JPS62117844A - Carbon fiber-strip like woven body and processing thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a carbon fiber strip-shaped woven body according to the general concept of claim 1, and a carbon fiber ribbon according to the general concept of claim 2. The present invention relates to a method for processing a belt-like woven body.

Intraatmospheric and spaceflight often present the problem of subjecting the surface of the vehicle to high temperatures and high flow velocities at the same time. Examples of this include all types of shed propulsion mechanisms and spacecraft during re-entry into the atmosphere. In the case of a flight in which thermal and hydromechanical stresses are exerted over a long period of time or occur repeatedly at intervals of time, the surface of the aircraft exposed to these stresses will not cause damage to one member. Even small diapers are constructed and protected so that damage progresses very slowly. For example, nozzles for long-burning rocket jets are generally liquid-cooled and constructed from mostly metallic materials with high melting points. If the stresses act for only a short time, as for example in rocket injection nozzles with short combustion durations, relatively severe thermal and mechanical damage (burnout, corrosion) can be tolerated. In such cases, the use of fiber-reinforced synthetic materials is advantageous - especially because this fiber-reinforced synthetic material has an advantageous strength-to-weight ratio of 7, and also because of its ease of manufacture and reasonable price. It will be considered for this reason.

A common material combination in this case until very recently was the phenolic resin-asbestos combination. However, in this case, asbestos will no longer be used in the future because it has properties that are detrimental to health. Meanwhile, carbon fiber is the e! ! Due to its good mechanical and thermal properties, it has come to be recognized as a useful alternative material. For example, the method of laminating the nozzle body onto mold 1 in a manner commonly used to make other structures from carbon fiber fabric and ashest allows the fabric layer to When manufactured in such a way that the fabric layers are laminated parallel to the contour (contour), thermal damage and mechanical stress occur during operation of the nozzle body, resulting in delamination throughout the fabric layers and this peeling. It is to be expected that the layer will be blown off and this will lead to very premature destruction of the nozzle body.

From German Patent Application No. 1203646, a laminated fiber-reinforced synthetic material wall for aircraft, rocket propulsion systems, etc. is known, in which such wear phenomena are largely avoided. In this fiber-reinforced synthetic wall, the fiberglass fabric strips impregnated in resin are arranged such that the cross-sections of the strips overlap each other like roof tiles and are positioned at an angle of about 20' to the direction of flow; The fabric strip is formed by being spirally wound onto the female die so that the edges oriented in the downflow direction form a flow profile. Although this reliably avoids detachment of the entire fabric layer due to blowing, it still causes detachment of the fabric threads arranged transversely to the direction of flow from the edge of the fabric strip forming the flow contour, which As a result, wear progresses slowly but constantly.

In contrast to such known techniques, the underlying problem of the present invention is to provide a belt-like woven body and a processing method thereof that take into account a further significant increase in the period of use of the structural body parts.

This object is achieved according to the invention by the features specified in claims 1 and 2.

What can be pointed out in connection with this is that the second claim
The method described in Section 1 is not only suitable for the winding formation of rotationally symmetrical structures, but also for the production of plate-like structures by juxtaposing individual band-shaped strip strings with one another, i.e. for example adjusting nozzle segments. It is also suitable for the production of flow guiding profiles or heat shield plates.

Claims 3 and 4 contain advantageous embodiments of the method according to claim 2.

The invention will now be described in detail with reference to embodiments illustrated in the accompanying drawings.

As seen in FIG. 1, carbon fiber-band-like woven material l
The weft threads 3 are woven into the warp threads 2 as U-shaped individual threads, oriented transversely in the loose direction 4 of the strip. In this case, of course, the Aki style (campus weave,
(twill weave, etc.), the weft yarns 3 are placed on the front side or behind the warp yarns according to a certain weave structure at the weave point with the warp yarns 2. Due to the protruding free ends of the weft threads 3, the width 5 of the weave strip is significantly smaller than the overall width of the carbon fiber weave strip 1. On the other hand, in the case of belt-like woven bodies according to known techniques, the weft yarns to be weaved are generally woven together with the warp yarns in a wavy pattern, and in this case, the weaving width of the belt-like woven body corresponds to the belt width.

From FIG. 2 it can be clearly seen how the special structure of the carbon fiber web strip l has an advantageous effect on the robustness of the structural part. In order to create a rotationally symmetrical hollow body 12,
The core 8 is helically wrapped in the carbon fiber web 1 in the flow direction 6 from the inlet region 10 via the main region 9 to the outlet region 11 . In this case, the outside of this core 8, which forms the flow contour 7, is laminated with a separating material. The carbon fiber strip-shaped woven body 1 is impregnated into a base material (for example, phenolic resin), not shown, before or during the lamination process. The inlet region 10 serves in such a way that, from a position parallel to the flow contour, the strip-like fabric section reaches the desired roof-shaped slope position in the main region by means of a first winding. The outlet area 11 serves as a resting place for the unneeded protruding weft threads 3 of the last winding of the carbon fiber web 1.

In the main region 9, it can be seen that the flow contour 7 is formed, apart from one thread, exclusively from the weft threads 3, which are arranged at an acute angle to this substrate.

