RU2235302C2 - Bench for shock-testing - Google Patents

Abstract

FIELD: shock-testing of structures.

SUBSTANCE: bench has accelerating device made of barrel, charge chamber with powder charge and igniter, carriage for the article to be tested jointed to the guides, and braking device. The acceleration device is mounted on the barrel of a gun through the bearing and race with a yoke. The guides are flexible and made of steel ropes passing through the slots in the bearing and tightened along the barrel of the gun..

EFFECT: improved design.

4 cl, 9 dwg

Description

The invention relates to the field of testing. The primary area of application is missile and artillery weapon testing.

Tests of products for resistance to impact, simulating starting accelerations during firing, occupy a significant amount when testing newly developed weapons and protecting batches of products manufactured in production.

This issue is especially acute when developing artillery guided missiles (AUR), since it is necessary to ensure not only the mechanical strength of the rocket elements, but also the operability of numerous electronics elements when exposed to large accelerations.

One of the analogues of the present invention selected stand for testing products for impact (see Burago A. N. Stands for testing products for impact, "Leningrad House of Scientific and Technical Propaganda", L., 1960, p. 18, paragraph 18 3).

The stand contains cable (made of steel ropes) guides 78 m long, stretched vertically on the bed. The desktop (carriage) is mounted on a frame that can move along the guides.

The frame is held separately by a moving beam with a block through which the cable is thrown. Then the cable passes through the blocks mounted on the bed, and is wound on a winch drum with an electric motor. The electric motor has an electromagnetic brake that precisely stops the table at the right time when it rises to a predetermined height. The device for holding the frame with the table has an electric release, expanding the grips and releasing the frame with the table for falling. At the bottom of the frame with a table attached steel rod. A pillow made of lead was laid on the base of the stand.

During testing, the frame with the table with the product fixed on it rises to the required height. Then the electric trigger is turned on, expanding the grips holding the frame, which begins to fall. At the end of the fall, the steel rod penetrates the lead cushion, where it begins to brake. At the same time, the required acceleration acts on the frame with the table. The magnitude of the acceleration depends on the height of the frame, the diameter of the rod and its shape.

Friction of lead on the surface of the rod dampens vibrations, including unwanted lateral vibrations.

The magnitude of peak accelerations ranges from 200 to 2000 ms ^-2 .

When fired, the AUR acceleration values lie in a wide range from 15000 ms ^-2 to 150000 ms ^-2 , which is unattainable when using the stand in question.

In addition, when testing on this bench, the product is first subjected to acceleration at the stage of acceleration and only then is subjected to the required acceleration at the stage of braking. Under natural conditions, starting accelerations act on a stationary rocket.

Closest to the proposed technical solution is a stand selected as a prototype for studying the separation process of a missile object (see Russian patent No. 2153155, IPC 7 G 01 M 7/08, 05/08/1998, publication date 07/20/2000).

This stand contains a base on which an acceleration device is installed, made in the form of a barrel and a pressure source, a piston located in the barrel, a device for securing a missile object (carriage) and a brake device located in front of the barrel cut. A device for securing a missile object is made in the form of guides installed outside the barrel, the longitudinal axes of which are arranged in pairs in planes intersecting along a line coinciding with the longitudinal axis of the barrel and configured to connect carriages with the missile object. Moreover, in the carriages coaxial with the guides installed damper bushings of plastic material, made with thickenings in the direction of movement of the missile object. The carriages are placed on the rails so that each of the parts of the missile object can be moved along a specific pair of rails.

The length of the piston is selected from the condition of ensuring contact of one of the parts of the missile object with the front end of the piston in the direction of movement.

The brake device is made in the form of metal bushings mounted on the guides, the profile of the outer surface of which can be in the form of a truncated cone, facing a smaller base towards the projectile.

The lengths of the metal bushings for each individual pair of rails are selected from the condition of ensuring braking of the missile object without impacting each other. Metal bushings are mounted on rails with the possibility of limiting their movement in the direction of movement of the object.

The functioning of the stand is as follows.

When an electrical impulse is applied to the initiating device, the powder charge placed in the charging chamber ignites. The resulting powder gases are pressed against the piston located in the barrel. A piston, resting with its front end on the rear of the missile object, worn on the barrel, pushes the missile object. Under the influence of overload arising during acceleration of a missile object, a pyrotechnic separation mechanism is activated, the combustion products of which separate the front from the back upon reaching a predetermined pressure value. The movement of parts of the propelled object in the process of joint acceleration, separation and subsequent autonomous movement is carried out along its own pair of guides. After the carriages reach the metal bushings installed in their path, their braking begins.

