RU2279044C1 - Plant for check of hermetic structural members of spacecraft for serviceability - Google Patents

Abstract

FIELD: testing technology; check of spread of surface and through cracks in specimens simulating hermetic structural members of spacecraft.

SUBSTANCE: proposed plant is provided with test vacuum chamber, forming optical unit consisting of cooled limiting diaphragm and kaleidoscope, vacuum system and leak detector with calibrators.

EFFECT: extended functional capabilities of plant due to simulating conditions close to natural.

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Description

The invention relates to the field of testing equipment and can be used to study the propagation of surface and through cracks in samples simulating sealed structural elements of spacecraft systems.

Known vacuum installation for the study of various objects in conditions close to space, containing a vacuum chamber, a vacuum system, a simulator of solar radiation (see G.S.Baguev, A.S. Bolshikh, A.Z. Vorobyov and others. Testing technique: Reference book in 2 books / Under the editorship of V.V. Klyuyev. - M.: Mashinostroenie, 1982. - book 1., Pp. 516-517).

The disadvantage of this installation is its narrow functionality, since it is unsuitable for studying the regimes of gas outflow through through cracks formed during thermal cyclic tests of airtight compartments and elements of spacecraft systems.

A known installation for studying thermal fatigue of refractory metals and alloys in a vacuum, containing a vacuum chamber, a heating unit, a vacuum system, a variable pinch mechanism of the sample (see DP Sinyavsky, V.A. Strizhalo. "Installation for studying thermal fatigue of refractory metals and alloys in a vacuum "in the journal" Factory Laboratory ", 1970, N1, p.93 ÷ 95).

The disadvantage of this installation is that thermocyclic loading is carried out under uniaxial stress state, and not biaxial, the sample is heated not from the surface, but by direct transmission of current, the forced cooling system of the sample is not provided, which does not correspond to the loading conditions of the shell of the pressurized casing or pressurized system element spacecraft, changes the parameters of the zone of plastic deformation at the top of the crack and affects the speed of its propagation.

The closest in technical essence (prototype) to the proposed installation is a setup for studying the thermal strength of cylindrical shells under combined loading, containing a source of high-intensity radiant flux, a shutter, a loading device and a measuring system (see P.V. Gerasimenko, Yu.V. Pavutnitsky, M.V. Vedernikov "Installation for studying the thermal strength of cylindrical shells under combined loading" in the journal "Problems of Strength", 1987, N2, p.107 ÷ 110).

The disadvantage of this installation is that it lacks a vacuum chamber, a vacuum system, a leak detector with calibrators and an optical device that consists of a cooled restrictive diaphragm and a kaleidoscope and allows to obtain a uniform distribution of radiation intensity along the radius of the light spot. The absence of these elements does not allow creating conditions corresponding to the conditions of the influence of space factors on the sealed structural elements of spacecraft systems. In addition, this installation does not allow to study the regimes of the outflow of gases through the through cracks formed in the process of thermal cycling tests of sealed compartments of spacecraft.

The objective of the invention is to provide a facility for researching the performance of sealed structural components of spacecraft systems, providing a technical result consisting in expanding functionality by creating operating conditions close to full-scale, in the study and assessment of the performance of sealed structural components of spacecraft systems.

This technical result in the installation for studying the operability of sealed structural components of spacecraft systems containing a radiant flux source, a shutter, a loading device and a measuring system is achieved by the fact that it is equipped with a vacuum test chamber cooled by a restriction diaphragm, a kaleidoscope, a vacuum system and a leak detector with calibrators while the test vacuum chamber is mounted on a coordinate device, made in the form of a hollow cylinder with a cooling jacket deposition and has three flanges, the first of which is located laterally normal to the generatrix of the test vacuum chamber in its middle part and is connected to the vacuum system, the second flange is used to mount quartz glass and install a cooled restriction diaphragm, the third flange is connected to the loading device, the first and the second flanges are identical, the vacuum system includes a mechanical vacuum pump, a steam-oil diffusion pump, an ionization-thermocouple vacuum gauge, vacuum valves and a nitrogen trap, a leak detector the spruce is connected through a valve to the vacuum system, and the kaleidoscope is mounted coaxially inside the test vacuum chamber, and the source of the radiant flux is mounted coaxially to the test vacuum chamber above its second flange, the loading device is made in the form of a sealed chamber, has two flanges, the first of which it is connected to the third the flange of the test vacuum chamber, the second flange is designed for fastening the test samples and includes a gas supply fitting from a high pressure source, a gas outlet fitting to atmospheres y and an electrothermal input for connecting to a device for measuring the temperature of the sample, while the nozzle for blowing the internal surface of the sample is mounted on the gas supply fitting, the measuring system includes thermocouples that are installed on the internal surface of the sample, pressure gauges connected to the vacuum system, and pressure sensors of the loading system .

Figure 1 shows a schematic diagram of the installation, figure 2 and figure 3 is a General view of a test vacuum chamber with various types of samples.

