JP2726288B2 - Brake integrated control system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an integrated control system for hydraulic brakes used at the time of landing, gliding, and parking of an aircraft.

(Prior Art) A hydraulic brake system for landing gear of an aircraft is mainly composed of a power brake valve 2 and an anti-skid mechanism A as shown in FIG. 6, for example.

That is, when the pilot depresses the brake pedal 4, the opening of the power brake valve 2 is controlled, and the hydraulic pressure proportional to the opening is applied to the anti-skid valve 5.
Is supplied to the hydraulic brake 1 via

When skid (slipping) occurs on the wheels 10 due to this braking, the anti-skid controller 11 determines the rotational speed of the wheels 10 detected by the rotational speed sensor 12 and the speed of an on-board speedometer.
Detects this, calculates the opening that gives the maximum braking force in a range where no skid occurs, and outputs a control signal to the anti-skid valve 5. The anti-skid valve 5 throttles the hydraulic pressure from the power brake valve 2 based on this control signal and reduces the pressure to prevent the occurrence of skid.

In some cases, an automatic brake mechanism B is provided in addition to the anti-skid mechanism A. The auto-brake mechanism B sets the braking deceleration at the time of landing by the pilot according to the condition of the landing runway, and maintains the automatically set deceleration without the intervention of the brake pedal 4.
The auto-brake controller 13 calculates the hydraulic pressure supplied to the hydraulic brake 1 and controls the opening of the auto-brake valve 6 by a signal output based on the calculation result.

(Problems of the Invention) Incidentally, such a braking system has the following problems. That is: 1) Even if the brake pressure is maintained constant, the generated braking force (braking torque) is different due to the difference in the friction characteristics of the brake friction material, so that the braking distance is not constant.

2) Even if the same friction material is used, the braking distance generated by each brake at the same pressure varies, so that the braking distance also varies.

3) When the skid occurs, the braking force intended by the pilot is reduced by the anti-skid valve 5 until the normal state is restored, and the braking distance is lengthened accordingly.
It is desirable that the landing run distance of the aircraft be as short as possible. For this reason, it is desirable to start braking immediately after landing, but immediately after landing, the lift is large, and a skid is likely to occur when a large braking force is applied.

4) Generally, the friction characteristics of a friction material vary greatly depending on the friction sliding speed and temperature, and the braking torque greatly varies for the same pressure. This fluctuation of the braking torque changes the braking distance and also has an unfavorable effect on the riding comfort.

In addition to the above problems, the use of carbon-carbon composite material, which has recently been put into practical use, as a friction material is completely different from conventional organic and sintered friction materials. Due to the frictional characteristics, the following problem further occurs.

B) Unlike conventional materials, the coefficient of friction at rest is much lower than that of running, so when the engine is stopped and the engine is operated to increase thrust, despite the brake pressure being applied, The aircraft may start moving.

B) Braking torque is generated rapidly with the supply of brake pressure. For this reason, when the pilot depresses the brake pedal 4 little by little during the skiing and the brake pressure is turned on / off, the braking force suddenly rises or falls off, resulting in a state where the brakes are jerky and the riding comfort is deteriorated. .

C) When the humidity is high or when it gets wet with rainwater, the coefficient of friction is extremely reduced and the sliding distance is greatly increased.

D) A very high peak braking force may be generated immediately after the brake pressurization at the time of landing, etc., and it may be necessary to change the design strength standard of the support leg of the wheel 10 so as to be able to counter this braking force. is there.

An object of the present invention is to realize a smooth and accurate braking operation by controlling the supply of hydraulic pressure to a brake based on a braking torque that is actually generated, thereby contributing to solving the above-mentioned problems. And

(Means for Achieving the Object) For this purpose, the present invention provides a valve mechanism for controlling a hydraulic pressure supplied from a hydraulic source to a hydraulic brake provided on a wheel, a means for detecting a braking torque applied to the wheel by the hydraulic brake, Means for inputting a braking command amount; means for calculating a target braking torque according to the braking command amount; means for controlling the valve mechanism so that the detected braking torque matches the target braking torque; Means for detecting the speed, means for determining the skid of the wheel from the rotational speed of the wheel and the sliding speed of the fuselage, and means for correcting the valve mechanism in accordance with the determination result of the skid. As the input means of the amount, a brake pedal and a means for calculating a braking instruction amount from a wheel rotation speed and a sliding speed based on a panel display for designating a braking distance are provided.

(Operation) The opening degree of the valve mechanism is controlled so that the detected braking torque matches the target braking torque, and the opening degree is corrected based on the skid determination, thereby changing conditions such as a runway surface and friction materials. Is compensated, and a braking torque closest to the target braking torque is obtained while preventing a braking torque or skid that matches the target braking torque.

(Embodiment) FIGS. 1 to 5 show an embodiment of the present invention.