The lengths of the metal sleeves are designed so that the braking of both parts of the missile object begins at the same time or the rear of the missile object begins to brake first, and then the front. This ensures shock-free braking of parts of the object. Braking is carried out due to the deformation of the damper bushings during their interaction with the metal bushings mounted on the rails, first the damper bush moves along the conical part of the metal bush (damper device), which reduces the amount of overload at the beginning of braking, which is also facilitated by the implementation of the damper bushings of plastic material . Further, the carriage bushings move along the cylindrical part of the metal bushings (energy absorber), where the kinetic energy of the moving carriage is finally spent on overcoming the friction forces.

The disadvantages of the famous stand are:

- the presence of a powerful foundation, since the base takes great effort and recoil momentum during the shot;

- unstable operation of the booster device, especially when using charges of large mass, since the power of the electric igniter is insufficient to ignite the entire charge and, as a result, large dispersions of specified accelerations;

- the inability to obtain the required accelerations during braking due to the limited length of the guides and the absence of a length adjustment device.

The technical task of the invention is the ability to test products for impact in a wide range of accelerations with the minimum possible accelerations during braking, to obtain stable values of the required accelerations of impact at a minimum cost.

EFFECT: obtaining information on the strength and performance of products and their elements under impact in a wide range of accelerations, both axial and transverse, under conditions as close as possible to real ones.

The problem is solved due to the fact that in the stand for testing products for impact, containing an accelerating device in the form of a barrel with a powder charge and initiator, a carriage for installing the test product, connected by eyelets with guides, and a brake device, the accelerating device is installed on the barrel artillery guns through the support, the mandrel and the clamp, and the guides are made of flexible steel ropes, passed through the grooves in the support and stretched along the barrel of the gun, while they are made diverging under glom to each other in the direction of movement of the carriage, and the supporting surface of the eyes interacts with the guides along the beam of their divergence to the longitudinal axis of the stand.

This design of the stand allows testing products with a small mass and relatively small accelerations of the order of up to 15000 ms ^-2 , when the carriage with the product is braked by the separation of the ropes, bringing them together, and the kinetic energy of the carriage acquired during firing is spent on friction and deformation.

In this case, low-mass powder charges are used and the electric initiator is sufficient to ensure the stability of the charge, which ensures an acceptable spread of the specified accelerations.

If you want to test products for impact with an acceleration of 30,000 ... 130,000 ms ^-2 , the accelerating and braking devices are more complex.

The problem is solved as follows.

In the accelerating device of the impact test bench containing a barrel with a combustion chamber with a powder charge placed therein, an initiating device and a bottom cover, the initiating device is made in the form of a prechamber with a powder charge and an electric igniter mounted perpendicular to the axis of the barrel and communicating with a radial channel with an annular cavity formed by the inner cylindrical surface of the chamber and an annular groove with an angular jumper from the side of the charging chamber; flax on the lateral surface of the bottom cover, and in the jumper around the perimeter made holes communicating the annular cavity with the combustion chamber.

In the brake device of the impact test bench, comprising a damper device and an energy absorber, the damper device is installed behind the brake section and is made in the form of bushings put on each guide rail, interconnected by an elastic connection, for example, from a shock-absorbed cord, while the connection is made of several links of different stiffness, and in the links with less rigidity a steel rope is installed, the length of which is equal to the length of the link at the maximum deformation of the link, and the guides lowered through the blocks mounted on the base in the form of a frame at the end of the brake section, and the energy absorber is made in the form of a tape of elastic material, the inertial mass of which is distributed along the length of the brake section according to the law, providing the required acceleration of the carriage with the product during braking, and the ends of the tape are connected steel ropes on one side with the carriage, covering it on the outer cylindrical surface at an angle to the axis of the carriage in the direction opposite to the movement, and on the other hand with the base, and at the end of the torus -religious trap portion installed tape.

The use of flexible guides simplifies the installation of the stand, they can be made of considerable length, which makes it possible to reduce braking acceleration.

The execution of the rails diverging at an angle to each other provides automatic braking of the carriage.

The use of artillery as a base eliminates the need for a powerful foundation and ensures optimal operation of the booster.

The implementation of the eyes of an elongated shape and different lengths of the front and rear eliminates the possibility of jamming the carriage and increases its stability when moving along the guides.

The introduction of a prechamber and an annular cavity into the design of the booster device provides not only stable burning of the propellant charge and, as a result, acceleration of shock impact on products with an acceptable dispersion, but also allows testing the product under the influence of alternating transverse accelerations due to the effect of the transverse pulse of the prechamber on the barrel. As a result of this, vibrations of the stem and the carriage with the test product relative to each other occur.

