RU2777995C1 - Pneumatic accelerating device - Google Patents

Abstract

FIELD: mechanical engineering.

SUBSTANCE: invention relates to the field of mechanical engineering, namely to the study of high-speed impact phenomena. The accelerating pneumatic device contains a high-pressure chamber, on the side surface of which a pressure measuring device is installed, communicated with its internal cavity, a barrel with a hole in the side surface and with a missile object placed in it. There is a valve that communicates the internal cavities of the high-pressure chamber and the barrel, the attachment point for the test sample and speed sensors. The device is equipped with a bushing installed in the barrel, a pressure regulator, electromagnetic and emergency valves communicated with the internal cavity of the high pressure chamber. The barrel passes through the internal cavity of the high-pressure chamber, and the through hole made on the side surface of the barrel is located inside the high-pressure chamber with the possibility of being blocked by a projectile placed in the sleeve, with at least one hole aligned with the through hole in the side wall of the barrel . At the end of the barrel on the outside of the high-pressure chamber, a fitting is installed, against which the sleeve rests. Velocity sensors are installed on the mount of the test sample, installed on the side of the free end of the barrel at a predetermined distance.

EFFECT: improved measurement accuracy.

2 cl, 4 dwg

Description

The invention relates to experimental mechanics and testing techniques, namely to the study of high-speed impact phenomena, and can be used as a throwing device for experiments on shock-wave loading of ammunition and other products.

For a detailed study of the region of transition from elastic to plastic formation and the kinetic initiation of spall fractures in materials, it is necessary to control the impact rate of the impactor with the test sample with a high degree of accuracy.

Known pneumatic installation for shock testing [p. RF No. 2023246, IPC (1990.01) G01M 7/00, prior. 05/03/1990, publ. 11/15/1994], containing a receiver (high-pressure chamber), a barrel with a firing pin (thrown object) placed in it, a diaphragm (valve) separating the internal cavities of the receiver and barrel. The installation also contains an electric detonator, a detonation line, a detonation pulse shaper, a holder and a detonated charge made in the form of strips of a film explosive fixed on the diaphragm along its radii.

The disadvantages of the known installation are: the inability to break the diaphragm with a regulated force (pressure), therefore it is impossible to reproduce the force of the shock pulse on the striker (thrown object) accurately and in the same way several times. In addition, the process of opening the diaphragm may be accompanied by the detachment of fragments, which, acting on the drummer and barrel, reduce the reliability of the results. The presence of an explosive requires consumable explosives, can be destructive, and leads to large fluctuations in the values of the measured parameters.

Known shock stand, described in the invention under the title "Method of testing an object for a single impact" [p. RF No. 2267107, MPK7 G01M 7/08, prior. January 20, 2004, publ. 27.12.2005], containing a barrel on the surface of which a pressure sensor (a device for measuring pressure) is installed, communicated through a through hole in the wall of the barrel with its internal cavity, a high-pressure chamber, a pre-chamber, a carriage with an object (a test sample attachment unit) and acceleration (speed) sensors. The barrel is fixed on the rail with a stop. The carriage consists of a piston, a pusher, a platform and shoes with which the carriage slides along the rail. The object is fixed on the carriage platform. The prechamber consists of a perforated cup, a perforated tube, a lid, a powder charge, a powder igniter charge, thin paper covering the holes, an annular paper wad pressing the charge in the cup.

The disadvantages of the stand are the use of gunpowder to create gas pressure in the high pressure chamber, burned in the prechamber. A pyrotechnic impact requires a very high accuracy of powder weighing, which is practically impossible, has poor repeatability of test results, makes it difficult to adjust the impact profile, and leads to large measurement errors.

Known installation for impact testing [p. RF No. 2202106, MPK7 G01M 7/08 G01N 3/30, prior. 06/19/2000, publ. 04/10/2003], containing a compressed gas chamber (high pressure chamber), on the side surface of which a pressure gauge (pressure measuring device) is installed, communicated through a through hole in the side wall of the compressed gas chamber with its internal cavity, an acceleration pipe (barrel) with a hole in the side surface and with a striker (thrown object) placed in it, a valve communicating the internal cavities of the high-pressure chamber and the barrel, the test sample and a block of speed photo sensors (velocity sensors). The sample is installed in a groove made at the end of the runaway tube. The openings of the acceleration pipe are made in the form of diametral slots, located so that the plane passing through the end of the slot is as close as possible to the plane passing through the bottom of the groove. The block of speed photo sensors covers the acceleration pipe at the location of the slots.

The disadvantages of the installation lie in the location of the acceleration sensors on the acceleration tube close to the test sample, which leads to a large error in obtaining the results of the impact velocity of the striker and the test sample. The presence of slotted holes and a groove at the end of the pipe, the appearance of which is caused by the placement of speed control sensors, to a certain extent can be considered as defects in the working surface of the acceleration pipe, which, in turn, can lead to unwanted vibrations of the pipe at the final stage of the striker movement and, as a result , distortion of the trajectory of its flight, which makes it impossible to accurately repeat the experiments. The location of the test sample at the end of the runaway tube limits the range of experimental data. In addition, the service life of the acceleration tube as a whole is significantly reduced, since the groove and slots are undesirable stress concentrators.