In FIG. 1, the wheel 10 is provided with a rotational speed sensor 12 and a torque sensor 15 for detecting a braking torque by a brake pressure of the hydraulic brake 1 as a reaction force and outputting a braking torque signal as a braking torque detecting means. A brake module 17 as a valve mechanism for controlling a brake pressure is interposed in an oil passage connecting the hydraulic source 3 and the hydraulic brake 1. The brake module 17 mainly includes an electromagnetic proportional control valve that changes an opening degree according to an input signal. The parking module holds the hydraulic brake 1 in an ON state in a parked state, and the hydraulic pressure of the hydraulic brake 1 in an emergency. And a valve mechanism having a function such as an emergency switching valve that opens the tank to the tank.

Further, as means for calculating the target braking torque, means for controlling the opening of the electromagnetic proportional control valve of the valve module 17 based on the target braking torque, and means for correcting this opening based on the braking torque detected by the torque sensor 15 A brake control computer 16 is provided, and is connected to the brake module 17 by a signal circuit.

The torque sensor 15 and the rotation speed sensor 12 are connected to the brake control computer 16 by a signal circuit. The installation position of the torque sensor 15 can be variously selected as shown in FIGS.

For example, in FIG. 2, a support leg 21 for supporting the axle 10A of the wheel 10 and a brake housing 22 for the hydraulic brake 1 are shown.
A pressure sensor 23 composed of a strain gauge, a piezoelectric element, or the like is interposed between the connecting portion with the (fixed side). The sensor 23 detects a torque reaction force exerted on the hydraulic brake 1 during braking by the wheels 10 by detecting a compression force acting between the brake housing 22 and the support leg 21.

As shown in FIG. 3, a brake rotor disk 24 to be braked by a brake stator disk and wheels 10 are fixed via a key 25, and a similar sensor 23 is provided between the key 25 and the brake rotor disk 24. May be interposed.

As shown in FIG. 4, in an aircraft in which the front and rear wheels 10 are supported by support legs 21 via bogies 26, a sensor 23 is provided in the middle of a torque rod 27 supported by the support legs 21 so that the brake housing 22 does not rotate. It can be interposed.

Further, in an aircraft in which the wheels 10 are arranged on both sides of the support legs 21 as shown in FIG. 5, the left and right brake housings 22 are connected by levers 28, and a sensor is provided between the lever 28 and the support legs 21.
23 may be interposed.

A brake pedal 4 which is a means for inputting a braking instruction amount is provided.
Is provided with a position sensor 18. The position sensor 18 electrically or optically detects the displacement caused by the depression of the brake pedal 4 and outputs a signal corresponding to the depression position as a braking torque instruction signal to the brake control computer 16 connected by a signal circuit. The same function can be obtained by interposing a pressure sensor on the brake pedal 4 and detecting the depressing force applied to the brake pedal 4. The same applies when a manual control stick is used instead of the brake pedal 4.

Reference numeral 19 denotes a panel display unit in the cockpit which includes a display unit such as an input switch for inputting an instruction to the brake control computer 16 and a control data failure detection monitor. Reference numeral 20 denotes a power supply device. A flight control computer 30 is provided as a separate unit, and exchanges data with the brake control computer 16 such as the gliding speed of the aircraft.

The brake control computer 16 sends an initial control signal to the brake module 17 as a control target value using a braking torque instruction signal input through the depressing operation of the brake pedal 4 or a braking torque calculated from the braking distance input from the panel display unit 19. Is output. Next, a braking torque signal sequentially input from the torque sensor 15 is compared with the control target value, and a control signal corrected to eliminate these differences is output to the brake module 17. Then, by repeating this output, the braking torque acting on the wheels 10 is made to coincide with the control target value. At the same time, the rotation speed sensor
The rotational speed signal of the wheel 10 input from 12 is converted into the gliding speed of the aircraft and the slip rate of the wheel 10 and compared with the actual sliding speed input from the flight computer 30 and the set ideal slip rate. Is determined, and if necessary, the control signal is corrected so as to prevent skid and output to the brake module 17.

 Next, the operation will be described.

In the braking operation via the brake pedal 4, first, the position sensor 18 detects the depressed position of the brake pedal 4 and outputs a signal to the brake control computer 16, and the brake control computer 16 generates a braking torque corresponding to the instruction signal. First, an initial control signal is output to the brake module 17 as a control target value. Hydraulic source 3
A brake module 17 interposed between the hydraulic brake 1 and the hydraulic brake 1 supplies a hydraulic pressure according to the control signal to the hydraulic brake 1, and the hydraulic brake 1 brakes the wheels 10 by the hydraulic pressure.

On the other hand, the torque sensor 15 detects the braking torque due to the brake pressure as a reaction force, and outputs a braking torque signal to the brake control computer 16. The brake control computer 16 compares the input braking torque signal with the control target value, and if there is a difference between them, outputs a control signal corrected to eliminate the difference to the brake module 17.

