RU2542632C2 - Case-bonded charge of solid rocket fuel - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: case-bonded charge of solid rocket fuel comprises a body, a fuel charge and a heat shielding coating with ledges facing inside the charge. Each ledge is made as capable to take the ring shape in the assembled charge. The heat shielding coating is made from material, chemically compatible with fuel and excluding diffusion of fuel components into it.

EFFECT: invention makes it possible to increase manufacturability and operational reliability of a charge.

2 cl, 5 dwg

Description

The invention relates to the field of rocketry and can be used in solid propellant rocket engines (solid propellant rocket engines) with mixed fuel charges bonded to the walls of the hull.

In the prior art, solid propellant charges are bonded to the walls of a solid propellant rocket motor housing and have the following pattern for attaching a charge to the walls of a rocket engine: first, a heat-shielding coating is applied to the inner surface of the housing, and then a solid fuel charge is adhered to it (US Pat. Nos. 4,601,862, 3,578,520) .

The disadvantage of the above analogues is the complexity of the design and manufacturing technology of the charge due to the multilayer scheme of fastening it to the body, since in addition to the heat-protective coating, the protective-fixing layer (ZKS), which attaches the charge of solid fuel to the heat-insulated inner surface of the housing, an adhesive layer is required between the heat-protective coating and body.

Preparing the body and applying glue to the inner surface of the body is a laborious, fire hazardous and environmentally harmful operation.

In addition, a plasticizer from fuel diffuses into the glue and ZKS. And in modern fuels with a high content of plasticizers, the parameters of the mechanical state are largely determined by the concentration of plasticizer. A plasticizer deficiency in the casing zones of the fuel charges determines a decrease in the overall charge efficiency.

Known charge according to the patent of the Russian Federation No. 2374213 (publication date 11/27/2009), containing a housing, fuel charge and thermal insulation coating.

A disadvantage of the known charge is the design complexity due to the presence, in addition to the heat-protective coating (TZP), of a protective-fixing layer in the form of rubber, duplicated with a bulk fabric and glue, which makes the manufacturing technology of a bonded charge difficult. In addition, the design of the prototype has an insufficiently high degree of reliability due to the possibility of delamination of the fuel from the ZKS during the operation of the charge.

The charge is known according to the patent of the Russian Federation No. 2216641 (publication date 11/20/2003), containing a housing, a fuel charge and a layer placed between them, which performs the functions of a heat-protective coating and a layer fastening the coating with a charge.

The known charge eliminates the need to use glue for bonding a layer having thermal protection ability (TZP) with the body through the use of a material that is calendaring sheet material (rubber compound), which spread the inner surface of the body with subsequent vulcanization of the rubber mixture at elevated temperatures (140- 170 ° C) and pressure (5-15 kgf / cm ² ) while gluing it to the body.

A disadvantage of the known charge is the need to introduce into the composition of TZP, which has a polymer base different from the fuel charge, an additional component (paradinitrosobenzene) to give TZ an acceptable adhesive ability to the fuel charge, which complicates the process of obtaining TZP with such functions. There is every reasonable reason to believe that the introduction of an additional component is not enough for high-quality fastening of the charge to the body, since there are end cuffs that are glued into the body with an adhesive layer. This increase in the number of individual structural elements leads to additional technological operations in the manufacture of the charge, reduce the reliability of the charge due to the possible detachment of the cuffs from the housing, TZP and fuel charge during operation of the charge. In addition, the design of the charge excludes the possibility of using, in accordance with the existing need, a fuel charge combined from different fuels, since it provides for bonding (chemical interaction) of a specific fuel with a specific (in chemical composition) fuel-grade compound developed exclusively for this fuel, which reduces operational capabilities.

Closest to the proposed one is the charge of US Pat. No. 4,649,823, adopted as a prototype, comprising a housing, a fuel charge, and a heat-shielding coating with protrusions facing the inside of the charge.

In the description of the known invention, it is declared that the presented constructive execution of the charge is aimed at creating a mechanical connection between the fuel charge and the thermal barrier coating. However, not in all of its incarnations, the known technical solution is made exclusively glueless. There is every reasonable reason to believe that mechanical bonding does not provide unconditional performance and reliable functioning of the charge as a whole when using the fuel, which is described in the description as follows - "there can be any composition, preferably low viscosity, so that pores do not form during molding". Measures are envisaged to supplement the mechanical bond with the use of adhesive material deposited on the surface of the heat-protective coating and the surface of the protrusions. In cases of glueless fastening of a heat-shielding coating with a fuel charge, it is possible to vary the height of the protrusions and / or make holes in the protrusions to increase the contact of the fuel charge material with the protrusions. Those. the prototype does not in all cases provide sufficient strength to peel the TZP from fuel.

