RU2451273C1 - Inertia apparatus for stopping holder block when testing aircraft for resistance to bird strikes - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: apparatus has a support with a centre hole and a buffer, wherein the support lies at a calculated distance from the section of an air gun barrel and is rigidly mounted on guide axes mounted at the end of the barrel of the air gun. Brake plates are freely mounted on the guide axes at a calculated distance from each other and have centre holes which are in line with the barrel of the air gun. The number and weight of the brake plates is selected in accordance with the speed and weight of the holder block and the bird. The diameter of the centre hole of the first plate is 10±1 mm smaller than the outer diameter of the holder block, and the diameter of the centre holes of the next plates and the support is 20±1 mm larger than the inner diameter of the holder block.

EFFECT: design of apparatus which enables to keep the holder block intact after a sufficiently large number of strikes, broaden functional capabilities of the air gun, cut the time spent preparing to shoot and make manufacturing of the apparatus and holder block easier.

3 cl, 3 dwg

Description

The invention relates to the field of aircraft construction and flight safety and can be used to study the processes of impact interaction of aircraft structural elements in a collision with a bird or other foreign objects.

To simulate a blow in flight conditions and give the simulator a predetermined speed, pneumatic devices or guns are used to launch. To give the bird carcass a stable speed, it is placed in a special cage, which is stopped with a special braking device, which allows the bird carcass to be separated, which should reach the test object without auxiliary items.

Known devices for stopping clips, which are nozzles on a section of a barrel of an air gun in the form of a detachable conical confuser, tapering in the direction of flight of the carcass, which stops the clip with gradually increasing friction against the confuser ("Standard Test Method for Glasses of an Aircraft Cockpit for Impact by Bird Carcasses", international standard ASTM, F 330-89, re-approved 2004, p. 2, 4, 5).

The main disadvantage is the low conicity of the conical confuser and a considerable length, which creates complexity and high complexity in manufacturing.

It is also known a device designed to stop the cage, which is an annular stop with a buffer mounted on the edge of the barrel of the air gun, which stops the cage, while the carcass is freed from the cage and continues to fly by inertia in the direction of the test object (“Designing test benches for aircraft engines” , Yu.I. Pavlov, Yu.A. Shayn, B.I. Abramov, Moscow, “Mechanical Engineering”, p. 70, Fig. 4.5).

When loading a carcass into a clip, it is necessary to charge the carcass from the side of the barrel cut, as well as to dismantle the device from the gun. Sometimes, due to the collision force of the cage against the stop, it is not possible to keep the cage intact, which makes the experiment more expensive and increases the preparation time for the shot, and when the force of the gas pressure on the charge is exceeded when fired, the cage in the device also breaks down.

The technical objective of the proposed solution is to create a device that allows you to keep the clip intact after a sufficiently large number of shots, expand the functionality of the air gun, reduce the time to prepare for the shot, reduce the complexity and complexity of manufacturing the device and clips, reduce the cost of testing.

The technical result in the proposed device is achieved by the fact that the inertial device for stopping the clip when testing aircraft for bird resistance contains a stop with a central hole and a buffer, and the stop is located at a calculated distance from the cut of the barrel of the air gun and is rigidly fixed to the guide axes installed at the end of the barrel of the air gun while braking plates are freely placed on the guide axes at a calculated distance from each other and provided with central holes coaxial with scrap airgun. The number and weight of the braking plates are selected in accordance with the speed and weight of the bird cage and carcass. The diameter of the central hole of the first plate is 10 ± 1 mm smaller than the outer diameter of the cage, and the diameter of the central holes of the subsequent plates and the stop is 20 ± 1 mm larger than the inner diameter of the cage.

Figure 1 schematically shows a General view of an air gun and an inertial device for stopping the clip when testing aircraft for bird resistance.

Figure 2 shows a General view of the device before firing.

Figure 3 shows a General view of the device at the time of stop of the clip.

Figure 1 shows the air gun 1, equipped with a device 2 for stopping the clip when testing aircraft for bird resistance.

The device (figure 2) contains a guide axis 3, mounted in the threaded holes of the flange 4 at the end of the air gun barrel, designed to guide the movement of the brake plates 5, which are freely placed on the guide axles at a certain distance from each other, and the first plate 6 is removed at a distance about 10 cm from the cut of the trunk. The brake plates have central holes 7, which are mounted coaxially with the air gun barrel when placed on the guide axles, the diameter of the central hole of the first plate being 10 ± 1 mm smaller than the outer diameter of the cage and the diameter of the central holes of subsequent plates 20 ± 1 mm larger than the inner diameter of the cage . The number and mass of the braking plates are calculated depending on the mass and speed of the bird’s cage and carcass. A stop 8 is installed at the end of the guide axes, which is a plate with a central hole 20 mm in diameter larger than the inner diameter of the cage.

The buffer 9, which is a rubber sleeve, resting on a stop at the end of the guide axles, limits the overall stroke of the brake plates and dampens the impact force transmitted to the air gun barrel.

Figure 3 shows a General view of the device after a shot at the moment of stop of the clip 10. In this case, the clip sequentially moves the braking plates 6 and 5, which are in contact with each other, accumulating the total mass and stopping the clip. At this time, the bird carcass 11 is released from the cage and flies by inertia in the direction of the test object.

An inertial device for stopping the clip when testing aircraft for bird resistance works as follows.

After the operation of pointing the barrel of the air gun to the target, the device is installed at the end of the barrel, the braking plates are placed at the calculated distance, then the buffer and the stop are installed. They load the airgun with a bird’s carcass in a holder and carry out all the necessary operations for firing according to the developed technology.

During the shot, the cage flying out of the barrel with the bird’s carcass comes in contact with the first braking plate, slows down its speed, advances the first plate until it touches the second plate, then with the third and so on, thus accumulating the total mass of the plates inhibiting the movement of the clip. In this case, the bird carcass is released from the cage and continues its inertia movement through the central holes in the braking plates in the direction of the test object.

Claims (3)

1. An inertial device for stopping the clip when testing aircraft for bird resistance, containing an emphasis with a central hole and a buffer, characterized in that the emphasis is located at a calculated distance from the cut of the air gun barrel and is rigidly fixed to the guide axes mounted on the end of the air gun barrel, while braking plates are freely placed on the guide axes at an estimated distance from each other, equipped with central holes coaxial with the air gun barrel. 2. The inertial device according to claim 1, characterized in that the number and mass of the braking plates are selected in accordance with the speed and weight of the cage and carcasses of the bird. 3. The inertial device according to claim 1 or 2, characterized in that the diameter of the central hole of the first plate is (10 ± 1) mm smaller than the outer diameter of the cage, and the diameter of the central holes of subsequent plates and the stop is (20 ± 1) mm larger than the inner diameter clips.

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