摘要:
The aim of the present invention is a process for manufacturing boron nitride fibers, in particular continuous boron nitride fibers with good mechanical properties, which may be used for producing ceramic composite materials such as BN/BN composites, thermostructural parts or antenna radomes.It provides and uses a precursor polymer of formula (I) below: in which n is a whole number, R1 and R2, identical or different, represent independently an alkyl group, and R3 represents an amino group, a hydrogen atom, an alkyl, a cycloalkyl or a boryl.
摘要:
A process for the production of a vessel for high pressure gas, particularly helium, for a space launcher or for a satellite with a short lifetime, includes the steps of: a production of an internal skin of a plastic material selected from polyethylene and crystallized polyamide, a winding a reinforcement of fibers and resins, and a providing the obtained vessel with the necessary conduits and control valves.
摘要:
A temporary connection and pyrotechnic separation device (10) normally connects two elements (12, 14). This device comprises a connecting part (18), of which a bottom portion (38) is fixed to one (12) of the elements. Active portions (40) of the connecting part (18) cover a space (20) in which there is pyrotechnic expansion tube (16). The active portions are deformable and comprise hook-shaped ends (50) that fit into a notch (36) formed in the second element (14), so that normally there is a pressure connection between the two elements. The effect of firing is to deform the active parts and consequently break this pressure connection.
摘要:
A pyrotechnic actuator comprises a deformable membrane (24) separating a first chamber (20), which is able to receive pyrotechnic combustion gases, from a second chamber (22) containing a control member (32) displaceable by the membrane (24) during the operation of the actuator. In the inoperative state, the membrane (24) is prestressed counter to its deformation controlled by the intake of gases into the first chamber (20). In this way the functional travel is increased, which e.g. makes it possible to open or close a circuit with a larger cross-section without increasing the actuator size.
摘要:
A process for the production of a vessel for high pressure gas, particularly helium, for a space launcher or for a satellite with a short lifetime. The process includes the step of producing an internal skin of a plastic material selected from polyethylene and crystallized polyamide. The process also includes winding a reinforcement of fibers and resins around the internal skin, and then providing the obtained vessel with the necessary conduits and control valves.
摘要:
The invention concerns a method for manufacturing a tank (1) for fluids under pressure comprising two compartments (8, 10). According to the invention, the method comprises the following steps: assembling a winding mandrel; placing a metal wall (4) on the mandrel, said wall (4) being in a folded shape; forming the external wall (2) by winding around an assembly comprising the mandrel and the folded wall (4); polymerising the wall (2) and dismantling the mandrel; unfolding the metal wall (2), in such a way as to obtain a first compartment (8) within the interior of the metal wall (4), and a second compartment (10) between the two walls (2, 4). The invention also applies to a tank (1) such as that obtained by the method described here above. Application in the field of launch vehicles and rockets.
摘要:
The aim of the present invention is a process for manufacturing boron nitride fibres, in particular continuous boron nitride fibres with good mechanical properties, which may be used for producing ceramic composite materials such as BN/BN composites, thermostructural parts or antenna radomes. It provides and uses a precursor polymer of formula (I) below: 1 in which n is a whole number, R1 and R2, identical or different, represent independently an alkyl group, and R3 represents an amino group, a hydrogen atom, an alkyl, a cycloalkyl or a boryl.
摘要:
The pointed end of a central spike, used in an engine of a space launcher, may have a deformable structure that can adopt either a folded position or a deployed position.
摘要:
The temporary connection of two elements (12, 14) is ensured by U-shaped connecting components (16) held in place by a moving part (18). A pyrotechnic composition (20) is housed between two shoulders (32, 36) situated respectively on the first of the elements (12) and on the moving part. Igniting the pyrotechnic composition (20) causes the moving part (18) to slide over the first element (12). The connecting components (16) are released and the connection between the elements (12, 14) is eliminated without breaking any parts.
摘要:
A process for selectively lacing filaments on multi-dimensional textile preforms made of rods, the rods are displaced by the filament and pressed vertically downwardly by a needle with an open eye which, after passing through the piece to be laced, is opened at an insertion station for the filament to receive the filament, then is raised to pass the filament through the space freed by the rod.