| 摘要 |
In a resistance-connected, pilot-controlled hot-gas switching valve (Fig. 2) for reversing a thrust-generating hot-gas stream in a solid-propellant jet engine, the entire pilot control stage (34) is insulated thermally and in terms of flow from the hot-gas stream and is operated with a separate, cooling and residue-free control medium, the supply pressure of which is above the working pressure of the hot gas, and arranged at the hot-gas end of the guiding gap (12) between the housing bore (14) and the valve element (10) controlling the hot-gas stream is a dynamic hot gas barrier (54, 58) which comprises an annular channel (54) continuously supplied with control medium at supply pressure and an annular gap (58) which adjoins the said annular channel, is wider than the guiding gap (12) and opens in a wedge shape towards the hot-gas side of the valve. The guiding gap (12) is shielded in an effective manner from thermal disturbing effects and those caused by impurities by the hot-gas barrier (54, 58) and the scavenging flow which passes continuously through the latter towards the hot-gas side. <IMAGE>
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