JPH0350058A - Brake system for aircraft - Google Patents

Abstract

PURPOSE:To perform braking action smoothly by correcting a travel-time pressure signal to be outputted to a valve mechanism at the travelling time in such a way that the detected braking torque coincides with the target braking torque as well as outputting a separately-set stop-time pressure signal to the valve mechanism at the time of the airframe speed being zero. CONSTITUTION:At the travelling time, a travel-time pressure signal from an output means 104 is corrected by a pressure signal correcting means 107 in such a way that the actually generated torque coincides with the target braking torque operated on the basis of the break indicating quantity, so that the peak torque is averaged, and the braking torque corresponding to the target braking torque is stably generated. When the speed of an airframe is zero, a stop-time pressure signal from an output means 105 is outputted. The travel or stop time pressure signal is thus outputted to a valve mechanism 102 to operate a hydrau lic brake 101. Accordingly, the difference between a static friction coefficient and a dynamic friction coefficient is compensated so as to obtain sufficient resraint to the stopped wheel.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a hydraulic brake system for braking the wheels of an aircraft.

(Prior Art) In a brake system for braking the wheels of an aircraft, for example, as shown in FIG. 4, biloft generates brake pulp, which is applied to a brake valve 21 and supplied from a hydraulic source 6 to a brake piston 3 via a brake pulp 21. The friction material 4 brakes the rotation of the wheel 1 by the applied hydraulic pressure.

Further, in order to prevent the wheel 1 from skidding, an anti-skid valve 22 is interposed between the brake pulp 21 and the brake 2, and an anti-skid controller 23 is provided to control the anti-skid valve 22. The anti-skid controller 723 is connected to the rotational speed sensor 10 provided in the wheel 1 through a signal circuit, and converts the rotational speed detected by the rotational speed sensor 10 into a traveling speed, while also converting this speed into a signal from the speedometer on the aircraft. It compares the input aircraft speed to determine whether or not the wheel 1 is skidding, and if a skid occurs, outputs a signal to the anti-skid valve 22 and supplies it from the brake valve 21 to the brake piston 3. Reduce the oil pressure.

In this way, the brake piston 3 is supplied with hydraulic pressure corresponding to the amount of depression of the brake beggle 8 within a range that does not cause the wheel 1 to skid.

(Problem to be solved by the invention) However, when a carbon-based material is used for the friction material 4 in such a brake system, the static friction coefficient is significantly smaller than the kinetic friction coefficient, which is a unique friction characteristic of carbon. When the brake 2 was used, the restraining force of the wheel 1 by the friction material 4 tended to be insufficient.

On the other hand, when sliding or traveling on the ground, due to the characteristics of carbon material, peak torque occurs immediately after pressurizing the brake piston 3, and the brake 2 tends to become so-called "sluggish".
In order to prevent a worsening of the ride comfort and to prevent an excessive load from being applied to the support legs that support the wheel 1, extremely delicate braking was required.

The present invention has been made in view of the above problem 5α, and provides a hydraulic brake system that generates stable braking torque in the L7 ground running state without skidding, while obtaining the maximum wheel restraint force in the stopped state. The goal is to provide a huge amount of information.

(Means for Achieving the Object) As shown in FIG. 1, the present invention comprises a hydraulic brake 101 that brakes sliding wheels, and a valve that adjusts the pressure supplied to the hydraulic brake in response to a pressure signal. l[102 and
A means 10 for inputting a braking instruction amount, and a means 10 for calculating a target braking torque during driving based on the input braking instruction amount and outputting a pressure signal for driving in accordance with the calculation result.
4, a means 105 for outputting a pressure signal for stopping based on the braking instruction 1, a means 106 for detecting the braking torque exerted by the hydraulic brake on the wheels during running, and a means 106 for detecting the braking torque that the hydraulic brake exerts on the wheels during running, and detecting the detected braking torque as the target braking torque. means 107 for correcting the pressure signal during running so as to match; means 108 for detecting the speed of the aircraft; and a means 108 for detecting the speed of the aircraft when the detected speed of the aircraft is zero; It also includes means 109 for switching and outputting a pressure signal for driving to a valve mechanism.

