RU2251014C1 - Method of manufacture of rocket engine solid-propellant charge igniter - Google Patents

Abstract

FIELD: rocket engines.

SUBSTANCE: proposed method of manufacture of solid-propellant charge igniter includes vacuum forming of surface of polymeric film case which is carried out directly on seat in rocket engine housing, for instance in engine cover.

EFFECT: improved mass and dimensional characteristics of rocket engine, simplified technology of manufacture.

7 cl, 3 dwg

Description

The invention relates to the field of rocket technology and can be used in the manufacture of rocket engines of solid fuel (solid propellant rocket engines) and ignition devices for them.

The most technologically advanced and technically effective (low weight, reliability of penetration by a squib, lack of slag, simplicity of design, etc.) are the design of igniters, the shells of which are made of polymer films. In practice, two types of film igniters are used: packet (Pat. RU 2170842) and bulk (Pat. RU 2185522).

The design of the igniters is predetermined by the existing manufacturing technology and the equipment used. Film igniters are made either in the form of rectangular bags, or in the form of volumetric structures, usually of cylindrical shape.

In the first case, due to the filling of the package with a sample of no more than 50-80% of its volume, the coefficient of volumetric filling of the seat for the igniter in the engine is significantly reduced. The volume igniter design is more advanced in this regard, but requires the preparation of a special cylindrical seat in the engine. On the one hand, this complicates the design of the engine, on the other hand, it does not allow the effective use of the free volume of the combustion chamber of the engine as a whole: various grooves, grooves, sinuses, etc. Thus, the implementation of film igniters in the form of strictly regulated forms (packages, cylinders) reduces the compactness of the engine design and, as a result, worsens its weight and size characteristics.

The elimination of the noted drawbacks of igniter designs within the framework of the existing technology (molding of volume ignitor bodies on prefabricated die dies, equipment with a hitch of igniter composition and subsequent welding of the case with a cover) is associated with significant difficulties, primarily the need to manufacture die dies of a very complex shape . In this case, even with minor modifications to the structural elements of the rocket engine containing a seat for the igniter, both during development and improvements in serial production, it is necessary to replace previously used die dies.

The closest method to patentable is a method of manufacturing a design of a film igniter device of a complex configuration according to US Pat. RU 2185522. The method allows to make the design of an igniter device that effectively uses for its placement, due to the equidistance of the housing surface to the footprint, the free volume in a particular solid propellant rocket engine. The invention according to US Pat. RU 2185522 adopted by the authors as a prototype.

However, the prototype has a number of disadvantages:

1) a method of manufacturing an igniter according to US Pat. RU 2185522 requires complex forming tooling (dies);

2) by virtue of the implementation of the molding of the body, although an equidistant profile on the dies between the molded body and the seat (cover) of the engine, there is a certain clearance (due to tolerances for manufacturing parts);

3) the presence of a gap reduces the survivability of the igniter housing and does not allow protecting the engine housing (cover) from the thermal effects of the combustion products of solid rocket fuel (TRT).

The technical task of the patented invention is the development of a method of manufacturing solid propellant igniters for taxiways, providing improved weight and size characteristics of the engine, simplifying manufacturing techniques and reducing labor costs.

The invention is illustrated by the following graphic materials:

Figure 1. Rocket engine cover.

Figure 2. Forming the igniter body.

Figure 3. Placing the ignition assembly in the rocket engine cover.

In the figures indicated:

1 - engine cover;

2 - crackers for mounting supports under charge;

3 - a divider of a squib;

4 - technological boss (cork);

5 - moldable igniter housing;

6 - technological boss (insert);

7 - support for the charge (it is the igniter retainer from axial movements);

8 - squib;

9 - igniter cover.

The igniter made according to the patented method contains a hitch of igniter composition, placed in a polymer film case, the surface of which is made in the form of a volume block equidistant to the surface of the seat in the engine. Moreover, all external contours of the igniter body are made equal in size and shape to the seat in the engine and can be attached to it.

