RU204025U1 - AERODROME BRAKE TROLLEY FOR DETERMINING BRAKING CONDITIONS OF AIRCRAFT PNEUMATIC WHEELS - Google Patents

Abstract

The airfield brake bogie is designed to determine the braking conditions of aviation pneumatic wheels on artificial airfield surfaces by the value of the adhesion coefficient (Ksc) and is a further improvement of the previously developed bogie, protected by RF patent No. 165080. The objective of this technical solution is to create an airfield brake bogie for more accurate determination conditions of braking aviation pneumatic wheels by the value of the coefficient of adhesion. The technical result is to increase the measurement accuracy by damping the dynamic vibrations of the measuring wheel when the bogie moves along the runway. The specified technical result is achieved by the fact that the airfield brake bogie is used to determine the braking conditions of aviation pneumatic wheels according to the value of the adhesion coefficient includes a means for recording measurements by a strain gauge measuring sensor of the values of the adhesion coefficient and is a wheel semitrailer with a bearing frame, a casing, a cover and a drawbar, to the bearing frame by means of an independent link suspension with a stroke of up to 110 mm and including levers, shock absorbers and preloaded springs, a measuring wheel with an aircraft tire and a driving wheel are mounted, and the drive shaft the torque from the driving wheel to the measuring, through the hinges of equal angular velocities is connected to the hubs of the measuring and driving wheels, and on the driving wheel there is an on / off clutch of the measuring wheel, and the drawbar consists of a central drawbar for fastening and towing the bogie and a side drawbar in the form of a load-bearing element loading of the measuring sensor, and the loading of the measuring sensor is provided by a guide rod movable along the guide. A safety ring and a damper are installed on a guide rod movable along the guide rod, and the springs have a stiffness of 50 N / mm each and are pre-compressed with a total force of 980 N. 1 z.p. f-ly, 5yll.

Description

The aerodrome brake bogie is designed to determine the braking conditions of aviation pneumatic wheels on artificial airfield surfaces by the value of the adhesion coefficient (K _ss ) and is a further improvement of the previously developed bogie, protected by a patent for a useful model RU No. 165080.

In this regard, the closest of the known is an aerodrome brake bogie for determining the braking conditions of aviation pneumatic wheels by the value of the adhesion coefficient, including a means for recording measurements of the adhesion coefficient values, a semitrailer with a frame having a drawbar with articulated central and side rods installed on a driving wheel and a measuring wheel with an aircraft tire, a cardan shaft, by means of which the driving and measuring wheels installed on the corresponding carriages are kinematically connected to the unlocking clutch, and the driving and measuring wheels are mounted on hubs fixed on movable carriages in linear guides, each of which is made in the form of a guide and a pair of rolling bearings providing vertical movement of the wheel axles along linear guides, and the wheels are installed in shock absorbers and equipped with springs to damp dynamic vibrations when the measuring point moves oles [RU 165080 U1, 10.10.2016].

The disadvantage of the known measuring carriage is that the measurement accuracy is influenced by the fact that vibration damping is realized due to the frictional forces that arose between the guides and sealing rings, which led to measurement errors.

The objective of this technical solution is to create an airfield brake bogie to determine with high accuracy the braking conditions of aviation pneumatic wheels by the value of the adhesion coefficient.

The technical result is to increase the measurement accuracy by damping the dynamic vibrations of the measuring wheel when the trolley moves along the runway (GDP).

