RU2372511C1 - Solid-fuel gas generator for catapult piston device of rocket - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: solid-fuel gas generator of catapult piston device of the rocket includes an afterburner with combined propellant charge and pressurisation chamber with solid-fuel charge, which are connected to each other with a common gas link - gas pipeline and mixing chamber. Pressurisation chamber charge is made in the form of two channel cartridges armoured along external surface and placed in perforated metal jackets. In the latter, between end surfaces of jackets and cartridges there located are shims made from electric-grade cardboard, their thickness is 1-3 mm, and wooden inserts. The latter are in contact with jacket edges and shims, and shims are in contact with edges of charges.

EFFECT: steady operation of gas generator at high start-up gradients of pressure increase in gas generator combustion chamber and at high axial overloads acting on inserted solid fuel charges.

2 cl, 4 dwg

Description

The invention relates to the field of rocketry and can be used in the design, development and manufacture of gas generators (GT) of solid fuel for ejection devices (KU) of missiles, as well as to other

highly dynamic devices using solid propellant charges.

Gas generators are known according to patents RU 2213245 (published September 27, 2003, application RU 2002108237 dated April 1, 2002), RU 2289036 (published August 10, 2006, application RU 2005104915 dated February 22, 2005).

The gas generator according to the patent RU 2289036 IPC F02k 9/95 with plug-in charges placed in the perforated jackets of the boost chamber is selected by the authors for the prototype (Figure 1, Figure 2).

The disadvantage of the prototype is the reduced operational reliability of the GG due to high contact stresses at the ends of the checkers placed in the shirts of the boost chamber.

(Фиг.3), что приводит к удару твердотопливных шашек (12) в торцевую стенку (14) перфорированных рубашек (13), сопровождающемуся высокими контактными напряжениями на торцах последних в конструкции прототипа, и соответственно к возможному разрушению шашек при отрицательных температурах. Аналогичная ситуация может происходить при случайном падении снаряженного зарядами ГТ катапульты на жесткое основание в вертикальном положении.Indeed (Figure 1), in the boost chamber of the prototype (11) when the afterburner charge (8) is triggered, a shock wave of gaseous products of combustion (PS) with a gradient of pressure increase (P / t) to

(Figure 3), which leads to the impact of solid fuel checkers (12) in the end wall (14) of perforated shirts (13), accompanied by high contact stresses at the ends of the latter in the design of the prototype, and, accordingly, to the possible destruction of the checkers at low temperatures. A similar situation can occur when the catapult equipped with the charges of the GT accidentally falls on a rigid base in an upright position.

A well-known solution to this problem in technology - the use of rubber gaskets as shock absorbers for shock absorbers in relation to the structure under consideration, is usually ineffective: at low negative temperatures (up to minus 50 ... minus 60 ° C) inherent in the temperature range of rocketry operation, rubber gaskets significantly lose their elastic properties. The dynamic modulus of elasticity of known rubbers under compression, as applied to the indicated loading gradient, at negative temperatures reaches (5-10) · 10 ⁴ kgf / cm ² (the state of brittle glass), while at the same loading speeds, but in positive the temperature range it is about (5-10) · 10 ¹ kgf / cm ² .

In addition, in the design of the GT prototype according to Patent RU 2289036, the charges of the boost chamber are usually selected according to the length depending on the rate of combustion of the TPT, and for increased rates of combustion of the TPT when cutting charges to the required length, a substantial gap is realized between the ends of the charge and the ends of the jackets of the boost chamber . The presence of an increased gap exacerbates the problem of ensuring the strength (integrity) of the charge due to the possibility of significant movement and impact of the charge on the end walls of the shirts.

An object of the invention is to develop the design of a piston catapult gas generator, eliminating the destruction of the solid fuel charge, both when the GG enters the operating mode and when the loaded GT accidentally falls onto a rigid base during operation (bench tests, loading, unloading, etc.), when the level of loads on the end of the solid fuel charge is commensurate with the level of loads inherent in the output of the GT to the operating mode.

The specified technical problem is solved according to the patented invention (Figure 4) by placing between the solid checkers and the end walls of the perforated metal shirts gaskets (27), (28) made of electric cardboard according to GOST 2824-86 sheet brand EV and wood inserts (31) (32) ) from lumber according to GOST 8486-86, compensating for the length of the charge. As tests of dynamically working systems have shown, the best damper of large axial loads in the temperature range from 50 ° C to minus 60 ° C is not rubber, not other polymeric materials, namely electric cardboard - a durable, but pliable material, characterized by a small spread of physical mechanical characteristics in a wide temperature range, moreover, moisture resistant in comparison with ordinary cardboard.

