluid pressure barely is applied to the proportional control valve. As a result, the initial response is improved, and the feeling of delay in the effect of the initial braking can be reduced.

Further, in the vehicle braking device of the present invention, it is possible to adopt a configuration in which the bias current pulsates. Due to the operation of the configuration in which the bias current pulsates, the proportional control valve always slightly moves, whereby the transition from the state in which no brake fluid pressure is applied to the rise of the fluid pressure becomes quick, and the initial response of the brake fluid pressure is further improved. .

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an embodiment of a vehicular braking device according to the present invention.

(A) Structure of the vehicle braking device As shown in FIG. 1, the vehicle braking device of this embodiment includes a brake switch 2 for detecting whether the brake pedal 1 is depressed, and a brake switch 2 for detecting whether the brake pedal 1 is depressed. Angle sensor 3 for detecting the amount of depression and brake pedal 1
Urging member 4 to generate a reaction force commensurate with the stepping amount and to return to a predetermined position while generating a reaction force, a controller 5 (control current generating means) for controlling each part of the device, and a brake fluid pressure. An accumulator 6 for accumulating, a reservoir 7 for temporarily storing brake fluid, and a pump for sending the brake fluid in the reservoir 7 to the accumulator 6 side and increasing the brake fluid pressure in the accumulator 6 to a predetermined pressure. 8, a proportional control valve 9 provided corresponding to the wheels and controlled to open and close by a control current applied from the controller 5, and a hydraulic pressure of the brake fluid supplied to the brake device 11 is detected. Hydraulic pressure sensor 1 that outputs the result
0.

The proportional control valve 9 is connected to the accumulator 6 via a pipe 13 and to the reservoir 7 via a pipe 14. And it is connected to the brake device 11 via the pipe 15. One proportional control valve 9 is provided for each wheel or for each of the left and right front wheels and the left and right rear wheels. FIG. 1 shows only one of them.

The controller 5 includes a CPU and a CPU.
And a work memory used in the operation of the CPU. The controller 5 calculates the depression amount of the brake pedal 1 by calculation from the output of the angle sensor 3, and further calculates the brake command current value by multiplying the determined depression amount by a predetermined conversion coefficient. On the other hand, the predetermined bias current value stored in the memory is generated in the controller 5 at the same time when the power of the vehicle braking device of the present invention is turned on.
Then, a brake command current value is added to the predetermined bias current, and the resulting control current is applied to the proportional control valve 9.

If the brake pedal 1 is not depressed, the bias current value is applied to the proportional control valve 9 as a control current. That is, the controller 5
When the brake pedal 1 is depressed, that is, at the time of braking, a brake command current value and a bias current value corresponding to the depressed amount are added, and the result is applied to the proportional control valve 9 as a control current. When the pedal is not depressed, that is, at the time of non-braking, a control current having a bias current value that does not generate brake fluid pressure is applied to the proportional control valve 9.

As an example of the bias current,
When an electromagnetic valve is used as the proportional control valve 9, as shown in FIG. 2, the controller 5 generates a pulsating current centered on a DC component. Then, a micro-vibration is generated in the valve body in the proportional control valve 9 by the bias current which is the pulsating current. The maximum value is set to a value that does not generate brake fluid pressure. That is, the maximum amplitude and frequency of the pulsating current are set so that the proportional control valve 9 stops while slightly vibrating at the position immediately before the operation for generating the brake fluid pressure. Therefore, as soon as the brake pedal 1 is depressed and the brake command current value is generated, the valve element in the proportional control valve 9 is caused by the micro-vibration.
The operation can smoothly shift to the operation for generating the brake fluid pressure.

The frequency of the pulsating current is approximately 100
Approximately 300 Hz is optimal. If the frequency is lower than 100 Hz, the vibration of the valve element in the proportional control valve 9 is too large, which affects the brake fluid pressure. Microtremors will not occur.