The necessity of introducing an adhesive layer, making protrusions of different heights, making holes in them substantially complicate the charge manufacturing technology.

It is not possible to carry out a fuel charge with a combination of different fuels (in each embodiment of the invention, the charge is made of only one fuel), which reduces the operational capabilities of the known technical solution.

The objective of the proposed technical solution is to develop the design of the bonded charge of rocket solid fuel, which allows to expand operational capabilities, to improve the manufacturability by creating conditions that provide high peeling strength between the fuel-and-chemical composition and fuel with the sufficient use of only mechanical bonding between them without the need for additional structural elements that increase the contact of the thermal barrier with the fuel charge.

The problem is solved by the proposed fixed charge of rocket solid fuel, comprising a housing, a fuel charge and a heat-shielding coating with protrusions facing the inside of the charge, characterized in that each protrusion is configured to take the form of a ring in the assembled charge, the heat-shielding coating is made of a material chemically compatible with fuel and excluding the diffusion of fuel components into it.

In particular, the charge is made of one fuel or is made combined of different fuels.

The implementation of TZP with protrusions of the claimed form, together with the remaining essential features, ensures its reliable mechanical fastening with a fuel charge, is a factor that allows the use of different fuels in the charge design at the same time in accordance with the existing need to obtain various functional results achieved by the engine when using a combination of fuels. In addition, the laborious, fire hazardous and environmentally harmful operation of applying glue is completely eliminated.

If a combination of fuels is used in the manufacture of a charge, material ТЗП is selected for a particular fuel, which ensures compatibility with this fuel and prevents the diffusion of fuel components into it. Moreover, in special cases of the embodiment of the invention, the claimed design of the TZP allows the use of the same TZP for all fuels used in the combination, which is completely excluded in the practical application of the charge design of the prototype.

The proposed bonded charge of rocket solid fuel is illustrated by graphic images:

FIG. 1 - a longitudinal section of the charge with TZP.

FIG. 2 - section AA in figure 1 with solid protrusions in the assembled charge taking the form of rings.

FIG. 3. - section AA in figure 1 with intermittent protrusions in the assembled charge taking the form of individual pins (prototype).

FIG. 4 is a photograph of a TZP sample with solid protrusions.

FIG. 5 is a photograph of the surface of the destruction of the fuel, bonded with the claimed TZP.

In FIG. 3, the position 5 denotes protrusions in the form of individual pins, which are one of the embodiments of the prototype. In the prototype, they are described as gears in the form of handles with a head.

The photograph shown in FIG. 5, shows that the destruction occurs on fuel, and not on the fuel-TZP border. The tests performed on the samples showed the stability of the results.

The bonded charge of solid rocket fuel contains a housing 1, TZP 2, fuel charge 3. The TZP is equipped with solid (extending without interruptions) protrusions 4, in the assembled charge taking the form of rings. The protrusions 4 perform the function of fasteners.

The specific dimensions of the protrusions and the material TZP determine when designing a specific charge.

The inner surface of the housing 1 is combined with a rubber-like flexible TZP 2 (for example, rubber 51-2110 according to TU 381051528-90, rubber 51-1615 according to TU 1051177-82), vulcanization is carried out, at which the TZP 2 is connected to the case 1. At the same time Thus, the housing 1 is filled with a fuel charge 3, which, being cured, is mechanically fastened to the TZP 2.

The chemical compatibility of the thermal barrier coating material and the fuel material is usually checked at elevated temperatures (thermal stability). To assess the thermal stability, instruments for measuring the pressure (volume) of gas evolution are used.

Such devices include, for example, VULKAN-2000 measuring and computing complex (IVK) (Digital Dragon LLC), designed to measure the pressure and temperature of vapors and gases in a closed volume in an isothermal mode to determine the thermal stability of substances. IVK is a device for general industrial use and is intended for use in factory and research laboratories of various industries

The proposed technical solution is practicable and allows you to solve the problem.

Claims (2)

1. A bonded charge of solid rocket fuel, comprising a housing, a fuel charge and a heat shield with protrusions facing the inside of the charge, characterized in that each protrusion is configured to take the shape of a ring in the assembled charge, the heat shield is made of a material chemically compatible with the fuel and excluding the diffusion of fuel components into it. 2. The bonded charge according to claim 1, characterized in that it is made of one fuel or is made combined of different fuels.

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