The technical result of the invention consists in vacuum forming igniter bodies made of polymer materials directly on the seat in the engine (using the engine cover, pre-nozzle volume, etc.). This can be used as a structural element of the engine as a whole (cover (1), Fig. 1), and its part containing a seat for the igniter. This allows you to provide all the external contours of the case, which correspond to (equal to) the size and shape of the seat in the taxiway, taking into account the placement (Fig. 1) of crackers (2) for attaching the support (7) to the charge of the TRT. In this case, the shape of the seat for the igniter can be almost arbitrary, which extends the design capabilities of the engine elements based on their direct purpose. If it is necessary to carry out in the moldable housing (5) the igniter of additional recesses of various configurations (Fig. 2), the response process bosses (4) are installed (before molding) in the corresponding sections of the engine seat. To exclude mechanical damage to the molded bodies of the igniters by the protruding sharp edges of the seat, for example, a divider of the squib (3), they are preliminarily covered with technological inserts (6) with smooth contours before molding (FIG. 2). To increase the heat-shielding and weight and size characteristics of the engine, its weight perfection, an adhesive layer is applied to the surface of the seat, fastening the outer surface of the igniter body to the seat (engine cover). At the same time, to increase the manufacturability of manufacturing the igniter body, a duplicated polymer film with an adhesive layer is used, and the vacuum formation of the igniter body at the engine seat is carried out at a temperature close to the melting temperature of the adhesive layer of the duplicated film. To improve the manufacturability of the patented method when vacuum forming the igniter body, evacuation can be carried out through an opening in the engine cover under the igniter (8). After the vacuum forming of the igniter body is completed, a hitch of the igniter composition is placed in it and sealed with its cover (9).

The novelty of the proposed manufacturing method is characterized by the following distinctive features:

1) the execution of the surface of the housing of the igniter in contact with the engine, completely coinciding with the surface of the seat, i.e. the surface of the igniter is not only equidistant, but a copy (impression) from the surface of the seat in the engine (the external dimensions of the body of the igniter are equal to the dimensions of the seat on the surface of the molding);

2) the use in the molding of the housing of the igniter directly structural elements of a rocket engine containing a seat for the igniter, as a stamp;

3) preliminary preparation of the seat before forming the bodies of the igniters regarding the installation of technological inserts with smooth contours enclosing the sharp edges of the seat, and applying an adhesive layer to the surface of the seat;

4) installation of additional bosses on the seat for receiving reciprocal recesses on the igniter body of the configuration required by the drawing (for example, under a squib or electric igniter);

5) the use of a duplicated film for the manufacture of the igniter body, the implementation of the molding process at a temperature above the temperature of the adhesive layer of the film.

The technical result of the invention is:

1) in reducing labor costs and simplifying technology by eliminating complex tooling (dies) from the process;

2) in improving the weight and size characteristics of the engine by achieving the maximum layout effect (compactness) when installing the igniter in the engine (figure 3).

3) in providing additional heat-shielding effect of the design of solid propellant rocket motors and its weight perfection.

The developed method is practically implemented in the manufacture of a volumetric annular film igniter:

- as a matrix during vacuum molding used an annular toroidal front engine cover (figure 1);

- igniter case material - polyethylene 0.8 mm thick;

- molding modes - in accordance with known methods.

Claims (7)

1. A method of manufacturing an igniter containing a portion of the igniter composition, placed in a polymer film casing, the surface of which is made in the form of a volumetric block equidistant to the surface of the seat in the engine, while the outer edges of the body of the igniter are made equal in size and shape to the seat in the engine for solid fuel charge of a rocket engine by vacuum molding, characterized in that the vacuum molding of the igniter film body is carried out directly on and a seat in the rocket engine housing, for example, in the engine cover. 2. The method according to claim 1, characterized in that the technological inserts of the desired configuration are installed in separate sections of the seat before vacuum molding. 3. The method according to any one of claims 1 and 2, characterized in that the surface of the igniter body is bonded to the surface of the seat in the engine. 4. The method according to any one of claims 1 to 3, characterized in that an adhesive layer is applied to the engine seat before vacuum forming the igniter body. 5. The method according to any one of claims 1 to 4, characterized in that film polyethylene is used as a polymer film for the igniter body. 6. The method according to any one of claims 1 to 3, characterized in that for the manufacture of the body using a duplicated polymer film with an adhesive layer, and the vacuum formation of the igniter body in the engine seat is carried out at a temperature close to the melting temperature of the adhesive layer of the film. 7. The method according to any one of claims 1 to 6, characterized in that when vacuum forming the igniter body, the evacuation is carried out through an opening in the engine cover under the igniter.

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