The specified technical result is achieved in that the aerodrome brake bogie for determining the braking conditions of aviation pneumatic wheels by the value of the adhesion coefficient includes a means for recording measurements of the adhesion coefficient values by a strain gauge measuring sensor and is a wheeled semi-trailer with a carrier frame, a casing, a cover and a drawbar, to the carrier frame by means of independent link suspension, which has a stroke of up to 110 mm and includes levers, shock absorbers and pre-compressed springs with a maximum total working force of 3865 N, a measuring wheel with an aircraft tire and a driving wheel are mounted, and the drive shaft, which transfers torque from the driving wheel to the measuring wheel, through hinges of equal angular velocities are connected to the hubs of the measuring and driving wheels, and on the driving wheel there is an on / off clutch for the measuring wheel, and the drawbar consists of a central drawbar for attaching and towing the trolley and drawbar side new in the form of a load element of the measuring sensor, and the loading of the measuring sensor is provided by a guide rod movable along the guide. At the same time, a safety ring and a damper are installed on a guide rod movable along the guide rod, and the springs have a stiffness of 50 N / mm each and are preloaded with a total force of 980 N.

The specified parameters of the link suspension are selected from the condition of simulating the real loading conditions of the measuring wheel in the mode of measuring the coefficient of adhesion at a speed of 60-70 km / h. These device parameters are applicable to the use of a measuring (aircraft) wheel (660 × 160 × 355 model 36A).

The causal relationship of the signs with the technical result is due to the fact that with the described constructive implementation of its constituent interconnected parts, an increase in the accuracy of measurements of the coefficient of adhesion by 5-7% compared to the prototype is ensured, which is ensured by the indicated value of the suspension travel, as well as the preliminary stress of its springs of the indicated values - the springs are preloaded with a maximum total working force of 3865 N.

FIG. 1 shows a general view of the proposed trolley.

FIG. 2 is a longitudinal section of the bogie along the shaft.

FIG. 3 is a rear view of the cart.

FIG. 4 is a section along AA in Fig. 3.

FIG. 5 - thrust with sensor and damper.

The aerodrome brake bogie for determining the braking conditions of aviation pneumatic wheels by the value of the adhesion coefficient includes:

1 - frame (under casing 4);

2 - measuring wheel;

3 - driving wheel;

4 - casing;

5 - cover;

6 - drive shaft;

7 - joints of equal angular velocities (SHRUS);

8 - hub;

9 - wheel clutch (hub);

10 - lever;

11 - shock absorber spring;

12 - shock absorber;

13 - central drawbar;

14 - lateral drawbar;

15 - support wheel;

16 - strain gauge sensor;

17 - damper with springs;

18 - thrust;

19 - guide;

20 - safety ring.

The airfield brake bogie ATT-2M-02 is a measuring device that combines a mechanical unit (see Fig. 1-5) and an electronic computing device.

The mechanical unit is a wheeled semi-trailer, which consists of a supporting frame 1, a measuring wheel 2, a driving wheel 3, a casing 4 with a cover 5 and a drawbar. To transmit the torque from the driving wheel 3 to the measuring 2, the drive shaft 6 is used, which is attached to the hubs 8 of the measuring and driving wheels through the CV joint 7. To turn on and off the measuring wheel 2, the trolley is equipped with a wheel clutch - hub 9, which is located on the driving wheel 3. By means of the hub 9, kinematic coupling occurs - the measuring 2 and driving 3 wheels are disengaged.

To increase the measurement accuracy, the bogie is equipped with an independent link suspension, consisting of levers 10, pre-compressed with a given force of springs 11 and shock absorbers 12 to damp dynamic vibrations when the bogie moves at a speed of 60-70 km / h runway. The amount of travel of the independent link suspension up to 110 mm allows to ensure the required measurement accuracy with allowable irregularities at their location on the runway.

The drawbar structurally consists of a central drawbar 13, designed for fastening and towing a bogie, a side drawbar 14, which serves as a load-bearing element in the loading circuit of the measuring sensor 16, and a support wheel 15. For carrying out, preferably linear, loading of the measuring sensor is a drawbar 18, which moves along guides 19 in the form of pipes. To limit the movement of the rod and prevent rupture of the sensor, a safety ring and a damper 17 are installed on the rod.

The electronic computing system (not shown) of the trolley is a known type of strain gauge sensor connected in a functional sequence, a measuring unit including an ADC (analog-to-digital converter), an antenna, as well as a unit for measuring and recording the coefficient of adhesion with software connected to the display and printer for information output.