(Function) By correcting the pressure signal during driving so that the torque actually generated during driving matches the target braking torque calculated based on the braking instruction amount, the peak torque is averaged and matches the target braking torque. Braking torque is generated stably.

In addition, when the aircraft speed is zero, the pressure signal for stopping is
At other times, by outputting a pressure signal for running, the difference between the static friction coefficient and the dynamic friction coefficient is compensated for, and a sufficient restraint force can be obtained for the stopped wheels.

(Example) Embodiments of the present invention are shown in FIGS. 2 and 3.

In this figure, 1 is a wheel of an aircraft, 2 is a brake that brakes the wheel 1, and a hydraulically operated brake piston 3 applies braking torque to the wheel 1 via a friction material 4 made of carbon.

A brake hydraulic module 5 is interposed between the brake 2 and the hydraulic pressure fi6 as a valve mechanism for adjusting this braking hydraulic pressure. The brake hydraulic module 5 adjusts the hydraulic pressure supplied to the brake piston 3 in response to a pressure signal input from a brake control computer 7 connected to it via a signal circuit.

The brake control computer 7 includes an angle sensor 9 that detects the depression angle of the brake beggle 8, which is a means for inputting a braking instruction amount, a rotational speed sensor 10, which detects the rotational speed of the wheel 1, and a cockpit sensor that serves as a means for detecting the aircraft speed. A speedometer 11 provided for this purpose and a torque sensor 12 serving as means for detecting braking torque are each connected through a signal circuit.

The torque sensor 12 is constructed using a strain gauge or a piezoelectric element, is interposed between the brake 2 and a member supporting the brake 2, and detects the braking torque exerted by the brake 2 on the wheel 1 via its reaction force. , is output to the brake control computer 7 as a braking torque signal.

The brake control computer 7 has a means for calculating a target braking torque and outputting a pressure signal for driving, a means for correcting this pressure signal so that the braking torque matches the target braking torque, and a means for outputting a pressure signal for when stopping. It functions as a means for outputting, and a means for switching and outputting a pressure signal for stopping and a pressure signal for traveling to the brake hydraulic module 5 according to the speed of the aircraft. That is, as shown in Figure 3,
When the speed signal input from the speedometer 11 is not zero,
A target braking torque is calculated based on the input signal from the angle sensor 9, and a corresponding pressure signal is output to the brake hydraulic monomer 5. Then, the braking torque signal inputted from the torque sensor 12 is compared with this target braking torque, and the pressure signal is corrected so that the braking torque matches the target braking torque, and is output to the brake hydraulic module 5.

On the other hand, when the speed signal input from the speedometer 11 is zero, the brake control combiator 7
A pressure signal that is set in advance to be higher than the input signal for stopping is output to the brake hydraulic module 5.

Furthermore, during taxiing and taxiing, the brake control computer 7 calculates the aircraft speed from the rotational speed of the wheel 1 that is input as a signal from the rotational speed sensor 10, and compares this with the speed signal from the speedometer 11 to determine the presence or absence of a skid. judge. In response to the occurrence of skid, the pressure signal is corrected by a predetermined width in the pressure decreasing direction and output to the brake hydraulic mono-air 5.

Next, the effect will be explained.

When the pilot depresses the brake pedal 8 in a planing or grounding state, a braking amount instruction signal corresponding to the depressing angle is input from the angle sensor 9 to the brake control computer 7. In response, the brake control computer 7 first confirms that the speed signal input from the speedometer 11 is not zero, calculates the target braking torque from the braking amount instruction signal, and converts the corresponding pressure signal for driving into the brake. Output to the hydraulic module 5. The brake hydraulic modulator 5 adjusts the pressure of hydraulic fluid supplied from the hydraulic source 6 to the brake piston 3 in response to this pressure signal.