The presence of an energy absorber in the form of a tape, the mass of which is distributed according to a certain law along the length of the brake section, and elastic ties between the guides allows you to create the required braking acceleration and consume significant kinetic energy acquired by the carriage with the product when fired.

The invention is illustrated by drawings, which show:

figure 1 - stand for testing products for impact on the basis of the gun-howitzer D-30 (side view);

figure 2 is the same (top view);

figure 3 - booster device, the carriage with the test product, mounting the booster device on the barrel of the gun-howitzer (completely the gun is not shown) in the context (top view);

figure 4 - carriage (front view);

figure 5 - booster device for testing products for impact in section (section 2 of the formula);

figure 6 - brake device stand for testing products for impact with flexible guides (gun not shown), side view (claim 3 of the formula);

Fig.7 - brake device stand for testing products for impact with flexible guides, top view (claim 3 of the formula);

on Fig - damper device of the brake device (view perpendicular to the plane of the rails);

Fig.9 - damper device of the brake device of the stand (view along the axis of the guides).

The inventive stand includes an artillery gun 1 (D-30 howitzer gun) mounted in the standard position for firing. An accelerating device 3 is fixed on the barrel 2 of the gun 1 in the form of a short barrel 4, which is attracted to the end of the barrel 2 of the gun 1 using an adapter 5, a support 6, a mandrel 7, a clamp 8 and bolts 9.

Inside the barrel 4, the back of the carriage 10 enters in the form of a piston 11 with a labyrinth seal 12 made on its outer surface. Between the ends of the piston 11 and the bottom of the barrel 4 there is a charging chamber 13 with a powder charge 14 placed therein and an electric initiator 15. There are eyelets on the carriage 10. 16, by which it interacts with flexible guides 17 of steel ropes along the beam of their divergence. The guides are stretched along the barrel 2 of the gun 1 and the barrel 4 and passed through the grooves in the support 6. From the support 6, the guides 17 diverge at an angle α to each other. The ends 18 of the guides 17 are fixed with supports 19 on the base. At the end of the brake section 20, the guides 17 are passed through blocks 21 mounted on the frame 22.

In the booster device (claim 2), a prechamber 23 is installed perpendicular to the axis of the barrel 4 (Figure 5) with an additional charge 24 of powder and an electric igniter 25. The prechamber 23 is connected by a radial channel 26 with an annular cavity 27 formed by the inner cylindrical surface of the charging chamber 13 and made on the side surface of the bottom cover 28, an annular groove 29 with an angular jumper 30 from the side of the chamber 13. The annular cavity 27 is connected to the chamber 13 with holes 31 made in the jumper 30 around the perimeter.

The brake device of the stand (claim 3 of the claims) consists of a damper device 32, made behind the brake section 20 after blocks 21, and an energy absorber 33 in the form of a tape 34 of elastic material (Fig.6 and 7).

The damper device (Figs. 8 and 9) consists of bushings 35 in the form of coils worn on guides 17 and adapters 36. The bushings 35 with adapters 36 are connected to each other by links 37 of several turns 38 of the shock absorber cord.

On the adapters 36, the ends of the steel rope 39 are fixed, the length of which is equal to the length of the link at the maximum deformation of the cord. The tape 34 of the energy absorber 33 is laid on the base along the axis of the stand. The rear end 40 of the tape 34 with a double steel rope 41 is connected to the carriage 10, covering it on the outer surface 42 at an acute angle 43 to its longitudinal axis in the direction opposite to its movement (the loop of the rope 41 covers the carriage and is laid in stream lodges made on the side the surface of the carriage; lodgement streams are formed by curly brackets welded to the side surface of the carriage, providing the rope branches at an acute angle of 43 and the possibility of slipping the loop of the rope along the lodging streams), and the front end 44 from the base ropes 45 m.

At the end of the brake section 20, a trap 46 of the tape 34 is installed in the form of a concrete wall 47 with a shock absorber 48 mounted on it, designed to stop the tape 34.

The mass of the tape 34 is distributed along the length of the brake section according to the law that provides the required acceleration during braking.

This is achieved due to the profile of the tape and, if necessary, the execution of the tape is multilayer.

Tape 34 is flashed with steel wire 49.

Work on the stand is carried out as follows.