Comparative laboratory tests of gaskets made of: electrical cardboard, frost-resistant polymer material - thermoplastic elastomer (TEP) for end-face solid fuel charge bookings (mechanical glass transition temperature minus 90 ° C) and others on a Schob instrument according to GOST 27110-86 showed that it is the electric cardboard that has the best damping properties . It allows you to reduce stresses on the impacted end face of solid fuel checkers by half in comparison with the steel supporting surface (table) (k = 0.5, stress reduction coefficient). Ordinary cardboard - cardboard for containers, packaging GOST 7933-89, or cardboard calibrated according to GOST 1933-73 has reduced physical and mechanical characteristics, is subject to moisture, which helps to reduce its damping properties at low temperatures.

Table Contact material charge support Test temperature ° C Elasticity (R)% rebound ^*) Steel 17 twenty Electric board 17 40 Electrocardboard + TEP 17 26 ^*) "Impact dynamics" Zukas J.A., Nikolos T.I. et al., M., from "Mir", 1985

To test the effectiveness of the proposed invention in the KU gas generator, in one case, rubber gaskets 1 mm thick were installed between the solid checkers and the end walls, and in the other, electric card gaskets also 1 mm thick. The free gap was filled with a wood liner. The catapult for a rocket weighing 0.6 tons was an afterburner (Fig. 2) with a combined charge (smoke powder + fine-solid solid bombs) with a total mass of 0.2 kg, connected by means of a mixing chamber to a boost chamber, in which were placed as part of perforated metal shirts are two solid fuel checkers made of quick-burning gunpowder, cylindrical with a central channel, and booked on the outer surface. The weight of each piece was 0.38 kg. The mixing chamber was connected to the cylinder in which the piston with the rod was located. The rod through the hook was connected to the rocket.

During the fire tests (OI), the afterburner triggered a shock wave with a pressure gradient

которая, воздействуя на шашки основного заряда, обеспечивала (Фиг.3) не только их воспламенение, но и приводила к удару о стенки перфорированных рубашек. Демпфирование ударной нагрузки за счет установки резиновых прокладок по месту удара при температуре минус 50°С не обеспечивалось по причине высокой жесткости (высокий динамический модуль упругости при сжатии) резиновых прокладок, и шашки разрушились. Замена резиновых прокладок на прокладки из электрокартона по ГОСТ 2824-86 листового марки ЭВ толщиной 1 мм позволила исключить разрушение шашек при ОИ, в том числе при сбрасываниях снаряженных зарядами газогенераторов КУ в вертикальном положении с высоты 10 м на жесткое основание. При этом между прокладками из электрокартона и торцами рубашек устанавливались древесные вкладыши (компенсаторы осевого зазора).

which, acting on the checkers of the main charge, ensured (Figure 3) not only their ignition, but also led to an impact on the walls of the perforated shirts. Damping of the shock due to the installation of rubber gaskets at the place of impact at a temperature of minus 50 ° C was not provided due to the high rigidity (high dynamic modulus of elasticity under compression) of the rubber gaskets, and the pieces were destroyed. Replacing rubber gaskets with gaskets in accordance with GOST 2824-86 of the EV grade sheet with a thickness of 1 mm made it possible to exclude the destruction of the checkers during the test run, including when the KU gas generators charged with charges were dropped in a vertical position from a height of 10 m to a rigid base. At the same time, wood inserts (axial clearance compensators) were installed between the gasket gaskets and the ends of the shirts.

The experiments with different thicknesses of gaskets made of electric cardboard showed that with a thickness of gaskets from 1 to 3 mm, a coefficient of voltage reduction at the support end of the charge k-0.5 is provided. With a charge mass of up to 1.0 ... 2.0 kg (to maintain its integrity), 1 mm gasket thickness is sufficient, and with a charge mass of more than 2 kg it is necessary to use gaskets of increased thickness within 3 mm. The large thickness of the gasket practically does not increase the effect of reducing stress, but it may require an increase in the length of the shirts and the boost chamber as a whole. At the same time, experiments were carried out using, as a separator, between the gasket from the electric cardboard and the ends of the wood shirt, compensating for the free axial clearance of the liners.

The technical result of the invention is to develop a solid fuel gas generator ejection piston device, including an afterburner and a boost chamber with a solid fuel charge. In this case, the afterburner and the boost chamber are connected by a common gas connection - the mixing chamber and the gas duct. The charge of the boost chamber is made in the form of two channel pieces, armored on the outer surface. In this case, the checkers are placed in perforated metal shirts. Between the end surfaces of the checkers and metal shirts there are gaskets made of EV sheet metal sheet. The thickness of the gaskets is 1-3 mm. Between the gaskets and the end surfaces of the shirts are wood inserts, the thickness of which corresponds to a free axial clearance.

The invention is illustrated in figure 1, figure 2, figure 3, figure 4.