Installation for investigating the health of sealed structural components of spacecraft systems contains a test vacuum chamber 1 (Fig. 1, 2, 3), a cooled restriction diaphragm 2 (Fig. 1, 2, 3), a kaleidoscope 3 (Fig. 1, 2, 3) , leak detector 4 (FIG. 1) with calibrators, a source of radiant flux 5 (FIG. 1), a shutter 6 (FIG. 1) with a pneumatic actuator, a loading device 8 (FIGS. 2, 3). The forming optical device is designed to obtain a uniform distribution of the intensity of the radiant flux within the light spot. The elements of the forming optical device are a cooled restrictive diaphragm 2 (Fig. 1, 2, 3) and a kaleidoscope 3 (Fig. 1, 2, 3). The cooled restriction diaphragm 2 (FIGS. 1, 2, 3) serves to pre-align the power density of the radiant flux by “truncating the wings” of the normal distribution. The surface of the diaphragm facing the source of the radiant flux is polished and chrome-plated. The cooled restriction diaphragm itself is made in the cooled version, which allows, in addition to the restrictive function, to protect the structural elements of the test vacuum chamber 1 from overheating (Figs. 1, 2, 3). Kaleidoscope 3 (figures 1, 2, 3) is made of a copper pipe, the inner surface of which is polished and has a high reflection coefficient. This allows as a result of multiple reflection of the radiant flux from the inner surface of the kaleidoscope to achieve a fairly uniform distribution of the irradiation intensity over the surface of the working part of the sample 9 (Fig.1, 2, 3). The test vacuum chamber 1 (Fig. 1, 2, 3) is mounted on a coordinate device (not shown) and is made in the form of a hollow cylinder with a cooling jacket 7 (Fig. 2, 3), and has three flanges 4, 5, 10 (Fig. .2, 3). The flange 5 (Fig.2, 3) is located laterally normal to the generatrix of the test vacuum chamber 1 (Fig.1, 2, 3) in its middle part and is connected to the vacuum system. The flange 10 (figure 2) is used to mount the quartz glass 6 (figure 2) and install a cooled restrictive diaphragm 2 (figure 2). The flange 4 (Fig.2, 3) is connected to the loading device 8 (Fig.2, 3). Flanges 10 and 5 (figure 2, 3) are identical, which allows you to test different types of samples 9 (figure 1, 2, 3) depending on which of the flanges 10 or 5 is used to connect to the vacuum system. Figure 2 shows the position of the test vacuum chamber for testing samples 9 in the form of flat round plates and spherical segments. Figure 3 shows the position of the test vacuum chamber for testing thin-walled tubular samples 9. The third flange 4 (figure 2, 3) of the test vacuum chamber is used to install a loading device 8 (figure 2, 3) with the test sample 9 (figure 1 , 2, 3). The cooling jacket 7 (figure 2, 3) allows you to maintain the required residual pressure in the test vacuum chamber, protects the elements of the test vacuum chamber from overheating, reduces the influence of the thermal background of the chamber walls on the sample, and also protects the test samples from oiling. The vacuum system includes a mechanical vacuum pump 7 (Fig. 1), a steam-oil diffusion pump 8, vacuum valves 10, 11, 12 and 13, 19, an ionization-thermocouple vacuum gauge 14, a nitrogen trap 15. The leak detector 4 (Fig. 1) is connected to calibrators through valve 13 with a vacuum system. It is designed to control the tightness of the vacuum system and the test object. In addition, the leak detector allows you to record the moment of occurrence of a through crack, as well as measure the values of gas leaks through through cracks using special calibrators and study the regimes of gas outflow through them. Calibrators calibrate the test vacuum chamber - leak detector system. One calibrator is made in the form of a collector, consisting of five reference helium leaks of different leakages, each of which is connected to the collector through vacuum valves. The calibrator allows you to set various helium fluxes over a wide range. Another calibrator is universal and designed to calibrate the system if during the vacuum tests not only pure helium is used, but also helium-air mixtures of various concentrations. The main elements of the calibrator are a glass pipeline, the mirror wrote with the linear volume of the pipeline indicated on it, a special device for determining the volumetric flow rate of the test gas, and a needle valve. The magnitude of the leaks defined by this calibrator is determined by the area of the orifice of the needle valve. A kaleidoscope 3 (Fig. 1, 2) is mounted coaxially inside the test vacuum chamber 1 (Fig. 1, 2), and the source of the radiant flux 5 (Fig. 1) is mounted coaxially to the test vacuum chamber 1 (Fig. 1, 2) above its flange 10 (FIG. 2). The loading device 8 (Fig. 2, 3) is made in the form of a sealed chamber, has two flanges, one of which is connected to the flange 4 of the test vacuum chamber 1 (Figs. 1, 2, 3), the second flange is designed for fastening the test samples 9 (figure 1, 2, 3). The loading device 8 (FIGS. 2, 3) contains a nozzle 11 (FIGS. 2, 3) for supplying gas from high pressure sources 16 and 17 (FIG. 1), a fitting 12 (FIGS. 2, 3) for venting gas to the atmosphere, and an electro-pressure gland 13 (Fig. 2, 3) for connecting with a thermocouple 18 (Fig. 1) measuring the temperature of the sample 9 (Figs. 1, 2, 3), while the nozzle 14 is fixed on the gas supply fitting 11 (Fig. 2, 3) (figure 2, 3) blowing the inner surface of the sample 9 (figure 1, 2, 3). The measuring system of the installation includes thermocouples 18 (Fig. 1) mounted on the inner surface of the sample 9 (Figs. 1, 2, 3), pressure gauges 20 and 21 (Fig. 1) connected to a vacuum system, and a pressure sensor 22 (Fig. 1). 1) loading system. The installation also includes a pressure gauge 23 (Fig. 1), electro-power 24 (Fig. 1), program control device 25 (Fig. 1), a light-beam oscilloscope 26 (Fig. 1), a power supply rack 27 (Fig. 1) , electro-pneumatic valve 28 (figure 1), providing the testing process of samples 9 (figures 1, 2, 3).