The test product 50 is installed in the carriage 10. A powder charge 14 is placed in the chamber 13 of the barrel 4. The piston 11 of the carriage 10 is pushed into the barrel 4 until it stops. Then an electric igniter is installed. The electric igniter 15 is connected to a source of electric current before firing. After the preparatory operations are completed, an electric signal is supplied to the electric igniter 15, which fires and ignites the powder charge 14. The powder gases generated in this case create the necessary pressure in the chamber 13 and accelerate the carriage 10 with the test article 50 with the required acceleration. The magnitude of the acceleration (pressure) is regulated by the mass of the powder charge 14 and the volume of the chamber 13.

After the shot, the carriage 10 is braked by diverging guides 17, bringing them together.

The forces of the recoil pulse that occur during the shot are perceived by the recoil device of the gun

When firing, pressure is recorded in the chamber, sensors can be installed on the test object that measure the magnitude of the acceleration in places of interest to the researcher.

, определяют ускорение (перегрузку), действующее на изделие.By pressure P, mass m (weight ω) of the movable part of the stand (carriage with the test product) and the cross-sectional area S of the piston 11 according to the formula

determine the acceleration (overload) acting on the product.

When using the accelerating device, made in accordance with claim 2, when an electric signal is supplied to the electric igniter 25, an additional powder charge 24 is ignited in the prechamber 23. The gases formed in this way through the radial channel 26 enter the annular cavity 27, filling it. From the cavity 27, gases through the openings 31 made in the jumper 30 are directed to the main charge 14, igniting it.

In this case, igniter gases cover the entire charge 14, provide reliable ignition and, therefore, stable operation with an acceptable pressure dispersion.

The braking of the carriage with the product after firing when using the brake device according to claim 3 of the claims is as follows.

When moving the carriage 10 accelerates first the steel ropes 41, and then the elastic tape 34.

Since they are stacked towards the movement of the carriage, their mass is connected to the movement gradually, while not only the total mass increases, but the mass depending on time (length), which achieves the specified braking law. The energy of the carriage 10 is mainly spent on accelerating the tape 34.

Part of the energy spent on friction, deformation of the guides 17 and the damper device 32.

The energy acquired by the tape 34 is absorbed in the trap 46 upon impact.

When the carriage 10 moves along the guides 17, they are brought together. The angle α of the divergence of the guides 17 as the carriage 10 moves along them increases, gradually increasing the braking force and causing deformation (elongation) of the guides 17.

In the absence of a damper device, hazardous stresses can occur in the guides 17, which requires limiting the efforts in tensioning the ropes.

In the presence of a damper device 32, the elongation of the guides 17 in the brake section occurs due to the deformation of its elastic ties (cushioning cord), which allow significant amounts of deformation. In addition, the damper device allows you to optimize the conditions for the movement of the carriage along the guides at the beginning of its movement, removing the sagging (vibrations) of the ropes in front of the carriage.

Claims (4)

1. Stand for testing products for impact, containing an accelerating device in the form of a barrel, a charging chamber with a powder charge and initiator, a carriage for installing the test product, connected by means of eyes with rails, and a braking device, characterized in that it has an accelerating device mounted on the barrel of the artillery gun through the support, a mandrel with a clamp, and the guides are made of flexible steel ropes passed through grooves in the support and stretched along the barrel of the gun, while they are made angular to each other in the direction of movement of the carriage, and the supporting surface of the eyes interacts with the guides along the beam of their divergence to the longitudinal axis of the stand. 2. The booster device for impact testing of the product, comprising a charging chamber with a powder charge, a bottom cover and an initiating device, characterized in that the initiating device is made in the form of a pre-chamber, in which an additional powder charge and an electric igniter are installed perpendicular to the axis the barrel and communicating radial channel with an annular cavity formed by the inner cylindrical surface of the charging chamber and an annular groove with an angular jumper with Rhone charging chamber groove formed on the side surface of the bottom cover, wherein in the bridge perimeter formed hole communicating the annular space with the charging chamber. 3. The brake device of the stand for testing products for impact, comprising a damper device and an energy absorber, characterized in that the damper device is installed behind the brake section and is made in the form of bushings put on each guide rail, interconnected by an elastic coupling, and the guides are missing through blocks installed on the base at the end of the brake section, and the energy absorber is made in the form of a tape of elastic material, the inertial mass of which is distributed along the length of the brake section according to the law, providing the required acceleration of the carriage with the product during braking, and the ends of the tape are connected by steel ropes on one side to the carriage, covering it on an external cylindrical surface at an acute angle to the axis of the carriage in the direction opposite to its movement, and on the other hand, from the base, and at the end of the brake section, a tape trap is installed. 4. The brake device according to claim 3, characterized in that the elastic coupling is made of several links of different stiffness, and a steel rope is installed in the links with less rigidity, the length of which is equal to the length of the link at its maximum allowable deformation.

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