DE1811330A1 - Attachment for the propellant of a solid rocket engine - Google Patents

Description

Messersohmltt-Bolkow _u ^ 0ttobrunn, 2 ₅ .Nov. Limited liability company BP 7 ^ Ottobrunn Taei Munich ^?

Attachment for the propellant of a solid rocket engine four

The invention relates to a fastening device for the propellant charge of a solid rocket engine by means of one or more, essentially arranged in the axial direction Fasteners on the one hand with a

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fixed to the housing member fixedly connected and on the other hand, in the solid propellant or in e _s inen engage fixedly associated part via a thread or thread-like profile form fit.

In the case of solid rocket engines, due to the fact that the propellant made up of chemical substances has a significantly higher thermal expansion coefficient than the engine housing made of metal, it is necessary to arrange the propellant in the housing in such a way that it moves in both the radial and the axial direction, and zvi sr in the latter case can expand freely in one direction, while it is fixed in the other axial direction.

According to the German patent specification 1 2 ^ £ 276 it is in solid rocket engines known to provide an annular insulation plate on the rear face of the propellant and this with one consisting of two support rings To screw the support structure, the lower Trsgring with the thrust nozzle body also with screws connected is.

The attachment or mounting of the solid propellant in the axial direction is difficult, in that the existing steel fasteners have a much smaller coefficient of expansion than the group consisting of chemical substances formed propellant or associated with the propellant charge, usually made of plastic _/ insulation plate. For this reason, there is a risk that in the event of high temperature fluctuations, such as those that occur in deserts between day and night or, in general, between summer and winter, the fastening screws in the propellant or in the insulation will be damaged by undesirable

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The diameter differences between the threaded bolt and the threaded hole loosen. This can lead to damaging * displacement of the propellant during the transport or loading of the rocket lead, whereby leaks between the radial expansion gap and the thrust nozzle occur, which after to allow propellant gases to escape during the combustion of the propellant, which would destroy the missile housing caused by overheating of the same.

It is therefore the object of the invention to provide a safe, secure, i.e., even with thermal fluctuations, absolutely stable Connection between the fastening element or elements and to manage the solid fuel.

The object is desired according to the invention in that the in particular made of steel with limited suspension properties manufactured fasteners wholly or partially hollow and its shaft, which is ring-shaped in cross section, with at least two longitudinal slots is provided and that the cavity of the Fastening elements or the shaft with propellant mass or with another material * its coefficient of expansion that corresponds to the propellant charge, filled or dali in the cavity of the fastening elements or the shaft a spring element pretensioned towards the outside in the radial direction is arranged.

In an embodiment of the invention, the proposed fastening elements know in a manner known per se with the Casting propellant, or the fastening elements can be designed as self-tapping threaded bolts. Around Self-ignitions between the propellant and the metal part manufactured fastener he. can be excluded the latter inside and outside with a:.: ignition knob.

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Be provided with an insulation cover.

Another, preferred option within the framework of the invention consists in arranging the fasteners In the propellant insert bushings made of a material, in particular plastic, such as ethyl cellulose, to be provided The expansion coefficient corresponds to that of the propellant. It is useful here to use the cavity of the shaft of the Fastening elements filling the core or filler pin made of the same material as the insert sleeves.

Another feature of the invention is, when using fastening elements with retaining heads, these in To use gradations of a base plate fixed in relation to the housing, the one bridging the narrowing of the gradation Neck of the fastening elements with a smaller cylindrical diameter than the inner diameter of the constriction Outer diameter or is designed with the propellant charge conically tapering outer diameter, so that between the neck and the constriction leave room for expansion.

The invention is a in all operating states Secure fit of the fastening elements in the propellant charge or in a propellant-resistant part guaranteed. This is achieved by achieves that the core or filler pin filling the cavity of the shaft of the fastening elements with increasing temperatures the slotted shaft of the fastening element by its own spatial enlargement towards the outside takes with it, so that the form fit between the threaded profile or the otherwise externally profiled slotted Shank of the fastening elements and the correspondingly profiled inner surface of the insert sleeves or the Solid propellant itself is preserved without play. at

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Manufacture of fasteners from high quality Steel, which by itself has resilience properties to a certain extent, is, with falling temperature, whereby reductions in volume occur, no or only one from the propellant charge or from the insert sleeves to make very little deformation work, so that in this regard no damage to the parts or surfaces that touch or move with respect to one another can be evoked.

In the drawing is an embodiment of the invention shown. Show it:

Figure 1 is a solid rocket engine in longitudinal section, Figure 2 is a section along the line II-II of Figure 1,

Figure J shows the arrangement of a fastener Figure 1 on an enlarged scale and

.Figure k- a single fastener.