When the bogie moves along the runway, due to the difference in the diameters of the driving and measuring wheels, the measuring wheel tire slip relative to the surface of the runway. The longitudinal adhesion force arising under the measuring wheel depends on the condition of the coating and through the structural elements of the bogie - the drawbar and the drawbar, the lateral 14 acts on the measuring element.

The tension force of the sensor is converted into an electrical signal using a well-known signal processing unit with an ADC, for example, the BRI3-KS-02 unit, and is displayed on a graphic display as the coefficient of adhesion of an aviation tire to the runway surface. To measure the speed of the brake carriage and the distance traveled, the GLONASS or GPS navigation system is used.

For the tests, a bogie (in the ATT-2M-02 modification) was used, which is a uniaxial semitrailer. The vehicle used as a towing vehicle has a coupling device that provides a rigid coupling with a bogie located at a height of 590 to 650 mm from the level of the pavement. Measurement of the adhesion coefficient is carried out while rolling the bogie over the investigated surface. The value of the adhesion coefficient is displayed on the display of the registration and measurement unit, for example, BRI3-KS (https://zavod31ga.ru/catalog/oborud/briz-ks/), at the airfield there is an air traffic control point.

As an example of implementation, a trolley with the following technical parameters, tested under the specified atmospheric characteristics, is considered:

Adhesion coefficient measurement range - 0.1-0.65.

The discreteness of the readout of the coefficient of adhesion is 0.01.

The error in determining the adhesion coefficient is no more than 0.01.

Brake trolley travel speed:

- measurement mode K _ai, km / h - 65 ± 5.

Operating temperature range, ° С - from plus 35 to minus 30.

Atmospheric pressure, hPa - 700-1070.

Relative air humidity,% - up to 98 at 25 ° С.

Vertical load on the measuring wheel, kgf -125.

Horizontal load on the strain gauge sensor, kgf - 0-100.

During the tests, the metrological characteristics of the bogie were determined in accordance with clause 5 "Metrological maintenance (calibration)" of the BRI3-KS GAVR.411124.001-01RE Operation Manual.

The values of the metrological characteristics are valid when the technical parameters of the bogie are within:

tire pressure, kgf / cm ² :

- measuring wheel (660 × 160 × 355 model 36A) 0.7 ± 0.1;

- driving wheel (225/70 R15) 2.0 ± 0.1;

tread wear was determined by the presence of spikes in the tire grooves.

Slippage of the measuring wheel during continuous braking,

no more than% 12 ± 1.

Cart weight, kg - no more than 470.

With such characteristics, an increase in the measurement accuracy (in comparison with the prototype) by 5-7%, depending on the moisture content of the coating, is achieved by reducing the magnitude of vibrations of the trolley from dynamic influences during its movement.

Claims (2)

1. An aerodrome brake bogie for determining the braking conditions of aviation pneumatic wheels by the value of the adhesion coefficient, includes a means for recording measurements by a strain gauge measuring sensor of the adhesion coefficient values and is a wheeled semi-trailer with a supporting frame, a casing, a cover and a drawbar, to the supporting frame by means of an independent link suspension having a stroke of up to 110 mm and including levers, shock absorbers and pre-compressed springs with a maximum total working force of 3865 N, a measuring wheel with an aircraft tire and a driving wheel are mounted, and the drive shaft, which transfers torque from the driving wheel to the measuring one, through the joints of equal angular velocities connected to the hubs of the measuring and driving wheels, and on the driving wheel there is an on-off clutch of the measuring wheel, and the drawbar consists of a central drawbar for fastening and towing a bogie and a lateral drawbar in the form of a load-bearing element. a single sensor, and the loading of the measuring sensor is provided by a movable along the guide traction. 2. Aerodrome brake trolley according to claim 1, characterized in that on the moving along the guide the thrust is equipped with a safety ring and a damper, and the springs have a stiffness of 50 N / mm each and are preloaded with a total force of 980 N.

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