As described above, when the brake pedal 1 is not depressed, that is, when the brake is not applied, a bias current value that does not generate the brake fluid pressure is applied to the proportional control valve 9 as a control current, so that the brake fluid pressure is reduced. The delay of the initial response is improved, and the feeling of delay of the effect is eliminated. Further, by pulsating the bias current to finely move the proportional control valve 9, after the brake pedal is depressed, the valve element of the proportional control valve 9 moves to its operating position quickly, and the rise of the brake fluid pressure is quickly increased. Thus, the initial response of the brake fluid pressure is further improved. Here, FIG. 3 is a diagram showing the relationship between the control current applied to the proportional control valve 9 and the output of the proportional control valve 9, and the bias current I
By giving (A), when the brake pedal 1 is depressed, the brake fluid pressure quickly rises.

(B) Operation of the vehicle braking device Next, the controller 5 of the vehicle braking device of this embodiment will be described.
The operation at the time of braking will be described with reference to the flowchart shown in FIG. After the power is turned on to the device, first, in step S10, the output of the angle sensor 3 is captured.
Next, in step S12, the depression amount of the brake pedal 1 is calculated from the output of the angle sensor 3 just taken in. After obtaining the depression amount of the brake pedal 1, the process proceeds to step S14, and the brake instruction current value is obtained by multiplying the brake pedal depression amount by a predetermined conversion coefficient. Next, in step S16, the current depression amount of the brake pedal is compared with the previous depression amount of the brake pedal to determine whether or not the brake pedal 1 is depressed. In this determination, when it is determined that the brake pedal 1 is not depressed, the process proceeds to step S18, where the bias current value is read from the memory. Further, in step S20, a pulsating current is generated around the DC current of the read bias current value. Apply to proportional control valve 9.

On the other hand, if it is determined in step S16 that the brake pedal 1 is depressed, the process proceeds to step S22, in which the bias current which is the pulsating current applied when the power of the vehicle braking device is turned on. The brake command current value obtained in step S14 is added to the value, and this value is applied to the proportional control valve 9.

That is, when the brake pedal 1 is not depressed, the bias current, which is a pulsating current, is applied to the proportional control valve 9 as a control current. Further, when the brake pedal 1 is depressed, the brake command current value and the bias current corresponding to the depression amount of the brake pedal 1 at that time are added. As described above, even when the brake pedal 1 is not depressed, the bias current is applied to the proportional control valve 9 so that the brake fluid pressure is immediately applied to the brake device 11 when the brake pedal 1 is depressed. Can be suppressed.

Therefore, since the control current having a bias current value that does not generate the brake fluid pressure even when the brake is not applied is applied to the proportional control valve 9, the initial response of the brake fluid pressure is improved, and the effect of the brake fluid is delayed at the beginning of braking. Feeling is gone. Further, since the proportional control valve 9 is finely moved by the pulsating bias current, the rise of the brake fluid pressure is quickened, and the initial response of the brake fluid pressure is further improved.

[0020]

As described above, according to the present invention,
Since a bias current that does not generate the brake fluid pressure is applied to the proportional control valve even during non-braking when the brake pedal is not depressed, a delay in the initial response of the brake fluid pressure can be improved. Further, according to the present invention, the proportional control valve is finely moved using the bias current as the pulsating current, so that the rise of the brake fluid pressure becomes quick, so that the delay of the initial response of the brake fluid pressure can be further improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a vehicular braking device according to the present invention.

FIG. 2 is a waveform diagram of a current applied to a proportional control valve of the vehicle braking device according to the embodiment;

FIG. 3 is a diagram showing a relationship between a current applied to a proportional control valve and a hydraulic pressure output from the proportional control valve in the vehicle brake system according to the embodiment;

FIG. 4 is a flowchart illustrating an operation of the vehicle braking device according to the embodiment;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Brake pedal 2 Brake switch 3 Angle sensor 5 Controller 6 Accumulator 7 Reservoir 8 Pump 9 Proportional control valve 11 Brake device

Claims (2)

[Claims] 1. A vehicular braking device that generates a brake control current corresponding to the amount of depression of a brake pedal and generates a braking force on a brake device based on the brake control current. A proportional control valve that controls the brake fluid pressure supplied to the brake device in accordance with the brake command current value and a brake command current value that corresponds to the amount of depression of the brake pedal are calculated, and this brake command current value is a bias current that does not apply braking to the wheels. Control current generating means for applying a value to the proportional control valve as a control current,
A vehicle braking device comprising: 2. The vehicular braking apparatus according to claim 1, wherein said bias current pulsates.