This device is taken as a prototype, as the closest in technical essence to the claimed invention.

The technical result, to which the claimed invention is directed, is to increase the accuracy of measuring the speed of the striking elements and increase the range of experimental data, as well as the possibility of repeating the experiment.

This technical result is achieved in that the accelerating pneumatic device contains a high-pressure chamber, on the side surface of which a pressure measuring device is installed, communicated through a through hole in the side wall of the high-pressure chamber with its internal cavity, a barrel with a hole in the side surface and placed in projectile, a valve connecting the internal cavities of the high-pressure chamber and the barrel, the attachment point of the test sample and speed sensors, according to the invention, it is equipped with a pressure regulator, additional through holes are made on the side surface of the high-pressure chamber for installing at least one solenoid valve and a pressure regulator, while the barrel passes through the internal cavity of the high pressure chamber, and the through hole made on the side surface of the barrel located inside the high pressure chamber is blocked by a projectile placed in the sleeve, at least with at least one hole aligned with a through hole in the side wall of the barrel, at the end of which, on the outside of the high-pressure chamber, a fitting is installed, against which the sleeve rests, the valve connecting the internal cavities of the high-pressure chamber and the barrel is connected on one side with the fitting on the end of the shaft, and on the other hand, through the gas pipeline with an additional hole in the side surface of the high-pressure chamber, the speed sensors are installed on the attachment point of the test sample, installed from the side of the free end of the shaft at a predetermined distance.

Thus, equipping the device with a pressure regulator that provides a given pressure in the chamber with an accuracy of 0.01 atmospheres, as well as the passage of the barrel through the internal cavity of the high-pressure chamber, on the side surface of which a through hole is made, blocked by a missile object placed in the sleeve, at least with at least one hole aligned with the through hole in the side wall of the barrel, ensures the passage of gas from the high pressure chamber into the barrel, creating in it a precisely specified stable pressure that acts on the projectile, allows for accurate repeatability of the experiment. The installation of speed sensors on the attachment point of the test sample ensures the registration of the speed of the collision of the projectile with the test sample with a high degree of accuracy, which makes it possible to increase the accuracy of measuring the speed of the striking elements. Installing the test sample from the side of the free end of the barrel at a given distance, provides the ability to change the distance from the barrel to the test sample, which allows you to expand the range of experimental data.

In addition, in order to increase the accuracy of hitting the target area of the test sample and adjust the flight path of the projectile, an adjusting sleeve with a laser designator is installed at the free end of the barrel.

The presence in the claimed invention of features that distinguish it from the prototype, allows us to consider it as corresponding to the condition of "novelty".

New features, which are contained in the distinctive part of the claims, are not identified in technical solutions of a similar purpose, on this basis, we can conclude that the claimed invention complies with the "inventive step" condition.

The invention is illustrated by drawings:

in fig. 1 shows a general view of the accelerating pneumatic device;

in fig. 2 - longitudinal section of the high pressure chamber;

in fig. 3 - section A-A in Fig. 2;

in fig. 4 - longitudinal section of the sleeve 15.

The accelerating pneumatic device contains a high-pressure chamber, a barrel 1, a missile object, a pressure measuring device 2, a valve 3, a fastening unit 4 of the test sample with speed sensors and a pressure regulator 5 (Fig. 1, 2).

The high-pressure chamber consists of a housing 6 and a flange 7. The housing 6 is made in the form of a glass, at the base of which a central through hole is made, and at least five through holes with a conical thread are made on the cylindrical surface, into which fittings 8 are screwed (Fig. 2, 3). Flange 7 is fixed with studs on the free end of body 6. Pressure measuring device 2, valve 3, pressure regulator 5, solenoid valve 9 with gas pipeline 10 for remote filling of the chamber with gas from gas cylinder 11, and emergency valve 12 are connected to body 6 through fitting 8 for the safe operation of the device in an emergency.

The barrel 1 passes through the central through hole in the base of the body 6 and the flange 7. On the side surface of the barrel 1, a hole 13 is made, through which the internal cavity of the body 6 communicates with the internal cavity of the barrel 1. A fitting 14 is installed on the outer side of the flange 7 at the end of the barrel 1. A sleeve 15 is installed in the barrel 1, abutting against the fitting 14. On the side surface of the sleeve 15, at least one hole is made in diameter, aligned with the hole 13 on the side surface of the barrel 1. The holes in the side surface of the sleeve 15 allow you to control the gas flow from the chamber high pressure into the barrel 1, due to which the gas pressure in the barrel 1 is regulated, and, accordingly, the speed of the missile object, which allows expanding the testing area (Fig. 4). At the free end of the barrel 1, an adjusting sleeve 19 is installed with a laser designator fixed on it, which makes it possible to adjust the flight path of the projectile to accurately hit a certain area of the test sample.

The thrown object is made in the form of a wad 16 and a striker 17, in the form of a steel ball, or can be made in the form of a steel cylinder. The projectile is placed in the sleeve 15 located inside the barrel 1 in such a way that it overlaps the branch 13 of the barrel 1 and the hole of the sleeve 15 aligned with it.

