JPH05254421A - Brake system for aircraft - Google Patents

Abstract

PURPOSE:To surely operate a brake even when a brake control system fails by providing an emergency valve selectively feeding the operating oil from a master cylinder to the brake from an actuator when the oil pressure becomes low in response to the oil pressure fed from an oil pressure source. CONSTITUTION:When the high-pressure operating oil is not fed to a control valve 10 for some cause, the portion between a selector valve 9 and the control valve 10 is made a low pressure, the control valve 10 is switched to an emergency valve 11, a passage 4 is connected to an emergency port 16, and a feel spring 12 is connected to a tank port 14 respectively. The operating oil flowing out from a contraction master cylinder 2 is fed to a brake 7 via the emergency port 16, and the brake 7 performs a braking action via the oil pressure. The oil pressure is fed without passing through an electronic control system at all.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an aircraft braking system of a brake-by-wire system in which a brake is operated via an electric signal.

[0002]

2. Description of the Related Art In recent years, a brake-by-wire system that electronically operates a brake is being adopted even in a small aircraft.

This brake system is constructed, for example, as shown in FIG. 3. When the pilot depresses the brake pedal 1, the displacement detector 3 detects the amount of depression of the brake pedal 1 and outputs a corresponding signal to the controller 5. It is like this.

The controller 5 outputs a pressure signal based on this signal to the control valve 10, controls the hydraulic pressure supplied from the hydraulic source by the control valve 10 to a pressure corresponding to this pressure signal, and supplies it to the brake 7.

[0005]

In such a brake-by-wire type brake system, various safety measures such as multiplexing signal circuits are provided so that the brake operates even if a failure occurs in a part of the system. Has been taken.

However, this tends to complicate the configuration of the brake system and make maintenance of the system difficult.

Further, there is a problem that the weight of the entire brake system is increased and the cost required for the brake system is greatly increased especially in a small machine.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a backup system having a simple structure capable of reliably operating the brake even when the brake control system fails.

[0009]

SUMMARY OF THE INVENTION The present invention provides a brake for braking a wheel according to a supplied hydraulic pressure, a means for detecting the amount of depression of a brake pedal, and a pressure signal based on the amount of depression detected by the detecting means. In an aircraft brake system including a means for outputting and a control valve for controlling a hydraulic pressure supplied to a brake from a hydraulic pressure source to a pressure corresponding to the pressure signal, a hydraulic fluid that contracts in response to depression of a brake pedal is enclosed. Master cylinder, an actuator for introducing hydraulic oil discharged from the master cylinder, and when the hydraulic pressure becomes low in response to the hydraulic pressure supplied from the hydraulic pressure source, the hydraulic oil from the master cylinder is switched and supplied from the actuator to the brake. It is equipped with an emergency valve.

[0010]

In normal times, the detection means, the signal output means, and the control valve control the hydraulic oil from the hydraulic pressure source to a pressure corresponding to the depression amount of the brake pedal and supply the hydraulic fluid to the brake to operate the brake. Further, the actuator receives the hydraulic oil flowing out from the master cylinder to maintain the operation feeling of the brake pedal.

When the oil pressure supplied from the oil pressure source drops for some reason, the emergency valve connects the master cylinder to the brake and supplies the hydraulic oil flowing out from the master cylinder to the brake according to the depression amount of the brake pedal. To activate the brake.

[0012]

1 and 2 show an embodiment of the present invention.

In FIG. 1, reference numeral 1 is a brake pedal,
The brake pedal 1 has a master cylinder 2 and a displacement detector 3
Is attached.

The master cylinder 2 contracts in accordance with the depression amount of the brake pedal 1 and causes hydraulic oil to flow out to the hydraulic module 6 via the hydraulic passage 4.

Further, the displacement detector 3 detects the depression amount of the brake pedal 1 and outputs a corresponding electric signal to the controller 5 which is a signal output means. A force detector may be used instead of the displacement detector 3.

The controller 5 sends a pressure signal to the hydraulic module 6 based on the depression amount signal input from the displacement detector 3.
Output to. Note that the relationship between the depression amount and the pressure signal is preset inside the controller 5.

The brake 7 is operated by the hydraulic pressure supplied via the hydraulic module 6.

As shown in FIG. 2, the hydraulic module 6 includes a solenoid valve 8, a selector valve 9, a control valve 10, an emergency valve 11, a feel spring (actuator) 12, a pump port 13, a tank port 14, a normal port 15 and an emergency port. 16 is integrated as a module.

The pump port 13 is connected to a hydraulic pressure source P provided in the aircraft, and the tank port 14 is also a reservoir R.
Connected to. Further, the normal port 15 and the emergency port 16 are selectively connected to the brake 7 only on the high pressure side via a shuttle valve (not shown). The brake 7 is operated by the hydraulic pressure supplied through any one of these ports.

The pump port 13 is connected to the normal port 12 via the filter 20, the selector valve 9 and the control valve 10. Further, a part of the hydraulic oil supplied from the hydraulic power source P to the pump port 13 is supplied as the switching pressure of the selector valve 9 via the solenoid valve 8.

The solenoid valve 8 is switched by the input of the pressure signal from the controller 5, and the pump port 1
The selector valve 9 is switched by the hydraulic pressure of 3 to connect the pump port 13 to the control valve 10.