The drawing never shows it is designed as a star burner Solid propellant i arranged in the engine housing in such a way that between it and it both a radial Expansion play as well as in the axial direction to the front a free expansion possibility is given. For axial Bracket of the propellant charge 1 are hollow fasteners 3 in the form of head screws are provided, the thread provided shaft 4 over its entire or almost its entire length with at least two (opposite) Longitudinal slots 5a and ^ b is provided. The individual fasteners 3 sit with holding heads β in gradations 7 of an annular base plate 8, which is in the engine housing 2 is fixed, forward against a Shoulder: 2a and backwards through the nozzle body 9, the

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is even secured to the rear by means of a snap ring 10. A neck 11 of the fastening elements bridging the constriction 7a of the gradation 7 is designed with a smaller diameter than the internal diameter of the constriction 7a, so that there is no obstruction in the area of the constriction 7a when the individual shaft segments expand radially. The fastening elements 3 or their slotted shafts 4 sit with their profiling in insert sleeves 12 which are fixedly arranged in the propellant charge 1, in particular glued or cast. In the example, the insert sleeves 12, which have the same coefficient of thermal expansion as the propellant charge 1, are provided with a correspondingly profiled threaded bore into which the shaft k of the fastening elements 5 is screwed. In the cavity of each shaft 4, a filler pin Ij5 is inserted, which consists of the same material as the insert sleeves 12 in the example. Before arrangement of the filling pin 13, the blind hole is filled up in the use of liners with a plastic adhesive compound 14, after insertion of the filling pin I ^ the remaining cavity of the shaft is k or of the fastening element there j5 also filled with a plastic adhesive I5 at least partially, so that the Filler pin secured and the cavity of the fastener is sealed. As spring elements, snakes * springs 18 with pretensioning can be used in the shaft % wit indicated in FIG. However, there is also the possibility, for example, of inserting a filler core made of heat-resistant rubber or similar material in the cavity in question.

The mode of operation of the invention is as follows? When the temperature increases, the filler pen IJ> expands in the same way as the insert sleeve 12 and niffimfc the sectors of the g-eschlitusfcen shaft % rsdisl outwards with it,

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that is, the outer profile of the shaft 4 is determined by the Ausdelinung the PUllstiftes 13 forced exactly the inner profile the insert sleeve 12 to follow, so that no play and thus no loosening between the two aforementioned Profiling (threads) occurs.

With 16 is an annular floor insulation layer and with 17 denotes an outer insulation layer of the propellant charge 1. Two seals 19 in the base plate 8 ensure that no propellant gases from the radial annular gap between propellant charge 1 and housing 2 can escape in the direction of the exhaust nozzle.

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Claims (1)

Messerschniitt-Bölkow O Ottobrunn, 25 J Nov. 1968 Limited Liability Society BP 787 Ottobrunn near Müriclieri. SXJ5 Hn / yes a Claims 1. Fastening device for the propellant of a solid rocket engine " by means of one or more, im essentially axially arranged fastening ■ elements;,: on the one hand with a component fixed to the housing connected and on the other hand lh the solid propellant - cats or in a part assigned to this feet ^^ a G-ev / indc or gewiridc'ihnlichos profile form-fitting engage, characterized ^- g c ken η ζ η et verifiable that the ir.sLesoridere steel rr.it limited FederungseigsnsciiEft <-n Befeotigungselernente produced (3) are hollow and their ausgelührt ringfürraiyer in cross section sheep υ (4) having at least two Longitudinal slots (5? - · and 5b} is provided and that the cavity of the shaft (^ with propellant mass or with another material, the expansion coefficient of which corresponds to that of propellant (1), filled or that in the cavity of the fastening elements or the Shaft (4) an ir. Radial direction outwardly pretensioned spring element (l6) is arranged. 2. Fastening device according to claim 1, characterized in that g e k e r: η ζ e i c h η et that the fasteners. (j>; in ■ r.n it interferes with the propellant (1; are shed. J. Befestigungseinrichtung.nach claim 1, characterized ge e k π π ζ ei c h η et, that the fastening elements (3) - ^ε selcstschneidende formed Geviindebolzen are. "-" 00983370795 . _1J; «BAD ORIGINAL 4. Fastening device according to claim 1 to ^ _t, characterized in that the fastening elements (3) are provided inside and outside with an icolation cover, in particular made of plastic. 5. Fastening device according to claim 1, characterized in that for the arrangement of the fastening elements (^) are provided in the propellant charge (1; insert sleeves (12) made of a material whose coefficient of expansion corresponds to that of the propellant charge (1). 6. Fastening device according to claim ¹ J, characterized ζ ° indicates that the core or filler (1 ^) filling the cavity of the shaft (4) of the fastening elements (j5) consists of the same material as the insert sleeves (12). 7. Fastening device according to one or more of the preceding claims, characterized in "g e k e η η, that with fasteners (^) with holding clamps (6) the latter in gradations (Y) one sit opposite the housing (1) fixed base plate (8), the narrowing (7a) of the gradation (7) bridging neck (11) of fasteners (^) with a smaller cylindrical outer diameter than the inner diameter of the constriction (.7a) or with the Propellant charge (1) is designed towards conically tapering outer diameter. 009833/0795 Blank page