Installation works as follows.

The test sample 9 (Figs. 1, 2, 3) is installed in the loading device 8 (Figs. 2, 3), which then fits into the test vacuum chamber 1 (Figs. 1, 2, 3). The vacuum system pumps the test vacuum chamber 1 (FIGS. 1, 2, 3) to the required residual pressure. The source of the radiant flux 5 (Fig. 1) is brought to the required power mode, and the sample 9 (Figs. 1, 2, 3) is loaded with internal pressure created in the loading device 8 (Figs. 2, 3).

After opening the shutter 6 (Fig. 1), the sample 9 (Figs. 1, 2, 3) is heated to the required temperature by the radiant flux. After closing the shutter 6 (Fig. 1), the cooling of the sample 9 (Figs. 1, 2, 3) is carried out by blowing its internal surface with a stream of cold gases through the nozzle 11 (Figs. 2, 3) of the gas supply and the blowing nozzle 14 (Fig. 2) , 3). Then the heating-cooling cycle is repeated. A characteristic feature of this methodology for thermocyclic testing of samples is the constancy of the temperature range during testing, which better reflects the operating conditions of sealed structural components of spacecraft systems in real space flight conditions. Tests of samples 9 (figures 1, 2, 3) are completed when a through crack appears on the back surface of the sample. The moment of crack propagation through the wall of specimen 9 (Figs. 1, 2, 3) is registered by leak detector 4 (Fig. 1) at the beginning of a gas leak, which is measured using special calibrators, which allows one to study the regimes of gas outflow through a through crack. At the same time, the cycle counter of the control device 25 (Fig. 1) records the number of loading cycles of these samples. The test cycle is completed by depressurization of the test vacuum chamber 1 (figure 1, 2, 3) and removing the sample 9 (figure 1, 2, 3) from the loading device 8 (figure 2, 3). The test results of the samples contain the necessary data both for assessing the performance of sealed elements at the stage of propagation of surface cracks, and for calculating the duration of the operation of the spacecraft’s hermetic systems in the presence of through cracks.

Thus, the proposed installation allows to obtain a technical result, which consists in expanding the functionality by creating operating conditions close to full-scale, in the study and evaluation of the performance of sealed structural elements of spacecraft systems.

Claims (1)

Installation for researching the operability of sealed structural components of spacecraft systems, containing a radiant flux source, a shutter, a loading device and a measuring system, characterized in that it is equipped with a test vacuum chamber cooled by a restriction diaphragm, a kaleidoscope, a vacuum system and a leak detector with calibrators, while the test the vacuum chamber is mounted on a coordinate device, made in the form of a hollow cylinder with a cooling jacket and has three flanges, the first of which is located laterally normal to the generatrix of the test vacuum chamber in its middle part and connected to the vacuum system, the second flange is used to mount quartz glass and install a cooled restriction diaphragm, the third flange is connected to the loading device, the first and second flanges being identical, the vacuum the system includes a mechanical vacuum pump, a steam-oil diffusion pump, an ionization-thermocouple vacuum gauge, vacuum valves and a nitrogen trap, the leak detector is connected through a valve to a vacuum system, and a kaleidoscope is mounted coaxially inside the test vacuum chamber, and the source of the radiant flux is mounted coaxially to the test vacuum chamber above its second flange, the loading device is made in the form of a sealed chamber, has two flanges, the first of which is connected to the third flange of the test vacuum chamber, the second flange is designed for fastening the test samples and includes a gas supply fitting from a high pressure source, a gas outlet fitting to the atmosphere, and an electric pressure seal for soy pressure with a device for measuring the temperature of the sample, while the nozzle for blowing the internal surface of the sample is fixed on the gas supply fitting, the measuring system includes thermocouples that are installed on the inner surface of the sample, pressure gauges connected to the vacuum system, and pressure sensors of the loading system.

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