In the brake 2, the brake piston 3 driven by this hydraulic pressure applies braking torque to the wheel 1 via the friction material 4, and a torque reaction force acts on the friction material 4 accordingly. Torque sensor 12 detects this torque reaction force and outputs a braking torque signal to brake control computer 7.

The brake control computer 7 compares this braking torque signal with a target braking torque, and increases the pressure when the braking torque is less than the target braking torque, and decreases the pressure when the braking torque exceeds the target braking torque. The pressure signals for driving are respectively corrected and output to the brake hydraulic module 5 so as to allow the vehicle to move. This signal correction is
This continues until the braking torque signal matches the target braking torque. In this way, braking torque that accurately corresponds to the amount of depression of the brake pedal 8 can be obtained.

Furthermore, the brake control computer 7 converts the rotational speed of the wheel 1, which is input as a signal from the rotational speed sensor 12, into the speed of the aircraft, and compares this with the speed of the speedometer 11, and determines that the difference between them increases beyond a certain level. Immediately, the pressure signal for driving is corrected in the direction of pressure reduction and output to the brake hydraulic module 5. As a result, the hydraulic pressure supplied to the brake piston 3 decreases, and the braking torque decreases regardless of the target braking torque. Such control suppresses the occurrence of skids and maintains the braking torque at a level closest to the target braking torque within a range that does not cause skids.

On the other hand, when the pilot steps on the play q beggle 8 while the aircraft is stopped, the brake control computer 7 receives a signal from the brake pedal 8 via the angle sensor 9 because the speed signal input from the speedometer 11 is zero. A pressure signal for stopping, which is set in advance to be higher than the input braking instruction amount, is output to the brake hydraulic module 5 in place of a pressure signal for driving. As a result, a larger pressure is supplied to the brake 2 for the same amount of depression of the brake beggle 8 as when sliding or traveling on the ground, so the frictional characteristics of the carbon material whose static friction coefficient is smaller than the dynamic friction coefficient are compensated for. The brake 2 exerts a sufficient restraining force on the stopped wheel 1 to maintain the aircraft in a stopped state.

(Effects of the Invention) As described above, the present invention corrects the pressure signal during running so that the detected braking torque matches the target braking torque and outputs it to the valve fil, while at the same time outputting the detected braking torque to the valve fil. In this case, a separately set stop pressure signal is output to the valve mechanism, so stable braking torque corresponding to the braking command amount can be obtained when skidding or ground running, while the wheels are restrained when stopped. Can maintain maximum power.

This has the effect of smoothing the braking operation and increasing the holding power of the aircraft in a stopped state, especially in aircraft that use carbon-based friction materials for brakes.

[Brief explanation of drawings]

FIG. 1 is a diagram corresponding to the claims of the present invention, FIG. 2 is a block diagram of a brake system showing an embodiment of the present invention, and FIG. 3 is a 70-chart explaining the main part of the braking operation. Further, FIG. 4 is a block diagram of a conventional brake system. DESCRIPTION OF SYMBOLS 1... Wheel, 2... Brake, 3... Brake piston, 4... Friction material, 5... Brake hydraulic module, 6... Hydraulic pressure fi, 7... Brake control combination 1- Ta, 8... Brake beggle, 9...
・Angle sensor, 10...Rotational speed sensor, 11...
Speedometer, 12...torque sensor.

Claims (1)

[Claims] A hydraulic brake that brakes the sliding wheels; a valve mechanism that adjusts the pressure supplied to the hydraulic brake in response to a pressure signal; a means for inputting a braking instruction amount; A means for calculating a target braking torque for the wheels and outputting a pressure signal for driving according to the calculation result, a means for outputting a pressure signal for stopping based on the braking instruction amount, and a means for outputting a pressure signal for driving when the hydraulic brake is applied to the wheels when driving. means for detecting a braking torque exerted on the aircraft; means for correcting the pressure signal during traveling so that the detected braking torque matches the target braking torque; a means for detecting the speed of the aircraft; 1. An aircraft brake system comprising means for switching and outputting a stop pressure signal to a valve mechanism when the pressure is zero, and a means for switching and outputting a running pressure signal to a valve mechanism at other times.