Figure 1. The design of the prototype

1 - perforated tube-igniter;

2 - front cover;

3 - the tapering end of the pilot tube;

4 - a support lattice;

5 - radial holes of the pilot tube;

6 - gas duct GG;

7 - a squib;

8 - afterburner charge;

9 - afterburner body;

10 - mixing chamber

11 - boost chamber;

12 - solid fuel checkers;

13 - perforated shirts;

14 - end (supporting) walls of the shirts;

15 - perforation of shirts;

16 - gas pipeline KU;

17 - a stock;

18 - subpiston space;

19 - a piston;

20 - cylinder;

21 - bleeding holes;

Figure 2. Afterburner section (prototype)

22 - sections with solid fuel checkers;

23 - sections with smoke powder;

Figure 3. Dependence "pressure-time" at the output of the KU gas generator to the operating mode

24 - dependence "pressure-time" for T = 50 ° C;

25 is a pressure-time relationship for T = minus 50 ° C;

Figure 4. Solid propellant gas generator ejection piston device

26 - armor plating solid propellant checkers;

27 - a back laying from an electrocardboard;

28 - head gasket made of electrical cardboard;

29 - the head hole of the shirt;

30 - the back hole of the shirt;

31 - rear wood liner;

32 - front wood liner.

The essence of the invention is to reduce contact stresses on the supporting ends of the solid fuel charge of the boost chamber to a level at which its normal operation and operation are guaranteed. The latter is achieved through the use of damping pads made of electric cardboard with a thickness of 1-3 mm, installed between the charge and the end walls of perforated metal shirts. To compensate for the free axial clearance between the charge and the ends of the shirts, wood inserts are installed that are in contact with the cardboard gaskets and the ends of the shirts.

The use of wood liners as a compensator for axial clearance is preferable as with t.z. chemical compatibility with TPT charge, and so on. reducing contact stress ("charge-gasket"). The use of metal inserts as applied to solving the technical problem is unacceptable because of the high heat capacity of the latter, which significantly distorts the true pressure-time dependence P (τ) due to additional heat losses, as well as due to a decrease in the weight excellence of the GG. The use of plastic liners is unacceptable due to the thermal decomposition of the latter, which violates the calculated gas thermodynamics of the boost chamber and KU as a whole, and is accompanied by a decrease in the total pressure impulse in the GW sub-piston space.

Patented gas generator (Figure 4) includes the afterburner body (9) and the combustion chamber (11) of boost, equipped with afterburner charges (8) and solid fuel checkers (12) with armored coating (26). In this case, solid fuel checkers are placed in shirts (13) with perforations (15) of the latter. The afterburner is equipped with a front cover (2), a squib (7), a perforated pilot tube (1) with radial holes (5), the tapering end (3) of which is facing the gas duct (6), and a mixing chamber (10) GG. The gas generator by means of a gas duct (16) is connected to the sub-piston space (18) of the ejection device. The ejection device itself includes a cylinder (20) equipped with a piston (19) with a stem (17) and bleed holes (21). The boost chamber is also equipped with a head (29) and rear (30) holes in the shirts. Between the end surfaces of the checkers (12) and the ends of the shirts (13), electric cardboard rolling was installed - head (28) and rear (27), as well as rear (31) and front (32) wood inserts.

The gas generator operates as follows (Figure 4): when the igniter (7) is activated, and then the afterburner charge (8), the shock wave of the resulting gaseous products of combustion (PS) through the gas duct (6) and the mixing chamber (10), and the head openings (29 ) reaches solid fuel checkers (12). Under the influence of a PS shock wave, solid fuel checkers, when ignited, collide with rear gaskets (27) from an electric cardboard, which due to their constant properties in a wide temperature range dampen the shock, reducing the voltage at the impacted end face of the solid fuel checkers. Wood inserts (31) also soften the blow. After the checkers rebound and under the influence of an already weakened PS pressure wave on the checker from the side of the rear holes (30), the checkers hit the head gaskets (28) with weakened force, which, together with the wood inserts (32), absorb this shock. Subsequently, the PS through the gas duct KU enter the piston space (18) and move the piston (19) together with the rod (17). Moving along the cylinder (20), the piston provides a rocket bailout and passes the bleed holes (21), through which PS are released into the atmosphere.

The present invention was tested in a rocket launcher of a rocket weighing 0.6 tons. As a solid fuel charge in the pressurization chamber, 2 drafts of ballistic solid rocket fuel weighing 0.38 kg each were used.

The positive effect of the invention is to ensure the normal (stable) operability of the KU gas generator (or rocket engine) with high starting gradients of pressure increase in the GG (RD) combustion chamber - up to 40,000 (kgf / cm ² / s and at high axial overloads acting on TRT charges.

Claims (2)

1. A solid fuel gas generator of a rocket ejection piston device, including an afterburner with a combined powder charge and a boost chamber with a solid fuel charge, connected by a common gas connection - a gas duct and a mixing chamber, while the charge of the boost chamber is made in the form of two channel blocks armored on the outer surface and placed in perforated metal shirts, characterized in that in the perforated metal shirts between the end surfaces of the shirts and the checkers gasket pads, the thickness of which is 1-3 mm, and wood inserts, while the latter are in contact with the ends of the shirts and gaskets, and the pads are in contact with the ends of the charges. 2. The solid fuel gas generator of the ejection piston device of the rocket according to claim 1, characterized in that the gaskets are made of sheet electric cardboard of the brand EV.

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