That is, for example, when the brake disc of the hydraulic brake 1 is worn or wet, the braking torque exerted on the wheels 10 by the hydraulic brake 1 relative to the same hydraulic pressure supplied to the hydraulic brake 1 becomes relatively small. Accordingly, the torque reaction force detected by the torque sensor 15 also decreases. Then
The brake control computer 16 determines from the input braking torque signal that the braking torque is insufficient, outputs a control signal corrected in a direction to increase the hydraulic pressure supply to the brake module 17, and increases the braking torque. By feeding back the torque reaction force exerted on the hydraulic brake 1 during braking by the wheels 10 to the control of the hydraulic pressure supply to the hydraulic brake 1 in this manner, the difference in the internal state of the hydraulic brake 1 and the condition of the runway surface can be reduced. It is automatically compensated and the braking torque is precisely controlled to the control target value.

The carbon composite material that is frequently used in recent years for the brake disk of the hydraulic brake 1 has special properties such as reversal of the static friction coefficient and the dynamic friction coefficient, and the friction coefficient becomes extremely small when wet. Therefore, the braking effect is likely to change suddenly, impairing ride comfort, and
However, this braking device also compensates for such a change in conditions relating to the material of the brake disc, and enables smooth braking at all times.

In addition to the above control, the brake control computer 16 compares the rotation speed of the wheel 10 input from the rotation speed sensor 12 with the sliding speed obtained from the flight control computer 30, and further determines the slip rate of the wheel 10. Then, the presence / absence of skid of the wheel 10 is determined, and the control signal output to the brake module 17 is corrected as necessary, thereby performing the same anti-skid control as in the conventional example. Therefore, for the skid of wheel 10, the wheel
Even if the braking torque of 10 cannot reach the control target value, the braking torque is automatically controlled so that the wheels 10 do not skid and are as close as possible to the target value.

Further, a braking distance is designated from the panel display section 19, and the brake control computer 16 calculates a necessary braking torque from the current speed and other data of the aircraft obtained from the flight control computer 30, and uses this as a control target value in the same manner as described above. Control.

The determination as to whether the aircraft is stationary or running is made based on a rotation speed signal input from the rotation speed sensor 12 to the brake control computer 16.

(Effects of the Invention) As described above, in the present invention, the braking instruction amount is calculated from the wheel rotation speed and the sliding speed based on the brake pedal and the panel display for designating the braking distance as input means for the braking instruction amount. With the provision of the means, it is possible to prevent skidding when the aircraft lands, and to stop the skiing accurately in accordance with the instruction from the brake pedal or the braking distance specified on the panel display unit. In addition, hardware that has been divided into several parts such as a power brake valve and an anti-skid valve has been integrated into one valve mechanism. As a result, the following effects can be obtained.

1) The weight of the brake system is reduced by transmitting the pilot's braking instruction through a signal circuit without passing through a mechanical means such as a link or a cable.

2) The integration of hardware such as valves reduces the weight and improves the reliability of operation.

3) By executing commands and feedback via electric or optical means, analog and digital can be freely applied, and a multiplexing of these can construct a highly reliable brake-by-wire system.

4) Very smooth and accurate braking can be obtained as compared with the prior art, and the need to rely on the pilot's experience and intuition is significantly reduced.

5) Even if friction materials having different friction characteristics are used, the same braking torque can be obtained, which is extremely advantageous in terms of convenience of brake maintenance such as replacement of friction materials.

[Brief description of the drawings]

FIG. 1 is a control circuit diagram of a hydraulic brake system for explaining an embodiment of the present invention, FIG. 2 is a perspective view of a brake housing and supporting legs showing an interposition position of a torque sensor, and FIG. 3 is an interposition of a torque sensor. FIG. 4 is a perspective view of a brake rotor showing another embodiment in terms of position, FIG. 4 is a side view of a brake housing and support legs showing still another embodiment, and FIG. 5 is a brake housing and support legs showing still another embodiment. It is a perspective view of. FIG. 6 is a control circuit diagram of a hydraulic brake system for explaining a conventional example. 1 ... Hydraulic brake, 3 ... Hydraulic source, 4 ... Brake pedal, 10 ... Wheel, 12 ... Rotation speed sensor, 15 ... Torque sensor, 16 ... Brake control computer,
17 …… Brake module, 18 …… Position sensor, 19 ……
Panel display.

 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-63-242758 (JP, A) JP-A-61-285162 (JP, A)

Claims (1)

(57) [Claims] A valve mechanism for controlling a hydraulic pressure supplied from a hydraulic pressure source to a hydraulic brake provided on a wheel; a means for detecting a braking torque exerted on the wheel by the hydraulic brake; an input means for inputting a braking instruction amount; Means for calculating a target braking torque according to the amount; means for controlling the valve mechanism such that the detected braking torque matches the target braking torque;
Means for detecting the rotation speed of the wheel, means for determining the skid of the wheel from the rotation speed of the wheel and the sliding speed of the aircraft, and means for correcting the valve mechanism according to the determination result of the skid, Brake integrated control, characterized in that a brake pedal and means for calculating a braking command amount from a wheel rotation speed and a sliding speed based on a panel display unit for specifying a braking distance are provided as input means for the braking command value. system.