The weft threads 3 cover the warp threads 2 and protect them from adverse thermal and flow mechanical effects. During operation, the substrate in the region of the surface (flow contour 7) is burned out, but its back side remains securely anchored in the weft thread 3 in the outer structure layer.
Together they form a reliable protective layer for the radially outwardly bordering material. A favorable arrangement of the weft thread 3 for flow approximately in the flow direction 6 also contributes to this purpose. To further increase the strength of the structure,
In the main region 9, a winding structure 13 having extremely high strength and based on carbon fibers (laminated fabric, roving, etc.) is placed on the winding of the carbon fiber-band-like woven body 1. After the hollow body 12 has hardened and the core 8 has been removed, the protruding web-like webs that do not belong to the structure of the inlet region 10 and the outlet region 11 are cut from the main region 9. In order to simplify the drawing, only the structure of the annular cylindrical hollow body is shown in FIG. 2, but in this case, the main region 9 is also shown in a significantly shortened form. However, this construction style is particularly amenable to building a complete nozzle body for Laval nozzles. In order to be able to extract the wick 8 from the hardened structure, it must be split transversely to its axis in the area of the nozzle neck (narrowed cross-section).

Depending on the thermal and mechanical requirements in the area of the warp threads 2, additional fiber reinforcements (such as rovings) are incorporated between the turns of the carbon fiber web 1. In this case, these fiber reinforcements - as well as the warp threads 2 - completely extend to the weft threads 3.
guaranteed to be covered. Figure 3 shows carbon fiber.
Other possibilities for the use of the strip-shaped woven body 1, namely the metal protective layer 16 of the nozzle 15 of a solid-rocket propulsion mechanism 14 of known construction type.
It shows that it can be used to laminate. In known shed propulsion mechanisms, the metal protective structure is connected to a thick graphite ring in the nozzle neck region. The curtain and diffusion areas are laminated with phenol/asbestos fibers. As shown in FIG. 3, the laminated portion 17 of the metal protective structure 16 in the drooping part and the diffusion part of the nozzle 15 is made of carbon fiber strip-like woven material with a roof tile-like arrangement compared to the embodiment according to FIG. Consists of 1 roll. In this case, however, the lamination of the metal protective structure 16 is carried out in a spiral fashion relative to the flow direction, and the base material firmly adheres the strip-like fabric to the protective structure (male).

Other structural features of the solid-rocket propulsion mechanism 14, such as the graphite ring 18, the fuel 19 arrangement, etc., remain unchanged. With reference to FIG. 3, the invention is therefore advantageous in terms of materials, since first of all asbestos, which is a health hazard, is replaced by other materials. As already mentioned in the introduction to the description, the ribbon-like fabric according to the invention and the associated processing method have numerous application possibilities (heat shield panels, adjustment nozzle segments,
(as flow-guiding profiles, etc.), and the structure structure always relies on a roof-tile-like step-like arrangement of equal cross-sections of strip-like woven fabrics with wefts on the flow sides.

[Brief explanation of drawings]

Fig. 1 is a partial plan view of a carbon fiber strip-like woven body according to the present invention, Fig. 2 is a vertical cross-sectional view of the upper half of a rotationally symmetrical hollow body with a female die (core), and Fig. 3 is a solid - FIG. 2 is a longitudinal cross-sectional view of the nozzle area of the rocket propulsion mechanism. The symbols in the figure are: 2... Warp 3... Weft 4... Band-shaped woven body longitudinal direction 5... Band-shaped woven body width

Claims (1)

[Claims] 1. Rocket propulsion with a particularly short combustion duration for creating a protective layer for or for creating structures subjected to the action of media with high temperatures and high flow rates. In a carbon fiber band-like woven body consisting of warp and weft yarns for making the nozzle lining of a mechanism, weft yarns (
3) is arranged as a single U-shaped thread;
The straight parts of this weft thread (U-shaped legs) are oriented parallel to each other and - oriented in the longitudinal direction 4 of the strip-like fabric - transversely to the weft thread (2), the weft thread ( 3) The above-mentioned carbon fiber, characterized in that all the free ends are present on the same side surface of the band-like woven body, and the free ends of the wefts protrude from the band-like woven body by at least the width (5) of the weft. Band-like woven body. 2. For making structures consisting entirely or partially of carbon fiber-strip woven material and a suitable substrate, in particular a heat-resistant substrate, by means of female molds or by stacking male molds. In the method, the carbon fiber-band-like woven body (1) is actually formed transversely to the flow direction by a method known per se, with cross-sections of the successive strip-like woven bodies overlapping each other like roof tiles at an acute angle in the flow direction. laminating in such a way as to form a flowing contour, the protruding free ends of the weft threads (3) being oriented in the downflow direction within the cross-section of the strip-shaped woven fabric and arranged together with the substrate - in each case in the downflow direction; overlying the weft thread (2) - forming the flow contour and, when producing using a female mold, carrying out the subsequent layering using a fiber composite material with a particularly high mechanical strength; A method for making the above-mentioned carbon fiber-band-like woven body, characterized in that: 3. A main area (9) to form the flow profile (7) of the hollow body (12) in the core (8), as well as an inlet area (10) and an outlet area (11) within the extension of the flow profile (7). ), and at this time, the lengths of both regions (10 and 11) described later are approximately equal to the entire width of the carbon fiber-band-like woven body (1) (including the protruding weft threads) in the flow direction (6). correspondingly, covering the core (8) with the carbon fiber web (1) in a spiral pattern (in the direction of flow) from the inlet area (10) to the outlet area (11); In the region (9), a winding structure (13) with extremely high strength based on carbon fibers (carbon fiber fabric, carbon fiber roving, etc.) is laminated, and the structure (hollow body 12) is hardened. characterized in that after removing the sesakatsu core (8), the sections of the band-like woven body (inlet and outlet regions) (10 and 11) protruding from the main region are cut; 3. A method as claimed in claim 2 for producing an essentially rotationally symmetrical hollow body, in particular a nozzle body of a rocket propulsion mechanism, using a core. 4. A metal structure for stacking male molds, characterized in that the carbon fiber-band-like woven body (1) is placed on the male mold (metal structure 16) gradually in the flow direction. A method according to claim 2 for laminating.