The device for measuring pressure 2 is made in the form of a pressure sensor that allows you to remotely monitor the pressure level in the high pressure chamber. The device for measuring pressure 2 is connected to the internal cavity of the high pressure chamber through one of the fittings 8 on the cylindrical surface of the housing 6.

The valve 3 communicates the internal cavity of the high-pressure chamber with the internal cavity of the barrel 1. On the one hand, the valve 3 is connected to the fitting 14 at the end of the barrel 1, and on the other hand, through the gas pipeline 18, it is connected to one of the fittings 8 on the cylindrical surface of the housing 6. As a valve 3 a solenoid valve was used to remotely control the supply of gas from the cavity of the high-pressure chamber to the cavity of the barrel 1.

Mounting unit 4 of the test sample is installed on the side of the adjusting sleeve 19 with a laser designator mounted on the free end of the barrel 1, at a predetermined distance.

Velocity sensors 20 are mounted directly on the test sample to more accurately measure the speed at the moment of collision of the projectile with the test sample.

The pressure regulator 5 is mounted on the cylindrical surface of the housing 6 and communicates with its internal cavity through the solenoid valve 21 and one of the fittings 8. Installing the pressure regulator 5 through the solenoid valve 21 allows you to remotely control the pressure in the chamber.

The device works as follows

Mounting unit 4 of the test sample is installed at the required distance from the adjusting sleeve 19 with a laser designator. Adjust the pressure regulator 5 to the desired gas flow rate. Using a laser designator mounted on the adjusting sleeve 19, barrel 1 is aimed at the test sample. The solenoid valve 9 is opened remotely and the internal cavity of the housing 6 of the high-pressure chamber is filled with gas through the gas pipeline 10 from the gas cylinder 11. The pressure in the chamber is monitored according to the readings of the pressure measuring device 2. After reaching the required excess pressure level in the chamber, the gas supply is stopped by shutting off the solenoid valve 9. Then, by opening the solenoid valve 21 remotely, the pressure regulator 5 releases excess gas in the high pressure chamber. Having received the exact pressure in the internal cavity of the housing 6 of the high-pressure chamber, the electromagnetic valve 21 is closed, stopping the gas discharge through the pressure regulator 5. The valve 3 is opened, the gas from the housing 6 enters the internal cavity of the barrel 1, setting in motion the wad 16, pushing the drummer in front of it 17. Moving the wad 16 releases the coupled hole of the sleeve 15 and the hole 13 of the barrel 1. The gas filling the cavity of the high-pressure chamber through the hole 13 and the hole of the sleeve 15 enters the internal cavity of the barrel 1, accelerating the wad 16 with the striker 17 to a given speed of the striker 17 by exit from the barrel 1. Drummer 17, flying out of the barrel 1, hits the test sample. The speed of the impactor 17 obtained during the impact is recorded by the speed sensors 20. The data obtained is transmitted to the operator.

To exclude an arbitrary shot of the drummer 17 from the barrel 1 in emergency situations, an emergency valve 12 is used, which is in the closed position during operation of the device in the operating mode. In an emergency, the emergency valve 12 opens remotely and releases gas from the high pressure chamber, excluding an unauthorized firing of the striker 17.

Thus, the above information testifies to the fulfillment of the following set of conditions when using the claimed invention:

• The tool that embodies the claimed invention in its implementation is intended for experimental mechanics and test equipment, namely for the study of high-speed impact phenomena;

• For the claimed device in the form as it is described in the claim, the possibility of its implementation is confirmed;

• The tool, embodying the claimed invention in the implementation, is able to increase the accuracy of measuring the speed of the striking elements and increase the range of experimental data, as well as the repeatability of the experiment.

Therefore, the claimed invention meets the condition "Industrial applicability".

Claims (2)

1. A pneumatic accelerating device, containing a high-pressure chamber, on the side surface of which a pressure measuring device is installed, communicated with its internal cavity, a barrel with a hole in the side surface and with a projectile placed in it, a valve communicating the internal cavities of the high-pressure chamber and of the barrel, the attachment point of the test sample and speed sensors, characterized in that it is equipped with a sleeve installed in the barrel, a pressure regulator, electromagnetic and emergency valves communicated with the internal cavity of the high pressure chamber, while the barrel passes through the internal cavity of the high pressure chamber, and a through hole made on the side surface of the barrel is located inside the high-pressure chamber with the possibility of overlapping by a missile object placed in the sleeve, with at least one hole aligned with the through hole in the side wall of the barrel, at the end of which, on the outside of the high-pressure chamber at a fitting is installed against which the sleeve rests, and the valve connecting the internal cavities of the high-pressure chamber and the barrel is connected on one side to the fitting at the end of the barrel, and on the other hand through the gas pipeline with the internal cavity of the high-pressure chamber, in addition, speed sensors are installed on the mount of the test sample installed from the side of the free end of the barrel at a given distance. 2. The accelerating pneumatic device according to claim 1, characterized in that an adjusting sleeve with a laser designator is installed at the free end of the barrel.

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