Further, the control valve 10 controls the hydraulic pressure of the pump port 13 to a pressure corresponding to the pressure signal input from the controller 5 and supplies it to the normal port 15.

The emergency valve 11 is a four-way valve for selectively connecting the passage 4 communicating with the master cylinder 2 and the tank port 14 to the emergency port 16 and the feel spring 12, and between the selector valve 9 and the control valve 10. Switching by hydraulic pressure.

The feel spring 12 has an oil chamber defined in the cylinder by a free piston urged by the spring, and the working oil flowing out of the master cylinder 2 through the passage 4 is temporarily stored in this oil chamber. Along with
By imparting elastic resistance corresponding to the spring pressure to the contracting master cylinder 2, the brake pedal 1 is given a feeling of operation. The back side of the piston of the feel spring 12 is released to the atmosphere, and the piston expands and contracts the oil chamber according to only the balance between the hydraulic pressure due to the contracting pressure of the master cylinder 2 and the spring. Feel spring 12 is brake pedal 1
The operation feeling given to can be set arbitrarily by changing the spring load of the spring used for the feel spring 12 and the diameter of the cylinder of the feel spring 12.

In order to brake the left and right wheels, the hydraulic module 6 is provided with a control valve 10, an emergency valve 11, a feel spring 12, two normal ports 15 and two emergency ports 16, each of which is provided from the controller 5. They operate synchronously in response to the pressure signal.

Next, the operation will be described.

During non-braking, the controller 5 does not output a signal to the hydraulic module 6, both the normal port 15 and the emergency port 16 of the hydraulic module 6 communicate with the tank port 14, and the brake 7 is released.

When the pilot depresses the brake pedal 1 from this state, the displacement detector 3 detects the displacement amount of the brake pedal 1 and outputs a depression amount signal to the controller 5.

Based on this signal, the controller 5 sends a corresponding pressure signal to the solenoid valve 8 of the hydraulic module 6.
To the control valve 10.

As a result, in the hydraulic module 6,
The selector valve 9 is switched by the hydraulic pressure supplied from the pump port 13 via the solenoid valve 8, and the pump port 13 is connected to the control valve 10.

The control valve 10 is the pump port 1
The pressure of the hydraulic oil supplied from 3 is controlled so as to match the pressure signal from the controller 5, and the normal port 15
Supply to.

The brake 7 performs a braking operation according to the pressure supplied through the normal port 15.

On the other hand, due to the high pressure between the selector valve 9 and the control valve 10, the emergency valve 1
1 holds the passage 4 connected to the feel spring 12 and the emergency port 16 connected to the tank port 14, respectively, and temporarily stores the working oil flowing out from the master cylinder 2 via the passage 4 in the feel spring 12. The hydraulic oil is returned to the master cylinder 2 by the pressure of the feel spring 12 when the brake pedal 1 is returned to its original position.

That is, the hydraulic oil from the master cylinder 2 is not used in the normal braking operation, and the brake 7 is operated by the hydraulic pressure via the control valve 10.

On the other hand, when the high pressure hydraulic oil is no longer supplied to the control valve 10 for some reason,
Since the pressure between the selector valve 9 and the control valve 10 becomes low, the emergency valve 11 is switched, the passage 4 is connected to the emergency port 16, and the feel spring 12 is connected to the tank port 14.

As a result, the hydraulic oil flowing out from the contracting master cylinder 2 is supplied to the brake 7 through the emergency port 16, and the brake 7 performs the braking operation by this hydraulic pressure. Since the hydraulic pressure is supplied without any electronic control system, the braking operation can be performed without any trouble even if the hydraulic pump for supplying the pressure oil to the pump port 13, the controller 5, or the like fails.

[0037]

As described above, according to the present invention, the master cylinder driven by the brake pedal is connected to the brake through the emergency valve. Therefore, when the hydraulic pressure for brake operation is not supplied for some reason, ,
The low pressure switches the emergency valve, and the hydraulic pressure supplied from the master cylinder actuates the brake.

Therefore, even if the brake control by the fly-by-wire system fails, the operation of the brake is guaranteed, and the reliability of the brake can be improved with a simple structure.

[Brief description of drawings]

FIG. 1 is a block diagram of a brake system showing an embodiment of the present invention.

FIG. 2 is a circuit diagram of a hydraulic module of the same.

FIG. 3 is a block diagram of a brake system showing a conventional example.

[Explanation of symbols]

 1 Brake pedal 2 Master cylinder 3 Displacement detector 5 Controller 7 Brake 10 Control valve 11 Emergency valve 12 Feel spring

Claims (1)

[Claims] 1. A brake for braking a wheel according to a supplied hydraulic pressure, a means for detecting a stepping amount of a brake pedal, a means for outputting a pressure signal based on the stepping amount detected by the detecting means, and a hydraulic pressure source. In a brake system of an aircraft, which is provided with a control valve that controls the hydraulic pressure supplied to the brake to a pressure corresponding to the pressure signal, a master cylinder enclosing a hydraulic fluid that contracts in response to the depression of a brake pedal, and a master cylinder An actuator that allows the discharged hydraulic oil to flow in and an emergency valve that supplies the hydraulic oil from the master cylinder to the brake when the hydraulic pressure becomes low in response to the hydraulic pressure supplied from the hydraulic pressure source are provided. Characteristic aircraft braking system.